Search results for: exposure rate
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 9658

Search results for: exposure rate

7258 Development of Fuzzy Logic and Neuro-Fuzzy Surface Roughness Prediction Systems Coupled with Cutting Current in Milling Operation

Authors: Joseph C. Chen, Venkata Mohan Kudapa

Abstract:

Development of two real-time surface roughness (Ra) prediction systems for milling operations was attempted. The systems used not only cutting parameters, such as feed rate and spindle speed, but also the cutting current generated and corrected by a clamp type energy sensor. Two different approaches were developed. First, a fuzzy inference system (FIS), in which the fuzzy logic rules are generated by experts in the milling processes, was used to conduct prediction modeling using current cutting data. Second, a neuro-fuzzy system (ANFIS) was explored. Neuro-fuzzy systems are adaptive techniques in which data are collected on the network, processed, and rules are generated by the system. The inference system then uses these rules to predict Ra as the output. Experimental results showed that the parameters of spindle speed, feed rate, depth of cut, and input current variation could predict Ra. These two systems enable the prediction of Ra during the milling operation with an average of 91.83% and 94.48% accuracy by FIS and ANFIS systems, respectively. Statistically, the ANFIS system provided better prediction accuracy than that of the FIS system.

Keywords: surface roughness, input current, fuzzy logic, neuro-fuzzy, milling operations

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7257 Evaluation of the Role of Bacteria-Derived Flavins as Plant Growth Promoting Molecules

Authors: Nivethika Ajeethan, Lord Abbey, Svetlana Yurge

Abstract:

Riboflavin is a water-soluble vitamin and the direct precursor of the flavin cofactors flavin mononucleotide and flavin adenine dinucleotide. Flavins (FLs) are bioactive molecules that have a beneficial effect on plant growth and development. Sinorhizobium meliloti strain 1021 is an α-proteobacterium that forms agronomically important N₂-fixing symbiosis with Medicago plants and secretes a considerable amount of FLs (FL⁺ strain). This strain was also implicated in plant growth promotion in its association with non-legume host plants. However, the mechanism of this plant growth promotion is not well understood. In this study, we evaluated the growth and development of tomato plants inoculated with S. meliloti 1021 and its mutant (FL⁻ strain) with limited ability to secrete FLs. Our preliminary experiments indicated that inoculation with FL⁺ strain significantly increased seedlings' root and shoot length and surface area compared to those of plants inoculated with FL⁻ strain. For example, the root lengths of 9-day old seedlings inoculated with FL⁺ strain were 35% longer than seedlings inoculated with the mutant. Proteomic approaches combined with the analysis of plant physiological responses such as growth and photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll content will be used to evaluate the host-plant response to bacteria-derived FLs.

Keywords: flavin, plant growth promotion, riboflavin, Sinorhizobium meliloti

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7256 Survey and Analysis of the Operational Dilemma of the Existing Used Clothes Recycling Model in the Community

Authors: Qiaohui Zhong, Yiqi Kuang, Wanxun Cai, Libin Huang

Abstract:

As a community public facility, the popularity and perfection of old clothes recycling products directly affect people's impression of the whole city, which is related to the happiness index of residents' lives and is of great significance to the construction of eco-civilized cities and the realization of sustainable urban development. At present, China's waste clothing is characterized by large production and a high utilization rate, but the current rate of old clothes recycling is low, and the ‘one-size-fits-all’ recycling model makes people's motivation for old clothes recycling low, and old clothes recycling is in a dilemma. Based on the two online and offline recycling modes of old clothes recycling in Chinese communities, this paper conducts an in-depth survey on the public, operators, and regulators from the aspects of activity scene analysis, crowd attributes analysis, and community space analysis summarizes the difficulties of old clothes recycling for the public - nowhere to recycle, inconvenient to recycle and unwilling to recycle, and analyzes the factors that lead to these difficulties, and gives a solution with foreign experience to solve these problems. It also analyzes the factors that lead to these difficulties and gives targeted suggestions in combination with foreign experience, exploring and proposing a set of appropriate modern old-clothes recycling modes.

Keywords: community, old clothes recycling, recycling mode, sustainable urban development

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7255 Nitrification and Denitrification Kinetic Parameters of a Mature Sanitary Landfill Leachate

Authors: Tânia F. C. V. Silva, Eloísa S. S. Vieira, João Pinto da Costa, Rui A. R. Boaventura, Vitor J. P. Vilar

Abstract:

Sanitary landfill leachates are characterized as a complex mixture of diverse organic and inorganic contaminants, which are usually removed by combining different treatment processes. Due to its simplicity, reliability, high cost-effectiveness and high nitrogen content (mostly under the ammonium form) inherent in this type of effluent, the activated sludge biological process is almost always applied in leachate treatment plants (LTPs). The purpose of this work is to assess the effect of the main nitrification and denitrification variables on the nitrogen's biological removal, from mature leachates. The leachate samples were collected after an aerated lagoon, at a LTP nearby Porto, presenting a high amount of dissolved organic carbon (1.0-1.3 g DOC/L) and ammonium nitrogen (1.1-1.7 g NH4+-N/L). The experiments were carried out in a 1-L lab-scale batch reactor, equipped with a pH, temperature and dissolved oxygen (DO) control system, in order to determine the reaction kinetic constants at unchanging conditions. The nitrification reaction rate was evaluated while varying the (i) operating temperature (15, 20, 25 and 30ºC), (ii) DO concentration interval (0.5-1.0, 1.0-2.0 and 2.0-4.0 mg/L) and (iii) solution pH (not controlled, 7.5-8.5 and 6.5-7.5). At the beginning of most assays, it was verified that the ammonium stripping occurred simultaneously to the nitrification, reaching up to 37% removal of total dissolved nitrogen. The denitrification kinetic constants and the methanol consumptions were calculated for different values of (i) volatile suspended solids (VSS) content (25, 50 and 100 mL of centrifuged sludge in 1 L solution), (ii) pH interval (6.5-7.0, 7.5-8.0 and 8.5-9.0) and (iii) temperature (15, 20, 25 and 30ºC), using effluent previously nitrified. The maximum nitrification rate obtained was 38±2 mg NH4+-N/h/g VSS (25ºC, 0.5-1.0 mg O2/L, pH not controlled), consuming 4.4±0.3 mg CaCO3/mg NH4+-N. The highest denitrification rate achieved was 19±1 mg (NO2--N+NO3--N)/h/g VSS (30ºC, 50 mL of sludge and pH between 7.5 and 8.0), with a C/N consumption ratio of 1.1±0.1 mg CH3OH/mg (NO2--N+NO3--N) and an overall alkalinity production of 3.7±0.3 mg CaCO3/mg (NO2--N+NO3--N). The denitrification process showed to be sensitive to all studied parameters, while the nitrification reaction did not suffered significant change when DO content was changed.

Keywords: mature sanitary landfill leachate, nitrogen removal, nitrification and denitrification parameters, lab-scale activated sludge biological reactor

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7254 Health Outcomes and Economic Growth Nexus: Testing for Long-run Relationships and Causal Links in Nigeria

Authors: Haruna Modibbo Usman, Mustapha Muktar, Nasiru Inuwa

Abstract:

This paper examined the long run relationship between health outcomes and economic growth in Nigeria from 1961 to 2012. Using annual time series data, Augmented Dickey-Fuller (ADF) test is conducted to check the stochastic properties of the variables. Also, the long run relationship among the variables is confirmed based on Johansen Multivariate Cointegration approach whereas the long run and short run dynamics are observed using Vector Error Correction Mechanism (VECM). In addition, VEC Granger causality test is employed to examine the direction of causality among the variables. On the whole, the results obtained revealed the existence of a long run relationship between health outcomes and economic growth in Nigeria and that both life expectancy and crude death rate as measures of health are found to have a long run negative and statistically significant impact on the economic growth over the study period. This is further buttressed by the results of Granger causality test which indicated the existence of unidirectional causality running from life expectancy and crude death rate to economic growth. The study therefore, calls for governments at various levels to create preconditions for health improvements in Nigeria in order to boost the level of health outcomes.

Keywords: cointegration, economic growth, Granger causality, health outcomes, VECM

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7253 Application of Enzyme-Mediated Calcite Precipitation for Surface Control of Gold Mining Tailing Waste

Authors: Yogi Priyo Pradana, Heriansyah Putra, Regina Aprilia Zulfikar, Maulana Rafiq Ramadhan, Devyan Meisnnehr, Zalfa Maulida Insani

Abstract:

This paper studied the effects and mechanisms of fine-grained tailing by Enzyme-Mediated Calcite Precipitation (EMCP). Grouting solution used consists of reagents (CaCl₂ and (CO(NH₂)₂) and urease enzymes which react to produce CaCO₃. In sample preparation, the test tube is used to investigate the precipitation rate of calcite. The grouting solution added is 75 mL for one mold sample. The solution was poured into a mold sample up to as high as 5 mm from the top surface of the tailing to ensure the entire surface is submerged. The sample is left open in a cylinder for up to 3 days for curing. The direct mixing method is conducted so that the cementation process occurs by evenly distributed. The relationship between the results of the UCS test and the calcite precipitation rate likely indicates that the amount of calcite deposited in treated tailing could control the strength of the tailing. The sample results are analyzed using atomic absorption spectroscopy (AAS) to evaluate metal and metalloid content. Calcium carbonate deposited in the tailing is expected to strengthen the bond between tailing granules, which are easily slipped on the banks of the tailing dam. The EMCP method is expected to strengthen tailing in erosion-control surfaces.

Keywords: tailing, EMCP, UCS, AAS

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7252 Computer Anxiety and the Use of Computerized System by University Librarians in Delta State University Library, Nigeria

Authors: L. Arumuru

Abstract:

The paper investigates computer anxiety and the use of computerized library system by university librarians in Delta State University library, Abraka, Nigeria. Some of the root causes of computer anxiety among university librarians such as lack of exposure to computers at early age, inadequate computer skills, inadequate computer training, fear at the sight of a computer, lack of understanding of how computers work, etc. were pin-pointed in the study. Also, the different services rendered in the university libraries with the aid of computers such as reference services, circulation services, acquisition services, cataloguing and classification services, etc. were identified. The study employed the descriptive survey research design through the expo-facto method, with a population of 56 librarians, while the simple percentage and frequency counts were used to analyze the data generated from the administered copies of the questionnaire. Based on the aforementioned root causes of computer anxiety and the resultant effect on computerized library system, recommendations were proffered in the study.

Keywords: computer anxiety, computerized library system, library services, university librarians

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7251 Unravelling Glyphosates Disruptive Effects on the Photochemical Efficiency of Amaranthus cruentus

Authors: Jacques M. Berner, Lehlogonolo Maloma

Abstract:

Context: Glyphosate, a widely used herbicide, has raised concerns about its impact on various crops. Amaranthus cruentus, an important grain crop species, is particularly susceptible to glyphosate. Understanding the specific disruptions caused by glyphosate on the photosynthetic process in Amaranthus cruentus is crucial for assessing its effects on crop productivity and ecological sustainability. Research Aim: This study aimed to investigate the dose-dependent impact of glyphosate on the photochemical efficiency of Amaranthus cruentus using the OJIP transient analysis. The goal was to assess the specific disruptions caused by glyphosate on key parameters of photosystem II. Methodology: The experiment was conducted in a controlled greenhouse environment. Amaranthus cruentus plants were exposed to different concentrations of glyphosate, including half, recommended, and double the recommended application rates. The photochemical efficiency of the plants was evaluated using non-invasive chlorophyll a fluorescence measurements and subsequent analysis of OJIP transients. Measurements were taken on 1-hour dark-adapted leaves using a Hansatech Handy PEA+ chlorophyll fluorimeter. Findings: The study's results demonstrated a significant reduction in the photochemical efficiency of Amaranthus cruentus following glyphosate treatment. The OJIP transients showed distinct alterations in the glyphosate-treated plants compared to the control group. These changes included a decrease in maximal fluorescence (FP) and a delay in the rise of the fluorescence signal, indicating impairment in the energy conversion process within the photosystem II. Glyphosate exposure also led to a substantial decrease in the maximum quantum yield efficiency of photosystem II (FV/FM) and the total performance index (PItotal), which reflects the overall photochemical efficiency of photosystem II. These reductions in photochemical efficiency were observed even at half the recommended dose of glyphosate. Theoretical Importance: The study provides valuable insights into the specific disruptions caused by glyphosate on the photochemical efficiency of Amaranthus cruentus. Data Collection and Analysis Procedures: Data collection involved non-invasive chlorophyll a fluorescence measurements using a chlorophyll fluorimeter on dark-adapted leaves. The OJIP transients were then analyzed to assess specific disruptions in key parameters of photosystem II. Statistical analysis was conducted to determine the significance of the differences observed between glyphosate-treated plants and the control group. Question Addressed: The study aimed to address the question of how glyphosate exposure affects the photochemical efficiency of Amaranthus cruentus, specifically examining disruptions in the photosynthetic electron transport chain and overall photochemical efficiency. Conclusion: The study demonstrates that glyphosate severely impairs the photochemical efficiency of Amaranthus cruentus, as indicated by the alterations in OJIP transients. Even at half the recommended dose, glyphosate caused significant reductions in photochemical efficiency. These findings highlight the detrimental effects of glyphosate on crop productivity and emphasize the need for further research to evaluate its long-term consequences and ecological implications in agriculture. The authors gratefully acknowledge the support from North-West University for making this research possible.

Keywords: glyphosate, amaranthus cruentus, ojip transient analysis, pitotal, photochemical efficiency, chlorophyll fluorescence, weeds

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7250 Physiological and Psychological Influence on Office Workers during Demand Response

Authors: Megumi Nishida, Naoya Motegi, Takurou Kikuchi, Tomoko Tokumura

Abstract:

In recent years, power system has been changed and flexible power pricing system such as demand response has been sought in Japan. The demand response system is simple in the household sector and the owner, decision-maker, can gain the benefits of power saving. On the other hand, the execution of the demand response in the office building is more complex than household because various people such as owners, building administrators and occupants are involved in making decisions. While the owners benefit from the demand saving, the occupants are forced to be exposed to demand-saved environment certain benefits. One of the reasons is that building systems are usually centralized control and each occupant cannot choose either participate demand response event or not, and contribution of each occupant to demand response is unclear to provide incentives. However, the recent development of IT and building systems enables the personalized control of office environment where each occupant can control the lighting level or temperature around him or herself. Therefore, it can be possible to have a system which each occupant can make a decision of demand response participation in office building. This study investigates the personal behavior upon demand response requests, under the condition where each occupant can adjust their brightness individually in their workspace. Once workers participate in the demand response, their task lights are automatically turned off. The participation rates in the demand response events are compared between four groups which are divided by different motivation, the presence or absence of incentives and the way of participation. The result shows that there are the significant differences of participation rates in demand response event between four groups. The way of participation has a large effect on the participation rate. ‘Opt-out’ group, where the occupants are automatically enrolled in a demand response event if they don't express non-participation, will have the highest participation rate in the four groups. The incentive has also an effect on the participation rate. This study also reports that the impact of low illumination office environment on the occupants, such as stress or fatigue. The electrocardiogram and the questionnaire are used to investigate the autonomic nervous activity and subjective symptoms about the fatigue of the occupants. There is no big difference between dim workspace during demand response event and bright workspace in autonomic nervous activity and fatigue.

Keywords: demand response, illumination, questionnaire, electrocardiogram

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7249 Assessing Relationships between Glandularity and Gray Level by Using Breast Phantoms

Authors: Yun-Xuan Tang, Pei-Yuan Liu, Kun-Mu Lu, Min-Tsung Tseng, Liang-Kuang Chen, Yuh-Feng Tsai, Ching-Wen Lee, Jay Wu

Abstract:

Breast cancer is predominant of malignant tumors in females. The increase in the glandular density increases the risk of breast cancer. BI-RADS is a frequently used density indicator in mammography; however, it significantly overestimates the glandularity. Therefore, it is very important to accurately and quantitatively assess the glandularity by mammography. In this study, 20%, 30% and 50% glandularity phantoms were exposed using a mammography machine at 28, 30 and 31 kVp, and 30, 55, 80 and 105 mAs, respectively. The regions of interest (ROIs) were drawn to assess the gray level. The relationship between the glandularity and gray level under various compression thicknesses, kVp, and mAs was established by the multivariable linear regression. A phantom verification was performed with automatic exposure control (AEC). The regression equation was obtained with an R-square value of 0.928. The average gray levels of the verification phantom were 8708, 8660 and 8434 for 0.952, 0.963 and 0.985 g/cm3, respectively. The percent differences of glandularity to the regression equation were 3.24%, 2.75% and 13.7%. We concluded that the proposed method could be clinically applied in mammography to improve the glandularity estimation and further increase the importance of breast cancer screening.

Keywords: mammography, glandularity, gray value, BI-RADS

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7248 Efficiency of Lavandula angustifolia Mill and Zataria multiflora Boiss essential oils on nutritional indices of Tribolium confusum Jacquelin du Val (Col.: Tenebrionidae)

Authors: Karim Saeidi

Abstract:

One of the most important pests in the warehouses is the flour beetle, Tribolium confusum Jacquelin du Val (Col.: Tenebrionidae). Regarding the high degree of damage of stored product pests and dangerous effects of the chemical control using plant extracts and their components are some of the best approaches to control these pests. Antifeedant activity of plant extracts from Lavandula angustifolia Mill and Zataria multiflora Boiss using hydro-distillation were tested against the flour beetle, Tribolium confusum Jacquelin du Val. The nutritional indices: relative growth rate (RGR), relative consumption rate (RCR), the efficiency of conversion of ingested food (ECI), and feeding deterrence index (FDI) were measured for adult insects. Treatments were evaluated using a flour disk bioassay in the dark; at 25±1ᵒC and 60±5% R. H. Concentrations of 0, 0.1, 0.5, 0.75, 1, 1.5, and 2 μl/disk were prepared from each essential oil. After 72 h, nutritional indices were calculated. L. angustifolia oils were more effective than Z. multiflora oils by significantly decreasing the RGR, RCR, and ECI. Feeding deterrence index (FDI) of L. angustifolia essential oil was increased significantly as essential oil concentration increased. The essential oil of L. angustifolia was more effective on FDI than Z. multiflora in some concentration.

Keywords: essential oil, nutritional indices, Tribolium confusum

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7247 Modelling of Solidification in a Latent Thermal Energy Storage with a Finned Tube Bundle Heat Exchanger Unit

Authors: Remo Waser, Simon Maranda, Anastasia Stamatiou, Ludger J. Fischer, Joerg Worlitschek

Abstract:

In latent heat storage, a phase change material (PCM) is used to store thermal energy. The heat transfer rate during solidification is limited and considered as a key challenge in the development of latent heat storages. Thus, finned heat exchangers (HEX) are often utilized to increase the heat transfer rate of the storage system. In this study, a new modeling approach to calculating the heat transfer rate in latent thermal energy storages with complex HEX geometries is presented. This model allows for an optimization of the HEX design in terms of costs and thermal performance of the system. Modeling solidification processes requires the calculation of time-dependent heat conduction with moving boundaries. Commonly used computational fluid dynamic (CFD) methods enable the analysis of the heat transfer in complex HEX geometries. If applied to the entire storage, the drawback of this approach is the high computational effort due to small time steps and fine computational grids required for accurate solutions. An alternative to describe the process of solidification is the so-called temperature-based approach. In order to minimize the computational effort, a quasi-stationary assumption can be applied. This approach provides highly accurate predictions for tube heat exchangers. However, it shows unsatisfactory results for more complex geometries such as finned tube heat exchangers. The presented simulation model uses a temporal and spatial discretization of heat exchanger tube. The spatial discretization is based on the smallest possible symmetric segment of the HEX. The heat flow in each segment is calculated using finite volume method. Since the heat transfer fluid temperature can be derived using energy conservation equations, the boundary conditions at the inner tube wall is dynamically updated for each time step and segment. The model allows a prediction of the thermal performance of latent thermal energy storage systems using complex HEX geometries with considerably low computational effort.

Keywords: modelling of solidification, finned tube heat exchanger, latent thermal energy storage

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7246 Detection the Abundance of Chicken Skin in Hamburger in Tehran

Authors: Ghazanfari Masoumeh, Hajimohammadi Bahador, Eskandari Soheyl, Karimian Khosroshahi Nader

Abstract:

Consumption of ready to cook meat products such as hamburgers, sausages and etc is being increased in the worldwide specially in the big cities , so safety and quality required for food products is very important and vital for consumers with consideration of meat price and increasing demands for meat products, possibility of substitution of cheep and unauthorized textures such as undesirable enclosures animals (massacre, lung tissue, breast of spleen, the organs abdominal cavity, gizzard chicken, skin, etc. ) have increased in the recent years, in this study 30 industrial and 30 handmade hamburgers in fast food restaurants detected out of Iranian national standard for hamburger No. 2304 in using the unauthorized textures. The purpose of this study was to determine using of chicken skin in produced hamburgers from chicken meat in Tehran base on histology methods. The rates of skin used were, 2 % in industrial and 9 % in handmade formula samples. Statistically using the unauthorized textures had significant higher rate in handmade (P < 0.05) in compare with the industrial samples. The results showed the handmade hamburgers with higher adulteration rate and non-compliance with the hamburger national standard could be a potentially health hazard.

Keywords: histology, adulteration, unauthorized textures, undesirable enclosures animals

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7245 An Experimental Study on the Optimum Installation of Fire Detector for Early Stage Fire Detecting in Rack-Type Warehouses

Authors: Ki Ok Choi, Sung Ho Hong, Dong Suck Kim, Don Mook Choi

Abstract:

Rack type warehouses are different from general buildings in the kinds, amount, and arrangement of stored goods, so the fire risk of rack type warehouses is different from those buildings. The fire pattern of rack type warehouses is different in combustion characteristic and storing condition of stored goods. The initial fire burning rate is different in the surface condition of materials, but the running time of fire is closely related with the kinds of stored materials and stored conditions. The stored goods of the warehouse are consisted of diverse combustibles, combustible liquid, and so on. Fire detection time may be delayed because the residents are less than office and commercial buildings. If fire detectors installed in rack type warehouses are inadaptable, the fire of the warehouse may be the great fire because of delaying of fire detection. In this paper, we studied what kinds of fire detectors are optimized in early detecting of rack type warehouse fire by real-scale fire tests. The fire detectors used in the tests are rate of rise type, fixed type, photo electric type, and aspirating type detectors. We considered optimum fire detecting method in rack type warehouses suggested by the response characteristic and comparative analysis of the fire detectors.

Keywords: fire detector, rack, response characteristic, warehouse

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7244 An Automatic Speech Recognition of Conversational Telephone Speech in Malay Language

Authors: M. Draman, S. Z. Muhamad Yassin, M. S. Alias, Z. Lambak, M. I. Zulkifli, S. N. Padhi, K. N. Baharim, F. Maskuriy, A. I. A. Rahim

Abstract:

The performance of Malay automatic speech recognition (ASR) system for the call centre environment is presented. The system utilizes Kaldi toolkit as the platform to the entire library and algorithm used in performing the ASR task. The acoustic model implemented in this system uses a deep neural network (DNN) method to model the acoustic signal and the standard (n-gram) model for language modelling. With 80 hours of training data from the call centre recordings, the ASR system can achieve 72% of accuracy that corresponds to 28% of word error rate (WER). The testing was done using 20 hours of audio data. Despite the implementation of DNN, the system shows a low accuracy owing to the varieties of noises, accent and dialect that typically occurs in Malaysian call centre environment. This significant variation of speakers is reflected by the large standard deviation of the average word error rate (WERav) (i.e., ~ 10%). It is observed that the lowest WER (13.8%) was obtained from recording sample with a standard Malay dialect (central Malaysia) of native speaker as compared to 49% of the sample with the highest WER that contains conversation of the speaker that uses non-standard Malay dialect.

Keywords: conversational speech recognition, deep neural network, Malay language, speech recognition

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7243 Vital Pulp Therapy: A Paradigm Shift in Treating Irreversible Pulpitis

Authors: Fadwa Chtioui

Abstract:

Vital Pulp Therapy (VPT) is nowadays challenging the deep-rooted dogma of root canal treatment, being the only therapeutic option for permanent teeth diagnosed with irreversible pulpitis or carious pulp exposure. Histologic and clinical research has shown that compromised dental pulp can be treated without the full removal or excavation of all healthy pulp, and the outcome of the partial or full pulpotomy followed by a Tricalcium-Silicate-based dressing seems to show promising results in maintaining pulp vitality and preserving affected teeth in the long term. By reviewing recent advances in the techniques of VPT and their clinical effectiveness and safety in permanent teeth with irreversible Pulpitis, this work provides a new understanding of pulp pathophysiology and defense mechanisms and will reform dental practitioners' decision-making in treating irreversible pulpits from root canal therapy to vital pulp therapy by taking advantage of the biological effects of Tricalcium Silicate materials.

Keywords: irreversible pulpitis, vital pulp therapy, pulpotomy, Tricalcium Silicate

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7242 A Condition-Based Maintenance Policy for Multi-Unit Systems Subject to Deterioration

Authors: Nooshin Salari, Viliam Makis

Abstract:

In this paper, we propose a condition-based maintenance policy for multi-unit systems considering the existence of economic dependency among units. We consider a system composed of N identical units, where each unit deteriorates independently. Deterioration process of each unit is modeled as a three-state continuous time homogeneous Markov chain with two working states and a failure state. The average production rate of units varies in different working states and demand rate of the system is constant. Units are inspected at equidistant time epochs, and decision regarding performing maintenance is determined by the number of units in the failure state. If the total number of units in the failure state exceeds a critical level, maintenance is initiated, where units in failed state are replaced correctively and deteriorated state units are maintained preventively. Our objective is to determine the optimal number of failed units to initiate maintenance minimizing the long run expected average cost per unit time. The problem is formulated and solved in the semi-Markov decision process (SMDP) framework. A numerical example is developed to demonstrate the proposed policy and the comparison with the corrective maintenance policy is presented.

Keywords: reliability, maintenance optimization, semi-Markov decision process, production

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7241 Pharmacodynamic Enhancement of Repetitive rTMS Treatment Outcomes for Major Depressive Disorder

Authors: A. Mech

Abstract:

Repetitive transcranial magnetic stimulation has proven to be a valuable treatment option for patients who have failed to respond to multiple courses of antidepressant medication. In fact, the American Psychiatric Association recommends TMS after one failed treatment course of antidepressant medication. Genetic testing has proven valuable for pharmacokinetic variables, which, if understood, could lead to more efficient dosing of psychotropic medications to improve outcomes. Pharmacodynamic testing can identify biomarkers, which, if addressed, can improve patients' outcomes in antidepressant therapy. Monotherapy treatment of major depressive disorder with methylated B vitamin treatment has been shown to be safe and effective in patients with MTHFR polymorphisms without waiting for multiple trials of failed medication treatment for depression. Such treatment has demonstrated remission rates similar to antidepressant clinical trials. Combining pharmacodynamics testing with repetitive TMS treatment with NeuroStar has shown promising potential for enhancing remission rates and durability of treatment. In this study, a retrospective chart review (ongoing) of patients who obtained repetitive TMS treatment enhanced by dietary supplementation guided by Pharmacodynamic testing, displayed a greater remission rate (90%) than patients treated with only NeuroStar TMS (62%).

Keywords: improved remission rate, major depressive disorder, pharmacodynamic testing, rTMS outcomes

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7240 Changes in the Body Weight and Wound Contraction Rate Following Treatment with Piper betel Extract in Diabetic Wounds

Authors: Nurul Z. Sani, Amalina N. Ghazali, Azree Elmy, Lee C. Yuen, Zar C. Thent

Abstract:

Piper betel (P. betel) leaves is widely used in Asian countries for treating diabetes mellitus and its complication. In our previous study, we observed the positive effect of P.betel extract on diabetic wounds following 3 and 7 days of treatment. The aim of the present study was to determine the effect of P.betel leaves extract in the diabetic rats was observed in terms of body weight and wound contraction rates following 5 days of the treatment. Total 64 male Sprague-Dawley rats were used and the experimental rats received a single dose of 60mg/kg of Streptozotocin (STZ) injection, intraperitoneally. Four full thickness (6mm) cutaneous wounds were created on dorsum of each rat. The rats were divideid into (n=8): Non-treated Control (NC), Non-treated Diabetic (ND), diabetic treated with commercial cream (SN) and diabetic treated with 50mg/kg of P.betel extract (PB). The rats were sacrificed on day 0 and 5 post wounding. Significant increased in wound closure rate, body weight was observed in PB group compared to ND. Histological deterioration was restored in the P. betel extract treated wounds. It is concluded that topical application with P.betel extract for 5 days of post wounding offers positive scientific value in diabetic rats.

Keywords: diabetes, piper betel, wound healing, body weight, morphology

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7239 A Mathematical Analysis of Behavioural Epidemiology: Drugs Users Transmission Dynamics Based on Level Education for Susceptible Population

Authors: Firman Riyudha, Endrik Mifta Shaiful

Abstract:

The spread of drug users is one kind of behavioral epidemiology that becomes a threat to every country in the world. This problem caused various crisis simultaneously, including financial or economic crisis, social, health, until human crisis. Most drug users are teenagers at school age. A new deterministic model would be constructed to determine the dynamics of the spread of drug users by considering level of education in a susceptible population. Based on the analytical model, two equilibria points were obtained; there were E₀ (zero user) and E₁ (endemic equilibrium). Existence of equilibrium and local stability of equilibria depended on the Basic Reproduction Ratio (R₀). This parameter was defined as the expected rate of secondary prevalence and primary prevalence in virgin population along spreading primary prevalence. The zero-victim equilibrium would be locally asymptotically stable if R₀ < 1 while if R₀ > 1 the endemic equilibrium would be locally asymptotically stable. The result showed that R₀ was proportional to the rate of interaction of each susceptible population based on educational level with the users' population. It is concluded that there was a need to be given a control in interaction, so that drug users population could be minimized. Numerical simulations were also provided to support analytical results.

Keywords: drugs users, level education, mathematical model, stability

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7238 Comparative Effects of Homoplastic and Synthetic Pituitary Extracts on Induced Breeding of Heterobranchus longifilis (Valenciennes, 1840) in Indoor Hatchery Tanks in Owerri South East Nigeria

Authors: I. R. Keke, C. S. Nwigwe, O. S. Nwanjo, A. S. Egeruoh

Abstract:

An experiment was carried out at Urban Farm and Fisheries Nigeria Ltd, Owerri Imo State South East Nigeria between February and June 2014 to induce Brood stock of Heterobranchus longifilis (mean wt 1.3kg) in concrete tanks (1.0 x 2.0 x 1.5m) in dimension using a synthetic hormone (Ovaprim) and pituitary extract from Heterobranchus longifilis. Brood stock males were selected as pituitary donors and their weights matched those of females to be injected at 1ml/kg body weight of Fish. Ovaprim, was injected at 0.5ml/kg body weight of female fish. A latency period of 12 hours was allowed after injection of the Brood stock females before stripping the egg and incubation at 23 °C. While incubating the eggs, samples were drawn and the rate of fertilization was determined. Hatching occurred within 33 hours and hatchability rate (%) was determined by counting the active hatchings. The result showed that Ovaprim injected Brood stock eggs fertilized up to 80% while the pituitary from the Heterobranchus longifilis had low fertilization and hatching success 20%. Ovaprim is imported and costly, so more effort is required to enhance the procedures for homoplastic hypophysation.

Keywords: heterobranchus longifilis, ovaprim, hypophysation, latency period, pituitary

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7237 A Computational Fluid Dynamics Simulation of Single Rod Bundles with 54 Fuel Rods without Spacers

Authors: S. K. Verma, S. L. Sinha, D. K. Chandraker

Abstract:

The Advanced Heavy Water Reactor (AHWR) is a vertical pressure tube type, heavy water moderated and boiling light water cooled natural circulation based reactor. The fuel bundle of AHWR contains 54 fuel rods arranged in three concentric rings of 12, 18 and 24 fuel rods. This fuel bundle is divided into a number of imaginary interacting flow passage called subchannels. Single phase flow condition exists in reactor rod bundle during startup condition and up to certain length of rod bundle when it is operating at full power. Prediction of the thermal margin of the reactor during startup condition has necessitated the determination of the turbulent mixing rate of coolant amongst these subchannels. Thus, it is vital to evaluate turbulent mixing between subchannels of AHWR rod bundle. With the remarkable progress in the computer processing power, the computational fluid dynamics (CFD) methodology can be useful for investigating the thermal–hydraulic characteristics phenomena in the nuclear fuel assembly. The present report covers the results of simulation of pressure drop, velocity variation and turbulence intensity on single rod bundle with 54 rods in circular arrays. In this investigation, 54-rod assemblies are simulated with ANSYS Fluent 15 using steady simulations with an ANSYS Workbench meshing. The simulations have been carried out with water for Reynolds number 9861.83. The rod bundle has a mean flow area of 4853.0584 mm2 in the bare region with the hydraulic diameter of 8.105 mm. In present investigation, a benchmark k-ε model has been used as a turbulence model and the symmetry condition is set as boundary conditions. Simulation are carried out to determine the turbulent mixing rate in the simulated subchannels of the reactor. The size of rod and the pitch in the test has been same as that of actual rod bundle in the prototype. Water has been used as the working fluid and the turbulent mixing tests have been carried out at atmospheric condition without heat addition. The mean velocity in the subchannel has been varied from 0-1.2 m/s. The flow conditions are found to be closer to the actual reactor condition.

Keywords: AHWR, CFD, single-phase turbulent mixing rate, thermal–hydraulic

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7236 Psychological Functioning of Youth Experiencing Community and Collective Violence in Post-conflict Northern Ireland

Authors: Teresa Rushe, Nicole Devlin, Tara O Neill

Abstract:

In this study, we sought to examine associations between childhood experiences of community and collective violence and psychological functioning in young people who grew up in post-conflict Northern Ireland. We hypothesized that those who grew up with such experiences would demonstrate internalizing and externalizing difficulties in early adulthood and, furthermore, that these difficulties would be mediated by adverse childhood experiences occurring within the home environment. As part of the Northern Ireland Childhood Adversity Study, we recruited 213 young people aged 18-25 years (108 males) who grew up in the post-conflict society of Northern Ireland using purposive sampling. Participants completed a digital questionnaire to measure adverse childhood experiences as well as aspects of psychological functioning. We employed the Adverse Childhood Experience -International Questionnaire (ACE-IQ¬) adaptation of the original Adverse Childhood Experiences Questionnaire (ACE) as it additionally measured aspects of witnessing community violence (e.g., seeing someone being beaten/killed, fights) and experiences of collective violence (e.g., war, terrorism, police, or gangs’ battles exposure) during the first 18 years of life. 51% of our sample reported experiences of community and/or collective violence (N=108). Compared to young people with no such experiences (N=105), they also reported significantly more adverse experiences indicative of household dysfunction (e.g., family substance misuse, mental illness or domestic violence in the family, incarceration of a family member) but not more experiences of abuse or neglect. As expected, young people who grew up with the community and/or collective violence reported significantly higher anxiety and depression scores and were more likely to engage in acts of deliberate self-harm (internalizing symptoms). They also started drinking and taking drugs at a younger age and were significantly more likely to have been in trouble with the police (externalizing symptoms). When the type of violence exposure was separated by whether the violence was witnessed (community violence) or more directly experienced (collective violence), we found community and collective violence to have similar effects on externalizing symptoms, but for internalizing symptoms, we found evidence of a differential effect. Collective violence was associated with depressive symptoms, whereas witnessing community violence was associated with anxiety-type symptoms and deliberate self-harm. However, when experiences of household dysfunction were entered into the models predicting anxiety, depression, and deliberate self-harm, none of the main effects remained significant. This suggests internalizing type symptoms are mediated by immediate family-level experiences. By contrast, significant community and collective violence effects on externalizing behaviours: younger initiation of alcohol use, younger initiation of drug use, and getting into trouble with the police persisted after controlling for family-level factors and thus are directly associated with growing up with the community and collective violence. Given the cross-sectional nature of our study, we cannot comment on the direction of the effect. However, post-hoc correlational analyses revealed associations between externalising behaviours and personal factors, including greater risk-taking and young age at puberty. The implications of the findings will be discussed in relation to interventions for young people and families living with the community and collective violence.

Keywords: community and collective violence, adverse childhood experiences, youth, psychological wellbeing

Procedia PDF Downloads 78
7235 Optimization of Cutting Parameters on Delamination Using Taguchi Method during Drilling of GFRP Composites

Authors: Vimanyu Chadha, Ranganath M. Singari

Abstract:

Drilling composite materials is a frequently practiced machining process during assembling in various industries such as automotive and aerospace. However, drilling of glass fiber reinforced plastic (GFRP) composites is significantly affected by damage tendency of these materials under cutting forces such as thrust force and torque. The aim of this paper is to investigate the influence of the various cutting parameters such as cutting speed and feed rate; subsequently also to study the influence of number of layers on delamination produced while drilling a GFRP composite. A plan of experiments, based on Taguchi techniques, was instituted considering drilling with prefixed cutting parameters in a hand lay-up GFRP material. The damage induced associated with drilling GFRP composites were measured. Moreover, Analysis of Variance (ANOVA) was performed to obtain minimization of delamination influenced by drilling parameters and number layers. The optimum drilling factor combination was obtained by using the analysis of signal-to-noise ratio. The conclusion revealed that feed rate was the most influential factor on the delamination. The best results of the delamination were obtained with composites with a greater number of layers at lower cutting speeds and feed rates.

Keywords: analysis of variance, delamination, design optimization, drilling, glass fiber reinforced plastic composites, Taguchi method

Procedia PDF Downloads 251
7234 Assessment of Biofilm Production Capacity of Industrially Important Bacteria under Electroinductive Conditions

Authors: Omolola Ojetayo, Emmanuel Garuba, Obinna Ajunwa, Abiodun A. Onilude

Abstract:

Introduction: Biofilm is a functional community of microorganisms that are associated with a surface or an interface. These adherent cells become embedded within an extracellular matrix composed of polymeric substances, i.e., biofilms refer to biological deposits consisting of both microbes and their extracellular products on biotic and abiotic surfaces. Despite their detrimental effects in medicine, biofilms as natural cell immobilization have found several applications in biotechnology, such as in the treatment of wastewater, bioremediation and biodegradation, desulfurization of gas, and conversion of agro-derived materials into alcohols and organic acids. The means of enhancing immobilized cells have been chemical-inductive, and this affects the medium composition and final product. Physical factors including electrical, magnetic, and electromagnetic flux have shown potential for enhancing biofilms depending on the bacterial species, nature, and intensity of emitted signals, the duration of exposure, and substratum used. However, the concept of cell immobilisation by electrical and magnetic induction is still underexplored. Methods: To assess the effects of physical factors on biofilm formation, six American typed culture collection (Acetobacter aceti ATCC15973, Pseudomonas aeruginosa ATCC9027, Serratia marcescens ATCC14756, Gluconobacter oxydans ATCC19357, Rhodobacter sphaeroides ATCC17023, and Bacillus subtilis ATCC6633) were used. Standard culture techniques for bacterial cells were adopted. Natural autoimmobilisation potentials of test bacteria were carried out by simple biofilms ring formation on tubes, while crystal violet binding assay techniques were adopted in the characterisation of biofilm quantity. Electroinduction of bacterial cells by direct current (DC) application in cell broth, static magnetic field exposure, and electromagnetic flux were carried out, and autoimmobilisation of cells in a biofilm pattern was determined on various substrata tested, including wood, glass, steel, polyvinylchloride (PVC) and polyethylene terephthalate. Biot Savart law was used in quantifying magnetic field intensity, and statistical analyses of data obtained were carried out using the analyses of variance (ANOVA) as well as other statistical tools. Results: Biofilm formation by the selected test bacteria was enhanced by the physical factors applied. Electromagnetic induction had the greatest effect on biofilm formation, with magnetic induction producing the least effect across all substrata used. Microbial cell-cell communication could be a possible means via which physical signals affected the cells in a polarisable manner. Conclusion: The enhancement of biofilm formation by bacteria using physical factors has shown that their inherent capability as a cell immobilization method can be further optimised for industrial applications. A possible relationship between the presence of voltage-dependent channels, mechanosensitive channels, and bacterial biofilms could shed more light on this phenomenon.

Keywords: bacteria, biofilm, cell immobilization, electromagnetic induction, substrata

Procedia PDF Downloads 182
7233 Residual Modulus of Elasticity of Self-Compacting Concrete Incorporated Unprocessed Waste Fly Ash after Expose to the Elevated Temperature

Authors: Mohammed Abed, Rita Nemes, Salem Nehme

Abstract:

The present study experimentally investigated the impact of incorporating unprocessed waste fly ash (UWFA) on the residual mechanical properties of self-compacting concrete (SCC) after exposure to elevated temperature. Three mixtures of SCC have been produced by replacing the cement mass by 0%, 15% and 30% of UWFA. Generally, the fire resistance of SCC has been enhanced by replacing the cement up to 15% of UWFA, especially in case of residual modulus of elasticity which considers more sensitive than other mechanical properties at elevated temperature. However, a strong linear relationship has been observed between the residual flexural strength and modulus of elasticity, where both of them affected significantly by the cracks appearance and propagation as a result of elevated temperature. Sustainable products could be produced by incorporating unprocessed waste powder materials in the production of concrete, where the waste materials, CO2 emissions, and the energy needed for processing are reduced.

Keywords: self-compacting high-performance concrete, unprocessed waste fly ash, fire resistance, residual modulus of elasticity

Procedia PDF Downloads 129
7232 A Two-Pronged Truncated Deferred Sampling Plan for Log-Logistic Distribution

Authors: Braimah Joseph Odunayo, Jiju Gillariose

Abstract:

This paper is aimed at developing a sampling plan that uses information from precedent and successive lots for lot disposition with a pretention that the life-time of a particular product assumes a Log-logistic distribution. A Two-pronged Truncated Deferred Sampling Plan (TTDSP) for Log-logistic distribution is proposed when the testing is truncated at a precise time. The best possible sample sizes are obtained under a given Maximum Allowable Percent Defective (MAPD), Test Suspension Ratios (TSR), and acceptance numbers (c). A formula for calculating the operating characteristics of the proposed plan is also developed. The operating characteristics and mean-ratio values were used to measure the performance of the plan. The findings of the study show that: Log-logistic distribution has a decreasing failure rate; furthermore, as mean-life ratio increase, the failure rate reduces; the sample size increase as the acceptance number, test suspension ratios and maximum allowable percent defective increases. The study concludes that the minimum sample sizes were smaller, which makes the plan a more economical plan to adopt when cost and time of production are costly and the experiment being destructive.

Keywords: consumers risk, mean life, minimum sample size, operating characteristics, producers risk

Procedia PDF Downloads 132
7231 Prevalence of Work Related Musculoskeletal Symptoms among Surgeons

Authors: Nirav P. Vaghela

Abstract:

Work-related musculoskeletal symptoms (WMS) are a major health issue in many occupations all over the world. Past research on hospital workers have mainly been focused on nurses [8] and very few studies have examined musculoskeletal symptoms among doctors in various specialties. The work of surgeons can involve high levels of mental concentration and very precise movements that can be categorized as mild-to-moderate physical demands. Design: Forty-three surgeons were enrolled in this study. To investigate musculoskeletal disorder among the surgeons we had used Standardised Nordic Questionnaire, Quick Exposure Check (QEC) and Workstyle Short Form. Result: In the current study, total 43 surgeons participants out of 30 males and 13 females. Their mean age was 42.07 ± 12.35, and the mean working years of the group were 15.14years ±9.017. On the average, they worked a total of about 8.58 h (±1.967) per day. The prevalence of work related musculoskeletal symptoms among the surgeons indicating 83.70% surgeons had atleast one joint affected while 16.30% had no symptoms at all. Conclusion: The present survey study has shown high prevalence rates of neck, back and shoulder musculoskeletal symptoms in surgeons.

Keywords: repetitive stress injury, pain, occupational hazards, disability, abneetism, physical health, quality of life

Procedia PDF Downloads 221
7230 Synergistic Studies of Liposomes of Clove and Cinnamon Oil in Oral Health Care

Authors: Sandhya Parameswaran, Prajakta Dhuri

Abstract:

Despite great improvements in health care, the world oral health report states that dental problems still persist, particularly among underprivileged groups in both developing and developed countries. Dental caries and periodontal diseases are identified as the most important oral health problems globally. Acidic foods and beverages can affect natural teeth, and chronic exposure often leads to the development of dental erosion, abrasion, and decay. In recent years, there has been an increased interest toward essential oils. These are secondary metabolites and possess antibacterial, antifungal and antioxidant properties. Essential oils are volatile and chemically unstable in the presence of air, light, moisture and high temperature. Hence many novel methods like a liposomal encapsulation of oils have been introduced to enhance the stability and bioavailability. This research paper focuses on two essential oils, clove and cinnamon oil. Clove oil was obtained from Syzygium aromaticum Linn using clavengers apparatus. It contains eugenol and β caryophyllene. Cinnamon oil, from the barks of Cinnamomum cassia, contains cinnamaldehyde, The objective of the current research was to develop a liposomal carrier system containing clove and cinnamon oil and study their synergistic activity against dental pathogens when formulated as a gel. Methodology: The essential oil were first tested for their antimicrobial activity against dental pathogens, Lactobacillus acidophillus (MTCC No. 10307, MRS broth) and Streptococcus Mutans (MTCC No .890, Brain Heart Infusion agar). The oils were analysed by UV spectroscopy for eugenol and cinnamaldehyde content. Standard eugenol was linear between 5ppm to 25ppm at 282nm and standard cinnamaldehde from 1ppm to 5pmm at 284nm. The concentration of eugenol in clove oil was found to be 62.65 % w/w, and that of cinnamaldehyde was found to be 5.15%s w/w. The oils were then formulated into liposomes. Liposomes were prepared by thin film hydration method using Phospholipid, Cholesterol, and other oils dissolved in a chloroform methanol (3:1) mixture. The organic solvent was evaporated in a rotary evaporator above lipid transition temperature. The film was hydrated with phosphate buffer (pH 5.5).The various batches of liposomes were characterized and compared for their size, loading rate, encapsulation efficiency and morphology. The prepared liposomes when evaluated for entrapment efficiency showed 65% entrapment for clove and 85% for cinnamon oil. They were also tested for their antimicrobial activity against dental pathogens and their synergistic activity studied. Based on the activity and the entrapment efficiency the amount of liposomes required to prepare 1gm of the gel was calculated. The gel was prepared using a simple ointment base and contained 0.56% of cinnamon and clove liposomes. A simultaneous method of analysis for eugenol and cinnamaldehyde.was then developed using HPLC. The prepared gels were then studied for their stability as per ICH guidelines. Conclusion: It was found that liposomes exhibited spherical shaped vesicles and protected the essential oil from degradation. Liposomes, therefore, constitute a suitable system for encapsulation of volatile, unstable essential oil constituents.

Keywords: cinnamon oil, clove oil, dental caries, liposomes

Procedia PDF Downloads 188
7229 Factors Affecting English Language Acquisition and Learning for Primary Schools in Nigeria

Authors: Chibuzor Dalmeida

Abstract:

This paper shall discuss the factors affecting English Language Acquisition and Learning for Primary School in Nigeria. Learning English language is a difficult task mostly those at the primary school level. Pupils find it more difficult on vocabulary, grammar and sentence structure, idioms, pronunciation etc. Researchers have discovered the reasons behind these discrepancies and have formulated theories that could be of utmost assistance to English language teachers and students. This paper further looked at the following factors that include Learner Characteristics and Personal Traits, Situational and Environmental Factors, Prior Language Development and Competence and Age and Brain Development. It further recommended that pupils must learn new vocabulary, rules for grammar and sentence structure, idioms, pronunciation. Pupils whose families and communities set high standards for language acquisition learn more quickly than those who do not. Exposure to high-quality programs also essential. Pupils do best when they are allowed to speak their native language.

Keywords: acquisition, affecting, factors, learning

Procedia PDF Downloads 617