Search results for: adaptive filter and average filter
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6277

Search results for: adaptive filter and average filter

1927 Cultivation of High-value Patent from the Perspective of Knowledge Diffusion: A Case Study of the Power Semiconductor Field

Authors: Lin Qing

Abstract:

[Objective/Significance] The cultivation of high-value patents is the focus and difficulty of patent work, which is of great significance to the construction of a powerful country with intellectual property rights. This work should not only pay attention to the existing patent applications, but also start from the pre-application to explore the high-value technical solutions as the core of high-value patents. [Methods/processes] Comply with the principle of scientific and technological knowledge diffusion, this study studies the top academic conference papers and their cited patent applications, taking the power semiconductor field as an example, using facts date show the feasibility and rationality of mining technology solutions from high quality research results to foster high value patents, stating the actual benefits of these achievements to the industry, giving patent protection suggestions for Chinese applicants comparative with field situation. [Results/Conclusion] The research shows that the quality of citation applications of ISPSD papers is significantly higher than the field average level, and the ability of Chinese applicants to use patent protection related achievements needs to be improved. This study provides a practical and highly targeted reference idea for patent administrators and researchers, and also makes a positive exploration for the practice of the spirit of breaking the five rules.

Keywords: high-value patents cultivation, technical solutions, knowledge diffusion, top academic conference papers, intellectual property information analysis

Procedia PDF Downloads 107
1926 Potential of Water Purification of Turbid Surface Water Sources in Remote Arid and Semi-Arid Rural Areas of Rajasthan by Moringa Oleifera (Drumstick) Tree Seeds

Authors: Pomila Sharma

Abstract:

Rajasthan is among regions with greatest climate sensitivity and lowest adaptive capabilities. In many parts of the Rajasthan surface water which can be highly turbid and contaminated with fecal coliform bacteria is used for drinking purposes. The majority rely almost exclusively upon traditional sources of highly turbid and untreated pathogenic surface water for their domestic water needs. In many parts of rural areas of Rajasthan, it is still difficult to obtain clean water, especially remote habitations with no groundwater due to quality issues or depletion and limited feasibility to connect with surface water schemes due to low density of population in these areas to justify large infrastructure investment. The most viable sources are rain water harvesting, community managed open wells, private wells, ponds and small-scale irrigation reservoirs have often been the main traditional sources of rural drinking water. Turbidity is conventionally removed by treating the water with expensive chemicals. This study has to investigate the use of crushed seeds from the tree Moringa oleifera (drumstick) as a natural alternative to conventional coagulant chemicals. The use of Moringa oleifera seed powder can produce potable water of higher quality than the original source. Moringa oleifera a native species of northern India, the tree is now grown extensively throughout the tropics and found in many countries of Africa, Asia & South America. The seeds of tree contains significant quantities of low molecular weight, water soluble proteins which carries the positive charge when the crushed seeds are added to water. This protein binds in raw water with negatively charged turbid water with bacteria, clay, algae, etc. Under proper mixing, these particles make flocks, which may be left to settle by gravity or be removed by filtration. Using Moringa oleifera as a replacement coagulation in such surface sources of arid and semi-arid areas can meet the need for water purification in remote places of Rajasthan state of India. The present study accesses to find out laboratory based investigation of the effect of seeds of Moringa tree on its coagulation effectiveness (purification) using turbid water samples of surface source of the Rajasthan state. In this study, moringa seed powder showed that filtering with seed powder may diminish water pollution and bacterial counts. Results showed Moringa oleifera seeds coagulate 90-95% of turbidity and color efficiently leading to an aesthetically clear supernatant & reduced about 85-90% of bacterial load reduction in samples.

Keywords: bacterial load, coagulant, turbidity, water purification

Procedia PDF Downloads 121
1925 The Urban Expansion Characterization of the Bir El Djir Municipality using Remote Sensing and GIS

Authors: Fatima Achouri, Zakaria Smahi

Abstract:

Bir El Djir is an important coastal township in Oran department, located at 450 Km far away from Algiers on northwest of Algeria. In this coastal area, the urban sprawl is one of the main problems that reduce the limited highly fertile land. So, using the remote sensing and GIS technologies have shown their great capabilities to solve many earth resources issues. The aim of this study is to produce land use and cover map for the studied area at varied periods to monitor possible changes that may occurred, particularly in the urban areas and subsequently predict likely changes. For this, two spatial images SPOT and Landsat satellites from 1987 and 2014 respectively were used to assess the changes of urban expansion and encroachment during this period with photo-interpretation and GIS approach. The results revealed that the town of Bir El Djir has shown a highest growth rate in the period 1987-2014 which is 521.1 hectares in terms of area. These expansions largely concern the new real estate constructions falling within the social and promotional housing programs launched by the government. Indeed, during the last census period (1998 -2008), the population of this town has almost doubled from 73 029 to 152 151 inhabitants with an average annual growth of 5.2%. This also significant population growth is causing an accelerated urban expansion of the periphery which causing its conurbation with the towns of Oran in the West side. The most urban expansion is characterized by the new construction in the form of spontaneous or peripheral precarious habitat, but also unstructured slums settled especially in the southeastern part of town.

Keywords: urban expansion, remote sensing, photo-interpretation, spatial dynamics

Procedia PDF Downloads 254
1924 Comparing Student Performance on Paper-Based versus Computer-Based Formats of Standardized Tests

Authors: Jin Koo

Abstract:

During the coronavirus pandemic, there has been a further increasing demand for computer-based tests (CBT), and now it has become an important test mode. The main purpose of this study is to investigate the comparability of student scores obtained from computerized-based formats of a standardized test in the two subject areas of reading and mathematics. Also, this study investigates whether there is an interaction effect between test modes of CBT and paper-based tests (PBT) and gender/ability level in each subject area. The test used in this study is a multiple-choice standardized test for students in grades 8-11. For this study, data were collected during four test administrations: 2015-16, 2017-18, and 2020-21. This research used a one-factor between-subjects ANOVA to compute the PBT and CBT groups’ test means for each subject area (reading and mathematics). Also, 2-factor between-subjects ANOVAs were conducted to investigate examinee characteristics: gender (male and female), ethnicity (African-American, Asian, Hispanic, multi-racial, and White), and ability level (low, average, and high-ability groups). The author found that students’ test scores in the two subject areas varied across CBT and PBT by gender and ability level, meaning that gender, ethnicity, and ability level were related to the score difference. These results will be discussed according to the current testing systems. In addition, this study’s results will open up to school teachers and test developers the possible influence that gender, ethnicity, and ability level have on a student’s score based on whether they take the CBT or PBT.

Keywords: ability level, computer-based, gender, paper-based, test

Procedia PDF Downloads 80
1923 Effect of Longitudinal Fins on Air-Flow Characteristics for Wing-Shaped Tubes in Cross Flow

Authors: Sayed Ahmed El Sayed, Osama M. Mesalhy, Mohamed A. Abdelatief

Abstract:

A numerical study has been conducted to clarify fluid flow characteristics, pressure distributions, and skin friction coefficient over a wing-shaped tubes bundle in staggered arrangement with the placement of longitudinal fins (LF) at downstream position of the tube. The air-side Rea were at 1.8 x 103 to 9.7 x 103. The tubes bundle were employed with various fin height [hf] and fin thickness (δ) from (2 mm ≤ hf ≤ 12 mm) and (1.5 mm ≤ δ ≤ 3.5 mm) respectively at the considered Rea range. The flow pattern around the staggered wing-shaped tubes bundle was predicted using the commercial CFD FLUENT 6.3.26 software package. The distribution of average skin friction coefficient around wing-shaped tubes bundle is studied. Correlation of pressure drop coefficient Pdc and skin friction coefficient (Cf) in terms of Rea, design parameters for the studied cases were presented. Results indicated that the values of Pdc for hf = 6 mm are lower than these of NOF and hf = 2 mm by about 11 % and 13 % respectively for considered Rea range. Cf decreases as Rea increases. LFTH with hf = 6 mm offers lower form drag than that with hf = 12 mm and that of NOF. The lowest values of the pumping power are achieved for arrangements of hf = 6 mm for the considered Rea range. δ has negligible effect on skin friction coefficient, while has a slightly variation in ∆Pa. The wing-shaped tubes bundle heat exchanger with hf = 6 mm has the lowest values of ∆Pa, Pdc, Cf, and pumping power and hence the best performance comparing with the other bundles. Comparisons between the experimental and numerical results of the present study and those obtained by similar previous studies showed good agreements.

Keywords: longitudinal fins, skin friction, flow characteristics, FLUENT, wing-shaped tubes

Procedia PDF Downloads 522
1922 Generation of Medical Waste in Hospitals in Interior of São Paulo, Brazil

Authors: Silvia Carla Da Silva André, Angela Maria Magosso Takayanagui

Abstract:

Introduction: The Medical Waste (MW) are responsible per 2% of total waste generated for a city and has merited attention due the risks that offers to the public health and environment, representing an important aspect in waste management. In Brazil, the Resolution 306/04 of the National Health Surveillance Agency classifies the MW into 5 groups as follows: Group A (GA) biological, Group B (GB) chemical, Group C (GC) radioactive waste, Group D (GD) common, and Group E (GE) sharps. Objective: This study aimed to determine the amount of waste generated in hospitals of Ribeirão Preto, São Paulo, Brazil. Material and Methods: This is a field research, exploratory, using quantitative variables. The survey was conducted in 11 hospitals in Ribeirão Preto, located in the State of São Paulo, Brazil. It is noted that the study sample included general hospitals, skilled, university, maternity, and psychiatric; public, private, and philanthropic; and large, medium, and small. To quantify the MW, the weighing of the waste was held for six days, following methodology adapted from PAHO. Data were analyzed using descriptive statistics, determining the average global generation of MW and for each group. This research was carried out after approval by the Ethics in Research of the University of São Paulo. Thus, in order to comply with the ethical principles of research, to present the results hospitals were numbered from 1 to 11. Results: The data revealed a greater generation of biological waste among teaching hospitals, which can be justified by the use of materials for the realization of techniques.

Keywords: environmental health, management of medical waste, medical waste, public health

Procedia PDF Downloads 344
1921 Ankle Arthroscopy: Indications, Patterns of Admissions, Surgical Outcomes, and Associated Complications Among Saudi Patients at King Abdul-Aziz Medical City in Riyadh

Authors: Mohammad Abdullah Almalki

Abstract:

Background: Despite the frequent usage of ankle arthroscopy, there is limited medical literature regarding its indications, patterns of admissions, surgical outcomes, and associated complicated at Saudi Arabia. Hence, this study would highlight the surgical outcomes of such surgical approach that will assist orthopedic surgeons to detect which surgical procedure needs to be done as well as to help them regarding their diagnostic workups. Methods: At the Orthopedic Division of King Abdul‑Aziz Medical City in Riyadh and through a cross‑sectional design and convenient sampling techniques, the present study had recruited 20 subjects who fulfill the inclusion and exclusion criteria between 2016 and 2018. Data collection was carried out by a questionnaire designed and revised by an expert panel of health professionals. Results: Twenty patients were reviewed (11M and 9F) with an average age of 40.1 ± 12.2. Only 30% of the patients (5M, 1F) have no comorbidity, but 70% of patients (7M, 8F) were having at least one comorbidity. The most common indications were osteochondritis dissecans (n = 7, 35%), ankle fracture without dislocation (n = 4, 20%), and tibiotalar impingement (n = 3, 15%). Patients recorded pain in all cases (100%). The top four symptoms after pain were instability (30%, n = 6), muscle weakness (15%, n = 3) swelling (15%, n = 3), and stiffness (5%, n = 1). Two‑third of cases reached to their full healthy status and toe‑touch weight‑bearing was seen in two patients (10%). Conclusion: Ankle arthroscopy improved the rehabilitation rates in our tertiary care center. In addition, the surgical outcomes are favorable in our hospital since it has a very short length of stay, unexpended surgery, and fewest physiotherapy sessions.

Keywords: ankle, arthroscopy, indications, patterns

Procedia PDF Downloads 65
1920 A Comparative Analysis of the Indoor Thermal Environment of a Room with and without Transitional Space or Threshold in Traditional Row Houses Adjacent to a Narrow Alley 'Rupchan Lane' in Old Dhaka, Bangladesh

Authors: Fatema Tasmia, Brishti Majumder, Atiqur Rahman

Abstract:

Attaining appropriate thermal comfort conditions in a place where the climate is hot and humid can be perplexing. Especially, when it resides at a congested place like old Dhaka Bangladesh, the provision of giving cross ventilation and building with proper orientation is quite difficult. This paper aims to investigate the indoor thermal environment of a room with and without transitional space or threshold in traditional row houses adjacent to a narrow alley of old Dhaka through field measurements. Transitional spaces are the part of buildings which are used for semi-outdoor household activities, social gathering and it is also proved to provide an indoor thermal effect. The field study was conducted by collecting thermal data (temperature, humidity and airflow) respectively, among the outdoor narrow alley, transitional space and adjacent indoor. This east-west elongated alley has an average width of 2.13 meter (varies from 1.5 to 2.6 meter) holding row houses on both sides. Among different aspects of thermal environment, the study of this paper is based on the analysis of temperature of corresponding cases. Other aspects and their variables were considered as constant (especially material) for accuracy and avoidance of confusion. This study focuses on the outcome that can ultimately contribute to the configuration of row houses with transitional spaces and in its relation to the adjacent outdoor space while achieving thermal comfort.

Keywords: alley, Old-Dhaka, row houses, temperature, thermal comfort, threshold, transitional space

Procedia PDF Downloads 167
1919 Formulation and in Vitro Evaluation of Cubosomes Containing CeO₂ Nanoparticles Loaded with Glatiramer Acetate Drug

Authors: Akbar Esmaeili, Zahra Salarieh

Abstract:

Cerium oxide nanoparticles (nano-series) are used as catalysts in industrial applications due to their free radical scavenging properties. Given that free radicals play an essential role in the pathology of many neurological diseases, we investigated the use of nanocrystals as a potential therapeutic agent for oxidative damage. This project synthesized nano-series from a new and environmentally friendly bio-pathway. Investigation of cerium nitrate in culture medium containing inoculated Lactobacillus acidophilus strain before incubation produces nano-series. Loaded with glatiramer acetate (GA) was formed by coating carboxymethylcellulose (CMC) and CeO2. FE-SEM analysis showed nano-series in the 9-11 nm range, spherical shape, and uniform particle size distribution. Cubic nanoparticles containing anti-multiple sclerosis (anti-Ms) treatment called GA were used. Glycerol monostearate (GMS) was used as a fat base, and evening primrose extract was used as an anti-inflammatory in cubosomes. Design-Expert® software was used to study the effects of different formulation factors on the properties of GAloaded cubic dispersions. Thirty GA-labeled cubic dispersions were prepared with GA-labeled carboxymethylcellulose and evaluated in vitro. The results showed an average nano-series size of 89.02 and a zeta potential of -49.9. Cubosomes containing GA-CMC/CeO2 showed a stable release profile for 180 min. The results showed that cubosomes containing GA-CMC/CeO2 could be a promising drug carrier with normal release behavior.

Keywords: ciochemistry, biotechnology, molecular, biology

Procedia PDF Downloads 24
1918 Groundwater Potential in the Central Part of Al Jabal Al Akhdar Area, Ne Libya

Authors: Maged El Osta, Milad Masoud

Abstract:

Al Jabal Al Akhdar in the north-eastern part of Libya represents a region with promising ecological underpinning for grazing and other agricultural developments. The groundwater potential of both Upper Cretaceous and Eocene aquifers was studied based the available literature and a complete database for about 112 water wells drilled in the period 2003-2009. In this research, the hydrogeological methods will be integrated with the Geographic Information System (GIS) that played a main role in highlighting the spatial characteristics of the groundwater system. The results indicate that the depth to water for the Upper Cretaceous aquifer ranges from 150 to 458 m, and the piezometric surface decreases from over 500 m (m.s.l) in the northern parts to -20 m (m.s.l) in southeastern part. Salinity ranges between 303 and 1329 mg/l indicating that groundwater belongs to the slightly fresh water class. In the Eocene aquifer, the depth to groundwater ranges from 120 to 290.5 m and the potentiometric level decreases gradually southwards from 220 to -51 m (m.s.l) and characterized by steep slope in the southeastern part of the study area, where the aquifer characterized by relatively high productivity (specific capacity ranges between 10.08 and 332.3 m2/day). The groundwater salinity within this aquifer ranges between 198 and 2800 mg/l (fresh to brackish water class). The annual average rainfall (from 280 to 500 mm) plays a significant role in the recharge of the two aquifers. The priority of groundwater quality and potentiality increases towards the central and northern portions of the concerned area.

Keywords: Eocene and Upper Cretaceous aquifers, rainfall, potentiality, Geographic Information System (GIS)

Procedia PDF Downloads 197
1917 Ranking the Factors That Influence the Construction Project Success: The Jordanian Perspective

Authors: Ghanim A. Bekr

Abstract:

Project success is what must be done for the project to be acceptable to the client, stakeholders and end-users who will be affected by the project. The study of project success and the critical success factors (CSFs) are the means adopted to improve the effectiveness of project. This research is conducted to make an attempt to identify which variables influence the success of project implementation. This study has selected, through an extensive literature review and interviews, (83) factors categorized in (7) groups that the questionnaire respondents were asked to score. The responses from 66 professionals with an average of 15 years of experience in different types of construction projects in Jordan were collected and analyzed using SPSS and most important factors for success for various success criteria are presented depending on the relative importance index to rank the categories. The research revealed the significant groups of factors are: Client related factors, Contractor’s related factors, Project Manager (PM) related factors, and Project management related factors. In addition the top ten sub factors are: Assertion of the client towards short time of the project, availability of skilled labor, Assertion of the client towards high level of the quality, capability of the client in taking risk, previous experience of the PM in similar projects, previous experience of the contractor in similar projects, decision making by the client/ the client’s representative at the right time, assertion of client towards low cost of project, experience in project management in previous projects, and flow of the information among parties. The results would be helpful to construction project professionals in taking proactive measures for successful completion of construction projects in Jordan.

Keywords: construction projects, critical success factors, Jordan, project success

Procedia PDF Downloads 140
1916 An Intelligent Scheme Switching for MIMO Systems Using Fuzzy Logic Technique

Authors: Robert O. Abolade, Olumide O. Ajayi, Zacheaus K. Adeyemo, Solomon A. Adeniran

Abstract:

Link adaptation is an important strategy for achieving robust wireless multimedia communications based on quality of service (QoS) demand. Scheme switching in multiple-input multiple-output (MIMO) systems is an aspect of link adaptation, and it involves selecting among different MIMO transmission schemes or modes so as to adapt to the varying radio channel conditions for the purpose of achieving QoS delivery. However, finding the most appropriate switching method in MIMO links is still a challenge as existing methods are either computationally complex or not always accurate. This paper presents an intelligent switching method for the MIMO system consisting of two schemes - transmit diversity (TD) and spatial multiplexing (SM) - using fuzzy logic technique. In this method, two channel quality indicators (CQI) namely average received signal-to-noise ratio (RSNR) and received signal strength indicator (RSSI) are measured and are passed as inputs to the fuzzy logic system which then gives a decision – an inference. The switching decision of the fuzzy logic system is fed back to the transmitter to switch between the TD and SM schemes. Simulation results show that the proposed fuzzy logic – based switching technique outperforms conventional static switching technique in terms of bit error rate and spectral efficiency.

Keywords: channel quality indicator, fuzzy logic, link adaptation, MIMO, spatial multiplexing, transmit diversity

Procedia PDF Downloads 130
1915 Leveraging Remote Assessments and Central Raters to Optimize Data Quality in Rare Neurodevelopmental Disorders Clinical Trials

Authors: Pamela Ventola, Laurel Bales, Sara Florczyk

Abstract:

Background: Fully remote or hybrid administration of clinical outcome measures in rare neurodevelopmental disorders trials is increasing due to the ongoing pandemic and recognition that remote assessments reduce the burden on families. Many assessments in rare neurodevelopmental disorders trials are complex; however, remote/hybrid trials readily allow for the use of centralized raters to administer and score the scales. The use of centralized raters has many benefits, including reducing site burden; however, a specific impact on data quality has not yet been determined. Purpose: The current study has two aims: a) evaluate differences in data quality between administration of a standardized clinical interview completed by centralized raters compared to those completed by site raters and b) evaluate improvement in accuracy of scoring standardized developmental assessments when scored centrally compared to when scored by site raters. Methods: For aim 1, the Vineland-3, a widely used measure of adaptive functioning, was administered by site raters (n= 52) participating in one of four rare disease trials. The measure was also administered as part of two additional trials that utilized central raters (n=7). Each rater completed a comprehensive training program on the assessment. Following completion of the training, each clinician completed a Vineland-3 with a mock caregiver. Administrations were recorded and reviewed by a neuropsychologist for administration and scoring accuracy. Raters were able to certify for the trials after demonstrating an accurate administration of the scale. For site raters, 25% of each rater’s in-study administrations were reviewed by a neuropsychologist for accuracy of administration and scoring. For central raters, the first two administrations and every 10th administration were reviewed. Aim 2 evaluated the added benefit of centralized scoring on the accuracy of scoring of the Bayley-3, a comprehensive developmental assessment widely used in rare neurodevelopmental disorders trials. Bayley-3 administrations across four rare disease trials were centrally scored. For all administrations, the site rater who administered the Bayley-3 scored the scale, and a centralized rater reviewed the video recordings of the administrations and also scored the scales to confirm accuracy. Results: For aim 1, site raters completed 138 Vineland-3 administrations. Of the138 administrations, 53 administrations were reviewed by a neuropsychologist. Four of the administrations had errors that compromised the validity of the assessment. The central raters completed 180 Vineland-3 administrations, 38 administrations were reviewed, and none had significant errors. For aim 2, 68 administrations of the Bayley-3 were reviewed and scored by both a site rater and a centralized rater. Of these administrations, 25 had errors in scoring that were corrected by the central rater. Conclusion: In rare neurodevelopmental disorders trials, sample sizes are often small, so data quality is critical. The use of central raters inherently decreases site burden, but it also decreases rater variance, as illustrated by the small team of central raters (n=7) needed to conduct all of the assessments (n=180) in these trials compared to the number of site raters (n=53) required for even fewer assessments (n=138). In addition, the use of central raters dramatically improves the quality of scoring the assessments.

Keywords: neurodevelopmental disorders, clinical trials, rare disease, central raters, remote trials, decentralized trials

Procedia PDF Downloads 146
1914 Synthesis of Bisphenols Containing Pendant Furyl Group Based on Chemicals Derived from Lignocellulose and Their Utilization for Preparation of Clickable Poly(Arylene Ether Sulfone)s

Authors: Samadhan S. Nagane, Sachin S. Kuhire, Prakash P. Wadgaonkar

Abstract:

Lignocellulose-derived chemicals such as furfural, furandicarboxylic acid, syringol, guaiacol, etc are highly attractive as sustainable alternatives to petrochemicals for the synthesis of monomers and polymers. We wish to report herein the facile synthesis of fully bio-based bisphenols containing pendant furyl group by base-catalyzed condensation of furfural with guaiacol. Bisphenols possessing pendant furyl group represent valuable monomers for the synthesis of a range of polymers which include epoxy resins, polyesters, polycarbonates, poly(aryl ether)s, etc. Several new homo/co-poly(arylene ether sulfone)s have been prepared by the reaction of 4,4(-fluorodiphenyl sulfone (FDS) with 4,4'-(furan-2-ylmethylene)bis(2-methoxyphenol) (BPF) and 4,4(-isopropylidenediphenol (BPA) using different molar ratios of bisphenols. Poly(arylene ether sulfone)s showed inherent viscosities in the range 0.92-1.47 dLg-1 and number average molecular weights (Mn), obtained from gel permeation chromatography (GPC), were in the range 91,300 – 1,31,000. Poly(arylene ether sulfone)s could be cast into tough, transparent and flexible films from chloroform solutions. X-Ray diffraction studies indicated amorphous nature of poly(arylene ether sulfone)s. Poly(arylene ether sulfone)s showed Tg values in the range 179-191 oC. Additionally, the pendant furyl groups in poly(arylene ether sulfone)s provide reactive sites for chemical modifications and cross-linking via Diels-Alder reaction with maleimides and bismaleimides, respectively.

Keywords: bio-based, bisphenols, Diels-Alder reaction, poly(arylene ether sulfone)s

Procedia PDF Downloads 237
1913 Atmospheric Dispersion Modeling for a Hypothetical Accidental Release from the 3 MW TRIGA Research Reactor of Bangladesh

Authors: G. R. Khan, Sadia Mahjabin, A. S. Mollah, M. R. Mawla

Abstract:

Atmospheric dispersion modeling is significant for any nuclear facilities in the country to predict the impact of radiological doses on environment as well as human health. That is why to ensure safety of workers and population at plant site; Atmospheric dispersion modeling and radiation dose calculations were carried out for a hypothetical accidental release of airborne radionuclide from the 3 MW TRIGA research reactor of Savar, Bangladesh. It is designed with reactor core which consists of 100 fuel elements(1.82245 cm in diameter and 38.1 cm in length), arranged in an annular corefor steady-state and square wave power level of 3 MW (thermal) and for pulsing with maximum power level of 860MWth.The fuel is in the form of a uniform mixture of 20% uranium and 80% zirconium hydride. Total effective doses (TEDs) to the public at various downwind distances were evaluated with a health physics computer code “HotSpot” developed by Lawrence Livermore National Laboratory, USA. The doses were estimated at different Pasquill stability classes (categories A-F) with site-specific averaged meteorological conditions. The meteorological data, such as, average wind speed, frequency distribution of wind direction, etc. have also been analyzed based on the data collected near the reactor site. The results of effective doses obtained remain within the recommended maximum effective dose.

Keywords: accidental release, dispersion modeling, total effective dose, TRIGA

Procedia PDF Downloads 117
1912 Profit Efficiency and Technology Adoption of Boro Rice Production in Bangladesh

Authors: Fazlul Hoque, Tahmina Akter Joya, Asma Akter, Supawat Rungsuriyawiboon

Abstract:

Rice is the staple food in Bangladesh, and therefore, self-sufficiency in rice production remains a major concern. However, Bangladesh is experiencing insufficiency in rice production due to high production cost and low national average productivity of 2.848 ton/ha in comparison to other rice-growing countries in the world. This study aims to find out the profit efficiency and determinants of profit efficiency in Boro rice cultivation in Manikganj and Dhaka districts of Bangladesh. It also focuses on technology adoption and effect of technology adoption on profit efficiency of Boro rice cultivation in Bangladesh. The data were collected from 300 households growing Boro rice through face to face interviews by one set structured questionnaire; Frontier Version 4.1 and STATA 15 software were employed to analyze the data according to the purpose of the study. Maximum likelihood estimates of the specified profit model showed that profit efficiency of the farmer varied between 23% and 97% with a mean of 76% which implied as 24% of the profit is lost due to a combination of technical and allocative inefficiencies in Boro rice cultivation in the study area. The inefficiency model revealed that the education level of the farmer, farm size, variety of seed, and training and extension service influence the profit inefficiency significantly. The study also explained that the level of technology adoption index affects profit efficiency. The technology adoption in Boro rice cultivation is influenced by the education level of the farmer, farm size and farm capital.

Keywords: farmer, maximum likelihood estimation, profit efficiency, rice

Procedia PDF Downloads 115
1911 Assessment of Personal Level Exposures to Particulate Matter among Children in Rural Preliminary Schools as an Indoor Air Pollution Monitoring

Authors: Seyedtaghi Mirmohammadi, J. Yazdani, S. M. Asadi, M. Rokni, A. Toosi

Abstract:

There are many indoor air quality studies with an emphasis on indoor particulate matters (PM2.5) monitoring. Whereas, there is a lake of data about indoor PM2.5 concentrations in rural area schools (especially in classrooms), since preliminary children are assumed to be more defenseless to health hazards and spend a large part of their time in classrooms. The objective of this study was indoor PM2.5 concentration quality assessment. Fifteen preliminary schools by time-series sampling were selected to evaluate the indoor air quality in the rural district of Sari city, Iran. Data on indoor air climate parameters (temperature, relative humidity and wind speed) were measured by a hygrometer and thermometer. Particulate matters (PM2.5) were collected and assessed by Real Time Dust Monitor, (MicroDust Pro, Casella, UK). The mean indoor PM2.5 concentration in the studied classrooms was 135µg/m3 in average. The multiple linear regression revealed that a correlation between PM2.5 concentration and relative humidity, distance from city center and classroom size. Classroom size yields reasonable negative relationship, the PM2.5 concentration was ranged from 65 to 540μg/m3 and statistically significant at 0.05 level and the relative humidity was ranged from 70 to 85% and dry bulb temperature ranged from 28 to 29°C were statistically significant at 0.035 and 0.05 level, respectively. A statistical predictive model was obtained from multiple regressions modeling for PM2.5 and indoor psychrometric parameters.

Keywords: particulate matters, classrooms, regression, concentration, humidity

Procedia PDF Downloads 293
1910 Optimum Design of Hybrid (Metal-Composite) Mechanical Power Transmission System under Uncertainty by Convex Modelling

Authors: Sfiso Radebe

Abstract:

The design models dealing with flawless composite structures are in abundance, where the mechanical properties of composite structures are assumed to be known a priori. However, if the worst case scenario is assumed, where material defects combined with processing anomalies in composite structures are expected, a different solution is attained. Furthermore, if the system being designed combines in series hybrid elements, individually affected by material constant variations, it implies that a different approach needs to be taken. In the body of literature, there is a compendium of research that investigates different modes of failure affecting hybrid metal-composite structures. It covers areas pertaining to the failure of the hybrid joints, structural deformation, transverse displacement, the suppression of vibration and noise. In the present study a system employing a combination of two or more hybrid power transmitting elements will be explored for the least favourable dynamic loads as well as weight minimization, subject to uncertain material properties. Elastic constants are assumed to be uncertain-but-bounded quantities varying slightly around their nominal values where the solution is determined using convex models of uncertainty. Convex analysis of the problem leads to the computation of the least favourable solution and ultimately to a robust design. This approach contrasts with a deterministic analysis where the average values of elastic constants are employed in the calculations, neglecting the variations in the material properties.

Keywords: convex modelling, hybrid, metal-composite, robust design

Procedia PDF Downloads 199
1909 Genome-Wide Analysis of Long Terminal Repeat (LTR) Retrotransposons in Rabbit (Oryctolagus cuniculus)

Authors: Zeeshan Khan, Faisal Nouroz, Shumaila Noureen

Abstract:

European or common rabbit (Oryctolagus cuniculus) belongs to class Mammalia, order Lagomorpha of family Leporidae. They are distributed worldwide and are native to Europe (France, Spain and Portugal) and Africa (Morocco and Algeria). LTR retrotransposons are major Class I mobile genetic elements of eukaryotic genomes and play a crucial role in genome expansion, evolution and diversification. They were mostly annotated in various genomes by conventional approaches of homology searches, which restricted the annotation of novel elements. Present work involved de novo identification of LTR retrotransposons by LTR_FINDER in haploid genome of rabbit (2247.74 Mb) distributed in 22 chromosomes, of which 7,933 putative full-length or partial copies were identified containing 69.38 Mb of elements, accounting 3.08% of the genome. Highest copy numbers (731) were found on chromosome 7, followed by chromosome 12 (705), while the lowest copy numbers (27) were detected in chromosome 19 with no elements identified from chromosome 21 due to partially sequenced chromosome, unidentified nucleotides (N) and repeated simple sequence repeats (SSRs). The identified elements ranged in sizes from 1.2 - 25.8 Kb with average sizes between 2-10 Kb. Highest percentage (4.77%) of elements was found in chromosome 15, while lowest (0.55%) in chromosome 19. The most frequent tRNA type was Arginine present in majority of the elements. Based on gained results, it was estimated that rabbit exhibits 15,866 copies having 137.73 Mb of elements accounting 6.16% of diploid genome (44 chromosomes). Further molecular analyses will be helpful in chromosomal localization and distribution of these elements on chromosomes.

Keywords: rabbit, LTR retrotransposons, genome, chromosome

Procedia PDF Downloads 127
1908 A Neuropsychological Investigation of the Relationship between Anxiety Levels and Loss of Inhibitory Cognitive Control in Ageing and Dementia

Authors: Nasreen Basoudan, Andrea Tales, Frederic Boy

Abstract:

Non-clinical anxiety may be comprised of state anxiety - temporarily experienced anxiety related to a specific situation, and trait anxiety - a longer lasting response or a general disposition to anxiety. While temporary and occasional anxiety whether as a mood state or personality dimension is normal, nonclinical anxiety may influence many more components of information processing than previously recognized. In ageing and dementia-related research, disease characterization now involves attempts to understand a much wider range of brain function such as loss of inhibitory control, as against the more common focus on memory and cognition. However, in many studies, the tendency has been to include individuals with clinical anxiety disorders while excluding persons with lower levels of state or trait anxiety. Loss of inhibitory cognitive control can lead to behaviors such as aggression, reduced sensitivity to others, sociopathic thoughts and actions. Anxiety has also been linked to inhibitory control, with research suggesting that people with anxiety are less capable of inhibiting their emotions than the average person. This study investigates the relationship between anxiety and loss of inhibitory control in younger and older adults, using a variety of questionnaires and computers-based tests. Based on the premise that irrespective of classification, anxiety is associated with a wide range of physical, affective, and cognitive responses, this study explores evidence indicative of the potential influence anxiety per se on loss of inhibitory control, in order to contribute to discussion and appropriate consideration of anxiety-related factors in methodological practice.

Keywords: anxiety, ageing, dementia, inhibitory control

Procedia PDF Downloads 224
1907 A Study on Architectural Characteristics‎ of Traditional Iranian Ordinary Houses in Mashhad, Iran

Authors: Rana Daneshvar Salehi

Abstract:

In many Iranian cities including ‎‎Mashhad‎, the capital of ‎‎‎‎Razavi Khorasan Province‎, ‎ordinary samples of domestic architecture ‎on a ‎small scale is not ‎‎‎considered as ‎heritage. ‎While the ‎principals of house formation are ‎‎respected in all ‎‎traditional Iranian ‎‎‎‎houses‎; ‎from moderate to great ones. During the past decade, Mashhad has lost its identity, and has become a modern city. Identifying it as the capital of the Islamic Culture in 2017 by ISESCO and consequently looking for new developments and transfiguration caused to demolish a large ‎number ‎of ‎traditional modest habitation. ‎For this ‎reason, the present paper aims to introduce ‎the three ‎undiscovered houses with the ‎historical and monumental values located in the ‎oldest ‎neighborhoods of Mashhad which have been neglected in the cultural ‎heritage field. The preliminary phase of this approach will be a measured survey to identify the significant characteristics ‎of ‎selected dwellings and understand the challenges through focusing on building ‎form, orientation, ‎‎room function, space proportion and ornamental elements’ details. A comparison between the ‎‎case studies and the wealthy domestically buildings ‎presents that a house belongs to inhabitants ‎with an average income could introduce the same accurate, regular, harmonic and proportionate ‎design which can be found in the great mansions. It reveals that an ordinary traditional house can ‎be regarded as valuable construction not only for its historical characteristics but also ‎for its ‎aesthetical and architectural features that could avoid further destructions in the future.

Keywords: traditional ordinary house, architectural characteristic, proportion, heritage

Procedia PDF Downloads 123
1906 Laparoscopic Proximal Gastrectomy in Gastroesophageal Junction Tumours

Authors: Ihab Saad Ahmed

Abstract:

Background For Siewert type I and II gastroesophageal junction tumor (GEJ) laparoscopic proximal gastrectomy can be performed. It is associated with several perioperative benefits compared with open proximal gastrectomy. The use of laparoscopic proximal gastrectomy (LPG) has become an increasingly popular approach for select tumors Methods We describe our technique for LPG, including the preoperative work-up, illustrated images of the main principle steps of the surgery, and our postoperative course. Results Thirteen pts (nine males, four female) with type I, II (GEJ) adenocarcinoma had laparoscopic radical proximal gastrectomy and D2 lymphadenectomy. All of our patient received neoadjuvant chemotherapy, eleven patients had intrathoracic anastomosis through mini thoracotomy (two hand sewn end to end anastomoses and the other 9 patient end to side using circular stapler), two patients with intrathoracic anastomosis had flap and wrap technique, two patients had thoracoscopic esophageal and mediastinal lymph node dissection with cervical anastomosis The mean blood loss 80ml, no cases were converted to open. The mean operative time 250 minute Average LN retrieved 19-25, No sever complication such as leakage, stenosis, pancreatic fistula ,or intra-abdominal abscess were reported. Only One patient presented with empyema 1.5 month after discharge that was managed conservatively. Conclusion For carefully selected patients, LPG in GEJ tumour type I and II is a safe and reasonable alternative for open technique , which is associated with similar oncologic outcomes and low morbidity. It showed less blood loss, respiratory infections, with similar 1- and 3-year survival rates.

Keywords: LPG(laparoscopic proximal gastrectomy, GEJ( gastroesophageal junction tumour), d2 lymphadenectomy, neoadjuvant cth

Procedia PDF Downloads 101
1905 Comparison of Methods for the Synthesis of Eu+++, Tb+++, and Tm+++ Doped Y2O3 Nanophosphors by Sol-Gel and Hydrothermal Methods for Bioconjugation

Authors: Ravindra P. Singh, Drupad Ram, Dinesh K. Gupta

Abstract:

Rare earth ions doped metal oxides are a class of luminescent materials which have been proved to be excellent for applications in field emission displays and cathode ray tubes, plasma display panels. Under UV irradiation Eu+++ doped Y2O3 is a red phosphor and Tb+++ doped Y 2O3 is a green phosphor. It is possible that, due to their high quantum efficiency, they might serve as improved luminescent markers for identification of biomolecules, as already reported for CdSe and CdSe/ZnS nanocrystals. However, for any biological applications these particle powders must be suspended in water while retaining their phosphorescence. We hereby report synthesis and characterization of Eu+++ and Tb+++ doped yttrium oxide nanoparticles by sol-gel and hydrothermal processes. Eu+++ and Tb+++ doped Y2O3 nanoparticles have been synthesized by hydrothermal process using yttrium oxo isopropoxide [Y5O(OPri)13] (crystallized twice) and it’s acetyl acetone modified product [Y(O)(acac)] as precursors. Generally the sol-gel derived metal oxides are required to be annealed to the temperature ranging from 400°C-800°C in order to develop crystalline phases. However, this annealing also results in the development of aggregates which are undesirable for bio-conjugation experiments. In the hydrothermal process, we have achieved crystallinity of the nanoparticles at 300°C and the development of crystalline phases has been found to be proportional to the time of heating of the reactor. The average particle sizes as calculated from XRD were found to be 28 nm, 32 nm, and 34 nm by hydrothermal process. The particles were successfully suspended in chloroform in the presence of trioctyl phosphene oxide and TEM investigations showed the presence of single particles along with agglomerates.

Keywords: nanophosphors, Y2O3:Eu+3, Y2O3:Tb+3, sol-gel, hydrothermal method, TEM, XRD

Procedia PDF Downloads 384
1904 Evaluation of the Effects of Some Medicinal Plants Extracts on Seed

Authors: Areej Ali Baeshen, Hanaa Kamal Galal, Batoul Mohamed Abdullatif

Abstract:

In the present study, the allelopathic effects of Eruca sativa, Mentha peprinta, and Coriandrum sativum aqueous extracts, prepared by 25 gm and 50 gm of fresh leaves dissolved in 100 ml of double distilled water in addition to the crude extract (100%). The final concentrations were 100 %, 50%, 25% and 0% as control. The extracts were tested for their allelopathic effects on seed germination and other growth parameters of Phaseolous vulgaris. Laboratory experiments were conducted in sterilizes Petri dishes with 5 and 10 day time interval for seed germination and 24 h, 48 h and 72 h for radicle length on an average of 25°C. The effects of different concentrations of aqueous extract were compared to distilled water (0%). 25% and 50% aqueous extracts of Eruca sativa and Coriandrum sativum caused a pronounced inhibitory effect on seed germination and the tested growth parameters of the receptor plant. The inhibitory effect was proportional to the concentration of the extract. Mentha peprinta extracts, on the other hand, caused an increase in germination percentage and other growth parameters in Phaseolous vulgaris. Hence, it could be concluded that the aqueous extracts of Eruca sativa and Coriandrum sativum might contain water-soluble allelochemicals, which could inhibit the seed germination and reduce radicle length of Phaseolous vulgaris. Mentha peprinta has beneficial allelopathic effects on the receptor plant.

Keywords: Phaseolus vulgaris, Eruca sativa, Mentha peperinta, Coriandrum sativum, medicinal plants, seed germination

Procedia PDF Downloads 381
1903 Assessment of Soil Erosion Risk Using Soil and Water Assessment Tools Model: Case of Siliana Watershed, Northwest Tunisia

Authors: Sana Dridi, Jalel Aouissi, Rafla Attia, Taoufik Hermassi, Thouraya Sahli

Abstract:

Soil erosion is an increasing issue in Mediterranean countries. In Tunisia, the capacity of dam reservoirs continues to decrease as a consequence of soil erosion. This study aims to predict sediment yield to enrich soil management practices using Soil and Water Assessment Tools model (SWAT) in the Siliana watershed (1041.6 km²), located in the northwest of Tunisia. A database was constructed using remote sensing and Geographical Information System. Climatic and flow data were collected from water resources directorates in Tunisia. The SWAT model was built to simulate hydrological processes and sediment transport. A sensitivity analysis, calibration, and validation were performed using SWAT-CUP software. The model calibration of stream flow simulations shows a good performance with NSE and R² values of 0.77 and 0.79, respectively. The model validation shows a very good performance with values of NSE and R² for 0.8 and 0.88, respectively. After calibration and validation of stream flow simulation, the model was used to simulate the soil erosion and sediment load transport. The spatial distributions of soil loss rate for determining the critical sediment source areas show that 63 % of the study area has a low soil loss rate less than 7 t ha⁻¹y⁻¹. The annual average soil loss rate simulated with the SWAT model in the Siliana watershed is 4.62 t ha⁻¹y⁻¹.

Keywords: water erosion, SWAT model, streamflow, SWATCUP, sediment yield

Procedia PDF Downloads 86
1902 Fungicidal Action of the Mycogenic Silver Nanoparticles Against Aspergillus niger Inciting Collar Rot Disease in Groundnut (Arachis hypogaea L.)

Authors: R. Sarada Jayalakshmi Devi B. Bhaskar, S. Khayum Ahammed, T. N. V. K. V. Prasad

Abstract:

Use of bioagents and biofungicides is safe to manage the plant diseases and to avoid human health hazards which improves food security. Myconanotechnology is the study of nanoparticles synthesis using fungi and their applications. The present work reports on preparation, characterization and antifungal activity of biogenic silver nanoparticles produced by the fungus Trichoderma sp. which was collected from groundnut rhizosphere. The culture filtrate of Trichoderma sp. was used for the reduction of silver ions (Ag+) in AgNO3 solution to the silver (Ag0) nanoparticles. The different ages (4 days, 6 days, 8 days, 12 days, and 15 days) of culture filtrates were screened for the synthesis of silver nanoparticles. Synthesized silver nanoparticles were characterized using UV-Vis spectrophotometer, particle size and zeta potential analyzer, Fourier Transform Infrared Spectrophotometer (FTIR) and Transmission Electron Microscopy. Among all the treatments the silver nitrate solution treated with six days aged culture filtrate of Trichoderma sp. showed the UV absorption peak at 440 nm with maximum intensity (0.59) after 24 hrs incubation. The TEM micrographs showed the spherical shaped silver nanoparticles with an average size of 30 nm. The antifungal activity of silver nanoparticles against Aspergillus niger causing collar rot disease in groundnut and aspergillosis in humans showed the highest per cent inhibition at 100 ppm concentration (74.8%). The results points to the usage of these mycogenic AgNPs in agriculture to control plant diseases.

Keywords: groundnut rhizosphere, Trichoderma sp., silver nanoparticles synthesis, antifungal activity

Procedia PDF Downloads 480
1901 Awareness of Child Rights as a Determinant of Effective Student Personnel Services in Public Secondary Schools in Southwestern Nigeria

Authors: Ademola Ibukunolu Atanda, Gbenga Nathaniel Adeola

Abstract:

The study examined awareness of child rights as a determinant of effective student personnel services in public secondary schools in Southwestern Nigeria. It was survey research. The sample comprised 433 teachers, 137 school administrators, and 968 students who were drawn by simple random sampling techniques. The respondents were given copies of questionnaires tagged “school administrator/teacher’s awareness of child’s rights and student personnel services elements inventory.” Key Informant Interview (KII) was also employed. The data were analysed using frequency count, percentages, weighted average, grand mean, standard deviation, and Pearson Product Moment Correlation, while KII was qualitatively analysed. The findings of the study revealed that public secondary school administrator awareness of child rights was at a moderate level, but the awareness of child rights was low among the teachers. The study equally revealed that student personnel services are moderately provided in public secondary schools in Southwestern Nigeria, but security remains a major challenge. It was also found that there was a significant relationship between awareness of child rights and effective student personnel services. It was therefore recommended, based on the findings, that attention should be given to heightening awareness of child rights among public secondary school administrators and teachers for effective student personnel services. Copies of the Child Right Act 2003 should also be made available in all public secondary schools in Southwestern Nigeria, as the study revealed that the documents were not available.

Keywords: student personnel, child right, administrator awareness, practice of child right

Procedia PDF Downloads 127
1900 Big Data in Telecom Industry: Effective Predictive Techniques on Call Detail Records

Authors: Sara ElElimy, Samir Moustafa

Abstract:

Mobile network operators start to face many challenges in the digital era, especially with high demands from customers. Since mobile network operators are considered a source of big data, traditional techniques are not effective with new era of big data, Internet of things (IoT) and 5G; as a result, handling effectively different big datasets becomes a vital task for operators with the continuous growth of data and moving from long term evolution (LTE) to 5G. So, there is an urgent need for effective Big data analytics to predict future demands, traffic, and network performance to full fill the requirements of the fifth generation of mobile network technology. In this paper, we introduce data science techniques using machine learning and deep learning algorithms: the autoregressive integrated moving average (ARIMA), Bayesian-based curve fitting, and recurrent neural network (RNN) are employed for a data-driven application to mobile network operators. The main framework included in models are identification parameters of each model, estimation, prediction, and final data-driven application of this prediction from business and network performance applications. These models are applied to Telecom Italia Big Data challenge call detail records (CDRs) datasets. The performance of these models is found out using a specific well-known evaluation criteria shows that ARIMA (machine learning-based model) is more accurate as a predictive model in such a dataset than the RNN (deep learning model).

Keywords: big data analytics, machine learning, CDRs, 5G

Procedia PDF Downloads 122
1899 Psychological Characteristic Patients with Takotsubo - Etiology of Stress and Family Functioning

Authors: Treder Natalia, Siemiński Mariusz

Abstract:

Takotsubo cardiomyopathy (TC) is a recently defined clinical entity. First described by Japanese researchers, today is diagnosed worldwide in 1-2% of patients admitted with the preliminary diagnosis of Acute Coronary Syndrome. The etiology of takotsubo cardiomyopathy remains still largely unknown. Currently, the most likely cause of takotsubo is direct cytotoxicity caused by catecholamine surge triggered by emotional stress. There is a strong relation between recent severe emotional stress and TC. The aim of this study was to analysis the role of stress and personality as a risk factor of TT. The presented research involves 35 people who are diagnosed TC. All patients were women, mean age 60 years. The methods used in the research are popular psychological tests: Perceived Stress Scale, DS14 scale to measure type D personality, The Neo-Five Factor Inventory of Personality and psychological interview. The obtained results prove that stress events may directly precede or even release TC. The stressful events occurred directly before the symptoms in 75% examined. 65% assessed their family life as very stressful. Examiners have also a high level of experienced stress. Only 25% of the TC were classified as having type D personality but they have a high level of negative affectivity. The subjects had a high level of extraversion, openness to experiences and an average level of neuroticism. The results suggested that such a type of personality profile may predispose to the development of takotsubo cardiomyopathy. Patients with TT are the individuals who reveal joint tendency to the experience of negative emotions and very stressful family life.

Keywords: stress, personality trails, familiar problems, Takotsubo cardiomyopathy

Procedia PDF Downloads 358
1898 A Study on the Effect of Mg and Ag Additions and Age Hardening Treatment on the Properties of As-Cast Al-Cu-Mg-Ag Alloys

Authors: Ahmed. S. Alasmari, M. S. Soliman, Magdy M. El-Rayes

Abstract:

This study focuses on the effect of the addition of magnesium (Mg) and silver (Ag) on the mechanical properties of aluminum based alloys. The alloying elements will be added at different levels using the factorial design of experiments of 22; the two factors are Mg and Ag at two levels of concentration. The superior mechanical properties of the produced Al-Cu-Mg-Ag alloys after aging will be resulted from a unique type of precipitation named as Ω-phase. The formed precipitate enhanced the tensile strength and thermal stability. This paper further investigated the microstructure and mechanical properties of as cast Al–Cu–Mg–Ag alloys after being complete homogenized treatment at 520 °C for 8 hours followed by isothermally age hardening process at 190 °C for different periods of time. The homogenization at 520 °C for 8 hours was selected based on homogenization study at various temperatures and times. The alloys’ microstructures were studied by using optical microscopy (OM). In addition to that, the fracture surface investigation was performed using a scanning electronic microscope (SEM). Studying the microstructure of aged Al-Cu-Mg-Ag alloys reveal that the grains are equiaxed with an average grain size of about 50 µm. A detailed fractography study for fractured surface of the aged alloys exhibited a mixed fracture whereby the random fracture suggested crack propagation along the grain boundaries while the dimples indicated that the fracture was ductile. The present result has shown that alloy 5 has the highest hardness values and the best mechanical behaviors.

Keywords: precipitation hardening, aluminum alloys, aging, design of experiments, analysis of variance, heat treatments

Procedia PDF Downloads 137