Search results for: thermal response parameter (TRP)

Authors: Fatima Z. Cherhabil, Mammar Sedrati, Sonia-Sabrina Bendib‎

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In order to support the continued growth, critical latency of ‎IoT ‎applications, and ‎various obstacles of traditional data centers, ‎mobile edge ‎computing (MEC) has ‎emerged as a promising solution that extends cloud data-processing and decision-making to edge devices. ‎By adopting a MEC structure, IoT applications could be executed ‎locally, on ‎an edge server, different fog nodes, or distant cloud ‎data centers. However, we are ‎often ‎faced with wanting to optimize conflicting criteria such as ‎minimizing energy ‎consumption of limited local capabilities (in terms of CPU, RAM, storage, bandwidth) of mobile edge ‎devices and trying to ‎keep ‎high performance (reducing ‎response time, increasing throughput and service availability) ‎at the same ‎time‎. Achieving one goal may affect the other, making task offloading (TO), ‎resource allocation (RA), and service placement (SP) complex ‎processes. ‎It is a nontrivial multi-objective optimization ‎problem ‎to study the trade-off between conflicting criteria. ‎The paper provides a survey on different TO, SP, and RA recent multi-‎objective optimization (MOO) approaches used in edge computing environments, particularly artificial intelligent (AI) ones, to satisfy various objectives, constraints, and dynamic conditions related to IoT applications‎.

Keywords: mobile edge computing, multi-objective optimization, artificial ‎intelligence ‎approaches, task offloading, resource allocation, ‎ service placement

Procedia PDF Downloads 94

Authors: L. Cesari, L. Canabady-Rochelle, F. Mutelet

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The thermal conversion of lignin produces bio-oils that contain many compounds with high added-value such as phenolic compounds. In order to efficiently extract these compounds, the possible use of choline bis(trifluoromethylsulfonyl)imide [Choline][NTf2] ionic liquid was explored. To this end, a multistep approach was implemented. First, binary (phenolic compound and solvent) and ternary (phenolic compound and solvent and ionic liquid) solutions were investigated. Eight binary systems of phenolic compound and water were investigated at atmospheric pressure. These systems were quantified using the turbidity method and UV-spectroscopy. Ternary systems (phenolic compound and water and [Choline][NTf2]) were investigated at room temperature and atmospheric pressure. After stirring, the solutions were let to settle down, and a sample of each phase was collected. The analysis of the phases was performed using gas chromatography with an internal standard. These results were used to quantify the values of the interaction parameters of thermodynamic models. Then, extractions were performed on synthetic solutions to determine the influence of several operating conditions (temperature, kinetics, amount of [Choline][NTf2]). With this knowledge, it has been possible to design and simulate an extraction process composed of one extraction column and one flash. Finally, the extraction efficiency of [Choline][NTf2] was quantified with real bio-oils from lignin pyrolysis. Qualitative and quantitative analysis were performed using gas chromatographic connected to mass spectroscopy and flame ionization detector. The experimental measurements show that the extraction of phenolic compounds is efficient at room temperature, quick and does not require a high amount of [Choline][NTf2]. Moreover, the simulations of the extraction process demonstrate that [Choline][NTf2] process requires less energy than an organic one. Finally, the efficiency of [Choline][NTf2] was confirmed in real situations with the experiments on lignin pyrolysis bio-oils.

Keywords: bio-oils, extraction, lignin, phenolic compounds

Procedia PDF Downloads 95

Authors: Sachin Pawar, Suman Patra, Goutam Mukhopadhyay

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The primary function of a shaft is to transfer power. The shaft can be cast or forged and then machined to the final shape. Manufacturing of ~5 m length and 0.6 m diameter shaft is very critical. More difficult is to maintain its straightness during heat treatment and machining operations, which involve thermal and mechanical loads, respectively. During the machining operation of a such forged mandrel shaft, a deflection of 3-4mm was observed. To remove this deflection shaft was pressed at both ends which led to the development of cracks in it. To investigate the root cause of the deflection and cracking, the sample was cut from the failed shaft. Possible causes were identified with the help of a cause and effect diagram. Chemical composition analysis, microstructural analysis, and hardness measurement were done to confirm whether the shaft meets the required specifications or not. Chemical composition analysis confirmed that the material grade was 42CrMo4. Microstructural analysis revealed the presence of untempered martensite, indicating improper heat treatment. Due to this, ductility and impact toughness values were considerably lower than the specification of the mentioned grade. Residual stress measurement of one more bent shaft manufactured by a similar route was done by portable X-ray diffraction(XRD) technique. For better understanding, measurements were done at twelve different locations along the length of the shaft. The occurrence of a high amount of undesirable tensile residual stresses close to the Ultimate Tensile Strength(UTS) of the material was observed. Untempered martensitic structure, lower ductility, lower impact strength, and presence of a high amount of residual stresses all confirmed the improper tempering heat treatment of the shaft. Tempering relieves the residual stresses. Based on the findings of this study, stress-relieving heat treatment was done to remove the residual stresses and deflection in the shaft successfully.

Keywords: residual stress, mandrel shaft, untempered martensite, portable XRD

Procedia PDF Downloads 100

Authors: Zainab M. Almutairi, Amjad Alharbi

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The use of engineered nanomaterials has increased as a result of their positive impact on many sectors of the economy, including agriculture. Silver nanoparticles (AgNPs) are now used to enhance seed germination, plant growth, and photosynthetic quantum efficiency and as antimicrobial agents to control plant diseases. In this study, we examined the effect of AgNP dosage on the seed germination of three plant species: corn (Zea mays L.), watermelon (Citrullus lanatus [Thunb.] Matsum. & Nakai) and zucchini (Cucurbita pepo L.). This experiment was designed to study the effect of AgNPs on germination percentage, germination rate, mean germination time, root length and fresh and dry weight of seedlings for the three species. Seven concentrations (0.05, 0.1, 0.5, 1, 1.5, 2, and 2.5 mg/ml) of AgNPs were examined at the seed germination stage. The three species had different dose responses to AgNPs in terms of germination parameters and the measured growth characteristics. The germination rates of the three plants were enhanced in response to AgNPs. Significant enhancement of the germination percentage values was observed after treatment of the watermelon and zucchini plants with AgNPs in comparison with untreated seeds. AgNPs showed a toxic effect on corn root elongation, whereas watermelon and zucchini seedling growth were positively affected by certain concentrations of AgNPs. This study showed that exposure to AgNPs caused both positive and negative effects on plant growth and germination.

Keywords: citrullus lanatus, cucurbita pepo, seed germination, seedling growth, silver nanoparticles, zea mays

Procedia PDF Downloads 288

Authors: Rohini Das, Subhasish Das, Smruti Rekha Sahoo, Shagupta Yesmin

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The Paleoproterozoic Kolhan Group (Purana) ensemble constitutes the youngest lithostratigraphic 'outlier' in the Singhbhum Archaean craton. The Kolhan unconformably overlies both the Singhbhum granite and the Iron Ore Group (IOG). Representing a typical sandstone-shale ( +/- carbonates) sequence, the Kolhan is characterized by the development of thin and discontinuous patches of basal conglomerates draped by sandstone beds. The IOG-fault limits the western 'distal' margin of the Kolhan basin showing evidence of passive subsidence subsequent to the initial rifting stage. The basin evolved as a half-graben under the influence of an extensional stress regime. The assumption of a tectonic setting for the NE-SW trending Kolhan basin possibly relates to the basin opening to the E-W extensional stress system that prevailed during the development of the Newer Dolerite dyke. The Paleoproterozoic age of the Kolhan basin is based on the consideration of the conformable stress pattern responsible both for the basin opening and the development of the conjugate fracture system along which the Newer Dolerite dykes intruded the Singhbhum Archaean craton. The Kolhan sandstones show progressive change towards greater textural and mineralogical maturity in its upbuilding. The trend of variations in different mineralogical and textural attributes, however, exhibits inflections at different lithological levels. Petrological studies collectively indicate that the sandstones were dominantly derived from a weathered granitic crust under a humid climatic condition. Provenance-derived variations in sandstone compositions are therefore a key in unraveling regional tectonic histories. The basin axis controlled the progradation direction which was likely driven by climatically induced sediment influx, a eustatic fall, or both. In the case of the incongruent shift, increased sediment supply permitted the rivers to cross the basinal deep. Temporal association of the Kolhan with tectonic structures in the belt indicates that syn-tectonic thrust uplift, not isostatic uplift or climate, caused the influx of quartz. The sedimentation pattern in the Kolhan reflects a change from braided fluvial-ephemeral pattern to a fan-delta-lacustrine type. The channel geometries and the climate exerted a major control on the processes of sediment transfer. Repeated fault controlled uplift of the source followed by subsidence and forced regression, generated multiple sediment cyclicity that led to the fluvial-fan delta sedimentation pattern. Intermittent uplift of the faulted blocks exposed fresh bedrock to mechanical weathering that generated a large amount of detritus and resulted to forced regressions, repeatedly disrupting the cycles which may reflect a stratigraphic response of connected rift basins at the early stage of extension. The marked variations in the thickness of the fan delta succession and the stacking pattern in different measured profiles reflect the overriding tectonic controls on fan delta evolution. The accumulated fault displacement created higher accommodation and thicker delta sequences. Intermittent uplift of fault blocks exposed fresh bedrock to mechanical weathering, generated a large amount of detritus, and resulted in forced closure of the land-locked basin, repeatedly disrupting the fining upward pattern. The control of source rock lithology or climate was of secondary importance to tectonic effects. Such a retrograding fan delta could be a stratigraphic response of connected rift basins at the early stage of extension.

Keywords: Kolhan basin, petrology, sandstone, tectonics

Procedia PDF Downloads 486

Authors: Ziba R. Tehrani, Sanaz Moayer

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In the age of the knowledge-based economy, knowledge management has become a key factor in sustainable competitive advantage. Knowledge management is discovering, acquiring, developing, sharing, maintaining, evaluating, and using right knowledge in right time by right person in organization; which is accomplished by creating a right link between human resources, information technology, and appropriate structure, to achieve organisational goals. Studying knowledge management financial institutes shows the knowledge management in banking system is not different from other industries but because of complexity of bank’s environment, the implementation is more difficult. The bank managers found out that implementation of knowledge management will bring many advantages to financial institutes, one of the most important of which is reduction of threat to lose subsequent information of personnel job quit. Also Special attention to internal conditions and environment of the financial institutes and avoidance from copy-making in designing the knowledge management is a critical issue. In this paper, it is tried first to define knowledge management concept and introduce existing models of knowledge management; then some of the most important models which have more similarities with other models will be reviewed. In second step according to bank requirements with focus on knowledge management approach, most major objectives of knowledge management are identified. For gathering data in this stage face to face interview is used. Thirdly these specified objectives are analysed with the response of distribution of questionnaire which is gained through managers and expert staffs of ‘Karafarin Bank’. Finally based on analysed data, some features of exiting models are selected and a new conceptual model will be proposed.

Keywords: knowledge management, financial institute, knowledge management model, organisational knowledge

Procedia PDF Downloads 345

Authors: Magdalena Wilk-Kozubek, Jakub Pawłów, Maciej Czajkowski, Maria Zdończyk, Katarzyna Ślepokura, Joanna Cybińska

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Thermochromic materials belong to the family of intelligent materials that change their color in response to temperature changes; this ability is called thermochromism. Thermochromic behavior can be displayed by both isolated compounds and multicomponent mixtures. Fluoran leuco dye-based mixtures are well-known thermochromic systems used, for example, in heat-sensitive FAX paper. Weak acids often serve as color developers for such systems. As the temperature increases, the acids melt, and the mixtures become colored. The objective of this research is to determine the influence of acids showing a liquid crystalline nematic phase on the development of the fluoran dye. For this purpose, fluoran-based mixtures with 4-n-alkylbenzoic acids were prepared. The mixtures are colored at room temperature, but they become colorless upon the melting of the acids. The melting of acids is associated not only with a change in the color of the mixtures but also with a change in their emission color. Phase transitions were investigated by temperature-dependent powder X-ray diffraction and differential scanning calorimetry; nematic phases were visualized by polarized optical microscopy, and color and emission changes were studied by UV-Vis diffuse reflectance and photoluminescence spectroscopies, respectively. When 4-n-alkylbenzoic acids are used as color developers, the fluoran-based mixtures become colorless after the melting of the acids. This is because the melting of acids is accompanied by the transition from the crystalline phase to the nematic phase, in which the molecular arrangement of the acids does not allow the fluoran dye to be developed.

Keywords: color developer, leuco dye, liquid crystal, thermochromism

Procedia PDF Downloads 84

Authors: Nükhet Konuk, N. Gamze Turan, Yüksel Ardalı

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Solid waste management is the most environmental problem in Turkey as a result of the rapid increase in solid waste generation caused by the rapid population growth, urbanization, rapid industrialization and economic development. The large quantity of waste generated necessitates system of collection, transportation and disposal. The landfill method for the ultimate disposal of solid waste continues to be widely accepted and used due to its economic advantages. In Turkey, most of the disposal sites open dump areas. Open dump sites may result in serious urban, sanitary and environmental problems such as an unpleasant odor and the risk of explosion as well as groundwater contamination because of leachate percolation. Unsuitable management practices also result in the loss of resources and energy, which could be recycled and produced from a large part of the solid waste. Therefore, over the past few decades, particular attention has been drawn to the sustainable solid waste management as a response to the increase in environmental problems related to the disposal of waste. The objective of this paper is to assess the situation of landfilling practices in Turkey as a developing country and to identify any gaps in the system as currently applied. The results show that approximately 25 million tons of MSW are generated annually in Turkey. The percentage of MSW disposed to sanitary landfill is only 45% whereas more than 50% of MSW is disposed without any control.

Keywords: developing countries, open dumping, solid waste management, sustainable landfilling, sustainable solid waste management

Procedia PDF Downloads 285

Authors: Dineshsingh Thakur, S. Nagesh, J. Basha

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A lightweight High Speed Flexible Coupling (HSFC) is used to connect the Engine Gear Box (EGB) with an Accessory Gear Box (AGB) of the combat aircraft. The HSFC transmits the power at high speeds ranging from 10000 to 18000 rpm from the EGB to AGB. The HSFC is also accommodates larger misalignments resulting from thermal expansion of the aircraft engine and mounting arrangement. The HSFC has the series of metallic contoured annular thin cross-sectioned flexible plates to accommodate the misalignments. The flexible plates are accommodating the misalignment by the elastic material flexure. As the HSFC operates at higher speed, the flexural and axial resonance frequencies are to be kept away from the operating speed and proper prediction is required to prevent failure in the transmission line of a single engine fighter aircraft. To study the influence of flexible plate’s contour on the lateral critical speed (LCS) of HSFC, a mathematical model of HSFC as a elven rotor system is developed. The flexible plate being the bending member of the system, its bending stiffness which results from the contoured governs the LCS. Using transfer matrix method, Influence of various flexible plate contours on critical speed is analyzed. In the above analysis, the support bearing flexibility on critical speed prediction is also considered. Based on the study, a model is built with the optimum contour of flexible plate, for validation by experimental modal analysis. A good correlation between the theoretical prediction and model behavior is observed. From the study, it is found that the flexible plate’s contour is playing vital role in modification of system’s dynamic behavior and the present model can be extended for the development of similar type of flexible couplings for its computational simplicity and reliability.

Keywords: flexible rotor, critical speed, experimental modal analysis, high speed flexible coupling (HSFC), misalignment

Procedia PDF Downloads 199

Authors: H. Solomon, A. Abdul-Latif, R. Baleh, I. Deiab, K. Khanafer

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Aluminum foams were developed and tested due to their high energy absorption abilities for multifunctional applications. The aim of this research work was to investigate experimentally the effect of quasi-static biaxial loading complexity (combined compression-torsion) on the energy absorption capacity of highly uniform architecture open-cell aluminum foam manufactured by kelvin cell model. The two generated aluminum foams have 80% and 85% porosities, spherical-shaped pores having 11mm in diameter. These foams were tested by means of several square-section specimens. A patented rig called ACTP (Absorption par Compression-Torsion Plastique), was used to investigate the foam response under quasi-static complex loading paths having different torsional components (i.e., 0°, 37° and 53°). The main mechanical responses of the aluminum foams were studied under simple, intermediate and severe loading conditions. In fact, the key responses to be examined were stress plateau and energy absorption capacity of the two foams with respect to loading complexity. It was concluded that the higher the loading complexity and the higher the relative density, the greater the energy absorption capacity of the foam. The highest energy absorption was thus recorded under the most complicated loading path (i.e., biaxial-53°) for the denser foam (i.e., 80% porosity).

Keywords: open-cell aluminum foams, biaxial loading complexity, foams porosity, energy absorption capacity, characterization

Procedia PDF Downloads 104

Authors: Mario Alejandro Grisales, M. Daniela Chimá, Gilberto Bejarano Gaitán

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High entropy alloys (HEA) and nitride (HEN) are currently very attractive to the automotive, aerospace, metalworking and materials forming manufacturing industry, among others, for exhibiting higher mechanical properties, wear resistance, and thermal stability than binary and ternary alloys. In this work medium-entropy coatings of TiTaZrNb and the nitrides of (TiTaZrNb)Nx were synthesized on to AISI 420 and M2 steel samples by the direct current magnetron sputtering technique. The influence of the bias voltage supplied to the substrate on the microstructure, chemical- and phase composition of the matrix coating was evaluated, and the effect of nitrogen flow on the microstructural, mechanical and tribological properties of the corresponding nitrides was studied. A change in the crystalline structure from BCC for TiTaZrNb coatings to FCC for (TiTaZrNb)Nx was observed, that is associated with the incorporation of nitrogen into the matrix and the consequent formation of a solid solution of (TiTaZrNb)Nx. An increase in hardness and residual stresses was observed with increasing bias voltage for TiTaZrNb, reaching 12.8 GPa for the coating deposited with a bias of -130V. In the case of (TiTaZrNb)Nx nitride, a greater hardness of 23 GPa is achieved for the coating deposited with a N2 flow of 12 sccm, which slightly drops to 21.7 GPa for that deposited with N2 flow of 15 sccm. The slight reduction in hardness could be associated with the precipitation of the TiN and ZrN phases that are formed at higher nitrogen flows. The specific wear rate of the deposited coatings ranged between 0.5xexp13 and 0.6xexp13 N/m2. The steel substrate exhibited an average hardness of 2.0 GPa and a specific wear rate of 203.2exp13 N/m2. Both the hardness and the specific wear rate of the synthesized nitride coatings were higher than that of the steel substrate, showing a protective effect of the steel against wear.

Keywords: medium entropy coatings, hard coatings, magnetron sputtering, tribology, wear resistance

Procedia PDF Downloads 56

Authors: Wanwisa Deenin, Abdulhadee Yakoh, Chahya Kreangkaiwal, Orawon Chailapakul, Kanitha Patarakul, Sudkate Chaiyo

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LipL32 is an outer membrane protein present only on pathogenic Leptospira species, which are the causative agent of leptospirosis. Leptospirosis symptoms are often misdiagnosed with other febrile illnesses as the clinical manifestations are non-specific. Therefore, an accurate diagnostic tool for leptospirosis is indeed critical for proper and prompt treatment. Typical diagnosis via serological assays is generally performed to assess the antibodies produced against Leptospira. However, their delayed antibody response and complicated procedure are undoubtedly limited the practical utilization especially in primary care setting. Here, we demonstrate for the first time an early-stage detection of LipL32 by an integrated lateral-flow immunoassay with electrochemical readout (eLFIA). A ferrocene trace tag was monitored via differential pulse voltammetry operated on a smartphone-based device, thus allowing for on-field testing. Superior performance in terms of the lowest detectable limit of detection (LOD) of 8.53 pg/mL and broad linear dynamic range (5 orders of magnitude) among other sensors available thus far was established. Additionally, the developed test strip provided a straightforward yet sensitive approach for diagnosis of leptospirosis using the collected human sera from patients, in which the results were comparable to the real-time polymerase chain reaction technique.

Keywords: leptospirosis, electrochemical detection, lateral flow immunosensor, point-of-care testing, early-stage detection

Procedia PDF Downloads 76

Authors: Merouane Salhi, Mohamed Roudane, Abdelkader Kirad

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In this work, we present a new form of characteristics method, which is a technique for solving partial differential equations. Typically, it applies to first-order equations; the aim of this method is to reduce a partial differential equation to a family of ordinary differential equations along which the solution can be integrated from some initial data. This latter developed under the real gas theory, because when the thermal and the caloric imperfections of a gas increases, the specific heat and their ratio do not remain constant anymore and start to vary with the gas parameters. The gas doesn’t stay perfect. Its state equation change and it becomes for a real gas. The presented equations of the characteristics remain valid whatever area or field of study. Here we need have inserted the developed Prandtl Meyer function in the mathematical system to find a new model when the effect of stagnation pressure is taken into account. In this case, the effects of molecular size and intermolecular attraction forces intervene to correct the state equation, the thermodynamic parameters and the value of Prandtl Meyer function. However, with the assumptions that Berthelot’s state equation accounts for molecular size and intermolecular force effects, expressions are developed for analyzing the supersonic flow for thermally and calorically imperfect gas. The supersonic parameters depend directly on the stagnation parameters of the combustion chamber. The resolution has been made by the finite differences method using the corrector predictor algorithm. As results, the developed mathematical model used to design 2D minimum length nozzles under effect of the stagnation parameters of fluid flow. A comparison for air with the perfect gas PG and high temperature models on the one hand and our results by the real gas theory on the other of nozzles shapes and characteristics are made.

Keywords: numerical methods, nozzles design, real gas, stagnation parameters, supersonic expansion, the characteristics method

Procedia PDF Downloads 225

Authors: Han-Bin Park, Taesam Kang, SunKi Hong, Jeong Hoi Gu

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The piezoelectric material is being used widely for actuators due to its large power density with simple structure. It can generate a larger force than the conventional actuators with the same size. Furthermore, the response time of piezoelectric actuators is very short, and thus, it can be used for very fast system applications with compact size. To control the piezoelectric actuator, we need analog signal conditioning circuits as well as digital microcontrollers. Conventional microcontrollers are not equipped with analog parts and thus the control system becomes bulky compared with the small size of the piezoelectric devices. To overcome these weaknesses, we are developing one-chip micro controller that can handle analog and digital signals simultaneously using mixed signal FPGA technology. We used the SmartFusion™ FPGA device that integrates ARM®Cortex-M3, analog interface and FPGA fabric in a single chip and offering full customization. It gives more flexibility than traditional fixed-function microcontrollers with the excessive cost of soft processor cores on traditional FPGAs. In this paper we introduce the design of single chip controller using mixed signal FPGA, SmartFusion™[1] device. To demonstrate its performance, we implemented a PI controller for power driving circuit and a 5th order H-infinity controller for the system with piezoelectric actuator in the FPGA fabric. We also demonstrated the regulation of a power output and the operation speed of a 5th order H-infinity controller.

Keywords: mixed signal FPGA, PI control, piezoelectric actuator, SmartFusion™

Procedia PDF Downloads 507

Authors: Morteza Khashehchi, Kamel Hooman

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Thermal effects on the dynamics and stability of the flow past a circular cylinder operating in the mixed convection regime is studied experimentally for Reynolds number (ReD) between 1000 and 4000, and different cylinder wall temperatures (Tw) between 25 and 75°C by means of Particle Image Velocimetry (PIV). The experiments were conducted in a horizontal wind tunnel with the heated cylinder placed horizontally. With such assumptions, the direction of the thermally induced buoyancy force acting on the fluid surrounding the heated cylinder would be perpendicular to the flow direction. In each experiment, to acquire 3000 PIV image pairs, the temperature and Reynolds number of the approach flow were held constant. By adjusting different temperatures in different Reynolds numbers, the corresponding Richardson number (RiD = Gr/Re^2) was varied between 0:0 (unheated) and 10, resulting in a change in the heat transfer process from forced convection to mixed convection. With increasing temperature of the wall cylinder, significant modifications of the wake flow pattern and wake vortex shedding process were clearly revealed. For cylinder at low wall temperature, the size of the wake and the vortex shedding process are found to be quite similar to those of an unheated cylinder. With high wall temperature, however, the high temperature gradient in the wake shear layer creates a type of vorticity with opposite sign to that of the shear layer vorticity. This temperature gradient vorticity weakens the strength of the shear layer vorticity, causing delay in reaching the recreation point. In addition to the wake characteristics, the shedding frequency for the heated cylinder is determined for all aforementioned cases. It is found that, as the cylinder wall is heated, the organization of the vortex shedding is altered and the relative position of the first detached vortices with respect to the second one is changed. This movement of the first detached vortex toward the second one increases the frequency of the shedding process. It is also found that the wake closure length decreases with increasing the Richardson number.

Keywords: heated cylinder, PIV, wake, Reynolds number

Procedia PDF Downloads 380

Authors: Osama Moustafa Zayed

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Aim of the work: To evaluate the effectiveness of venous glucose, levels of serum lactate and base deficit in polytraumatized patients as simple parameters to predict the mortality in these patients. Compared to the predictive value of Trauma and injury severity (TRISS) and Acute Physiology And Chronic Health Evaluation IV (APACHE IV). Introduction: Trauma is a serious global health problem, accounting for approximately one in 10 deaths worldwide. Trauma accounts for 5 million deaths per year. Prediction of mortality in trauma patients is an important part of trauma care. Several trauma scores have been devised to predict injury severity and risk of mortality. The trauma and injury severity score (TRISS) was most common used. Regardless of the accuracy of trauma scores, is based on an anatomical description of every injury and cannot be assigned to the patients until a full diagnostic procedure has been performed. So we hypothesized that alterations in admission glucose, lactate levels and base deficit would be an early and easy rapid predictor of mortality. Patient and Method: a comparative cross-sectional study. 282 Polytraumatized patients attended to the Emergency Department(ED) of the Suez Canal university Hospital constituted. The period from 1/1/2012 to 1/4/2013 was included. Results: We found that the best cut off value of TRISS probability of survival score for prediction of mortality among poly-traumatized patients is = 90, with 77% sensitivity and 89% specificity using area under the ROC curve (0.89) at (95%CI). APACHE IV demonstrated 67% sensitivity and 95% specificity at 95% CI at cut off point 99. The best cutoff value of Random Blood Sugar (RBS) for prediction of mortality was>140 mg/dl, with 89%, sensitivity, 49% specificity. The best cut off value of base deficit for prediction of mortality was less than -5.6 with 64% sensitivity, 93% specificity. The best cutoff point of lactate for prediction of mortality was > 2.6 mmol/L with 92%, sensitivity, 42% specificity. Conclusion: According to our results from all evaluated predictors of mortality (laboratory and scores) and mortality based on the estimated cutoff values using ROC curves analysis, the highest risk of mortality was found using a cutoff value of 90 in TRISS score while with laboratory parameters the highest risk of mortality was with serum lactate > 2.6 . Although that all of the three parameter are accurate in predicting mortality in poly-traumatized patients and near with each other, as in serum lactate the area under the curve 0.82, in BD 0.79 and 0.77 in RBS.

Keywords: APACHE IV, emergency department, polytraumatized patients, serum lactate

Procedia PDF Downloads 282

Authors: Kawar Salih

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It has been proven that designing sustainable buildings starts from early stages of urban design. The design of urban blocks specifically, is considered as one of the pragmatic strategies of sustainable urbanism. There have been previous studies that focused on the impact of urban block design and regulation on the outdoor thermal comfort in the semi-arid regions. However, no studies have been found that concentrated on that impact on the internal behavior of buildings of those regions specifically the daylight quality and energy performance. Further, most studies on semi-arid regions are focusing only on the cooling load reduction, neglecting the heating load. The study has focused on two parameters of urban block distribution which are the block orientation and the surface-to-volume ratio with the consideration of both heating and cooling loads of buildings. In Duhok (a semi-arid city in Kurdistan region of Iraq), energy consumption and daylight quality of different types of residential blocks have been examined using dynamic simulation. The findings suggest that there is a considerable higher energy load for heating than cooling, contradicting many previous studies about these regions. The results also highlight that the orientation of urban blocks can vary the energy consumption to 8%. Regarding the surface-to-volume ratio (S/V), it was observed that after the twice enlargement of the S/V, the energy consumption increased 15%. Though, the study demonstrates as well that there are opportunities for reducing energy consumption with the increase of the S/V which contradicts many previous research on S/V impacts on energy consumption. These results can help to design urban blocks with the bigger S/V than existing blocks in the city which it can provide better indoor daylight and relatively similar energy consumption.

Keywords: blocke orienation, building energy consumption, urban block design, semi-arid regions, surfacet-to-volume ratio

Procedia PDF Downloads 338

Authors: A. N. Ghafar, O. A. Chaudhari, W. Oettel, P. Fontana

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This study is a part of the EU project GEOCOND-Advanced materials and processes to improve performance and cost-efficiency of shallow geothermal systems and underground thermal storage. In heat exchange boreholes, to improve the heat transfer between the pipes and the surrounding ground, the space between the pipes and the borehole wall is normally filled with geothermal grout. Traditionally, bentonite has been a crucial component in most commercially available geothermal grouts to assure the required stability and impermeability. The investigations conducted in the early stage of this project during the benchmarking tests on some commercial grouts showed considerable sensitivity of the rheological properties of the tested grouts to the mixing parameters, i.e., mixing time and velocity. Further studies on this matter showed that bentonite, which has been one of the important constituents in most grout mixes, was probably responsible for such behavior. Apparently, proper amount of shear should be applied during the mixing process to sufficiently activate the bentonite. The higher the amount of applied shear the more the activation of bentonite, resulting in change in the grout rheology. This explains why, occasionally in the field applications, the flow properties of the commercially available geothermal grouts using different mixing conditions (mixer type, mixing time, mixing velocity) are completely different than expected. A series of tests were conducted on the grout mixes, with and without bentonite, using different mixing protocols. The aim was to eliminate/reduce the sensitivity of the rheological properties of the geothermal grouts to the mixing parameters by replacing bentonite with polymeric (non-clay) stabilizers. The results showed that by replacing bentonite with a proper polymeric stabilizer, the sensitivity of the grout mix on mixing time and velocity was to a great extent diminished. This can be considered as an alternative for the developers/producers of geothermal grouts to provide enhanced materials with less uncertainty in obtained results in the field applications.

Keywords: flow properties, geothermal grout, mixing time, mixing velocity, rheological properties

Procedia PDF Downloads 112

Authors: Seyed Amin Vakili, Sahar Sadat Vakili, Seyed Ehsan Vakili, Nader Abdoli Yazdi

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Differential equations are of fundamental importance in engineering and applied mathematics, since many physical laws and relations appear mathematically in the form of such equations. The equilibrium state of structures consisting of one-dimensional elements can be described by an ordinary differential equation. The response of these kinds of structures under the loading, namely relationship between the displacement field and loading field, can be predicted by the solution of these differential equations and on satisfying the given boundary conditions. When the effect of change of geometry under loading is taken into account in modeling of equilibrium state, then these differential equations are partially integrable in quartered. They also exhibit instability characteristics when the structures are loaded compressively. The purpose of this paper is to represent the ability of the Modified Newmark Method in analyzing flexural-torsional instability of struts for both bifurcation and non-bifurcation structural systems. The results are shown to be very accurate with only a small number of iterations. The method is easily programmed, and has the advantages of simplicity and speeds of convergence and easily is extended to treat material and geometric nonlinearity including no prismatic members and linear and nonlinear spring restraints that would be encountered in frames. In this paper, these abilities of the method will be extended to the system of linear differential equations that govern strut flexural torsional stability.

Keywords: instability, torsion, flexural, buckling, modified newmark method stability

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Authors: Brindusa Grigoriu

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Inscribing itself in the field of the history of multilingual communities with a focus on the evolution of language didactics, our paper aims at providing a pragmatic-interactional approach on a corpus proposing to scholars of the international scientific community a relevant text of early modern European literature: the first romance in French, The Conte of Flore and Blanchefleur by Robert d’Orbigny (1150). The multicultural context described by the romance is one in which an Arab-speaking prince, Floire, and his Francophone protégée, Blanchefleur, learn Latin together at the court of Spain and become fluent enough to turn it into the language of their love. This learning process is made up of interactional patterns of affective relevance, in which the proficiency of the protagonists in the domain of emotive acts becomes a matter of linguistic and pragmatic emulation. From five to ten years old, the pupils are efficiently stimulated by their teacher of Latin, Gaidon – a Moorish scholar of the royal entourage – to cultivate their competencies of oral expression and reading comprehension (of Antiquity classics), while enjoying an ever greater freedom of written expression, including the composition of love poems in this second language of culture and emotional education. Another relevant parameter of the educational process at court is that Latin shares its prominent role as a language of culture with French, whose exemplary learner is the (Moorish) queen herself. Indeed, the adult 'First lady' strives to become a pupil benefitting from lifelong learning provided by a fortuitous slave-teacher with little training, her anonymous chambermaid and Blanchefleur’s mother, who, despite her status of a war trophy, enjoys her Majesty’s confidence as a cultural agent of change in linguistic and theological fields. Thus, the two foreign languages taught at Spains’s court, Latin and French – as opposed to Arabic -, suggest a spiritual authority allowing the mutual enrichment of intercultural pioneers of cross-linguistic communication, in the aftermath of religious wars. Durably, and significantly – if not everlastingly – the language of physical violence rooted in intra-cultural solipsism is replaced by two Romance languages which seem to embody, together and yet distinctly, the parlance of peace-making.

Keywords: multilingualism, history of European language learning, French and Latin learners, multicultural context of medieval romance

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Authors: Hai Hoang, Thanh Xuan Nguyen Thi, Guillaume Galliero

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Coarse-Grained (CG) molecular simulations have shown to be an efficient way to estimate thermophysical (static and dynamic) properties of fluids. Several strategies have been developed and reported in the literature for defining CG molecular models. Among them, those based on a top-down strategy (i.e. CG molecular models related to macroscopic observables), despite being heuristic, have increasingly gained attention. This is probably due to its simplicity in implementation and its ability to provide reasonable results for not only simple but also complex systems. Regarding simple Force-Fields associated with these CG molecular models, it has been found that the four parameters Mie chain model is one of the best compromises to describe thermophysical static properties (e.g. phase diagram, saturation pressure). However, parameterization procedures of these Mie-chain GC molecular models given in literature are generally insufficient to simultaneously provide static and dynamic (e.g. viscosity) properties. To deal with such situations, we have extended the corresponding states by using a quantity associated with the liquid viscosity. Results obtained from molecular simulations have shown that our approach is able to yield good estimates for both static and dynamic thermophysical properties for various real non-associating fluids. In addition, we will show that on simple (e.g. phase diagram, saturation pressure) and complex (e.g. thermodynamic response functions, thermodynamic energy potentials) static properties, results of our scheme generally provides improved results compared to existing approaches.

Keywords: coarse-grained model, mie potential, molecular simulations, thermophysical properties, phase equilibria

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Authors: Tarek M. Alguhane, Ayman H. Khalil, M. N. Fayed, Ayman M. Ismail

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A 15-storey RC building, studied in this paper, is representative of modern building type constructed in Madina City in Saudi Arabia before 10 years ago. These buildings are almost consisting of reinforced concrete skeleton, i. e. columns, beams and flat slab as well as shear walls in the stairs and elevator areas arranged in the way to have a resistance system for lateral loads (wind–earthquake loads). In this study, the dynamic properties of the 15-storey RC building were identified using ambient motions recorded at several spatially-distributed locations within each building. After updating the mathematical models for this building with the experimental results, three dimensional pushover analysis (nonlinear static analysis) was carried out using SAP2000 software incorporating inelastic material properties for concrete, infill and steel. The effect of modeling the building with and without infill walls on the performance point as well as capacity and demand spectra due to EQ design spectrum function in Madina area has been investigated. The response modification factor (R) for the 15 storey RC building is evaluated from capacity and demand spectra (ATC-40). The purpose of this analysis is to evaluate the expected performance of structural systems by estimating, strength and deformation demands in design, and comparing these demands to available capacities at the performance levels of interest. The results are summarized and discussed.

Keywords: seismic assessment, pushover analysis, ambient vibration, modal update

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Authors: Sheila R. Pai, Rekha D. Kini, Amrutha Mary

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Objective: To assess and compare the cardiac autonomic activity after mental stress among the wards of normal and hypertensive parents. Methods: The study included 67 subjects, 30 of them had a parental history of hypertension and rest 37 had normotensive parents. Subjects were divided into control group (wards of normotensive parents) and Study group (wards of hypertensive parents). The height, weight were noted, and Body Mass Index (BMI) was also calculated. The mental stress test was carried out. Blood pressure (BP) and electro cardiogram (ECG) was recorded during normal breathing and after mental stress test. Heart rate variability (HRV) analysis was done by time domain method HRV was recorded and analyzed by the time-domain method. Analysis of HRV in the time-domain was done using the software version 1.1 AIIMS, New Delhi. The data obtained was analyzed using student’s t-test followed by Mann-Whitney U-test and P < 0.05 was considered significant. Results: There was no significant difference in systolic blood pressure and diastolic blood pressure (DBP) between study group and control group following mental stress. In the time domain analysis, the mean value of pNN50 and RMSSD of the study group was not significantly different from the control group after the mental stress test. Conclusion: The study thus concluded that there was no significant difference in HRV between study group and control group following mental stress.

Keywords: heart rate variability, time domain analysis, mental stress, hypertensive

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Authors: Nazlı Çetindağ, Pelin Yılmaz Çetiner, Metin Mert İlgün, Emine Birci, Gizemnur Yıldız Uysal, Özcan Hatipoğlu, Ehsan Tuzcuoğlu, Gökhan Sır

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Water scarcity is an unavoidable issue impacting an increasing number of individuals daily, representing a global crisis stemming from swift population growth, urbanization, and excessive resource exploitation. Consequently, solutions that involve the reclamation of wastewater are considered essential. In this context, household wastewater, categorized as greywater, plays a significant role in freshwater used for residential purposes and is attributed to washing. This type of wastewater comprises diverse elements, including organic substances, soaps, detergents, solvents, biological components, and inorganic elements such as certain metal ions and particles. The physical characteristics of wastewater vary depending on its source, whether commercial, domestic, or from a hospital setting. Consequently, the treatment strategy for this wastewater type necessitates comprehensive investigation and appropriate handling. The advanced oxidation process (AOP) emerges as a promising technique associated with the generation of reactive hydroxyl radicals highly effective in oxidizing organic pollutants. This method takes precedence over others like coagulation, flocculation, sedimentation, and filtration due to its avoidance of undesirable by-products. In the current study, the focus was on exploring the feasibility of the AOP for treating actual household wastewater. To achieve this, a laboratory-scale device was designed to effectively target the formed radicals toward organic pollutants, resulting in lower organic compounds in wastewater. Then, the number of microorganisms present in treated wastewater, in addition to the chemical content of the water, was analyzed to determine whether the lab-scale device eliminates microbial accumulation with AOP. This was also an important parameter since microbes can indirectly affect human health and machine hygiene. To do this, water samples were taken from treated and untreated conditions and then inoculated on general purpose agar to track down the total plate count. Analysis showed that AOP might be an option to treat household wastewater and lower microorganism growth.

Keywords: usage of household water, advanced oxidation process, water reuse, modelling

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Authors: Rashida Rahmat Zohra, Afsheen Aman, Shah Ali Ul Qader

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Commercially important biopolymer, dextran, is enzymatically degraded into lower molecular weight fractions of vast industrial potential. Various organisms are associated with dextranase production, among which fungal, yeast and bacterial origins are used for commercial production. Dextranases are used to remove contaminating dextran in sugar processing industry and also used in oral care products for efficient removal of dental plaque. Among the hydrolytic products of dextran, isomaltooligosaccharides have prebiotic effect in humans and reduces the cariogenic effect of sucrose in oral cavity. Dextran derivatives produced by hydrolysis of high molecular polymer are also conjugated with other chemical and metallic compounds for usage in pharmaceutical, fine chemical industry, cosmetics, and food industry. Owing to the vast application of dextran and dextranases, current study focused on purification and analysis of kinetic parameters of dextranase from a newly isolated strain of Bacillus licheniformis KIBGE-IB25. Dextranase was purified up to 35.75 folds with specific activity of 1405 U/mg and molecular weight of 158 kDa. Analysis of kinetic parameters revealed that dextranase performs optimum cleavage of low molecular weight dextran (5000 Da, 0.5%) at 35ºC in 15 min at pH 4.5 with a Km and Vmax of 0.3738 mg/ml and 182.0 µmol/min, respectively. Thermal stability profiling of dextranase showed that it retained 80% activity up to 6 hours at 30-35ºC and remains 90% active at pH 4.5. In short, the dextranase reported here performs rapid cleavage of substrate at mild operational conditions which makes it an ideal candidate for dextran removal in sugar processing industry and for commercial production of low molecular weight oligosaccharides.

Keywords: Bacillus licheniformis, dextranase, gel permeation chromatograpy, enzyme purification, enzyme kinetics

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Authors: Dung V. H. Pham, Kathryn Cullen

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Introduction: 40% of adolescents with major depression (MDD) are unresponsive to 1st line antidepressant treatment. The neural mechanism underlying treatment-responsive and treatment-resistant depression in adolescent are unclear. Amygdala is important for emotion processing and has been implicated in mood disorders. Past research has shown abnormal amygdala connectivity in adolescents with MDD. This research study changes in amygdala resting-state functional connectivity to find neural correlates of successful antidepressant treatment. Methods: Thirteen adolescents aged 12-19 underwent rfMRI before and after 8-week antidepressant treatment and completed BDI-II at each scan. A whole-brain approach, using anatomically defined amygdala ROIs (1) identified brain regions that are highly synchronous with the amygdala, (2) correlated neural changes with changes in overall depression and specific symptom clusters within depression. Results: Some neural correlates were common across domains: (1) decreased amygdala RSFC with the default mode network (posterior cingulate, precuneus) is associated with improvement in overall depression and many symptom clusters, (2) increased amygdala RSFC with fusiform gyrus is associated with symptom improvement across many symptom clusters. We also found unique neural changes associated with symptom improvement in each symptom cluster. Conclusion: This is the first preliminary study that looks at neural correlates of antidepressant treatment response to overall depression as well as different clusters of symptoms of depression. The finding suggests both overlapping and distinct neural mechanisms underlying improvement in each symptom clusters within depression. Some brain regions found are also implicated in MDD among adults in previous literature.

Keywords: depression, adolescents, fMRI, antidepressants

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Authors: Manal Alosaimi

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Many rehabilitation strategies exist to aid persons with neurological disorders relearn motor skills through intensive training. Evidence supporting the theory that cortical areas involved in motor execution can be triggered by observing actions performed by others is attributed to the function of the mirror neuron system (MNS) indicates that activation of the MNS is associated with improvements in physical action and motor learning. Therefore, it is important to investigate the relationship between motor training (in this case, playing the drums) and the activation of the MNS. To achieve this, 15 healthy right-handed participants received drum-kit training for 21 weeks, during which time blood oxygen level-dependent (BOLD) signals were monitored in the brain using functional magnetic resonance imaging (fMRI). Participants were required to perform action–observation and action–execution fMRI tasks. The main results are that BOLD signals in classical regions of the MNS such as supramarginal gyri, inferior parietal lobule, and supplementary motor area increase significantly over the training period. Activation of these areas indicates that passive-observation of others performing these same skills may facilitate recovery of persons suffering from neurological disorders, and complement conventional rehabilitation programs that focus on action execution or intense training.

Keywords: fMRI, mirror neuron system, magnetic resonance imaging, neuroplasticity, drumming, learning, music, action observation, action execution

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Authors: Josephine Mirador

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Too often, one hears teachers complaining about how uncritical students can be, yet the notion of ‘criticality’ may be subject to variable understandings or interpretations. One challenge facing postgraduate students is the writing of essays responding to a specific reading assignment. Such an essay requires students not only to summarise, but to engage in a discussion of the significant points of the article, pointing out its strengths as well as its weaknesses. This paper presents the results of an investigation on criticality in written assignments of postgraduate students in applied linguistics and TESOL. The guiding questions for this investigation were: -How ‘critical’ are postgraduate students when writing their assignments? -What kind of ‘critical’ comments are they able to offer? A total of 70 essays were analysed, using two sets of corpora in the initial and follow-through phases of the research from three different universities in Asia. The essays were written by MA applied linguistics and TESOL students. Students were told that the response essay should definitely not just summarise, but should offer a reflection or critique on the ideas presented in the subject article. The initial findings from the investigation include: the identification of at least 10 general ‘moves’ each of which has a number of possible specific categories; presence of critique ‘nodes’ as distinguished from ‘support’ comments; and the identification of at least 4 moves as the most recurrent and possibly obligatory categories. This investigation has unearthed a few more questions or issues that are definitely worth investigating as extensions of this research, and will be of interest (most especially) to genre analysts and teachers of writing.

Keywords: criticality, discourse and genre analysis, postgraduate students, applied linguistics

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Authors: Chien Y. Lin, Jung Y. Huang, Leu-Wei Lo

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A growing body of data reveals that the membrane cholesterol molecules can alter the signaling pathways of living cells. However, the understanding about how membrane cholesterol modulates receptor proteins is still lacking. Single-molecule tracking can effectively probe into the microscopic environments and thermal fluctuations of receptor proteins in a living cell. In this study we applies single-molecule optical tracking on ligand-induced dimerization process of EGFRs in the plasma membranes of two cancer cell lines (HeLa and A431) and one normal endothelial cell line (MCF12A). We tracked individual EGFR and dual receptors, diffusing in a correlated manner in the plasma membranes of live cells. We developed an energetic model by integrating the generalized Langevin equation with the Cahn-Hilliard equation to help extracting important information from single-molecule trajectories. From the study, we discovered that ligand-bound EGFRs move from non-raft areas into lipid raft domains. This ligand-induced motion is a common behavior in both cancer and normal cells. By manipulating the total amount of membrane cholesterol with methyl-β-cyclodextrin and the local concentration of membrane cholesterol with nystatin, we further found that the amount of cholesterol can affect the stability of EGFR dimers. The EGFR dimers in the plasma membrane of normal cells are more sensitive to the local concentration changes of cholesterol than EGFR dimers in the cancer cells. Our method successfully captures dynamic interactions of receptors at the single-molecule level and provides insight into the functional architecture of both the diffusing EGFR molecules and their local cellular environment.

Keywords: membrane proteins, single-molecule tracking, Cahn-Hilliard equation, EGFR dimers

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Authors: Ahokas Mikko, Taskila Sanna, Varrio Kalle, Tanskanen Juha

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The present research aimed at the development of an energy efficient process for the concentration of starchy waste waters. The selected principle is mechanical vapor recompression evaporation (MVR) which leads to concentrated solid material and evaporated water phase. Evaporation removes water until a certain viscosity limit is reached. Materials with high viscosity cannot be concentrated using standard evaporators due to limitations of pumps and other constraints, such as wetting. Control of viscosity is thus essential for efficient evaporation. This applies especially to fluids in which due starch or other compounds the viscosity tends to increase via removal of water. In the present research, the effect of enzymes on evaporation of highly viscous starch industry waste waters was investigated. Wastewater samples were received from starch industry at pH of 4.8. Response surface methodology (RSM) was applied for the investigation of factor effects on the behaviour of concentrate during evaporation. The RSM was prepared using quadratic face-centered central composite design (CCF). The evaporation performance was evaluated by monitoring the viscosity of fluid during processing. Based on viscosity curves, the addition of glucoamylase reduced the viscosity during evaporation. This assumption was confirmed by CCF, suggesting that the use of starch decomposing glucoamylase allowed evaporation of the starchy wastewater to a relatively high total solid concentration without a detrimental increase in the viscosity. The results suggest that use of enzymes for reduction of viscosity during the evaporation allows more effective concentration of the wastewater and thereby recovery of potable water.

Keywords: viscous, wastewater, treatment, evaporation, concentration

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