Search results for: soil physical properties

Authors: Begum Serim-Yildiz

Abstract:

The aim of this study is to examine the role of parents' emotional and behavioral reactions on fears of children in the COVID-19 pandemic considering Rachman’s Three Pathways Theory. For this purpose, a phenomenological qualitative study was conducted. Thirteen participants living with their children were utilized through criterion and snowball sampling. In semi-structured interviews parents were asked about their own and their children’s beahavioral and emotional reactions in the COVID-19 pandemic, and they were expected to give detailed information about fears of their children before and in pandemic. Firstly, parents were asked about their behavioral and emotional reactions in the COVID-19 pandemic. As behavioral reactions, precautions taken by parents to protect the rest of the family from negative physical and emotional impact of the pandemic were mentioned, while emotional reactions were defined as acquisition of negative emotions like fear, anxiety, and worry. Secondly, parents were asked about their children’s behavioral and emotional reactions. Some of the parents talked about positive behavioral changes such as gaining self-control, while some others explained negative behavioral changes like increased time spent with technological tools. In the emotional changes section, all of the parents explained at least one negative emotion. All of the parents stated that their children had COVID-19 related fears. According to parents’ expressions, fears of children in pandemic were examined in two dimensions. Fears directly related to COVID-19 were fear of virus/microbes, illness or death of someone in family and death and fears. Fears indirectly related to COVID-19 were fear of going out, sleep alone at night, separation, touching stuff outside the home, and cold. Considering existing literature and based on the findings of this study, it can be concluded that children’s modelling experiences have impact on acquisition of negative emotions, especially fear, therefore, preventive interventions involving caregivers should be provided by mental health professionals working with children.

Keywords: children’s fears, COVID-19 pandemic, modelling experiences, parents’ reactions

Procedia PDF Downloads 163

Authors: Saksham

Abstract:

Concrete's versatility and affordability make it a highly competitive building material capable of meeting diverse requirements. However, the increasing demands placed on structures and the need for enhanced durability and performance have driven the development of distinct cementitious materials and concrete composites. One significant aspect of this advancement is the utilization of waste materials from industries, such as fly ash, to improve concrete's properties. Fly ash, a byproduct of coal combustion can enhance concrete's strength and durability while reducing environmental impact. Additionally, steel fibers can enhance concrete's toughness and crack resistance, contributing to improved structural performance. The experimental study aims to optimize the proportion of ingredients in M30-grade concrete, incorporating fly ash and steel fibers. By varying fly ash content (10% to 30%) and steel fiber dosage (0% to 1.5%), the research seeks to determine the optimal combination for achieving the desired compressive strength. Two sets of experiments are conducted: one focusing on varying fly ash content while keeping steel fiber dosage constant, and the other focusing on varying steel fiber dosage while keeping other parameters fixed. Through systematic testing, molding, curing, and evaluation according to specified standards, the research aims to analyze the impact of fly ash and steel fibers on concrete's compressive strength. The findings have the potential to inform engineers about optimized concrete mix designs that balance performance, cost-effectiveness, and sustainability, advancing toward more resilient and environmentally friendly building practices.

Keywords: concrete, sustainability, durability, compressive strength

Procedia PDF Downloads 46

Authors: George Mahalu

Abstract:

The Chua diode has been configured over time in various ways, using electronic structures like as operational amplifiers (OAs) or devices with gas or semiconductors. When discussing the use of semiconductor devices, tunnel diodes (Esaki diodes) are most often considered, and more recently, transistorized configurations such as lambda diodes. The paper-work proposed here uses in the modeling a lambda diode type configuration consisting of two Junction Field Effect Transistors (JFET). The original scheme is created in the MULTISIM electronic simulation environment and is analyzed in order to identify the conditions for the appearance of evolutionary unpredictability specific to nonlinear dynamic systems with chaos-induced behavior. The chaotic deterministic oscillator is one autonomous type, a fact that places it in the class of Chua’s type oscillators, the only significant and most important difference being the presence of a nonlinear device like the one mentioned structure above. The chaotic behavior is identified both by means of strange attractor-type trajectories and visible during the simulation and by highlighting the hypersensitivity of the system to small variations of one of the input parameters. The results obtained through simulation and the conclusions drawn are useful in the further research of ways to implement such constructive electronic solutions in theoretical and practical applications related to modern small signal amplification structures, to systems for encoding and decoding messages through various modern ways of communication, as well as new structures that can be imagined both in modern neural networks and in those for the physical implementation of some requirements imposed by current research with the aim of obtaining practically usable solutions in quantum computing and quantum computers.

Keywords: chaos, lambda diode, strange attractor, nonlinear system

Procedia PDF Downloads 79

Authors: T. H. Huang, C. L. Fern, Y. K. Tseng

Abstract:

The design and reliability of solar photovoltaic modules are crucial to the development of solar energy, and efforts are still being made to extend the life of photovoltaic modules to improve their efficiency because natural aging is time-consuming and does not provide manufacturers and investors with timely information, accelerated aging is currently the best way to estimate the life of photovoltaic modules. Bifacial solar cells not only absorb light from the front side but also absorb light reflected from the ground on the back side, surpassing the performance of single-sided solar cells. Due to the asymmetry of the two sides of the light, in addition to the difference in photovoltaic conversion efficiency, there will also be differences in heat distribution, which will affect the electrical properties and material structure of the bifacial solar cell itself. In this study, there are two types of experimental samples: packaged and unpackaged and then irradiated with UVC light sources and halogen lamps for accelerated aging, as well as a control group without aging. After two weeks of accelerated aging, the bifacial solar cells were visual observation, and infrared thermal images were taken; then, the samples were subjected to IV measurement, and samples were taken for SEM, Raman, and XRD analyses in order to identify the defects that lead to failure and chemical changes, as well as to analyze the reasons for the degradation of their characteristics. From the results of the analysis, it is found that aging will cause carbonization of the polymer material on the surface of bifacial solar cells, and the crystal structure will be affected.

Keywords: bifacial solar cell, accelerated aging, temperature, characterization, electrical measurement

Procedia PDF Downloads 104

Authors: Suzan Abd El Majid, Menachem Bamberger, Alexander Katsman

Abstract:

Two Al-4 wt. % Cu based alloys, A201 and A201+Si were investigated in the as-cast, solution treated and aged conditions. The addition of Si was used to improve the castability of the basic alloy. The all investigated alloys in the as-cast condition contained a eutectic structure along grain boundaries (GBs) with the composition Al-50at. %Cu that was found by HRSEM EDS. Addition of Si refined the grain structure and changed the amount of the eutectic regions, their size and shape. Additionally, the A201+Si microstructure contained Si rods and small amount of Al6Mn4Cu3Fe2Si-phase. Solution treatment (ST) at 550°C for ~ 20 hours resulted in a slight dissolution of the eutectic structure in the A201 alloy while substantial dissolution and change of the eutectic composition was detected in the A201+Si alloy. After ST, the A201alloy contained θ-Al2Cu, Al5Cu2Mn3 and Al9Cu7Mn3(Fe) phases associated to the GBs, while the ST A201+Si alloy contained θ-Al2Cu, Al6Mn4Cu3(Fe,Si) and Si94Mn3Al2Cu phases. Precipitation hardening during aging at 170°C was investigated for both alloys. The microhardness of the ST A201alloy increased during aging and reached the maximum value ~ 140 HV after 2 h of aging. Initial microhardness of the ST A201+Si alloy was distinctly higher than one of the ST A201 alloy, but it decreased during the first hour of aging, then increased and reached the same maximum value ~ 140 HV after ~ 4 h of aging. It was concluded that the Si addition influenced the precipitation sequence and slowed down the age hardening process. The Si induced grain refining and evolution of the eutectic structure during the heat treatments applied are discussed.

Keywords: A201 alloys, castability, microstructure, micro-hardness

Procedia PDF Downloads 287

Authors: Mairaj Ahmad, L. Paglia, F. Marra, V. Genova, G. Pulci

Abstract:

This study employed Rene N4 and FSX 414 superalloys, which are used in numerous turbine engine components due of their high strength, outstanding fatigue, creep, thermal, and corrosion-resistant properties. An in-depth examination of corrosion mechanisms with vapor present at high temperature is necessary given the industrial trend toward introducing increasing amounts of hydrogen into combustion chambers in order to boost power generation and minimize pollution in contrast to conventional fuels. These superalloys were oxidized in recent tests for 500, 1000, 2000, 3000 and 4000 hours at 982±5°C temperatures with a steady airflow at a flow rate of 10L/min and 1.5 bar pressure. These superalloys were also examined for wet corrosion for 500, 1000, 2000, 3000, and 4000 hours in a combination of air and water vapor flowing at a 10L/min rate. Weight gain, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS) were used to assess the oxidation and heat corrosion resistance capabilities of these alloys before and after 500, 1000, and 2000 hours. The oxidation/corrosion processes that accompany the formation of these oxide scales are shown in the graph of mass gain vs time. In both dry and wet oxidation, oxides like Al2O3, TiO2, NiCo2O4, Ni3Al, Ni3Ti, Cr2O3, MnCr2O4, CoCr2O4, and certain volatile compounds notably CrO2(OH)2, Cr(OH)3, Fe(OH)2, and Si(OH)4 are formed.

Keywords: hot corrosion, oxidation, turbine materials, high temperature corrosion, super alloys

Procedia PDF Downloads 83

Authors: Xiaoxiao Yu, Guodu He, Zihua Wu, Yuanyuan Wang, Huaqing Xie

Abstract:

Core-shell composite structure is a common method to regulate the spectral absorption of nanofluids, but there occur complex preparation processes, which limit the applications in some fields, such as photothermal utilization and catalysis. This work proposed point-mode Cu₂O/TiN plasmonic nanofluids to regulate the spectral capturing ability and simplify the preparation process. Non-noble TiN nanoparticles with the localized surface plasmon resonance effect are dispersed in Cu₂O nanoparticles for forming a multi-point resonance source to enhance the spectral absorption performance. The experimental results indicate that the multiple resonance effect of TiN effectively improves the optical absorption and expands the absorption region. When the radius of Cu₂O nanoparticles is equal to 150nm, the optical absorption of point-mode Cu₂O/TiN plasmonic nanoparticles is best. Moreover, the photothermal conversion efficiency of Cu₂O/TiN plasmonic nanofluid can reach 97.5% at a volume fraction of 0.015% and an optical depth of 10mm. The point-mode nanostructure effectively enhances the optical absorption properties and greatly simplifies the preparation process of the composite nanoparticles, which can promote the application of multi-component photonic nanoparticles in the field of solar energy.

Keywords: solar energy, nanofluid, point-mode structure, Cu₂O/TiN, localized surface plasmon resonance effect

Procedia PDF Downloads 57

Authors: Benhui Fan, Fahmi Bedoui, Jinbo Bai

Abstract:

Incorporated carbon nanotube-BaTiO₃ hybrids (H-CNT-BT) with core-shell structure, a better dispersion of CNTs can be achieved in a semi-crystalline polymeric matrix, polyvinylidene fluoride (PVDF). Carried by BT particles, CNTs are easy to mutually connect which helps to obtain an extremely low percolation threshold (fc). After thermal treatments, the dielectric constants (ε’) of samples further increase which depends on the conditions of thermal treatments such as annealing temperatures, annealing durations and cooling ways. Thus, in order to study more comprehensively about the influence of thermal treatments on composite’s dielectric behaviors, in situ synchrotron X-ray is used to detect re-crystalline behavior of PVDF. Results of wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) show that after the thermal treatment, the content of β polymorph (the polymorph with the highest ε’ among all the polymorphs of PVDF’s crystalline structure) has increased nearly double times at the interfacial region of CNT-PVDF, and the thickness of amorphous layers (La) in PVDF’s long periods (Lp) has shrunk around 10 Å. The evolution of CNT’s network possibly occurs in the procedure of La shrinkage, where the strong interfacial polarization may be aroused and increases ε’ at low frequency. Moreover, an increase in the thickness of crystalline lamella may also arouse more orientational polarization and improve ε’ at high frequency.

Keywords: dielectric properties, thermal treatments, carbon nanotubes, crystalline structure

Procedia PDF Downloads 321

Authors: Chayan Gupta, Arun Prasad

Abstract:

The quick evolution of industrialization causes the scarcity of precious land. Thus, it is vital need to influence the R&D societies to achieve sustainable, economic and social benefits from huge utilization of waste for universal aids. The current study promotes the influence of steel industries waste i.e. ground granulated blast furnace slag (GGBS) in geotechnical properties of jarosite waste (solid waste residues produced from hydrometallurgy operations involved in extraction of Zinc). Numerous strengths tests (unconfined compression (qu) and splitting tensile strength (qt)) are conducted on jarosite-GGBS blends (GGBS, 10-30%) with different curing periods (7, 28 & 90 days). The results indicate that both qu and qt increase with the increase in GGBS content along with curing periods. The increased strength with the addition of GGBS is also observed from microstructural study, which illustrates the occurrence of larger agglomeration of jarosite-GGBS blend particles. The Freezing-Thawing (F-T) durability analysis is also conducted for all the jarosite-GGBS blends and found that the reduction in unconfined compressive strength after five successive F-T cycles enhanced from 62% (natural jarosite) to 48, 42 and 34% at 7, 14 and 28 days curing periods respectively for stabilized jarosite-GGBS samples containing 30% GGBS content. It can be concluded from this study that blending of cementing additives (GGBS) with jarosite waste resulted in a significant improvement in geotechnical characteristics.

Keywords: jarosite, GGBS, strength characteristics, microstructural study, durability analysis

Procedia PDF Downloads 167

Authors: Maritza Estela Garay-Rodriguez, Mirella Gutierrez-Arzaluz, Miguel Torres-Rodriguez, Violeta Mugica-Alvarez

Abstract:

Arsenic is an element present in the earth's crust and is dispersed in the environment through natural processes and some anthropogenic activities. Naturally released into the environment through the weathering and erosion of sulphides mineral, some activities such as mining, the use of pesticides or wood preservatives potentially increase the concentration of arsenic in air, water, and soil. The natural arsenic release of a geological material is a threat to the world's drinking water sources. In aqueous phase is found in inorganic form, as arsenate and arsenite mainly, the contamination of groundwater by salts of this element originates what is known as endemic regional hydroarsenicism. The International Agency for Research on Cancer (IARC) categorizes the inorganic As within group I, as a substance with proven carcinogenic action for humans. It has been found the presence of As in groundwater in several countries such as Argentina, Mexico, Bangladesh, Canada and the United States. Regarding the concentration of arsenic in drinking water according to the World Health Organization (WHO) and the Environmental Protection Agency (EPA) establish maximum concentrations of 10 μg L⁻¹. In Mexico, in some states as Hidalgo, Morelos and Michoacán concentrations of arsenic have been found in bodies of water around 1000 μg L⁻¹, a concentration that is well above what is allowed by Mexican regulations with the NOM-127- SSA1-1994 that establishes a limit of 25 μg L⁻¹. Given this problem in Mexico, this research proposes the use of a natural Mexican zeolite (clinoptilolite type) native to the district of Etla in the central valley region of Oaxaca, as an adsorbent for the removal of arsenic. The zeolite was subjected to a conditioning with iron oxide by the precipitation-impregnation method with 0.5 M iron nitrate solution, in order to increase the natural adsorption capacity of this material. The removal of arsenic was carried out in a column with a fixed bed of conditioned zeolite, since it combines the advantages of a conventional filter with those of a natural adsorbent medium, providing a continuous treatment, of low cost and relatively easy to operate, for its implementation in marginalized areas. The zeolite was characterized by XRD, SEM/EDS, and FTIR before and after the arsenic adsorption tests, the results showed that the modification methods used are adequate to prepare adsorbent materials since it does not modify its structure, the results showed that with a particle size of 1.18 mm, an initial concentration of As (V) ions of 1 ppm, a pH of 7 and at room temperature, a removal of 98.7% was obtained with an adsorption capacity of 260 μg As g⁻¹ zeolite. The results obtained indicated that the conditioned zeolite is favorable for the elimination of arsenate in water containing up to 1000 μg As L⁻¹ and could be suitable for removing arsenate from pits of water.

Keywords: adsorption, arsenic, iron conditioning, natural zeolite

Procedia PDF Downloads 169

Authors: Priya Narayanan

Abstract:

Despite several studies having been conducted on the highly subjective concept of place attachment in the last 60 years, there is a lack of consensus among researchers about how it can be measured empirically. Further, there is no available literature that discusses how a place can be manipulated via design and/or policy to allow people to feel/get attached to it, an aspect that seems to be the need of the hour in a world where a substantial population is living in shelter homes as war/climate/social refugees. Consequently, this paper draws from studies on place, affordance and attachment to conceptualize an objectively measurable entity in place attachment affordance by asking ‘whether and to what degree a place allows one to form attachment bonds with it’ rather than the generally asked ‘whether and to what degree one is/feels attached to a place’. Towards this, the place attachment affordance scale (PAAS) has been developed to not only quantitatively measure place attachment affordance but also act as a point of entry into a more in-depth analysis of both place policy and place properties. To illustrate the validity of the scale, the study uses PAAS to compare shelter homes for women in crisis with the homes they once lived in to glean the degree to which both places afford the formation of place attachment bonds to the residents. PAAS has also been used to compare shelter homes as places of short-/long-term residence for the residents and as places of work for the staff. Based on the results, it is suggested that place attachment and built environment researchers employ the PAAS as an objective measurement tool to better understand not only the presence or absence of attachment bonds with place but also the attributes of place that encourage or discourage the same. The study also briefly discusses the universality of the PAAS, although further fieldwork might be required to substantiate the same.

Keywords: place attachment, affordance, shelter homes, home, scale, environmental psychology

Procedia PDF Downloads 22

Authors: Hari Krishna Ayyappa, Reenu Singh

Abstract:

Rising population and restricted land for development has led towards the growth of vertical buildings and small complexes. It provides many possibilities to change the shape and size of internal space in addition to the social impacts on the commercial spaces. With the increased volatility of necessities of people, the need for mental and physical comfort has continuously increased. . Living in a small space musts minimalist and space- saving cabinetwork results to sustain mortal good. This paper attempts to explore the Influence of Using Minimalist Furniture on the Efficiency of the commercial Space interiors by means of the variable resulting from preceding studies based on literature. A literature review was conducted on research articles to understand the contributing variables in a well designed small commercial spaces. A questionnaire survey was conducted to understand the layout of small commercial spaces with respect to Environmental impact, material, Design elements, Modern approach, Layered lightings, and colours. The problem of small spaces can be resolved by some ways; it's still needed for cabinetwork to develop to be more innovative to accommodate small living spaces. Since cabinetwork is a necessity and not luxury, everybody is in need of it. The spatial factors affecting overall satisfaction at a detailed position were bandied. The variable helped in proposing design ideation and mock ups to explore improved interiors. This paper concludes that most of the principles of the minimalist approach have been overlooked at, which had an impact on the space efficiency in commercial spaces like storage rooms, office area, retail stores, restaurants, and other spaces where business is conducted.

Keywords: materials, modern approach, space efficiency, tall commercial buildings

Procedia PDF Downloads 108

Authors: D. Geringswald, B. Hintze

Abstract:

The miniaturization of circuits is advancing. During chip manufacturing, structures are filled for example by metal organic chemical vapor deposition (MOCVD). Since this process reaches its limits in case of very high aspect ratios, the use of alternatives such as the atomic layer deposition (ALD) is possible, requiring the extension of existing coating systems. However, it is an unsolved question to what extent MOCVD can achieve results similar as an ALD process. In this context, this work addresses the characterization of a metal organic vapor deposition of titanium nitride. Based on the current state of the art, the film properties coating thickness, sheet resistance, resistivity, stress and chemical composition are considered. The used setting parameters are temperature, plasma gas ratio, plasma power, plasma treatment time, deposition time, deposition pressure, number of cycles and TDMAT flow. The derived process instructions for unstructured wafers and inside a structure with high aspect ratio include lowering the process temperature and increasing the number of cycles, the deposition and the plasma treatment time as well as the plasma gas ratio of hydrogen to nitrogen (H₂:N₂). In contrast to the current process configuration, the deposited titanium nitride (TiN) layer is more uniform inside the entire test structure. Consequently, this paper provides approaches to employ the MOCVD for structures with increasing aspect ratios.

Keywords: ALD, high aspect ratio, PE-MOCVD, TiN

Procedia PDF Downloads 296

Authors: Chung-Hyeon Ryu, Do-Hyoung Kim, Hak-Sung Kim

Abstract:

As the use of the composites was increased, the detecting method of hidden damages which have an effect on performance of the composite was important. Terahertz (THz) spectroscopy was assessed as one of the new powerful nondestructive evaluation (NDE) techniques for fiber reinforced composite structures because it has many advantages which can overcome the limitations of conventional NDE techniques such as x-rays or ultrasound. The THz wave offers noninvasive, noncontact and nonionizing methods evaluating composite damages, also it gives a broad range of information about the material properties. In additions, it enables to detect the multiple-delaminations of various nonmetallic materials. In this study, the pulse type THz spectroscopy imaging system was devised and used for detecting and evaluating the hidden delamination in the glass fiber reinforced plastic (GFRP) composite laminates. The interaction between THz and the GFRP composite was analyzed respect to the type of delamination, including their thickness, size and numbers of overlaps among multiple-delaminations in through-thickness direction. Both of transmission and reflection configurations were used for evaluation of hidden delaminations and THz wave propagations through the delaminations were also discussed. From these results, various hidden delaminations inside of the GFRP composite were successfully detected using time-domain THz spectroscopy imaging system and also compared to the results of C-scan inspection. It is expected that THz NDE technique will be widely used to evaluate the reliability of composite structures.

Keywords: terahertz, delamination, glass fiber reinforced plastic composites, terahertz spectroscopy

Procedia PDF Downloads 589

Authors: Anny Zambrano, German Gonzalez, Yair Quintero

Abstract:

The continuum damage concept is used to study the interaction between hydraulic fractures and natural fractures, the objective is representing the path and relation among this two fractures types and predict its complex behavior without the need to pre-define their direction as occurs in other finite element applications, providing results more consistent with the physical behavior of the phenomenon. The approach uses finite element simulations through Abaqus software to model damage fracturing, the fracturing process by damage propagation in a rock. The modeling the phenomenon develops in two dimensional (2D) so that the fracture will be represented by a line and the crack front by a point. It considers nonlinear constitutive behavior, finite strain, time-dependent deformation, complex boundary conditions, strain hardening and softening, and strain based damage evolution in compression and tension. The complete governing equations are provided and the method is described in detail to permit readers to replicate all results. The model is compared to models that are published and available. Comparisons are focused in five interactions between natural fractures (NF) and hydraulic fractures: Fractured arrested at NF, crossing NF with or without offset, branching at intersecting NFs, branching at end of NF and NF dilation due to shear slippage. The most significant new finding is, that is not necessary to use pre-defined addresses propagation and stress condition can be evaluated as a dominant factor in the process. This is important because it can model in a more real way the generated complex hydraulic fractures, and be a valuable tool to predict potential problems and different geometries of the fracture network in the process of fracturing due to fluid injection.

Keywords: continuum damage, hydraulic fractures, natural fractures, complex fracture network, stiffness

Procedia PDF Downloads 333

Authors: Senem Suna, Canan Ece Tamer, Ömer Utku Çopur

Abstract:

In this research, dried linden (Tilia argentea) leaves and blossoms were used as a raw material for mineral enriched herbal tea beverage production. For this aim, %1 dried linden was infused with boiling water (100 °C) for 5 minutes. After cooling, sucrose, citric acid, ascorbic acid, natural lemon flavor and natural mineral water were added. Beverage samples were plate filtered, filled into 200-mL glass bottles, capped then pasteurized at 98 °C for 15 minutes. Water soluble dry matter, titratable acidity, ascorbic acid, pH, minerals (Fe, Ca, Mg, K, Na), color (L*, a*, b*), turbidity, bioaccessible phenolics and antioxidant capacity were analyzed. Water soluble dry matter, titratable acidity, and ascorbic were determined as 7.66±0.28 g/100 g, 0.13±0.00 g/100 mL, and 19.42±0.62 mg/100 mL, respectively. pH was measured as 3.69. Fe, Ca, Mg, K and Na contents of the beverage were determined as 0.12±0.00, 115.48±0.05, 34.72±0.14, 48.67±0.43 and 85.72±1.01 mg/L, respectively. Color was measured as 13.63±0.05, -4.33±0.05, and 3.06±0.05 for L*, a*, and b* values. Turbidity was determined as 0.69±0.07 NTU. Bioaccessible phenolics were determined as 312.82±5.91 mg GAE/100 mL. Antioxidant capacities of chemical (MetOH:H₂O:HCl) and physiological extracts (in vitro digestive enzymatic extraction) with DPPH (27.59±0.53 and 0.17±0.02 μmol trolox/mL), FRAP (21.01±0.97 and 13.27±0.19 μmol trolox/mL) and CUPRAC (44.71±9.42 and 2.80±0.64 μmol trolox/mL) methods were also evaluated. As a result, enrichment with natural mineral water was proposed for the development of functional and nutritional values together with a good potential for commercialization.

Keywords: linden, herbal tea beverage, bioaccessibility, antioxidant capacity

Procedia PDF Downloads 168

Authors: Hana Aljumayi, Mohammed Issa

Abstract:

The aim of this study was to investigate the effect of the training program for professional athletes at the Saudi Archery Federation on the electrical activity of the muscles involved in pulling the bowstring, maximum muscle strength (MVC) and to identify the relationship between the electrical activity of these muscles and accuracy in shooting among female archers. The researcher used a descriptive approach that was suitable for the nature of the study, and a sample of nine female archers was selected using purposive sampling. An EMG device was used to measure signal amplitude, signal frequency, spectral energy signal, and MVC. The results showed statistically significant differences in signal amplitude among muscles, with F(8,1)=5.91 and a significance level of 0.02. There were also statistically significant differences between muscles in terms of signal frequency, with F(8,1)=8.23 and a significance level of 0.02. Bonferroni test results indicated statistically significant differences between measurements at a significance level of 0.05, with anterior measurements showing an average difference of 16.4 compared to other measurements. Furthermore, there was a significant negative correlation between signal amplitude in the calf muscle and accuracy in shooting (r=-0.78) at a significance level of 0.02. There was also a significant positive correlation between signal frequency in the calf muscle and accuracy in shooting (r=0.72) at a significance level of 0.04. In conclusion, it appears that the training program for archery athletes focused more on skill development than physical aspects such as muscle activity and strength development. However, it did have a statistically significant effect on signal amplitude but not on signal frequency or MVC development in muscles involved in pulling the bowstring.

Keywords: electrical activity of muscles, archery sport, shooting accuracy, muscles

Procedia PDF Downloads 59

Authors: H. M. Haytham, E. A. Azza, E.S. Mohamed, E. G. Nesreen

Abstract:

Thoracotomy is a great surgery that has serious pulmonary complications, so purpose of this study was to determine the response of diaphragmatic excursion to inspiratory muscle trainer post thoracotomy. Thirty patients of both sexes (16 men and 14 women) with age ranged from 20 to 40 years old had done thoracotomy participated in this study. The practical work was done in cardiothoracic department, Kasr-El-Aini hospital at faculty of medicine for individuals 3 days Post operatively. Patients were assigned into two groups: group A (study group) included 15 patients (8 men and 7 women) who received inspiratory muscle training by using inspiratory muscle trainer for 20 minutes and routine chest physiotherapy (deep breathing, cough and early ambulation) twice daily, 3 days per week for one month. Group B (control group) included 15 patients (8 men and 7 women) who received the routine chest physiotherapy only (deep breathing, cough and early ambulation) twice daily, 3 days per week for one month. Ultrasonography was used to evaluate the changes in diaphragmatic excursion before and after training program. Statistical analysis revealed a significant increase in diaphragmatic excursion in the study group (59.52%) more than control group (18.66%) after using inspiratory muscle trainer post operatively in patients post thoracotomy. It was concluded that the inspiratory muscle training device increases diaphragmatic excursion in patients post thoracotomy through improving inspiratory muscle strength and improving mechanics of breathing and using of inspiratory muscle trainer as a method of physical therapy rehabilitation to reduce post-operative pulmonary complications post thoracotomy.

Keywords: diaphragmatic excursion, inspiratory muscle trainer, ultrasonography, thoracotomy

Procedia PDF Downloads 318

Authors: Mohd Adil, Rosina Khan, Danishuddin, Asad U. Khan

Abstract:

The aim of this study was to evaluate the influence of the crude and active solvent fraction of Trachyspermum ammi on S. mutans cariogenicity, effect on expression of genes involved in biofilm formation and caries development in rats. GC–MS was carried out to identify the major components present in the crude and the active fraction of T. ammi. The crude extract and the solvent fraction exhibiting least MIC were selected for further experiments. Scanning electron microscopy was carried out to observe the effect of the extracts on S. mutans biofilm. Comparative gene expression analysis was carried out for nine selected genes. 2-Isopropyl-5-methyl-phenol was found as major compound in crude and the active fraction. Binding site of this compound within the proteins involved in biofilm formation was mapped with the help of docking studies. Real-time RT-PCR analyses revealed significant suppression of the genes involved in biofilm formation. All the test groups showed reduction in caries (smooth surface as well as sulcal surface caries) in rats. Moreover, it also provides new insight to understand the mechanism influencing biofilm formation in S. mutans. Furthermore, the data suggest the putative cariostatic properties of T. Ammi and hence can be used as an alternative medicine to prevent caries infection.

Keywords: bio-film, Streptococcus mutans, dental caries, bio-informatic

Procedia PDF Downloads 473

Authors: A. M. Daneshian Moghaddam, J. Shayegh, J. Dolghari Sharaf

Abstract:

This study was conducted to assessment the antibacterial activities of different part of basil essential oil on the standard gram-negative bacteria include Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and gram-positive ones including Bacillus cereus, Staphylococcus aureus, and Listeria monocytogen. The basil essential oil was provided from two part of plant (leaf and herb) at the two different developmental stage. The antibacterial properties of basil essential oil was studied Also agar disk diffusion, minimal inhibition concentration (MIC) and minimum bactericidal concentration (MBC) were detected. The results of agar disk diffusion tests showed the inhibition zones as follow: Listeria monocytogen 17.11-17.42 mm, St. aureus 29.20-30.56 mm, B. cereus 14.73-16.06 mm, E. coli 21.60-23.58 mm, Salmonella typhi 21.63-24.80 mm and for P. aeruginosa the maximum inhibition zones were seen on leaf essential oil. From the herb part of basil almost similar results were obtained: Listeria monocytogen 17.02-17.67 mm, St. aureus 29.60-30.41 mm, B. cereus 10.66-16.11 mm, E. coli 17.48-23.54 mm, Salmonella typhi 21.58-21.64 mm and for P. aeruginosa the maximum inhibition zones were seen. The MICs for gram-positive bacteria were as: B. cereus ranging 36-18 μg/mL, S. aureus 18 μg/mL, Listeria monocytogen 18-36 μg/mL and for gram-negative bacteria of E. coli, Salmonella typhi and P. aeruginosa were 18-9 μg/mL.

Keywords: basil (Ocimum basilicum) essential oil, gram-positive and gram negative bacteria, antibacterial activity, MIC, MBC

Procedia PDF Downloads 438

Authors: Spandana Ramisetty, Mandan Chidambaram, Ramesh Bhujade

Abstract:

Algal biomass is not only a potential source for biocrude but also for high value chemicals like carotenoids, fatty acids, proteins, polysaccharides, vitamins etc. Astaxanthin is one such high value vital carotenoid which has extensive applications in pharmaceutical, aquaculture, poultry and cosmetic industries and expanding as dietary supplement to humans. Green microalgae Haematococcus pluvialis is identified as the richest natural source of astaxanthin and is the key source of commercial astaxanthin. Several extraction processes from wet and dry Haematococcus pluvialis biomass have been explored by researchers. Extraction with supercritical CO₂ and various physical disruption techniques like mortar and pestle, homogenization, ultrasonication and ball mill from dried algae are widely used extraction methods. However, these processes require energy intensive drying of biomass that escalates overall costs notably. From the process economics perspective, it is vital to utilize wet processing technology in order to eliminate drying costs. Hydrothermal liquefaction (HTL) is a thermo-chemical conversion process that converts wet biomass containing over 80% water to bio-products under high temperature and high pressure conditions. Astaxanthin is a lipid soluble pigment and is usually extracted along with lipid component. Mild HTL at 200°C and 60 bar has been demonstrated by researchers in a microfluidic platform achieving near complete extraction of astaxanthin from wet biomass. There is very limited work done in this field. An integrated approach of sequential HTL offers cost-effective option to extract astaxanthin/lipid from wet algal biomass without drying algae and also recovering water, minerals and nutrients. This paper reviews past work and evaluates the astaxanthin extraction processes with focus on hydrothermal extraction.

Keywords: astaxanthin, extraction, high value chemicals, hydrothermal liquefaction

Procedia PDF Downloads 305

Authors: Tsukasa Ogawa, Mitsuhiro Okayasu

Abstract:

To examine the generation properties of electric power for piezoelectric (PbZrTiO3) ceramic plates, the electric-power generation characteristics were examined experimentally and numerically during cyclic bending under various loading fixtures with different contact condition, i.e., point and area contact. In the low applied loading condition between 10 and 50 N, increasing the load-contact area on the piezoelectric ceramic led to a nonlinear decrease in the generated voltage. Decreasing contact area, including the point contact, basically enhanced the generated voltage, although the voltage saturated during loading when the contact area is less than ϕ5 mm, which was attributed to the high strain status, resulting in the material failure, i.e., high stress concentration. In this case, severe plastic deformation and the domain switching were dominated failure modes in the ceramic. From this approach, it is clear that the applied load became more larger (50 ~100 N), larger contact area (ϕ10 ~ ϕ20 mm) became advantageous for power generation. Based upon this cyclic loading was carried out to investigate the fatigue characteristics of the piezoelectric ceramic late. For all contact conditions, electric voltage dropped in the beginning of the cyclic loading, although the higher electric generation was stable in the further cyclic loading for the contact area of ϕ10 ~ ϕ20 mm. In constant, further decrement of electric generation occurred for the point contact condition, and the low electric voltage was generated for the larger contact condition.

Keywords: electric power generation, piezoelectric ceramic, lead zirconate titanate ceramic, loading conditions

Procedia PDF Downloads 164

Authors: Fatihin Khoirul, Muhammad Muqorrobin Ist

Abstract:

Bojonegoro Regency is one of the districts that use the concept Agropolitan as the Territorial Development Policy. Three sub-district designated as Area Development District of Agropolitan are Kapas, Dander, and Kalitidu or commonly called KADEKA. Current policy has been shown results, but there was an inequality of results in some areas. One of them occurred in the Ngringinrejo village with the main commodities is Starfruit and Wedi village with the main commodities is Salak fruit. Therefore, a comparative study is used to search for causal factors of inequality result of the policy by using the 5 aspects compared, namely: (1) Management Development Agropolitan; (2) Physical Condition agropolitan Region; (3) Implementing Agency at the Village Level; (4) Village Government Support; and (5) Community support. Based on the discussion of qualitative analysis, it was found that five aspects have their respective roles in creating inequality of outcomes that occur in both villages. But beyond that, there are conditions where the two villages experienced the same condition that is when the initial implementation of the policy. The condition is referred to as 'the phenomenon of price trap.' The condition is caused by lower commodity prices, causing the village government's commitment in implementing policies too low, followed by public awareness in support of the policy is also low, so care for commodities is also low, and the quality is too low lead and eventually back causing low price. However, the difference is that the village Ngringinrejo able to get out of this condition with 'the new culture of administration' at the end of 2013. While the conditions in the village of Wedi compounded by not respected request assistance by the irrigation district.

Keywords: comparative policy analysis, qualitative comparative, inequallity, price trap, new culture of administration

Procedia PDF Downloads 283

Authors: Alae Lamtai, Said Elkoun, Hniya Kharmoudi, Mathieu Robert, Carl Diez

Abstract:

This study applies Taguchi's design of experiment methodology and grey relational analysis (GRA) for multi objective optimization of an industrial recycling line. This last is composed mainly of a mono and twin-screw extruder and a filtration system. Experiments were performed according to L₁₆ standard orthogonal array based on five process parameters, namely: mono screw design, screw speed of the mono and twin-screw extruder, melt pump pressure, and filter mesh size. The objective of this optimization is to improve the durability of the Polyethylene (PE) blend by decreasing the loss of Stress Crack resistance (SCR) using Notched Crack Ligament Stress (NCLS) test and Unnotched Crack Ligament Stress (UCLS) in parallel with increasing the gain of Izod impact strength of the Polyethylene (PE) blend before and after recycling. Based on Grey Relational Analysis (GRA), the optimal setting of process parameters was identified, and the results indicated that the mono-screw design and screw speed of both mono and twin-screw extruder impact significantly the mechanical properties of recycled Polyethylene (PE) blend.

Keywords: Taguchi, recycling line, polyethylene, stress crack resistance, Izod impact strength, grey relational analysis

Procedia PDF Downloads 76

Authors: Laura Isabel Guarin, Juliana Vargas, Philippe Chang

Abstract:

The analysis and study of Open Channel flow dynamics for River applications has been based on flow modelling using discreet numerical models based on hydrodynamic equations. The overall spatial characteristics of rivers, i.e. its length to depth to width ratio generally allows one to correctly disregard processes occurring in the vertical or transverse dimensions thus imposing hydrostatic pressure conditions and considering solely a 1D flow model along the river length. Through a calibration process an accurate flow model may thus be developed allowing for channel study and extrapolation of various scenarios. The Magdalena River in Colombia is a large river basin draining the country from South to North with 1550 km with 0.0024 average slope and 275 average width across. The river displays high water level fluctuation and is characterized by a series of meanders. The city of La Dorada has been affected over the years by serious flooding in the rainy and dry seasons. As the meander is evolving at a steady pace repeated flooding has endangered a number of neighborhoods. This study has been undertaken in pro of correctly model flow characteristics of the river in this region in order to evaluate various scenarios and provide decision makers with erosion control measures options and a forecasting tool. Two field campaigns have been completed over the dry and rainy seasons including extensive topographical and channel survey using Topcon GR5 DGPS and River Surveyor ADCP. Also in order to characterize the erosion process occurring through the meander, extensive suspended and river bed samples were retrieved as well as soil perforation over the banks. Hence based on DEM ground digital mapping survey and field data a 2DH flow model was prepared using the Iber freeware based on the finite volume method in a non-structured mesh environment. The calibration process was carried out comparing available historical data of nearby hydrologic gauging station. Although the model was able to effectively predict overall flow processes in the region, its spatial characteristics and limitations related to pressure conditions did not allow for an accurate representation of erosion processes occurring over specific bank areas and dwellings. As such a significant helical flow has been observed through the meander. Furthermore, the rapidly changing channel cross section as a consequence of severe erosion has hindered the model’s ability to provide decision makers with a valid up to date planning tool.

Keywords: erosion, finite volume method, flow dynamics, flow modelling, meander

Procedia PDF Downloads 317

Authors: Shirin Jalili, Sadegh Hasannia, Hadi Shirzad, Afshin Khara

Abstract:

Morphine is one of the most medicinally important analgesics and narcotics. Structurally, it is classified as an alkaloid because of the presence of nitrogen. Its structure is similar to that of codeine, thebaine, and heroin. An immunoassay to accurately discriminate between these analogous alkaloids would be highly beneficial. A key factor for such an assay is specificity with high sensitivity, which is totally dependent on the antibody employed. However, most antibodies against haptens are polyclonal serum antibodies that exhibit significant cross-reactivities with closely related compounds. The camel-derived single-chain antibody fragments (VHH) are the smallest molecules with antigen-binding capacity, possessing unique properties compared to other conventional antibodies. In this study, a library containing the VHH genes of a camel immunized with with morphine conjugated BSA following phage display technology was generated. By screening the camel-derived variable region of the heavy chain cDNA phage display library with the ability to bind the desired hapten, we obtained some nanobodies that recognize this hapten. Phage display expression of the Nbs from this library and pannings against this hapten resulted in a clear enrichment of four distinct Nb-displaying phages with specificity for morphine that could be a potential target site for the development of new strategies for the development of a biosensor for detecting illicit drug.

Keywords: phage display, nanobody, Morphine-3, glucuronide, ELISA, biosensor

Procedia PDF Downloads 422

Authors: Fatiha Besahraoui, M'hamed Guezzoul, Kheira Chebbah, M'hamed Bouslama

Abstract:

SnO₂ thin film is characterized by Atomic Force Microscopy (AFM) and Photoluminescence Spectroscopies. AFM images show a dense surface of columnar grains with a roughness of 78.69 nm. The PL measurements at 7 K reveal the presence of PL peaks centered in IR and visible regions. They are attributed to radiative transitions via oxygen vacancies, Sn interstitials, and dangling bonds. A bands diagram model is presented with the approximate positions of intrinsic point defect levels in SnO₂ thin films. The integrated PL measurements demonstrate the good thermal stability of our sample, which makes it very useful in optoelectronic devices functioning at room temperature. The unusual behavior of the evolution of PL peaks and their full width at half maximum as a function of temperature indicates the thermal sensitivity of the point defects present in the band gap. The shallower energy levels due to dangling bonds and/or oxygen vacancies are more sensitive to the temperature. However, volume defects like Sn interstitials are thermally stable and constitute deep and stable energy levels for excited electrons. Small redshifting of PL peaks is observed with increasing temperature. This behavior is attributed to the reduction of oxygen vacancies.

Keywords: transparent conducting oxide, photoluminescence, intrinsic point defects, semiconductors, oxygen vacancies

Procedia PDF Downloads 79

Authors: Yemane Kahsay Berhe

Abstract:

The multipurpose cactus pear plant with great potential as a source of food and livestock feed faced a threat from Dactylopius spp in different countries. Specifically, D. coccus is an important pest damaging significant areas in Tigray-Ethiopia. Using pest-resistant cultivars is an important element of an integrated pest management strategy, and studying the mechanisms of resistance is vital. It can be chemical or physical, such as oxalate crystals and other cladode characteristics. Cladode features of six cultivars (three O. ficus-indica, two O. cochenillifera, and one O. robusta) were examined for resistance to D. coccus in a completely randomized design (CRD) with three replications. ‘Rojo Pelón’ (O. ficus-indica), ‘Robusta’ (O. robusta), and ‘Bioplástico’ (O. cochinillifera) are resistant cultivars; and ‘Atlixco’ and ‘Chicomostoc’ (O. ficus-indica) and ‘Nopalea’ (O. cochinillifera) are susceptible. Cultivars showed a significant difference in cladode weight in g, cladode length, cladode width, and cladode thickness in cm, where cladode thickness was higher in ‘Rojo Pelón’ followed by ‘Robusta’. Calcium oxalates number per mm was higher in ‘Bioplástico’ (20.7+2.08) followed by ‘Robusta’ (18.9+2.31) and ‘Rojo Pelón’ (15.9+0.34); and similarly, epidermis thickness found higher in ‘Bioplástico’ (0.21+0.032) and ‘Robusta’ (0.19+0.014), but similar with ‘Rojo Pelón’ (0.18+0.026). However, cuticle thickness didn’t show a difference among cultivars. Cladode thickness, calcium oxalates number, and epidermis thickness had positive correlations with resistance. These results demonstrate that calcium oxalates number and epidermis thickness might positively affect D. coccus resistance in O. ficus-indica. This feeding-barring role and the insect-plant interaction need to be studied.

Keywords: cactus pear, resiatnce, druses, epidermis thickness

Procedia PDF Downloads 69

Authors: Shahana Sharmin

Abstract:

In the present study, the effect of cellulose polymers Ethyl Cellulose and Hydroxy Propyl Methyl Cellulose was evaluated on the release profile of drug from sustained release pellet. Diltiazem Hydrochloride, an antihypertensive, cardio-protective agent and slow channel blocker were used as a model drug to evaluate its release characteristics from different pellets formulations. Diltiazem Hydrochloride sustained release pellets were prepared by drug loading (drug binder suspension) on neutral pellets followed by different percentages of spraying, i.e. 2%,4%, 6%, 8% and 10% coating suspension using ethyl cellulose and hydroxy-propyl methyl cellulose polymer in a fixed 85:15 ratios respectively. The in vitro dissolution studies of Diltiazem Hydrochloride from these sustained release pellets were carried out in pH 7.2 phosphate buffer for 1, 2, 3, 4, 5, 6, 7, and 8 hrs using USP-I method. Statistically, significant differences were found among the drug release profile from different formulations. Polymer content with the highest concentration of Ethyl cellulose on the pellets shows the highest release retarding rate of the drug. The retarding capacity decreases with the decreased concentration of ethyl cellulose. The release mechanism was explored and explained with zero order, first order, Higuchi and Korsmeyer’s equations. Finally, the study showed that the profile and kinetics of drug release were functions of polymer type, polymer concentration & the physico-chemical properties of the drug.

Keywords: diltiazem hydrochloride, ethyl cellulose, hydroxy propyl methyl cellulose, release kinetics, sustained release pellets

Procedia PDF Downloads 407

Authors: Shian-Ling Keng, Onn Siong Yim, Poh San Lai, Soo Chong Chew, Anne Chong, Richard Ebstein

Abstract:

Research has demonstrated a positive association between mindfulness meditation and physical health. Little work, however, has examined the association between trait mindfulness and leukocyte telomere length (LTL), an emerging marker of cellular aging. The present study aimed to examine whether facets of trait mindfulness are correlated with longer LTL in a Singaporean Han Chinese sample and whether these facets may mediate the association between psychological symptoms and LTL. 158 adults (mean age = 27.24 years) completed measures assessing trait mindfulness and psychological symptoms (i.e., depression and stress) and provided blood samples for analyses of LTL using qPCR. Multiple regression analyses were conducted to assess the association between facets of trait mindfulness and LTL. Bootstrapping-based mediational analyses were run to examine the role of trait mindfulness as a mediator of the association between psychological symptoms and LTL. Of five facets of trait mindfulness (describe, act with awareness, observe, nonreactivity, and nonjudging), nonreactivity was significantly associated with LTL, after controlling for the effects of age, gender, and education, β = .21, p = .006. Further, there was a trend for overall trait mindfulness, β = .15, p = .06, and nonjudging, β = .13, p = .095, to each predict longer LTL. Nonreactivity significantly mediated the association between depression and LTL, BCa 95% CI [-.004, -.0004], p=.03, as well as the association between stress and LTL, BCa 95% CI [-.004, -.0004], p=.04. The results provide preliminary evidence for a positive association between selected facets of trait mindfulness and slower cellular aging, indexed by LTL. The findings suggest that individuals who are high on equanimity may experience slower aging at the cellular level, presumably through engaging in more effective coping mechanisms and modulation of stress. The findings also highlight the role of nonreactivity as a potential mechanism that underlies the association between LTL and psychological symptoms.

Keywords: depression, mindfulness, stress, telomere length

Procedia PDF Downloads 339