Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 19

Search results for: A. O. Raji

19 Tensile Properties of Aluminum Silicon Nickel Iron Vanadium High Entropy Alloys

Authors: Sefiu A. Bello, Nasirudeen K. Raji, Jeleel A. Adebisi, Sadiq A. Raji

Abstract:

Pure metals are not used in most cases for structural applications because of their limited properties. Presently, high entropy alloys (HEAs) are emerging by mixing comparative proportions of metals with the aim of maximizing the entropy leading to enhancement in structural and mechanical properties. Aluminum Silicon Nickel Iron Vanadium (AlSiNiFeV) alloy was developed using stir cast technique and analysed. Results obtained show that the alloy grade G0 contains 44 percentage by weight (wt%) Al, 32 wt% Si, 9 wt% Ni, 4 wt% Fe, 3 wt% V and 8 wt% for minor elements with tensile strength and elongation of 106 Nmm-2 and 2.68%, respectively. X-ray diffraction confirmed intermetallic compounds having hexagonal closed packed (HCP), orthorhombic and cubic structures in cubic dendritic matrix. This affirmed transformation from the cubic structures of elemental constituents of the HEAs to the precipitated structures of the intermetallic compounds. A maximum tensile strength of 188 Nmm-2 with 4% elongation was noticed at 10wt% of silica addition to the G0. An increase in tensile strength with an increment in silica content could be attributed to different phases and crystal geometries characterizing each HEA.

Keywords: HEAs, phases model, aluminium, silicon, tensile strength, model

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18 Islamization of Knowledge with Special Reference to Mohd Kamal Hassan's Perspective

Authors: Abdul Latheef O. Mavukkandy

Abstract:

Islamization of knowledge (IOK) is an intellectual movement emerged in the middle of 1970s to address the threats by modern western civilizational onslaughts. This paper analyzes the discourse of Islamization of knowledge with special reference to the views of Kamal Hassan who prefers an alternative term called 'Islamicization'. First of all the theoretical and practical outlines of IOK movement were presented by Ismail Raji al-Faruqi in his book 'Islamization of Knowledge; General Principles and Work Plan' in 1982. He identified that the educational system in the Muslim world accounted for the decline of Muslim Ummah through de-Islamization and demoralization. So, the need for IOK was an academic challenge to reconstruct the Ummah. Kamal Hassan kept just different view from Ismail Raji al-Faruqi and Muhammed Naquib al-Attas that he coined the terms 'Relevantization and Contextualization'. So, he wanted the 'Islamization of Islamic Revealed Knowledge'. So, he used Islamization of Human Knowledge (IOHK) instead of IOK. As part of this movement, the IOK identified that the textbooks used in Muslim educational institutions systematically keep the students estranged from Islam and its heritage. Furthermore, the modern secular knowledge develops secular attitude devoid of Islamic moral philosophy and the sense of mission in life. Based upon the content analysis of some of the sources, this study found that Islamization of Knowledge is an important movement in Islamic world, but the IOK project is not practicable completely because of the lack of trained teachers and resources. Although, the project resulted in the foundation of some universities and publishing more works, journals and doctoral thesis on different dimensions of Islamization of Knowledge.

Keywords: Islamization, Islamicization, releventization, human knowledge

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17 Lymphomas as Estrogen-Regulated Cancers

Authors: M. S. Hasni, J. Guan, K. Yakimchuk, M. Berglund, B. Sander, G. Enblad, R. M. Amini, S. Okret

Abstract:

Lymphomas are generally not considered as endocrine-related cancers. However, most lymphoid malignancies show gender differences in incidence and show prognosis with males being more affected. Furthermore, some epidemiological data indicate a protective role of estrogens against Non-Hodgkin lymphomas. Recent studies have demonstrated estrogen receptor β (ERβ) to be the major ER expressed in normal and malignant cells of lymphoid origin. We have analyzed the effects of estradiol and selective ERα and ERβ agonists on lymphoma growth in culture and in vivo. Treating lymphoma cells with estradiol or ERα selective agonist had minor or no effect on cell growth while selective ERβ agonist treatment showed an antiproliferative effect. When grafting mice with murine T lymphoma cells, male mice developed larger tumors compared to female mice, a difference that was abolished following ovariectomy, demonstrating estrogen-dependent growth in vivo. When subcutaneously grafting lymphoma cells to mice, so far growth of all tested human B lymphoma tumors (Raji and Ramos Burkitt lymphoma, SU.DHL4 (GC) and U2932 (ABC) DLBCL, Granta-519, Maver1 and Z138 MCL cells), were reduced following treatment with ERβ selective agonist (ref. 2 and unpublished). Moreover, the number and size of liver foci of disseminating Raji cells was reduced. We have identified target genes and mechanism that could explain the above effects of ERβ agonists. This included effects on angio and lymphangiogenesis. Now we have further analyzed effects of ERβ agonists on Ibrutinib-sensitive and -insensitive MCL cells in xenograft experiments as well as ERβ expression in primary lymphoma material (DLBCL). Preliminary statistical analysis has been done correlating ERβ expression to other biomarkers and clinical data.

Keywords: lymphomas, estrogen receptors, cancer, liver foci

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16 The Viscosity of Xanthan Gum Grout with Different pH and Ionic Strength

Authors: H. Ahmad Raji, R. Ziaie Moayed, M. A. Nozari

Abstract:

Xanthan gum (XG) an eco-friendly biopolymer has been recently explicitly investigated for ground improvement approaches. Rheological behavior of this additive strongly depends on electrochemical condition such as pH, ionic strength and also its content in aqueous solution. So, the effects of these factors have been studied in this paper considering various XG contents as 0.25, 0.5, 1, and 2% of water. Moreover, adjusting pH values such as 3, 5, 7 and 9 in addition to increasing ionic strength to 0.1 and 0.2 in the molar scale has covered a practical range of electrochemical condition. The viscosity of grouts shows an apparent upward trend with an increase in ionic strength and XG content. Also, pH affects the polymerization as much as other parameters. As a result, XG behavior is severely influenced by electrochemical settings

Keywords: electrochemical condition, ionic strength, viscosity, xhanthan gum

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15 Effects of Aging on Thermal Properties of Some Improved Varieties of Cassava (Manihot Esculenta) Roots

Authors: K. O. Oriola, A. O. Raji, O. E. Akintola, O. T. Ismail

Abstract:

Thermal properties of roots of three improved cassava varieties (TME419, TMS 30572, and TMS 0326) were determined on samples harvested at 12, 15 and 18 Months After Planting (MAP) conditioned to moisture contents of 50, 55, 60, 65, 70% (wb). Thermal conductivity at 12, 15 and 18 MAP ranged 0.4770 W/m.K to 0.6052W/m.K; 0.4804 W/m.K to 0.5530 W/m.K and 0.3764 to 0.6102 W/m.K respectively, thermal diffusivity from 1.588 to 2.426 x 10-7m2/s; 1.290 to 2.010 x 10-7m2/s and 0.1692 to 4.464 x 10-7m2/s and specific heat capacity from 2.3626 to 3.8991 kJ/kg.K; 1.8110 to 3.9703 kJ/kgK and 1.7311 to 3.8830 kJ/kg.K respectively within the range of moisture content studied across the varieties. None of the samples over the ages studied showed similar or definite trend in variation with others across the moisture content. However, second order polynomial models fitted all the data. Age on the other hand had a significant effect on the three thermal properties studied for TME 419 but not on thermal conductivity of TMS30572 and specific heat capacity of TMS 0326. Information obtained will provide better insight into thermal processing of cassava roots into stable products.

Keywords: thermal conductivity, thermal diffusivity, specific heat capacity, moisture content, tuber age

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14 Studies on Anaemia in Camels (Camelus dromedarius) Brought for Slaughter at Sokoto Metropolitan Abattoir: A Preliminary Report

Authors: Y. S. Baraya, B. Umar, A. Aliyu, A. A. Raji, K. A. N. Esievo

Abstract:

This study was performed to determine the presence of anaemia in randomly selected apparently healthy camels (Camelus dromedarius) brought for slaughter at the Sokoto metropolitan abattoir, Sokoto State, Nigeria. The camels were derived from both sexes, different age groups, functional usages and kept at various localities within and outside Sokoto town. In the study area, studies involving camels were limited in particular the emphasis on the anaemic status of camels brought daily for human consumption. A total of eighty (80) blood samples were collected once a week from these camels within the period of eight (8) weeks to investigate the haematological variations especially packed cell volume (PCV). The PCV analysis revealed anaemia in more than fifty (50) % of the camels studied. However, the actual cause of the anaemia was not investigated but could be caused by infectious agent like protozoan parasite Trypanosoma specie and non-infectious cause such as nutritional deficiency. The PCV examination as a simple, inexpensive and reliable procedure could be part of the routine ante-mortem assessment to evaluate camels for the existence of anaemia since many of the causes of anaemia besides being affecting the meat quality could also be of zoonotic significance.

Keywords: anaemia, camels, packed cell volume, Sokoto abattoir

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13 Assessment of Women Involvement in Fishing Activities: A Case Study of Epe and Ibeju Lekki LGA, Lagos

Authors: Temitope Adewale, Oladapo Raji

Abstract:

The study was designed to investigate the assessment of women's involvement in fishing. In order to give the study a direction, five research questions, as well as two hypotheses, were postulated, and a total of fifty (50) respondents each were selected from two local government areas for the study. This brings a total of one hundred (100) respondents selected from these local government areas in Lagos state. The outcome of the finding indicates that the percentage of the respondents’ age, 49% was between 31 and 35 years, 56% has a working experience of 6-10 years, 61% were married, 69% had secondary education as their educational level. However, findings show that socio-economic characteristics (x2 =15.504, df=6, p < 0.05) and income (r=0.83, p < 0.05) have a significant relationship on the fishing. It was established that the Women in Fish production/processing were faced with a lot of constraints such as high cost of inputs, inadequate electricity supply, lack of adequate capital, non-availability of the improved oven, non-availability of extension agents, inadequate fish landing, lack of transportation facilities, lack of training on financial management and loan acquisition which affected the level of output of women in Fish processing adversely.

Keywords: women, fishing, agriculture, Lagos

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12 Influence of Leadership Tenure and Succession on Institutional Goal Attainment in the University of Ibadan, Nigeria (2006-2015)

Authors: Ismial A. Raji, Blessing Egbezieme Oladejo, Babatunde Kasim Oladele

Abstract:

The study investigated the influence of leadership succession and tenure on goal attainment in the University of Ibadan. Leadership styles, tenure politics, organization succession, leadership succession, goal attainment in terms of research, teaching and public services were considered. The study adopted a descriptive survey design. The population of the study was 250 consisting 90 academic staff, 100 Senior Non-Teaching Staff and 60 Junior Non-Teaching Staff. Questionnaire was the instrument used to collect data. The instrument reliability coefficient was 0.88. Data collected were analysed with descriptive statistics. The result revealed that a significant relationship exist between leadership succession, tenure and goal attainment (r= .648, 0.466 and 0.479p< .0.5) Also, There was no statistical significant interaction between the effects of leadership tenure and leadership succession on goal attainment, F (38, 131) = 1.356, p = .104. The main influence of the independent variables on goal attainment were significant at F (24, 131) = 1.682, p=.034 and F (26, 131) = 2.182, p=.002. The study concluded that leadership succession and tenure are key factors for goal attainment in the University of Ibadan. The study recommended that an effective leadership succession and tenure processes should be maintained and sustained by higher institutions of learning.

Keywords: leadership tenure, style, succession, institutional goal

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11 Seasonal and Species Variations in Incidence of Foetal Loss at the Maiduguri Abattoir in Northern Nigeria

Authors: Abdulrazaq O. Raji, Abba Mohammed, Ibrahim D. Mohammed

Abstract:

This study was conducted to investigate foetal loss among slaughtered livestock species at the Maiduguri abattoir from 2009 to 2013. Record of animals slaughtered monthly and fetuses recovered were collected from the management of the Maiduguri abattoir. Data was subjected to Analysis of Variance using the General Linear Model of SPSS 13.0 with Season, Species and their interaction as fixed factors. Average yearly slaughter at the Maiduguri abattoir was 63,225 animals with cattle, camel, goat and sheep accounting for 19737, 7374, 19281 and 17540 of the total. The corresponding number of those pregnant were 3117, 839, 2281 and 2432 out of a total of 8522 animals. Thus, cattle, camel, goat and sheep accounted for 30.87, 11.53, 30.16 and 27.44%, respectively of the animals slaughtered at the Abattoir and 35.96, 9.68, 26.31 and 28.05% of the foetal loss. The effect of season and species on foetal loss was significant (P < 0.05). The number of pregnant animals slaughtered and foetal loss were higher during wet than dry season. Similarly, foetal loss at the abattoir was higher in the month of May in respect of camel, goat and sheep, and August for cattle. Camel was the least slaughtered animal and had the least number of pregnant females. Foetal loss (%) was higher (P < 0.05) for cattle compared to other species. The interaction showed that camel was the least slaughtered species in both seasons and cattle in the wet season had the highest foetal loss.

Keywords: abattoir, foetal loss, season, species

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10 Arabic Literature as a Tool for Educational Transformation in Nigeria

Authors: Abdulfatah A Raji

Abstract:

This paper started with the definitions of literature, Arabic literature, transformation and went further to highlight the components of educational transformation. The general history of Arabic literature was discussed with focus on how it undergoes some transformations from pre-Islamic period through Quranic era, Abbasid literature to renaissance period in which the modernization of Arabic literature started in Egypt. It also traces the spread of Arabic literature in Nigeria from the pre-colonial era during the Kanuri rulers to Jihad of Usman Dan Fodio and the development of literature which manifested to the Teacher’s Colleges and Bayero University in Northern Nigeria. Also, the establishment of primary and post-primary schools by Muslim organizations in many cities and towns of the Western part of Nigeria. Literary criticism was also discussed in line with Arabic literature. Poetry work of eminent poets were cited to show its importance in line with educational transformation in Nigerian literature and lessons from the cited Arabic poetry works were also highlighted to include: motivation to behave well and to tolerate others, better spirits of interaction, love and co-existence among different sexes, religion etc. All these can help in developing a better educational transformation in Nigeria which can in turn help in how to conduct researches for national development. The paper recommended compulsory Arabic literature at all levels of the nations’ educational system as well as publication of Arabic books and journals to encourage peace in this era of conflicts and further transform Nigeria’s educational system for better.

Keywords: Arabic, literature, peace, development, Nigeria

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9 Breast Cancer Risk Factors: A Big Data Analysis of Black and White Women in the USA

Authors: Tejasvi Parupudi, Mochen Li, Lakshya Mittal, Ignacio G. Camarillo, Raji Sundararajan

Abstract:

With breast cancer becoming a global pandemic, it is very important to assess a woman’s risk profile accurately in a timely manner. Providing an estimate of the risk of developing breast cancer to a woman gives her an opportunity to consider options to decrease this risk. Women at low risk may be suggested yearly screenings whereas women with a high risk of developing breast cancer would be candidates for aggressive surveillance. Fortunately, there is a set of risk factors that are used to predict the probability of a woman being diagnosed with breast cancer in the future. Studying risk factors and understanding how they correlate to cancer is important for early diagnosis, prevention and reducing mortality rates. The effect of crucial risk factors among black and white women was compared in this study. The various risk factors analyzed include breast density, age, cancer in a first-degree relative, menopausal status, body mass index (BMI) and prior breast cancer diagnosis, etc. Breast density, age at first full-term birth and BMI were utilized in this study as important risk factors for the comparison of incidence rates between women of black and white races in the USA. Understanding the differences could lead to the development of solutions to reduce disparity in mortality rates among black women by improving overall access to care.

Keywords: big data, breast cancer, risk factors, incidence rates, mortality, race

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8 Some Factors Affecting Reproductive Traits in Nigerian Indigenous Chickens under Intensive Management System

Authors: J. Aliyu, A. O. Raji, A. A. Ibrahim

Abstract:

The study was carried out to assess the fertility, early and late embryonic mortalities as well as hatchability by strain, season and hen’s weight in Nigerian indigenous chickens reared on deep litter. Four strains (normal feathered, naked neck, frizzle and dwarf) of hens maintained at a mating ratio of 1 cock to 4 hens, fed breeders mash and water ad libitum were used in a three year experiment. The data generated were subjected to analysis of variance using the SAS package and the means, where significant, were separated using the least significant difference (LSD). There were significant effects (P < 0.05) of strain on all the traits studied. Fertility was generally high (84.29 %) in all the strains. Early embryonic mortality was significantly lowest (P < 0.01) in naked neck which had the highest late embryonic mortality (P < 0.001). Hatchability was significantly highest (P < 0.01) in normal feathered (80.23 %) and slightly depressed in frizzle (74.95 %) and dwarf (72.27 %) while naked neck had the lowest (60.80 %). Season of the year had significant effects on early embryonic mortality. Dry hot season significantly (P < 0.05) depressed fertility while early embryonic mortality was depressed in the wet season (15.33 %). Early and late embryonic mortalities significantly increased (P < 0.05) with increasing weight of hen. Dwarf, frizzle and normal feathered hens could be used to improve hatchability as well as reduce early and late embryonic mortalities in Nigerian indigenous chickens.

Keywords: chicken, fertility, hatchability, indigenous, strain

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7 An Introduction to the Current Epistemology of Ethical Philosophy of Islamic Banking

Authors: Mohd Iqbal Malik

Abstract:

Ethical philosophy of Quran pinnacled virtue and economics as the part and parcel of human life. Human beings are to be imagined by the sign of morals. Soul and morality are both among the essences of human personality. Islam lays the foundation of ethics by installation of making a momentous variance between virtue and vice. It suggests for the distribution of wealth in-order to terminate accumulation of economic resources. Quran claims for the ambiguous pavement to attain virtue by saying, ‘Never will you attain the good (reward) until you spend (in the way of Allah) from that which you love. And whatever you spend indeed, Allah knows of it.’ The essence of Quran is to eliminate all the deep-seated approaches through which the wealth of nations is being accumulated within few hands. The paper will study the Quranic Philosophy Of Islamic Economic System. In recent times, to get out of the human resource development mystery of Muslims, Ismail Al-Raji Faruqi led the way in the so-called ‘Islamization’ of knowledge. Rahman and Faruqi formed opposite opinions on this project. Al-Faruqi thought of the Islamization of knowledge in terms of introducing Western learning into received Islamic values and vice versa. This proved to be a mere peripheral treatment of Islamic values in relation to Western knowledge. It is true that out of the programme of Islamization of knowledge arose Islamic universities in many Muslim countries. Yet the academic programmes of these universities were not founded upon a substantive understanding and application of the tawhidi epistemology.

Keywords: ethical philosophy, modern Islamic finance, knowledge of finance, Islamic banking

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6 Nanofluid-Based Emulsion Liquid Membrane for Selective Extraction and Separation of Dysprosium

Authors: Maliheh Raji, Hossein Abolghasemi, Jaber Safdari, Ali Kargari

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Dysprosium is a rare earth element which is essential for many growing high-technology applications. Dysprosium along with neodymium plays a significant role in different applications such as metal halide lamps, permanent magnets, and nuclear reactor control rods preparation. The purification and separation of rare earth elements are challenging because of their similar chemical and physical properties. Among the various methods, membrane processes provide many advantages over the conventional separation processes such as ion exchange and solvent extraction. In this work, selective extraction and separation of dysprosium from aqueous solutions containing an equimolar mixture of dysprosium and neodymium by emulsion liquid membrane (ELM) was investigated. The organic membrane phase of the ELM was a nanofluid consisting of multiwalled carbon nanotubes (MWCNT), Span80 as surfactant, Cyanex 272 as carrier, kerosene as base fluid, and nitric acid solution as internal aqueous phase. Factors affecting separation of dysprosium such as carrier concentration, MWCNT concentration, feed phase pH and stripping phase concentration were analyzed using Taguchi method. Optimal experimental condition was obtained using analysis of variance (ANOVA) after 10 min extraction. Based on the results, using MWCNT nanofluid in ELM process leads to increase the extraction due to higher stability of membrane and mass transfer enhancement and separation factor of 6 for dysprosium over neodymium can be achieved under the optimum conditions. Additionally, demulsification process was successfully performed and the membrane phase reused effectively in the optimum condition.

Keywords: emulsion liquid membrane, MWCNT nanofluid, separation, Taguchi method

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5 Evaluation of Chemopreventive Activity of Medicinal Plant, Gromwell Seed against Tumor Promoting Stage

Authors: Harukuni Tokuda, Takanari Arai, Xu FengHao, Nobutaka Suzuki

Abstract:

In our continuous search for anti-tumor promoting, chemopreventive active potency from natural source material, a kind of healthy tea, Gromwell seed (Coix lachryma-jobi) ext., and including compounds Monoolein and Trilinolein have been screened using the in vitro synergistic assay indicated by inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by TPA. In assay, Gromwell seed aqueous extract and hot aqueous extract exhibited the potential inhibitory effects on EBV-EA activation without strong cytotoxicity on Raji cells. In our experimental system, the inhibitory effects of both Gromwell extracts and compounds were greater than that of beta-carotene, which is known anti-tumor promoting agent and/or chemopreventive agent. These compounds were evaluated for their in vitro inhibitory effect on EBV-EA activation induced by TPA. The percentages of the inhibition of TPA-induced EBV-EA activation for these materials were 60% and 30% at concentration 100 μg. Based on the results obtained in vitro, we studied the inhibitory effect of compounds, in an in vivo two-stage carcinogenesis test of mouse skin papilloma using DMBA as an initiator and TPA as a potential promoter. The control animals showed a 100% incidence of papilloma at 20 weeks after DMBA-TPA tumor promotion, while treatment with compounds reduced the percentage of number of tumor to 60 % after 20 weeks. Results from in vitro and in vivo studies showing chemopreventive activity against TPA promoting stage and these data support the effective potency of carcinogenic stage in clinical evaluation of integrative oncology.

Keywords: gromwell seed, medicinal plant, chemoprevention, pharmaceutical medicine

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4 Optimization of Samarium Extraction via Nanofluid-Based Emulsion Liquid Membrane Using Cyanex 272 as Mobile Carrier

Authors: Maliheh Raji, Hossein Abolghasemi, Jaber Safdari, Ali Kargari

Abstract:

Samarium as a rare-earth element is playing a growing important role in high technology. Traditional methods for extraction of rare earth metals such as ion exchange and solvent extraction have disadvantages of high investment and high energy consumption. Emulsion liquid membrane (ELM) as an improved solvent extraction technique is an effective transport method for separation of various compounds from aqueous solutions. In this work, the extraction of samarium from aqueous solutions by ELM was investigated using response surface methodology (RSM). The organic membrane phase of the ELM was a nanofluid consisted of multiwalled carbon nanotubes (MWCNT), Span80 as surfactant, Cyanex 272 as mobile carrier, and kerosene as base fluid. 1 M nitric acid solution was used as internal aqueous phase. The effects of the important process parameters on samarium extraction were investigated, and the values of these parameters were optimized using the Central Composition Design (CCD) of RSM. These parameters were the concentration of MWCNT in nanofluid, the carrier concentration, and the volume ratio of organic membrane phase to internal phase (Roi). The three-dimensional (3D) response surfaces of samarium extraction efficiency were obtained to visualize the individual and interactive effects of the process variables. A regression model for % extraction was developed, and its adequacy was evaluated. The result shows that % extraction improves by using MWCNT nanofluid in organic membrane phase and extraction efficiency of 98.92% can be achieved under the optimum conditions. In addition, demulsification was successfully performed and the recycled membrane phase was proved to be effective in the optimum condition.

Keywords: Cyanex 272, emulsion liquid membrane, MWCNT nanofluid, response surface methology, Samarium

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3 Batch and Fixed-Bed Studies of Ammonia Treated Coconut Shell Activated Carbon for Adsorption of Benzene and Toluene

Authors: Jibril Mohammed, Usman Dadum Hamza, Muhammad Idris Misau, Baba Yahya Danjuma, Yusuf Bode Raji, Abdulsalam Surajudeen

Abstract:

Volatile organic compounds (VOCs) have been reported to be responsible for many acute and chronic health effects and environmental degradations such as global warming. In this study, a renewable and low-cost coconut shell activated carbon (PHAC) was synthesized and treated with ammonia (PHAC-AM) to improve its hydrophobicity and affinity towards VOCs. Removal efficiencies and adsorption capacities of the ammonia treated activated carbon (PHAC-AM) for benzene and toluene were carried out through batch and fixed-bed studies respectively. Langmuir, Freundlich and Tempkin adsorption isotherms were tested for the adsorption process and the experimental data were best fitted by Langmuir model and least fitted by Tempkin model; the favourability and suitability of fitness were validated by equilibrium parameter (RL) and the root square mean deviation (RSMD). Judging by the deviation of the predicted values from the experimental values, pseudo-second-order kinetic model best described the adsorption kinetics than the pseudo-first-order kinetic model for the two VOCs on PHAC and PHAC-AM. In the fixed-bed study, the effect of initial VOC concentration, bed height and flow rate on benzene and toluene adsorption were studied. The highest bed capacities of 77.30 and 69.40 mg/g were recorded for benzene and toluene respectively; at 250 mg/l initial VOC concentration, 2.5 cm bed height and 4.5 ml/min flow rate. The results of this study revealed that ammonia treated activate carbon (PHAC-AM) is a sustainable adsorbent for treatment of VOCs in polluted waters.

Keywords: volatile organic compounds, equilibrium and kinetics studies, batch and fixed bed study, bio-based activated carbon

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2 An Artificially Intelligent Teaching-Agent to Enhance Learning Interactions in Virtual Settings

Authors: Abdulwakeel B. Raji

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This paper introduces a concept of an intelligent virtual learning environment that involves communication between learners and an artificially intelligent teaching agent in an attempt to replicate classroom learning interactions. The benefits of this technology over current e-learning practices is that it creates a virtual classroom where real time adaptive learning interactions are made possible. This is a move away from the static learning practices currently being adopted by e-learning systems. Over the years, artificial intelligence has been applied to various fields, including and not limited to medicine, military applications, psychology, marketing etc. The purpose of e-learning applications is to ensure users are able to learn outside of the classroom, but a major limitation has been the inability to fully replicate classroom interactions between teacher and students. This study used comparative surveys to gain information and understanding of the current learning practices in Nigerian universities and how they compare to these practices compare to the use of a developed e-learning system. The study was conducted by attending several lectures and noting the interactions between lecturers and tutors and as an aftermath, a software has been developed that deploys the use of an artificial intelligent teaching-agent alongside an e-learning system to enhance user learning experience and attempt to create the similar learning interactions to those found in classroom and lecture hall settings. Dialogflow has been used to implement a teaching-agent, which has been developed using JSON, which serves as a virtual teacher. Course content has been created using HTML, CSS, PHP and JAVASCRIPT as a web-based application. This technology can run on handheld devices and Google based home technologies to give learners an access to the teaching agent at any time. This technology also implements the use of definite clause grammars and natural language processing to match user inputs and requests with defined rules to replicate learning interactions. This technology developed covers familiar classroom scenarios such as answering users’ questions, asking ‘do you understand’ at regular intervals and answering subsequent requests, taking advanced user queries to give feedbacks at other periods. This software technology uses deep learning techniques to learn user interactions and patterns to subsequently enhance user learning experience. A system testing has been undergone by undergraduate students in the UK and Nigeria on the course ‘Introduction to Database Development’. Test results and feedback from users shows that this study and developed software is a significant improvement on existing e-learning systems. Further experiments are to be run using the software with different students and more course contents.

Keywords: virtual learning, natural language processing, definite clause grammars, deep learning, artificial intelligence

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1 Analyzing the Heat Transfer Mechanism in a Tube Bundle Air-PCM Heat Exchanger: An Empirical Study

Authors: Maria De Los Angeles Ortega, Denis Bruneau, Patrick Sebastian, Jean-Pierre Nadeau, Alain Sommier, Saed Raji

Abstract:

Phase change materials (PCM) present attractive features that made them a passive solution for thermal comfort assessment in buildings during summer time. They show a large storage capacity per volume unit in comparison with other structural materials like bricks or concrete. If their use is matched with the peak load periods, they can contribute to the reduction of the primary energy consumption related to cooling applications. Despite these promising characteristics, they present some drawbacks. Commercial PCMs, as paraffines, offer a low thermal conductivity affecting the overall performance of the system. In some cases, the material can be enhanced, adding other elements that improve the conductivity, but in general, a design of the unit that optimizes the thermal performance is sought. The material selection is the departing point during the designing stage, and it does not leave plenty of room for optimization. The PCM melting point depends highly on the atmospheric characteristics of the building location. The selection must relay within the maximum, and the minimum temperature reached during the day. The geometry of the PCM container and the geometrical distribution of these containers are designing parameters, as well. They significantly affect the heat transfer, and therefore its phenomena must be studied exhaustively. During its lifetime, an air-PCM unit in a building must cool down the place during daytime, while the melting of the PCM occurs. At night, the PCM must be regenerated to be ready for next uses. When the system is not in service, a minimal amount of thermal exchanges is desired. The aforementioned functions result in the presence of sensible and latent heat storage and release. Hence different types of mechanisms drive the heat transfer phenomena. An experimental test was designed to study the heat transfer phenomena occurring in a circular tube bundle air-PCM exchanger. An in-line arrangement was selected as the geometrical distribution of the containers. With the aim of visual identification, the containers material and a section of the test bench were transparent. Some instruments were placed on the bench for measuring temperature and velocity. The PCM properties were also available through differential scanning calorimeter (DSC) tests. An evolution of the temperature during both cycles, melting and solidification were obtained. The results showed some phenomena at a local level (tubes) and on an overall level (exchanger). Conduction and convection appeared as the main heat transfer mechanisms. From these results, two approaches to analyze the heat transfer were followed. The first approach described the phenomena in a single tube as a series of thermal resistances, where a pure conduction controlled heat transfer was assumed in the PCM. For the second approach, the temperature measurements were used to find some significant dimensionless numbers and parameters as Stefan, Fourier and Rayleigh numbers, and the melting fraction. These approaches allowed us to identify the heat transfer phenomena during both cycles. The presence of natural convection during melting might have been stated from the influence of the Rayleigh number on the correlations obtained.

Keywords: phase change materials, air-PCM exchangers, convection, conduction

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