Search results for: raw earth material
757 Influence of Variable Calcium Content on Mechanical Properties of Geopolymer Synthesized at Different Temperature and Moisture Conditions
Authors: Suraj D. Khadka, Priyantha W. Jayawickrama
Abstract:
In search of a sustainable construction material, geopolymer has been investigated for past decades to evaluate its advantage over conventional products. Synthesis of geopolymer requires a source of aluminosilicate mixed with sodium hydroxide and sodium silicate at different proportions to maintain a Si/Al molar ratio of 1-3 and Na/Al molar ratio of unity. A comprehensive geopolymer study was performed with Metakaolin and Class C Fly ash as primary aluminosilicate sources. Synthesized geopolymer was analyzed for time-dependent viscosity, setting period and strength at varying initial moisture content, curing temperature and humidity. Different concentration of Ca(OH)₂ and CaSO₄.2H₂O were added to vary the amount of calcium contained in synthesized geopolymer. Influence of calcium content in unconfined compressive strength behavior of geopolymer were analyzed. Finally, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) was performed to investigate the hardened product. It was observed that fly ash based geopolymer had shortened setting time and faster increase in viscosity as compared to geopolymer synthesized from metakaolin. This was primarily attributed to higher calcium content resulting in formation of calcium silicate hydrates (CSH). SEM-EDS was performed to verify the presence of CSH phases. Spectral analysis of geopolymer prepared by addition of Ca(OH)₂ and CaSO₄.2H₂O indicated higher CSH phases at higher concentration. It was observed that lower concentration of added calcium favored strength gain in geopolymer. However, at higher calcium concentration, decrease in strength was observed. Strength variation was also observed with humidity at initial curing condition. At 100% humidity, geopolymer with added calcium presented higher strength compared to samples cured at ambient humidity condition (40%). Reduction in strength in these samples at lower humidity was primarily attributed to reduction in moisture content in specimen due to the formation of CSH phases and loss of moisture through evaporation. For low calcium content geopolymers, with increase in temperature, gain in strength was observed with maximum strength observed at 200 ˚C. However, samples with higher calcium content demonstrated severe cracking resulting in low strength at elevated temperatures.Keywords: calcium silicate hydrates, geopolymer, humidity, Scanning Electron Microscopy-Energy Dispersive Spectroscopy, unconfined compressive strength
Procedia PDF Downloads 127756 A Machine Learning Approach for Efficient Resource Management in Construction Projects
Authors: Soheila Sadeghi
Abstract:
Construction projects are complex and often subject to significant cost overruns due to the multifaceted nature of the activities involved. Accurate cost estimation is crucial for effective budget planning and resource allocation. Traditional methods for predicting overruns often rely on expert judgment or analysis of historical data, which can be time-consuming, subjective, and may fail to consider important factors. However, with the increasing availability of data from construction projects, machine learning techniques can be leveraged to improve the accuracy of overrun predictions. This study applied machine learning algorithms to enhance the prediction of cost overruns in a case study of a construction project. The methodology involved the development and evaluation of two machine learning models: Random Forest and Neural Networks. Random Forest can handle high-dimensional data, capture complex relationships, and provide feature importance estimates. Neural Networks, particularly Deep Neural Networks (DNNs), are capable of automatically learning and modeling complex, non-linear relationships between input features and the target variable. These models can adapt to new data, reduce human bias, and uncover hidden patterns in the dataset. The findings of this study demonstrate that both Random Forest and Neural Networks can significantly improve the accuracy of cost overrun predictions compared to traditional methods. The Random Forest model also identified key cost drivers and risk factors, such as changes in the scope of work and delays in material delivery, which can inform better project risk management. However, the study acknowledges several limitations. First, the findings are based on a single construction project, which may limit the generalizability of the results to other projects or contexts. Second, the dataset, although comprehensive, may not capture all relevant factors influencing cost overruns, such as external economic conditions or political factors. Third, the study focuses primarily on cost overruns, while schedule overruns are not explicitly addressed. Future research should explore the application of machine learning techniques to a broader range of projects, incorporate additional data sources, and investigate the prediction of both cost and schedule overruns simultaneously.Keywords: resource allocation, machine learning, optimization, data-driven decision-making, project management
Procedia PDF Downloads 39755 Implementation of Correlation-Based Data Analysis as a Preliminary Stage for the Prediction of Geometric Dimensions Using Machine Learning in the Forming of Car Seat Rails
Authors: Housein Deli, Loui Al-Shrouf, Hammoud Al Joumaa, Mohieddine Jelali
Abstract:
When forming metallic materials, fluctuations in material properties, process conditions, and wear lead to deviations in the component geometry. Several hundred features sometimes need to be measured, especially in the case of functional and safety-relevant components. These can only be measured offline due to the large number of features and the accuracy requirements. The risk of producing components outside the tolerances is minimized but not eliminated by the statistical evaluation of process capability and control measurements. The inspection intervals are based on the acceptable risk and are at the expense of productivity but remain reactive and, in some cases, considerably delayed. Due to the considerable progress made in the field of condition monitoring and measurement technology, permanently installed sensor systems in combination with machine learning and artificial intelligence, in particular, offer the potential to independently derive forecasts for component geometry and thus eliminate the risk of defective products - actively and preventively. The reliability of forecasts depends on the quality, completeness, and timeliness of the data. Measuring all geometric characteristics is neither sensible nor technically possible. This paper, therefore, uses the example of car seat rail production to discuss the necessary first step of feature selection and reduction by correlation analysis, as otherwise, it would not be possible to forecast components in real-time and inline. Four different car seat rails with an average of 130 features were selected and measured using a coordinate measuring machine (CMM). The run of such measuring programs alone takes up to 20 minutes. In practice, this results in the risk of faulty production of at least 2000 components that have to be sorted or scrapped if the measurement results are negative. Over a period of 2 months, all measurement data (> 200 measurements/ variant) was collected and evaluated using correlation analysis. As part of this study, the number of characteristics to be measured for all 6 car seat rail variants was reduced by over 80%. Specifically, direct correlations for almost 100 characteristics were proven for an average of 125 characteristics for 4 different products. A further 10 features correlate via indirect relationships so that the number of features required for a prediction could be reduced to less than 20. A correlation factor >0.8 was assumed for all correlations.Keywords: long-term SHM, condition monitoring, machine learning, correlation analysis, component prediction, wear prediction, regressions analysis
Procedia PDF Downloads 49754 The Impact of Hormone Suppressive Therapy on Quality of Life of Patients with Nodular Goiter
Authors: Emil Iskandarov, Nazrin Agayeva
Abstract:
Background: The effectiveness of hormone suppressive therapy (HST) in patients with nodular goiter (NG) is controversial. The aim of this study was to identify the impact of long-time HST on the Quality of Life (QoL) of patients with NG. Material and Methods: A retrospective analysis of 146 patients with NG showed treated with HST showed that in 38,4% of cases, HST was not effective. Nodules were increased in size and moreover, and new nodules were developed. Statistical procedure identified the predictors of resistant nodules: only one nodule in the left lobe; nodule size >17mm; calcinate within the nodule. 174 patients with NG, by whom predictors of resistant nodules were established, were informed about the results of previous research and surgery was suggested. Eighty-eight patients (the basic group) agreed with surgery and thyroidectomy was led. 86 patients (control group) ignored the suggestion and wished to receive HST. 3, 6 and 12 months after starting HST; control group patients were examined. HST was non-effective and patients, due to developing symptoms, were operated on. Patients in both groups were followed up 3, 6 and 12 months after thyroidectomy. Quality of Life was checked with the SF-36 survey form and compared between groups. The statistical analysis was performed with the non-parametric Mann–Whitney U test and with the Student t-test. P values <0.05 were considered statistically significant. Results and Discussions: QoL of patients in the basic and control groups 3 months after surgery was almost the same. However, Emotional problems severely interfered with patients in a control group with normal social activities with family, friends, and neighbors. The causes were related to the non-effective HST treatment before surgery: stress for forgetting to take drugs timely every day for a long time; blood tests for thyroid hormone level; needle biopsies of nodules for cancer screening and regular ultrasound investigations, which showed that nodules not diminished in size. Changing the treatment method after 1-year non-effective HST and delayed surgery negatively impacted patient's QoL. Social role functioning and mental health in the control group were also impaired and the difference between the results in the basic group was statistically significant (p <0.05). Conclusion: Predictors, such as only one nodule, the width of nodules more than 17mm, and the existence of calcinate within the nodule, are able to forecast the resistant nodules. HST in patients with resistant nodules is non-effective and surgery is suggested in patients with resistant nodules in the thyroid gland. Long time HST has a negative impact on the QoL patient after surgery.Keywords: thyroid gland, nodule, hormone suppressive therapy, quality of life
Procedia PDF Downloads 129753 Study of Chemical and Physical - Mechanical Properties Lime Mortar with Addition of Natural Resins
Authors: I. Poot-Ocejo, H. Silva-Poot, J. C. Cruz, A. Yeladaqui-Tello
Abstract:
Mexico has remarkable archaeological remains mainly in the Maya area, which are critical to the preservation of our cultural heritage, so the authorities have an interest in preserving and restoring these vestiges of the most original way, by employing techniques traditional, which has advantages such as compatibility, durability, strength, uniformity and chemical composition. Recent studies have confirmed the addition of natural resins extracted from the bark of trees, of which Brosium alicastrum (Ramon) has been the most evaluated, besides being one of the most abundant species in the vicinity of the archaeological sites, like that Manilkara Zapota (Chicozapote). Therefore, the objective is to determine if these resins are capable of being employed in archaeological restoration. This study shows the results of the chemical composition and physical-mechanical behavior of mortar mixtures eight made with commercial lime and off by hand, calcium sand, resins added with Brosium alicastrum (Ramon) and Manilkara zapota (Chicozapote), where determined and quantified properties and chemical composition of the resins by X-Ray Fluorescence (XRF), the pH of the material was determined, indicating that both resins are acidic (3.78 and 4.02), and the addition rate maximum was obtained from resins in water by means of ultrasonic baths pulses, being in the case of 10% Manilkara zapota, because it contains up to 40% rubber and for 40% alicastrum Brosium contain less rubber. Through quantitative methodology, the compressive strength 96 specimens of 5 cm x 5 cm x 5 cm of mortar binding, 72 with partial substitution of water mixed with natural resins in proportions 5 to 10% in the case was evaluated of Manilkara Zapota, for Brosium alicastrum 20 and 40%, and 12 artificial resin and 12 without additive (mortars witnesses). 24 specimens likewise glued brick with mortar, for testing shear adhesion was found where, then the microstructure more conducive additions was determined by SEM analysis were prepared sweep. The test results indicate that the addition Manilkara zapota resin in the proportion of 10% 1.5% increase in compressive strength and 1% with respect to adhesion, compared to the control without addition mortar; In the case of Brosium alicastrum results show that compressive strengths and adhesion were insignificant compared to those made with registered by Manilkara zapota mixtures. Mortars containing the natural resins have improvements in physical properties and increase the mechanical strength and adhesion, compared to those who do not, in addition to the components are chemically compatible, therefore have considered that can be employed in Archaeological restoration.Keywords: lime, mortar, natural resins, Manilkara zapota mixtures, Brosium alicastrum
Procedia PDF Downloads 371752 A Multi-Scale Study of Potential-Dependent Ammonia Synthesis on IrO₂ (110): DFT, 3D-RISM, and Microkinetic Modeling
Authors: Shih-Huang Pan, Tsuyoshi Miyazaki, Minoru Otani, Santhanamoorthi Nachimuthu, Jyh-Chiang Jiang
Abstract:
Ammonia (NH₃) is crucial in renewable energy and agriculture, yet its traditional production via the Haber-Bosch process faces challenges due to the inherent inertness of nitrogen (N₂) and the need for high temperatures and pressures. The electrocatalytic nitrogen reduction (ENRR) presents a more sustainable option, functioning at ambient conditions. However, its advancement is limited by selectivity and efficiency challenges due to the competing hydrogen evolution reaction (HER). The critical roles of protonation of N-species and HER highlight the necessity of selecting optimal catalysts and solvents to enhance ENRR performance. Notably, transition metal oxides, with their adjustable electronic states and excellent chemical and thermal stability, have shown promising ENRR characteristics. In this study, we use density functional theory (DFT) methods to investigate the ENRR mechanisms on IrO₂ (110), a material known for its tunable electronic properties and exceptional chemical and thermal stability. Employing the constant electrode potential (CEP) model, where the electrode - electrolyte interface is treated as a polarizable continuum with implicit solvation, and adjusting electron counts to equalize work functions in the grand canonical ensemble, we further incorporate the advanced 3D Reference Interaction Site Model (3D-RISM) to accurately determine the ENRR limiting potential across various solvents and pH conditions. Our findings reveal that the limiting potential for ENRR on IrO₂ (110) is significantly more favorable than for HER, highlighting the efficiency of the IrO₂ catalyst for converting N₂ to NH₃. This is supported by the optimal *NH₃ desorption energy on IrO₂, which enhances the overall reaction efficiency. Microkinetic simulations further predict a promising NH₃ production rate, even at the solution's boiling point¸ reinforcing the catalytic viability of IrO₂ (110). This comprehensive approach provides an atomic-level understanding of the electrode-electrolyte interface in ENRR, demonstrating the practical application of IrO₂ in electrochemical catalysis. The findings provide a foundation for developing more efficient and selective catalytic strategies, potentially revolutionizing industrial NH₃ production.Keywords: density functional theory, electrocatalyst, nitrogen reduction reaction, electrochemistry
Procedia PDF Downloads 21751 Chemical Composition of Volatiles Emitted from Ziziphus jujuba Miller Collected during Different Growth Stages
Authors: Rose Vanessa Bandeira Reidel, Bernardo Melai, Pier Luigi Cioni, Luisa Pistelli
Abstract:
Ziziphus jujuba Miller is a common species of the Ziziphus genus (Rhamnaceae family) native to the tropics and subtropics known for its edible fruits, fresh consumed or used in healthy food, as flavoring and sweetener. Many phytochemicals and biological activities are described for this species. In this work, the aroma profiles emitted in vivo by whole fresh organs (leaf, bud flower, flower, green and red fruits) were analyzed separately by mean of solid phase micro-extraction (SPME) coupled with gas chromatography mass spectrometry (GC-MS). The emitted volatiles from different plant parts were analysed using Supelco SPME device coated with polydimethylsiloxane (PDMS, 100µm). Fresh plant material was introduced separately into a glass conical flask and allowed to equilibrate for 20 min. After the equilibration time, the fibre was exposed to the headspace for 15 min at room temperature, the fibre was re-inserted into the needle and transferred to the injector of the CG and CG-MS system, where the fibre was desorbed. All the data were submitted to multivariate statistical analysis, evidencing many differences amongst the selected plant parts and their developmental stages. A total of 144 compounds were identified corresponding to 94.6-99.4% of the whole aroma profile of jujube samples. Sesquiterpene hydrocarbons were the main chemical class of compounds in leaves also present in similar percentage in flowers and bud flowers where (E, E)-α-farnesene was the main constituent in all cited plant parts. This behavior can be due to a protection mechanism against pathogens and herbivores as well as resistance to abiotic factors. The aroma of green fruits was characterized by high amount of perillene while the red fruits release a volatile blend mainly constituted by different monoterpenes. The terpenoid emission of flesh fruits has important function in the interaction with animals including attraction of seed dispersers and it is related to a good quality of fruits. This study provides for the first time the chemical composition of the volatile emission from different Ziziphus jujuba organs. The SPME analyses of the collected samples showed different patterns of emission and can contribute to understand their ecological interactions and fruit production management.Keywords: Rhamnaceae, aroma profile, jujube organs, HS-SPME, GC-MS
Procedia PDF Downloads 256750 Effect of Term of Preparation on Performance of Cool Chamber Stored White Poplar Hardwood Cuttings in Nursery
Authors: Branislav Kovačević, Andrej Pilipović, Zoran Novčić, Marina Milović, Lazar Kesić, Milan Drekić, Saša Pekeč, Leopold Poljaković Pajnik, Saša Orlović
Abstract:
Poplars present one of the most important tree species used for phytoremediation in the northern hemisphere. They can be used either as direct “cleaners” of the contaminated soils or as buffer zones preventing the contaminant plume to the surrounding environment. In order to produce appropriate planting material for this purpose, there is a long process of the breeding of the most favorable candidates. Although the development of the poplar propagation technology has been evolving for decades, white poplar nursery production, as well as the establishment of short-rotation coppice plantations, still considerably depends on the success of hardwood cuttings’ survival. This is why easy rooting is among the most desirable properties in white poplar breeding. On the other hand, there are many opportunities for the optimization of the technological procedures in order to meet the demands of particular genotype (clonal technology). In this study the effect of the term of hardwood cuttings’ preparation of four white poplar clones on their survival and further growth of rooted cuttings in nursery conditions were tested. There were three terms of cuttings’ preparation: the beginning of February (2nd Feb 2023), the beginning of March (3rd Mar 2023) and the end of March (21nd Mar 2023), which is regarded as the standard term. The cuttings were stored in cool chamber at 2±2°C. All cuttings were planted on the same date (11th Apr 2023), in soil prepared with rotary tillage, and then cultivated by usual nursey procedures. According to the results obtained after the bud set (29th Sept 2023) there were significant differences in the survival and growth of rooted cuttings between examined terms of cutting preparation. Also, there were significant differences in the reaction of examined clones on terms of cutting preparation. In total, the best results provided cuttings prepared at the first term (2nd Feb 2023) (survival rate of 39.4%), while performance after two later preparation terms was significantly poorer (20.5% after second and 16.5% after third term). These results stress the significance of dormancy preservation in cuttings of examined white poplar clones for their survival, which could be especially important in context of climate change. Differences in clones’ reaction to term of cutting preparation suggest necessity of adjustment of the technology to the needs of particular clone i.e. design of clone specific technology.Keywords: rooting, Populus alba, nursery, clonal technology
Procedia PDF Downloads 65749 Closed Mitral Valvotomy: A Safe and Promising Procedure
Authors: Sushil Kumar Singh, Kumar Rahul, Vivek Tewarson, Sarvesh Kumar, Shobhit Kumar
Abstract:
Objective: Rheumatic mitral stenosis continues to be a major public health problem in developing countries. When the left atrium (LA) is unable to fill the left ventricle (LV) at normal LA pressures due to impaired relaxation and impaired compliance, diastolic dysfunction occurs. The assessment of left ventricular (LV) diastolic function and filling pressures is of clinical importance to identify underlying cardiac disease, its treatment, and to assess prognosis. 2D echocardiography can detect diastolic dysfunction with excellent sensitivity and minimal risk when compared to the gold standard of invasive pressure-volume measurements. Material and Method: This was a one-year study consisting of twenty-nine patients of isolated rheumatic severe mitral stenosis. Data was analyzed preoperative and post operative (at one month follow-up). Transthoracic 2D echocardiographic parameters of the diastolic function are transmitral flow, pulmonary venous flow, mitral annular tissue doppler, and color M-mode doppler. In our study, mitral valve orifice area, ejection fraction, deceleration time, E/A-wave, E/E’-wave, myocardial performance index of left ventricle (Tei index ), and Mitral inflow propagation velocity were included for echocardiographic evaluation. The statistical analysis was performed on SPSS Version 15.0 statistical analysis software. Result: Twenty-nine patients underwent successful closed mitral commissurotomy for isolated mitral stenosis. The outcome measures were observed pre-operatively and at one-month follow-up. The majority of patients were in NYHA grade III (69.0%) in the preoperative period, which improved to NYHA grade I (48.3%) after closed mitral commissurotomy. Post-surgery mitral valve area increased from 0.77 ± 0.13 to 2.32 ± 0.26 cm, ejection fraction increased from 61.38 ± 4.61 to 64.79 ± 3.22. There was a decrease in deceleration time from 231.55 ± 49.31 to 168.28 ± 14.30 ms, E/A ratio from 1.70 ± 0.54 from 0.89 ± 0.39, E/E’ ratio from 14.59 ± 3.34 to 8.86 ± 3.03. In addition, there was improvement in TIE index from 0.50 ± 0.03 to 0.39 ± 0.06 and mitral inflow propagation velocity from 47.28 ± 3.71 to 57.86 ± 3.19 cm/sec. In peri-operative and follow-up, there was no incidence of severe mitral regurgitation (MR). There was no thromboembolic incident and no mortality.Keywords: closed mitral valvotomy, mitral stenosis, open mitral commissurotomy, balloon mitral valvotomy
Procedia PDF Downloads 85748 Stilbenes as Sustainable Antimicrobial Compounds to Control Vitis Vinifera Diseases
Authors: David Taillis, Oussama Becissa, Julien Gabaston, Jean-Michel Merillon, Tristan Richard, Stephanie Cluzet
Abstract:
Nowadays, there is a strong pressure to reduce the phytosanitary inputs of synthetic chemistry in vineyards. It is, therefore, necessary to find viable alternatives in order to protect the vine against its major diseases. For this purpose, we suggest the use of a plant extract enriched in antimicrobial compounds. Being produced from vine trunks and roots, which are co-products of wine production, the extract produced is part of a circular economy. The antimicrobial molecules present in this plant material are polyphenols and, more particularly, stilbenes, which are derived from a common base, the resveratrol unit, and that are well known vine phytoalexins. The stilbenoids were extracted from trunks and roots (30/70, w/w) by a double extraction with ethyl acetate followed by enrichment by liquid-liquid extraction. The produced extract was characterized by UHPLC-MS, then its antimicrobial activities were tested on Plasmopara viticola and Botrytis cinerea in the laboratory and/or in greenhouse and in vineyard. The major compounds were purified, and their antimicrobial activity was evaluated on B. cinerea. Moreover, after its spraying, the effect of the stilbene extract on the plant defence status was evaluated by analysis of defence gene expression. UHPLC-MS analysis revealed that the extract contains 50% stilbenes with resveratrol, ε-viniferin and r-viniferin as major compounds. The extract showed antimicrobial activities on P. viticola with IC₅₀ and IC₁₀₀ respectively of 90 and 300 mg/L in the laboratory. In addition, it inhibited 40% of downy mildew development in greenhouse. However, probably because of the sensitivity of stilbenes to the environment, such as UV degradation, no activity has been observed in vineyard towards P. viticola development. For B. cinerea, the extract IC50 was 123 mg/L, with resveratrol and ε-viniferin being the most active stilbenes (IC₅₀ of 88 and 142 mg/L, respectively). The analysis of the expression of defence genes revealed that the extract can induce the expression of some defence genes 24, 48, and 72 hours after treatment, meaning that the extract has a defence-stimulating effect at least for the first three days after treatment. In conclusion, we produced a plant extract enriched in stilbenes with antimicrobial properties against two major grapevine pathogenic agents P. viticola and B. cinerea. In addition, we showed that this extract displayed eliciting activity of plant defences. This extract can therefore represent, after formulation development, a viable eco-friendly alternative for vineyard protection. Subsequently, the effect of the stilbenoid extract on primary metabolism will be evaluated by quantitative NMR.Keywords: antimicrobial, bioprotection, grapevine, Plasmopara viticola, stilbene
Procedia PDF Downloads 218747 Synthesis of Temperature Sensitive Nano/Microgels by Soap-Free Emulsion Polymerization and Their Application in Hydrate Sediments Drilling Operations
Authors: Xuan Li, Weian Huang, Jinsheng Sun, Fuhao Zhao, Zhiyuan Wang, Jintang Wang
Abstract:
Natural gas hydrates (NGHs) as promising alternative energy sources have gained increasing attention. Hydrate-bearing formation in marine areas is highly unconsolidated formation and is fragile, which is composed of weakly cemented sand-clay and silty sediments. During the drilling process, the invasion of drilling fluid can easily lead to excessive water content in the formation. It will change the soil liquid plastic limit index, which significantly affects the formation quality, leading to wellbore instability due to the metastable character of hydrate-bearing sediments. Therefore, controlling the filtrate loss into the formation in the drilling process has to be highly regarded for protecting the stability of the wellbore. In this study, the temperature-sensitive nanogel of P(NIPAM-co-AMPS-co-tBA) was prepared by soap-free emulsion polymerization, and the temperature-sensitive behavior was employed to achieve self-adaptive plugging in hydrate sediments. First, the effects of additional amounts of AMPS, tBA, and cross-linker MBA on the microgel synthesis process and temperature-sensitive behaviors were investigated. Results showed that, as a reactive emulsifier, AMPS can not only participate in the polymerization reaction but also act as an emulsifier to stabilize micelles and enhance the stability of nanoparticles. The volume phase transition temperature (VPTT) of nanogels gradually decreased with the increase of the contents of hydrophobic monomer tBA. An increase in the content of the cross-linking agent MBA can lead to a rise in the coagulum content and instability of the emulsion. The plugging performance of nanogel was evaluated in a core sample with a pore size distribution range of 100-1000nm. The temperature-sensitive nanogel can effectively improve the microfiltration performance of drilling fluid. Since a combination of a series of nanogels could have a wide particle size distribution at any temperature, around 200nm to 800nm, the self-adaptive plugging capacity of nanogels for the hydrate sediments was revealed. Thermosensitive nanogel is a potential intelligent plugging material for drilling operations in natural gas hydrate-bearing sediments.Keywords: temperature-sensitive nanogel, NIPAM, self-adaptive plugging performance, drilling operations, hydrate-bearing sediments
Procedia PDF Downloads 171746 Comparative Study of Various Treatment Positioning Technique: A Site Specific Study-CA. Breast
Authors: Kamal Kaushik, Dandpani Epili, Ajay G. V., Ashutosh, S. Pradhaan
Abstract:
Introduction: Radiation therapy has come a long way over a period of decades, from 2-dimensional radiotherapy to intensity-modulated radiation therapy (IMRT) or VMAT. For advanced radiation therapy, we need better patient position reproducibility to deliver precise and quality treatment, which raises the need for better image guidance technologies for precise patient positioning. This study presents a two tattoo simulation with roll correction technique which is comparable to other advanced patient positioning techniques. Objective: This is a site-specific study is aimed to perform a comparison between various treatment positioning techniques used for the treatment of patients of Ca- Breast undergoing radiotherapy. In this study, we are comparing 5 different positioning methods used for the treatment of ca-breast, namely i) Vacloc with 3 tattoos, ii) Breast board with three tattoos, iii) Thermoplastic cast with three fiducials, iv) Breast board with a thermoplastic mask with 3 tattoo, v) Breast board with 2 tattoos – A roll correction method. Methods and material: All in one (AIO) solution immobilization was used in all patient positioning techniques for immobilization. The process of two tattoo simulations includes positioning of the patient with the help of a thoracic-abdomen wedge, armrest & knee rest. After proper patient positioning, we mark two tattoos on the treatment side of the patient. After positioning, place fiducials as per the clinical borders markers (1) sternum notch (lower border of clavicle head) (2) 2 cm below from contralateral breast (3) midline between 1 & 2 markers (4) mid axillary on the same axis of 3 markers (Marker 3 & 4 should be on the same axis). During plan implementation, a roll depth correction is applied as per the anterior and lateral positioning tattoos, followed by the shifts required for the Isocentre position. The shifts are then verified by SSD on the patient surface followed by radiographic verification using Cone Beam Computed Tomography (CBCT). Results: When all the five positioning techniques were compared all together, the produced shifts in Vertical, Longitudinal and lateral directions are as follows. The observations clearly suggest that the Longitudinal average shifts in two tattoo roll correction techniques are less than every other patient positioning technique. Vertical and lateral Shifts are also comparable to other modern positioning techniques. Concluded: The two tattoo simulation with roll correction technique provides us better patient setup with a technique that can be implemented easily in most of the radiotherapy centers across the developing nations where 3D verification techniques are not available along with delivery units as the shifts observed are quite minimal and are comparable to those with Vacloc and modern amenities.Keywords: Ca. breast, breast board, roll correction technique, CBCT
Procedia PDF Downloads 135745 Cellular Components of the Hemal Node of Egyptian Cattle
Authors: Amira E. Derbalah, Doaa M. Zaghloul
Abstract:
10 clinically healthy hemal nodes were collected from male bulls aged 2-3 years. Light microscopy revealed a capsule of connective tissue consisted mainly of collagen fiber surrounding hemal node, numerous erythrocytes were found in wide subcapsular sinus under the capsule. The parenchyma of the hemal node was divided into cortex and medulla. Diffused lymphocytes, and lymphoid follicles, having germinal centers were the main components of the cortex, while in the medulla there was wide medullary sinus, diffused lymphocytes and few lymphoid nodules. The area occupied with lymph nodules was larger than that occupied with non-nodular structure of lymphoid cords and blood sinusoids. Electron microscopy revealed the cellular components of hemal node including elements of circulating erythrocytes intermingled with lymphocytes, plasma cells, mast cells, reticular cells, macrophages, megakaryocytes and endothelial cells lining the blood sinuses. The lymphocytes were somewhat triangular in shape with cytoplasmic processes extending between adjacent erythrocytes. Nuclei were triangular to oval in shape, lightly stained with clear nuclear membrane indentation and clear nucleoli. The reticular cells were elongated in shape with cytoplasmic processes extending between adjacent lymphocytes, rough endoplasmic reticulum, ribosomes and few lysosomes were seen in their cytoplasm. Nucleus was elongated in shape with less condensed chromatin. Plasma cells were oval to irregular in shape with numerous dilated rough endoplasmic reticulum containing electron lucent material occupying the whole cytoplasm and few mitochondria were found. Nuclei were centrally located and oval in shape with heterochromatin emarginated and often clumped near the nuclear membrane. Occasionally megakaryocytes and mast cells were seen among lymphocytes. Megakaryocytes had multilobulated nucleus and free ribosomes often appearing as small aggregates in their cytoplasm, while mast cell had their characteristic electron dense granule in the cytoplasm, few electron lucent granules were found also, we conclude that, the main function of the hemal node of cattle is proliferation of lymphocytes. No role for plasma cell in erythrophagocytosis could be suggested.Keywords: cattle, electron microscopy, hemal node, histology, immune system
Procedia PDF Downloads 402744 Teaching Ethnic Relations in Social Work Education: A Study of Teachers' Strategies and Experiences in Sweden
Authors: Helene Jacobson Pettersson, Linda Lill
Abstract:
Demographic changes and globalization in society provide new opportunities for social work and social work education in Sweden. There has been an ambition to include these aspects into the Swedish social work education. However, the Swedish welfare state standard continued to be as affectionate as invisible starting point in discussions about people’s way of life and social problems. The aim of this study is to explore content given to ethnic relations in social work in the social work education in Sweden. Our standpoint is that the subject can be understood both from individual and structural levels, it changes over time, varies in different steering documents and differs from the perspectives of teachers and students. Our question is what content is given to ethnic relations in social work by the teachers in their strategies and teaching material. The study brings together research in the interface between education science, social work and research of international migration and ethnic relations. The presented narratives are from longer interviews with a total of 17 university teachers who teach in social work program at four different universities in Sweden. The universities have in different ways a curriculum that involves the theme of ethnic relations in social work, and the interviewed teachers are teaching and grading social workers on specific courses related to ethnic relations at undergraduate and graduate levels. Overall assesses these 17 teachers a large number of students during a semester. The questions were concerned on how the teachers handle ethnic relations in education in social work. The particular focus during the interviews has been the teacher's understanding of the documented learning objectives and content of literature and how this has implications for their teaching. What emerges is the teachers' own stories about the educational work and how they relate to the content of teaching, as well as the teaching strategies they use to promote the theme of ethnic relations in social work education. The analysis of this kind of pedagogy is that the teaching ends up at an individual level with a particular focus on the professional encounter with individuals. We can see the shortage of a critical analysis of the construction of social problems. The conclusion is that individual circumstance precedes theoretical perspective on social problems related to migration, transnational relations, globalization and social. This result has problematic implications from the perspective of sustainability in terms of ethnic diversity and integration in society. Thus these aspects have most relevance for social workers’ professional acting in social support and empowerment related activities, in supporting the social status and human rights and equality for immigrants.Keywords: ethnic relations in Swedish social work education, teaching content, teaching strategies, educating for change, human rights and equality
Procedia PDF Downloads 248743 The Quantitative Analysis of the Influence of the Superficial Abrasion on the Lifetime of the Frog Rail
Authors: Dong Jiang
Abstract:
Turnout is the essential equipment on the railway, which also belongs to one of the strongest demanded infrastructural facilities of railway on account of the more seriously frog rail failures. In cooperation with Germany Company (DB Systemtechnik AG), our research team focuses on the quantitative analysis about the frog rails to predict their lifetimes. Moreover, the suggestions for the timely and effective maintenances are made to improve the economy of the frog rails. The lifetime of the frog rail depends strongly on the internal damage of the running surface until the breakages occur. On the basis of Hertzian theory of the contact mechanics, the dynamic loads of the running surface are calculated in form of the contact pressures on the running surface and the equivalent tensile stress inside the running surface. According to material mechanics, the strength of the frog rail is determined quantitatively in form of the Stress-cycle (S-N) curve. Under the interaction between the dynamic loads and the strength, the internal damage of the running surface is calculated by means of the linear damage hypothesis of the Miner’s rule. The emergence of the first Breakage on the running surface is to be defined as the failure criterion that the damage degree equals 1.0. From the microscopic perspective, the running surface of the frog rail is divided into numerous segments for the detailed analysis. The internal damage of the segment grows slowly in the beginning and disproportionately quickly in the end until the emergence of the breakage. From the macroscopic perspective, the internal damage of the running surface develops simply always linear along the lifetime. With this linear growth of the internal damages, the lifetime of the frog rail could be predicted simply through the immediate introduction of the slope of the linearity. However, the superficial abrasion plays an essential role in the results of the internal damages from the both perspectives. The influences of the superficial abrasion on the lifetime are described in form of the abrasion rate. It has two contradictory effects. On the one hand, the insufficient abrasion rate causes the concentration of the damage accumulation on the same position below the running surface to accelerate the rail failure. On the other hand, the excessive abrasion rate advances the disappearance of the head hardened surface of the frog rail to result in the untimely breakage on the surface. Thus, the relationship between the abrasion rate and the lifetime is subdivided into an initial phase of the increased lifetime and a subsequent phase of the more rapid decreasing lifetime with the continuous growth of the abrasion rate. Through the compensation of these two effects, the critical abrasion rate is discussed to reach the optimal lifetime.Keywords: breakage, critical abrasion rate, frog rail, internal damage, optimal lifetime
Procedia PDF Downloads 225742 Digital Image Correlation: Metrological Characterization in Mechanical Analysis
Authors: D. Signore, M. Ferraiuolo, P. Caramuta, O. Petrella, C. Toscano
Abstract:
The Digital Image Correlation (DIC) is a newly developed optical technique that is spreading in all engineering sectors because it allows the non-destructive estimation of the entire surface deformation without any contact with the component under analysis. These characteristics make the DIC very appealing in all the cases the global deformation state is to be known without using strain gages, which are the most used measuring device. The DIC is applicable to any material subjected to distortion caused by either thermal or mechanical load, allowing to obtain high-definition mapping of displacements and deformations. That is why in the civil and the transportation industry, DIC is very useful for studying the behavior of metallic materials as well as of composite materials. DIC is also used in the medical field for the characterization of the local strain field of the vascular tissues surface subjected to uniaxial tensile loading. DIC can be carried out in the two dimension mode (2D DIC) if a single camera is used or in a three dimension mode (3D DIC) if two cameras are involved. Each point of the test surface framed by the cameras can be associated with a specific pixel of the image, and the coordinates of each point are calculated knowing the relative distance between the two cameras together with their orientation. In both arrangements, when a component is subjected to a load, several images related to different deformation states can be are acquired through the cameras. A specific software analyzes the images via the mutual correlation between the reference image (obtained without any applied load) and those acquired during the deformation giving the relative displacements. In this paper, a metrological characterization of the digital image correlation is performed on aluminum and composite targets both in static and dynamic loading conditions by comparison between DIC and strain gauges measures. In the static test, interesting results have been obtained thanks to an excellent agreement between the two measuring techniques. In addition, the deformation detected by the DIC is compliant with the result of a FEM simulation. In the dynamic test, the DIC was able to follow with a good accuracy the periodic deformation of the specimen giving results coherent with the ones given by FEM simulation. In both situations, it was seen that the DIC measurement accuracy depends on several parameters such as the optical focusing, the parameters chosen to perform the mutual correlation between the images and, finally, the reference points on image to be analyzed. In the future, the influence of these parameters will be studied, and a method to increase the accuracy of the measurements will be developed in accordance with the requirements of the industries especially of the aerospace one.Keywords: accuracy, deformation, image correlation, mechanical analysis
Procedia PDF Downloads 311741 Teaching Material, Books, Publications versus the Practice: Myths and Truths about Installation and Use of Downhole Safety Valve
Authors: Robson da Cunha Santos, Caio Cezar R. Bonifacio, Diego Mureb Quesada, Gerson Gomes Cunha
Abstract:
The paper is related to the safety of oil wells and environmental preservation on the planet, because they require great attention and commitment from oil companies and people who work with these equipments. This must occur from drilling the well until it is abandoned in order to safeguard the environment and prevent possible damage. The project had as main objective the constitution resulting from comparatives made among books, articles and publications with information gathered in technical visits to operational bases of Petrobras. After the visits, the information from methods of utilization and present managements, which were not available before, became available to the general audience. As a result, it is observed a huge flux of incorrect and out-of-date information that comprehends not only bibliographic archives, but also academic resources and materials. During the gathering of more in-depth information on the manufacturing, assembling, and use aspects of DHSVs, several issues that were previously known as correct, customary issues were discovered to be uncertain and outdated. Information of great importance resulted in affirmations about subjects as the depth of the valve installation that was before installed to 30 meters from the seabed (mud line). Despite this, the installation should vary in conformity to the ideal depth to escape from area with the biggest tendency to hydrates formation according to the temperature and pressure. Regarding to valves with nitrogen chamber, in accordance with books, they have their utilization linked to water line ≥ 700 meters, but in Brazilian exploratory fields, their use occurs from 600 meters of water line. The valves used in Brazilian fields are able to be inserted to the production column and self-equalizing, but the use of screwed valve in the column of production and equalizing is predominant. Although these valves are more expensive to acquire, they are more reliable, efficient, with a bigger shelf life and they do not cause restriction to the fluid flux. It follows that based on researches and theoretical information confronted to usual forms used in fields, the present project is important and relevant. This project will be used as source of actualization and information equalization that connects academic environment and real situations in exploratory situations and also taking into consideration the enrichment of precise and easy to understand information to future researches and academic upgrading.Keywords: down hole safety valve, security devices, installation, oil-wells
Procedia PDF Downloads 271740 Dogs Chest Homogeneous Phantom for Image Optimization
Authors: Maris Eugênia Dela Rosa, Ana Luiza Menegatti Pavan, Marcela De Oliveira, Diana Rodrigues De Pina, Luis Carlos Vulcano
Abstract:
In medical veterinary as well as in human medicine, radiological study is essential for a safe diagnosis in clinical practice. Thus, the quality of radiographic image is crucial. In last year’s there has been an increasing substitution of image acquisition screen-film systems for computed radiology equipment (CR) without technical charts adequacy. Furthermore, to carry out a radiographic examination in veterinary patient is required human assistance for restraint this, which can compromise image quality by generating dose increasing to the animal, for Occupationally Exposed and also the increased cost to the institution. The image optimization procedure and construction of radiographic techniques are performed with the use of homogeneous phantoms. In this study, we sought to develop a homogeneous phantom of canine chest to be applied to the optimization of these images for the CR system. In carrying out the simulator was created a database with retrospectives chest images of computed tomography (CT) of the Veterinary Hospital of the Faculty of Veterinary Medicine and Animal Science - UNESP (FMVZ / Botucatu). Images were divided into four groups according to the animal weight employing classification by sizes proposed by Hoskins & Goldston. The thickness of biological tissues were quantified in a 80 animals, separated in groups of 20 animals according to their weights: (S) Small - equal to or less than 9.0 kg, (M) Medium - between 9.0 and 23.0 kg, (L) Large – between 23.1 and 40.0kg and (G) Giant – over 40.1 kg. Mean weight for group (S) was 6.5±2.0 kg, (M) 15.0±5.0 kg, (L) 32.0±5.5 kg and (G) 50.0 ±12.0 kg. An algorithm was developed in Matlab in order to classify and quantify biological tissues present in CT images and convert them in simulator materials. To classify tissues presents, the membership functions were created from the retrospective CT scans according to the type of tissue (adipose, muscle, bone trabecular or cortical and lung tissue). After conversion of the biologic tissue thickness in equivalent material thicknesses (acrylic simulating soft tissues, bone tissues simulated by aluminum and air to the lung) were obtained four different homogeneous phantoms, with (S) 5 cm of acrylic, 0,14 cm of aluminum and 1,8 cm of air; (M) 8,7 cm of acrylic, 0,2 cm of aluminum and 2,4 cm of air; (L) 10,6 cm of acrylic, 0,27 cm of aluminum and 3,1 cm of air and (G) 14,8 cm of acrylic, 0,33 cm of aluminum and 3,8 cm of air. The developed canine homogeneous phantom is a practical tool, which will be employed in future, works to optimize veterinary X-ray procedures.Keywords: radiation protection, phantom, veterinary radiology, computed radiography
Procedia PDF Downloads 417739 Photocatalytic Disintegration of Naphthalene and Naphthalene Similar Compounds in Indoors Air
Authors: Tobias Schnabel
Abstract:
Naphthalene and naphthalene similar compounds are a common problem in the indoor air of buildings from the 1960s and 1970s in Germany. Often tar containing roof felt was used under the concrete floor to prevent humidity to come through the floor. This tar containing roof felt has high concentrations of PAH (Polycyclic aromatic hydrocarbon) and naphthalene. Naphthalene easily evaporates and contaminates the indoor air. Especially after renovations and energetically modernization of the buildings, the naphthalene concentration rises because no forced air exchange can happen. Because of this problem, it is often necessary to change the floors after renovation of the buildings. The MFPA Weimar (Material research and testing facility) developed in cooperation a project with LEJ GmbH and Reichmann Gebäudetechnik GmbH. It is a technical solution for the disintegration of naphthalene in naphthalene, similar compounds in indoor air with photocatalytic reforming. Photocatalytic systems produce active oxygen species (hydroxyl radicals) through trading semiconductors on a wavelength of their bandgap. The light energy separates the charges in the semiconductor and produces free electrons in the line tape and defect electrons. The defect electrons can react with hydroxide ions to hydroxyl radicals. The produced hydroxyl radicals are a strong oxidation agent, and can oxidate organic matter to carbon dioxide and water. During the research, new titanium oxide catalysator surface coatings were developed. This coating technology allows the production of very porous titan oxide layer on temperature stable carrier materials. The porosity allows the naphthalene to get easily absorbed by the surface coating, what accelerates the reaction of the heterogeneous photocatalysis. The photocatalytic reaction is induced by high power and high efficient UV-A (ultra violet light) Leds with a wavelength of 365nm. Various tests in emission chambers and on the reformer itself show that a reduction of naphthalene in important concentrations between 2 and 250 µg/m³ is possible. The disintegration rate was at least 80%. To reduce the concentration of naphthalene from 30 µg/m³ to a level below 5 µg/m³ in a usual 50 ² classroom, an energy of 6 kWh is needed. The benefits of the photocatalytic indoor air treatment are that every organic compound in the air can be disintegrated and reduced. The use of new photocatalytic materials in combination with highly efficient UV leds make a safe and energy efficient reduction of organic compounds in indoor air possible. At the moment the air cleaning systems take the step from prototype stage into the usage in real buildings.Keywords: naphthalene, titandioxide, indoor air, photocatalysis
Procedia PDF Downloads 143738 A Green Process for Drop-In Liquid Fuels from Carbon Dioxide, Water, and Solar Energy
Authors: Jian Yu
Abstract:
Carbo dioxide (CO2) from fossil fuel combustion is a prime green-house gas emission. It can be mitigated by microalgae through conventional photosynthesis. The algal oil is a feedstock of biodiesel, a carbon neutral liquid fuel for transportation. The conventional CO2 fixation, however, is quite slow and affected by the intermittent solar irradiation. It is also a technical challenge to reform the bio-oil into a drop-in liquid fuel that can be directly used in the modern combustion engines with expected performance. Here, an artificial photosynthesis system is presented to produce a biopolyester and liquid fuels from CO2, water, and solar power. In this green process, solar energy is captured using photovoltaic modules and converted into hydrogen as a stable energy source via water electrolysis. The solar hydrogen is then used to fix CO2 by Cupriavidus necator, a hydrogen-oxidizing bacterium. Under the autotrophic conditions, CO2 was reduced to glyceraldehyde-3-phosphate (G3P) that is further utilized for cell growth and biosynthesis of polyhydroxybutyrate (PHB). The maximum cell growth rate reached 10.1 g L-1 day-1, about 25 times faster than that of a typical bio-oil-producing microalga (Neochloris Oleoabundans) under stable indoor conditions. With nitrogen nutrient limitation, a large portion of the reduced carbon is stored in PHB (C4H6O2)n, accounting for 50-60% of dry cell mass. PHB is a biodegradable thermoplastic that can find a variety of environmentally friendly applications. It is also a platform material from which small chemicals can be derived. At a high temperature (240 - 290 oC), the biopolyester is degraded into crotonic acid (C4H6O2). On a solid phosphoric acid catalyst, PHB is deoxygenated via decarboxylation into a hydrocarbon oil (C6-C18) at 240 oC or so. Aromatics and alkenes are the major compounds, depending on the reaction conditions. A gasoline-grade liquid fuel (77 wt% oil) and a biodiesel-grade fuel (23 wt% oil) were obtained from the hydrocarbon oil via distillation. The formation routes of hydrocarbon oil from crotonic acid, the major PHB degradation intermediate, are revealed and discussed. This work shows a novel green process from which biodegradable plastics and high-grade liquid fuels can be directly produced from carbon dioxide, water and solar power. The productivity of the green polyester (5.3 g L-1 d-1) is much higher than that of microalgal oil (0.13 g L-1 d-1). Other technical merits of the new green process may include continuous operation under intermittent solar irradiation and convenient scale up in outdoor.Keywords: bioplastics, carbon dioxide fixation, drop-in liquid fuels, green process
Procedia PDF Downloads 189737 The Significance of Childhood in Shaping Family Microsystems from the Perspective of Biographical Learning: Narratives of Adults
Authors: Kornelia Kordiak
Abstract:
The research is based on a biographical approach and serves as a foundation for understanding individual human destinies through the analysis of the context of life experiences. It focuses on the significance of childhood in shaping family micro-worlds from the perspective of biographical learning. In this case, the family micro-world is interpreted as a complex of beliefs and judgments about elements of the ‘total universe’ based on the individual's experiences. The main aim of the research is to understand the importance of childhood in shaping family micro-worlds from the perspective of reflection on biographical learning. Additionally, it contributes to a deeper understanding of the familial experiences of the studied individuals who form these family micro-worlds and the course of the biographical learning process in the subjects. Biographical research aligns with an interpretative paradigm, where individuals are treated as active interpreters of the world, giving meaning to their experiences and actions based on their own values and beliefs. The research methods used in the project—narrative interview method and analysis of personal documents—enable obtaining a multidimensional perspective on the phenomenon under study. Narrative interviews serve as the main data collection method, allowing researchers to delve into various life contexts of individuals. Analysis of these narratives identifies key moments and life patterns, as well as discovers the significance of childhood in shaping family micro-worlds. Moreover, analysis of personal documents such as diaries or photographs enriches the understanding of the studied phenomena by providing additional contexts and perspectives. The research will be conducted in three phases: preparatory, main, and final. The anticipated schedule includes preparation of research tools, selection of research sample, conducting narrative interviews and analysis of personal documents, as well as analysis and interpretation of collected research material. The narrative interview method and document analysis will be utilized to capture various contexts and interpretations of childhood experiences and family relations. The research will contribute to a better understanding of family dynamics and individual developmental processes. It will allow for the identification and understanding of mechanisms of biographical learning and their significance in shaping identity and family relations. Analysis of adult narratives will enable the identification of factors determining patterns of behavior and attitudes in adult life, which may have significant implications for pedagogical practice.Keywords: childhood, adulthood, biographical learning, narrative interview, analysis of personal documents, family micro-worlds
Procedia PDF Downloads 28736 On Grammatical Metaphors: A Corpus-Based Reflection on the Academic Texts Written in the Field of Environmental Management
Authors: Masoomeh Estaji, Ahdie Tahamtani
Abstract:
Considering the necessity of conducting research and publishing academic papers during Master’s and Ph.D. programs, graduate students are in dire need of improving their writing skills through either writing courses or self-study planning. One key feature that could aid academic papers to look more sophisticated is the application of grammatical metaphors (GMs). These types of metaphors represent the ‘non-congruent’ and ‘implicit’ ways of decoding meaning through which one grammatical category is replaced by another, more implied counterpart, which can alter the readers’ understanding of the text as well. Although a number of studies have been conducted on the application of GMs across various disciplines, almost none has been devoted to the field of environmental management, and the scope of the previous studies has been relatively limited compared to the present work. In the current study, attempts were made to analyze different types of GMs used in academic papers published in top-tiered journals in the field of environmental management, and make a list of the most frequently used GMs based on their functions in this particular discipline to make the teaching of academic writing courses more explicit and the composition of academic texts more well-structured. To fulfill these purposes, a corpus-based analysis based on the two theoretical models of Martin et al. (1997) and Liardet (2014) was run. Through two stages of manual analysis and concordancers, ten recent academic articles entailing 132490 words published in two prestigious journals were precisely scrutinized. The results yielded that through the whole IMRaD sections of the articles, among all types of ideational GMs, material processes were the most frequent types. The second and the third ranks would apply to the relational and mental categories, respectively. Regarding the use of interpersonal GMs, objective expanding metaphors were the highest in number. In contrast, subjective interpersonal metaphors, either expanding or contracting, were the least significant. This would suggest that scholars in the field of Environmental Management tended to shift the focus on the main procedures and explain technical phenomenon in detail, rather than to compare and contrast other statements and subjective beliefs. Moreover, since no instances of verbal ideational metaphors were detected, it could be deduced that the act of ‘saying or articulating’ something might be against the standards of the academic genre. One other assumption would be that the application of ideational GMs is context-embedded and that the more technical they are, the least frequent they become. For further studies, it is suggested that the employment of GMs to be studied in a wider scope and other disciplines, and the third type of GMs known as ‘textual’ metaphors to be included as well.Keywords: English for specific purposes, grammatical metaphor, academic texts, corpus-based analysis
Procedia PDF Downloads 167735 A Development of Science Instructional Model Based on Stem Education Approach to Enhance Scientific Mind and Problem Solving Skills for Primary Students
Authors: Prasita Sooksamran, Wareerat Kaewurai
Abstract:
STEM is an integrated teaching approach promoted by the Ministry of Education in Thailand. STEM Education is an integrated approach to teaching Science, Technology, Engineering, and Mathematics. It has been questioned by Thai teachers on the grounds of how to integrate STEM into the classroom. Therefore, the main objective of this study is to develop a science instructional model based on the STEM approach to enhance scientific mind and problem-solving skills for primary students. This study is participatory action research, and follows the following steps: 1) develop a model 2) seek the advice of experts regarding the teaching model. Developing the instructional model began with the collection and synthesis of information from relevant documents, related research and other sources in order to create prototype instructional model. 2) The examination of the validity and relevance of instructional model by a panel of nine experts. The findings were as follows: 1. The developed instructional model comprised of principles, objective, content, operational procedures and learning evaluation. There were 4 principles: 1) Learning based on the natural curiosity of primary school level children leading to knowledge inquiry, understanding and knowledge construction, 2) Learning based on the interrelation between people and environment, 3) Learning that is based on concrete learning experiences, exploration and the seeking of knowledge, 4) Learning based on the self-construction of knowledge, creativity, innovation and 5) relating their findings to real life and the solving of real-life problems. The objective of this construction model is to enhance scientific mind and problem-solving skills. Children will be evaluated according to their achievements. Lesson content is based on science as a core subject which is integrated with technology and mathematics at grade 6 level according to The Basic Education Core Curriculum 2008 guidelines. The operational procedures consisted of 6 steps: 1) Curiosity 2) Collection of data 3) Collaborative planning 4) Creativity and Innovation 5) Criticism and 6) Communication and Service. The learning evaluation is an authentic assessment based on continuous evaluation of all the material taught. 2. The experts agreed that the Science Instructional Model based on the STEM Education Approach had an excellent level of validity and relevance (4.67 S.D. 0.50).Keywords: instructional model, STEM education, scientific mind, problem solving
Procedia PDF Downloads 192734 Palaeo-Environmental Reconstruction of the Wet Zone of Sri Lanka: A Zooarchaeological Perspective
Authors: Kalangi Rodrigo
Abstract:
Sri Lanka has been known as an island which has a diverse variety of prehistoric occupation among ecological zones. Defining the paleoecology of the past societies has been an archaeological thought developed in the 1960s. It is mainly concerned with the reconstruction from available geological and biological evidence of past biota, populations, communities, landscapes, environments, and ecosystems. Sri Lanka has dealt with this subject, and considerable research has been already undertaken. The fossil and material record of Sri Lanka’s Wet Zone tropical forests continues from c. 38,000–34,000 ybp. This early and persistent human fossil, technical, and cultural florescence, as well as a collection of well-preserved tropical-forest rock shelters with associated 'on-site' palaeoenvironmental records, makes Sri Lanka a central and unusual case study to determine the extent and strength of early human tropical forest encounters. Excavations carried out in prehistoric caves in the low country wet zone has shown that in the last 50,000 years, the temperature in the lowland rainforests has not exceeded 5°C. When taking Batadombalena alone, the entire seven layers have yielded an uninterrupted occupation of Acavus sp and Canerium zeylanicum, a plant that grows in the middle of the rainforest. Acavus, which is highly sensitive to rainforest ecosystems, has been well documented in many of the lowland caves, confirming that the wetland rainforest environment has remained intact at least for the last 50,000 years. If the dry and arid conditions in the upper hills regions affected the wet zone, the Tufted Gray Lunger (semnopithecus priam), must also meet with the prehistoric caves in the wet zone thrown over dry climate. However, the bones in the low country wet zone do not find any of the fragments belonging to Turfed Gray Lunger, and prehistoric human consumption is bestowed with purple-faced leaf monkey (Trachypithecus vetulus) and Toque Macaque (Macaca Sinica). The skeletal remains of Lyriocephalus scutatus, a full-time resident in rain forests, have also been recorded among lowland caves. But, in zoological terms, these remains may be the remains of the Barking deer (Muntiacus muntjak), which is currently found in the wet zone. For further investigations, the mtDNA test of genetic diversity (Bottleneck effect) and pollen study from lowland caves should determine whether the wet zone climate has persisted over the last 50,000 years, or whether the dry weather affected in the mountainous region has invaded the wet zone.Keywords: paleoecology, prehistory, zooarchaeology, reconstruction, palaeo-climate
Procedia PDF Downloads 140733 Comparative Study on Fire Safety Evaluation Methods for External Cladding Systems: ISO 13785-2 and BS 8414
Authors: Kyungsuk Cho, H. Y. Kim, S. U. Chae, J. H. Choi
Abstract:
Technological development has led to the construction of super-tall buildings and insulators are increasingly used as exterior finishing materials to save energy. However, insulators are usually combustible and vulnerable to fire. Fires like that at Wooshin Golden Suite Building in Busan, Korea in 2010 and that at CCTV Building in Beijing, China are the major examples of fire spread accelerated by combustible insulators. The exterior finishing materials of a high-rise building are not made of insulators only, but they are integrated with the building’s external cladding system. There is a limit in evaluating the fire safety of a cladding system with a single small-unit material such as a cone calorimeter. Therefore, countries provide codes to evaluate the fire safety of exterior finishing materials using full-scale tests. This study comparesKeywords: external cladding systems, fire safety evaluation, ISO 13785-2, BS 8414
Procedia PDF Downloads 242732 Single Cell Oil of Oleaginous Fungi from Lebanese Habitats as a Potential Feed Stock for Biodiesel
Authors: M. El-haj, Z. Olama, H. Holail
Abstract:
Single cell oils (SCOs) accumulated by oleaginous fungi have emerged as a potential alternative feedstock for biodiesel production. Five fungal strains were isolated from the Lebanese environment namely Fusarium oxysporum, Mucor hiemalis, Penicillium citrinum, Aspergillus tamari, and Aspergillus niger that have been selected among 39 oleaginous strains for their potential ability to accumulate lipids (lipid content was more than 40% on dry weight basis). Wide variations were recorded in the environmental factors that lead to maximum lipid production by fungi under test and were cultivated under submerged fermentation on medium containing glucose as a carbon source. The maximum lipid production was attained within 6-8 days, at pH range 6-7, 24 to 48 hours age of seed culture, 4 to 6.107 spores/ml inoculum level and 100 ml culture volume. Eleven culture conditions were examined for their significance on lipid production using Plackett-Burman factorial design. Reducing sugars and nitrogen source were the most significant factors affecting lipid production process. Maximum lipid yield was noticed with 15.62, 14.48, 12.75, 13.68 and 20.41g/l for Fusarium oxysporum, Mucor hiemalis, Penicillium citrinum, Aspergillus tamari, and Aspergillus niger respectively. A verification experiment was carried out to examine model validation and revealed more than 94% validity. The profile of extracted lipids from each fungal isolate was studied using thin layer chromatography (TLC) indicating the presence of monoacylglycerols, diaacylglycerols, free fatty acids, triacylglycerols and sterol esters. The fatty acids profiles were also determined by gas-chromatography coupled with flame ionization detector (GC-FID). Data revealed the presence of significant amount of oleic acid (29-36%), palmitic acid (18-24%), linoleic acid (26.8-35%), and low amount of other fatty acids in the extracted fungal oils which indicate that the fatty acid profiles were quite similar to that of conventional vegetable oil. The cost of lipid production could be further reduced with acid-pretreated lignocellulotic corncob waste, whey and date molasses to be utilized as the raw material for the oleaginous fungi. The results showed that the microbial lipid from the studied fungi was a potential alternative resource for biodiesel production.Keywords: agro-industrial waste products, biodiesel, fatty acid, single cell oil, Lebanese environment, oleaginous fungi
Procedia PDF Downloads 411731 Into the Dreamweaver’s World of the Mandaya and the Tboli: From Folklore to the Woven Fabric
Authors: Genevieve Jorolan Quintero
Abstract:
In Mindanao, the southern island of the Philippines, two provinces, Davao Oriental and Tboli of South Cotabato, respectively, are homes to indigenous communities known for their dream weavers. Davao Oriental is home to the Mandaya, while Lake Sebu is home to the Tboli. The dream weavers are mostly women who have continued the tradition of weaving, a spiritual practice of handicraft embodying the beliefs of the community. It is believed that a weaver is guided by the Tagamaling, or the nature spirit in Mandaya mythology, and Fu Dalu, or the spirit of the abaca among the Tboli. In the dream, the Tagamaling or Fu Dalu reveals to the weaver the design or the pattern of the dagmay as the abaca woven cloth is called among the Mandaya and the tnalak among the Tboli. The weaver then undertakes the production of this nature-spirit-inspired fabric based on her memory of the dream. This interaction between the spirit world and the human world inspired the theme of the short story with the title Loom of Dreams, published in 2015 by Kritika Kultura, an international peer-reviewed journal of language and literary/cultural studies of the Ateneo de Manila University in the Philippines. In Lake Sebu, a collection of the legendary tnalak with various designs is preserved by the cultural advocate and tnalak collector Reden S. Ulo. About a hundred tnalak designs are housed in a mini museum. The paper discusses how the dagmay and the tnalak of the two Philippine indigenous communities, the Mandaya and the Tboli, embody their folklore and cultural heritage. The specific objectives are: 1. To describe the role of the dreamweavers among the Mandaya and Tboli communities in the Philippines; 2. To analyse how folklore influences the designs on the woven fabric, the dagmay, and the tnalak, and 3. To discuss how dream-weaving helps preserve culture legacy. Ethnography was used in the conduct of this research. Specifically, the following data collection methods were done: 1. a series of visits to the Mandaya and Tboli communities; 2. face-to-face interviews with the respondents from the communities, and 3. the recording of the interviews with the knowledge-bearers and material culture keepers from both communities, the narratives of which were used as a basis for the data analysis. The influence of folklore in the culture and the arts of the indigenous communities is significantly evident in the designs of the dagmay and the tnalak. As the dream weavers continue to weave the dagmay and the tnalak, this cultural legacy will continue to prosper and be preserved for posterity.Keywords: dreamweaver's, Mandaya, mindanao, Philippine folklore, Tboli
Procedia PDF Downloads 100730 Students' ExperiEnce Enhancement Through Simulaton. A Process Flow in Logistics and Transportation Field
Authors: Nizamuddin Zainuddin, Adam Mohd Saifudin, Ahmad Yusni Bahaudin, Mohd Hanizan Zalazilah, Roslan Jamaluddin
Abstract:
Students’ enhanced experience through simulation is a crucial factor that brings reality to the classroom. The enhanced experience is all about developing, enriching and applications of a generic process flow in the field of logistics and transportations. As educational technology has improved, the effective use of simulations has greatly increased to the point where simulations should be considered a valuable, mainstream pedagogical tool. Additionally, in this era of ongoing (some say never-ending) assessment, simulations offer a rich resource for objective measurement and comparisons. Simulation is not just another in the long line of passing fads (or short-term opportunities) in educational technology. It is rather a real key to helping our students understand the world. It is a way for students to acquire experience about how things and systems in the world behave and react, without actually touching them. In short, it is about interactive pretending. Simulation is all about representing the real world which includes grasping the complex issues and solving intricate problems. Therefore, it is crucial before stimulate the real process of inbound and outbound logistics and transportation a generic process flow shall be developed. The paper will be focusing on the validization of the process flow by looking at the inputs gains from the sample. The sampling of the study focuses on multi-national and local manufacturing companies, third party companies (3PL) and government agency, which are selected in Peninsular Malaysia. A simulation flow chart was proposed in the study that will be the generic flow in logistics and transportation. A qualitative approach was mainly conducted to gather data in the study. It was found out from the study that the systems used in the process of outbound and inbound are System Application Products (SAP) and Material Requirement Planning (MRP). Furthermore there were some companies using Enterprises Resources Planning (ERP) and Electronic Data Interchange (EDI) as part of the Suppliers Own Inventories (SOI) networking as a result of globalized business between one countries to another. Computerized documentations and transactions were all mandatory requirement by the Royal Custom and Excise Department. The generic process flow will be the basis of developing a simulation program that shall be used in the classroom with the objective of further enhanced the students’ learning experience. Thus it will contributes to the body of knowledge on the enrichment of the student’s employability and also shall be one of the way to train new workers in the logistics and transportation filed.Keywords: enhancement, simulation, process flow, logistics, transportation
Procedia PDF Downloads 329729 Histological Grade Concordance between Core Needle Biopsy and Corresponding Surgical Specimen in Breast Carcinoma
Authors: J. Szpor, K. Witczak, M. Storman, A. Orchel, D. Hodorowicz-Zaniewska, K. Okoń, A. Klimkowska
Abstract:
Core needle biopsy (CNB) is well established as an important diagnostic tool in diagnosing breast cancer and it is now considered the initial method of choice for diagnosing breast disease. In comparison to fine needle aspiration (FNA), CNB provides more architectural information allowing for the evaluation of prognostic and predictive factors for breast cancer, including histological grade—one of three prognostic factors used to calculate the Nottingham Prognostic Index. Several studies have previously described the concordance rate between CNB and surgical excision specimen in determination of histological grade (HG). The concordance rate previously ascribed to overall grade varies widely across literature, ranging from 59-91%. The aim of this study is to see how the data looks like in material at authors’ institution and are the results as compared to those described in previous literature. The study population included 157 women with a breast tumor who underwent a core needle biopsy for breast carcinoma and a subsequent surgical excision of the tumor. Both materials were evaluated for the determination of histological grade (scale from 1 to 3). HG was assessed only in core needle biopsies containing at least 10 well preserved HPF with invasive tumor. The degree of concordance between CNB and surgical excision specimen for the determination of tumor grade was assessed by Cohen’s kappa coefficient. The level of agreement between core needle biopsy and surgical resection specimen for overall histologic grading was 73% (113 of 155 cases). CNB correctly predicted the grade of the surgical excision specimen in 21 cases for grade 1 tumors (Kappa coefficient κ = 0.525 95% CI (0.3634; 0.6818), 52 cases for grade 2 (Kappa coefficient κ = 0.5652 95% CI (0.458; 0.667) and 40 cases for stage 3 tumors (Kappa coefficient κ = 0.6154 95% CI (0.4862; 0.7309). The highest level of agreement was observed in grade 3 malignancies. In 9 of 42 (21%) discordant cases, the grade was higher in the CNB than in the surgical excision. This composed 6% of the overall discordance. These results correspond to the noted in the literature, showing that underestimation occurs more frequently than overestimation. This study shows that authors’ institution’s histologic grading of CNBs and surgical excisions shows a fairly good correlation and is consistent with findings in previous reports. Despite the inevitable limitations of CNB, CNB is an effective method for diagnosing breast cancer and managing treatment options. Assessment of tumour grade by CNB is useful for the planning of treatment, so in authors’ opinion it is worthy to implement it in daily practice.Keywords: breast cancer, concordance, core needle biopsy, histological grade
Procedia PDF Downloads 229728 Rheological Study of Chitosan/Montmorillonite Nanocomposites: The Effect of Chemical Crosslinking
Authors: K. Khouzami, J. Brassinne, C. Branca, E. Van Ruymbeke, B. Nysten, G. D’Angelo
Abstract:
The development of hybrid organic-inorganic nanocomposites has recently attracted great interest. Typically, polymer silicates represent an emerging class of polymeric nanocomposites that offer superior material properties compared to each compound alone. Among these materials, complexes based on silicate clay and polysaccharides are one of the most promising nanocomposites. The strong electrostatic interaction between chitosan and montmorillonite can induce what is called physical hydrogel, where the coordination bonds or physical crosslinks may associate and dissociate reversibly and in a short time. These mechanisms could be the main origin of the uniqueness of their rheological behavior. However, owing to their structure intrinsically heterogeneous and/or the lack of dissipated energy, they are usually brittle, possess a poor toughness and may not have sufficient mechanical strength. Consequently, the properties of these nanocomposites cannot respond to some requirements of many applications in several fields. To address the issue of weak mechanical properties, covalent chemical crosslink bonds can be introduced to the physical hydrogel. In this way, quite homogeneous dually crosslinked microstructures with high dissipated energy and enhanced mechanical strength can be engineered. In this work, we have prepared a series of chitosan-montmorillonite nanocomposites chemically crosslinked by addition of poly (ethylene glycol) diglycidyl ether. This study aims to provide a better understanding of the mechanical behavior of dually crosslinked chitosan-based nanocomposites by relating it to their microstructures. In these systems, the variety of microstructures is obtained by modifying the number of cross-links. Subsequently, a superior uniqueness of the rheological properties of chemically crosslinked chitosan-montmorillonite nanocomposites is achieved, especially at the highest percentage of clay. Their rheological behaviors depend on the clay/chitosan ratio and the crosslinking. All specimens exhibit a viscous rheological behavior over the frequency range investigated. The flow curves of the nanocomposites show a Newtonian plateau at very low shear rates accompanied by a quite complicated nonlinear decrease with increasing the shear rate. Crosslinking induces a shear thinning behavior revealing the formation of network-like structures. Fitting shear viscosity curves via Ostward-De Waele equation disclosed that crosslinking and clay addition strongly affect the pseudoplasticity of the nanocomposites for shear rates γ ̇>20.Keywords: chitosan, crossliking, nanocomposites, rheological properties
Procedia PDF Downloads 147