Search results for: glass fiber composite

Authors: J. Belovickis, V. Samulionis, J. Banys, M. V. Silibin, A. V. Solnyshkin, A. V. Sysa

Abstract:

Ferroelectric polymers exhibit good flexibility, processability and low cost of production. Doping of ferroelectric polymers with nanofillers may modify its dielectric, elastic or piezoelectric properties. Carbon nanotubes are one of the ingredients that can improve the mechanical properties of polymer based composites. In this work, we report on both the ultrasonic and the dielectric properties of the copolymer polyvinylidene fluoride/tetrafluoroethylene (P(VDF-TrFE)) of the composition 70/30 mol% with various concentrations of carbon nanotubes (CNT). Experimental study of ultrasonic wave attenuation and velocity in these composites has been performed over wide temperature range (100 K – 410 K) using an ultrasonic automatic pulse-echo tecnique. The temperature dependences of ultrasonic velocity and attenuation showed anomalies attributed to the glass transition and paraelectric-ferroelectric phase transition. Our investigations showed mechanical losses to be dependent on the volume fraction of the CNTs within the composites. The existence of broad hysteresis of the ultrasonic wave attenuation and velocity within the nanocomposites is presented between cooling and heating cycles. By the means of dielectric spectroscopy, it is shown that the dielectric properties may be tuned by varying the volume fraction of the CNT fillers.

Keywords: carbon nanotubes, polymer composites, PVDF-TrFE, ultrasonic spectroscopy

Procedia PDF Downloads 340

Authors: Tatiana S. Ogneva

Abstract:

Aluminum and nickel-based intermetallic compounds have attracted the attention of scientific community as promising materials for heat-resistant and wear-resistant coatings in such manufacturing areas as microelectronics, aircraft and rocket building and chemical industries. Magnetron sputtering makes possible to coat materials without formation of liquid phase and improves the mechanical and functional properties of nickel aluminides due to the possibility of nanoscale structure formation. The purpose of the study is the investigation of structure and properties of intermetallic coatings produced by magnetron sputtering technique. The feature of this work is the using of composite targets for sputtering, which were consisted of two semicircular sectors of cp-Ni and cp-Al. Plates of alumina, silicon, titanium and steel alloys were used as substrates. To estimate sputtering conditions on structure of intermetallic coatings, a series of samples were produced and studied in detail using scanning and transition electron microcopy and X-Ray diffraction. Besides, nanohardness and scratching tests were carried out. The varying parameters were the distance from the substrate to the target, the duration and the power of the sputtering. The thickness of the obtained intermetallic coatings varied from 0.05 to 0.5 mm depending on the sputtering conditions. The X-ray diffraction data indicated that the formation of intermetallic compounds occurred after sputtering without additional heat treatment. Sputtering at a distance not closer than 120 mm led to the formation of NiAl phase. Increase in the power of magnetron from 300 to 900 W promoted the increase of heterogeneity of the phase composition and the appearance of intermetallic phases NiAl, Ni₂Al₃, NiAl₃, and Al under the aluminum side, and NiAl, Ni₃Al, and Ni under the nickel side of the target. A similar trend is observed with increasing the distance of sputtering from 100 to 60 mm. The change in the phase composition correlates with the changing of the atomic composition of the coatings. Scanning electron microscopy revealed that the coatings have a nanoscale grain structure. In this case, the substrate material and the distance from the substrate to the magnetron have a significant effect on the structure formation process. The size of nanograins differs from 10 to 83 nm and depends not only on the sputtering modes but also on material of a substrate. Nanostructure of the material influences the level of mechanical properties. The highest level of nanohardness of the coatings deposited during 30 minutes on metallic substrates at a distance of 100 mm reached 12 GPa. It was shown that nanohardness depends on the grain size of the intermetallic compound. Scratching tests of the coatings showed a high level of adhesion of the coating to substrate without any delamination and cracking. The results of the study showed that magnetron sputtering of composite targets consisting of nickel and aluminum semicircles makes it possible to form intermetallic coatings with good mechanical properties directly in the process of sputtering without additional heat treatment.

Keywords: intermetallic coatings, magnetron sputtering, mechanical properties, structure

Procedia PDF Downloads 121

Authors: Malek Miladi, Miguel Vegara, Maria Perez-Infantes, Khaled Mohamed Ramadan, Antonio Ruiz-Canales, Damaris Nunez-Gomez

Abstract:

Coffee is the second consumed commodity worldwide, yet it also generates colossal waste. Proper management of coffee waste is proposed by converting them into products with higher added value to achieve sustainability of the economic and ecological footprint and protect the environment. Based on this, a study looking at the recovery of coffee waste is becoming more relevant in recent decades. Spent coffee grounds (SCG's) resulted from brewing coffee represents the major waste produced among all coffee industry. The fact that SCGs has no economic value be abundant in nature and industry, do not compete with agriculture and especially its high oil content (between 7-15% from its total dry matter weight depending on the coffee varieties, Arabica or Robusta), encourages its use as a sustainable feedstock for bio-oil production. The bio-oil extraction is a crucial step towards biodiesel production by the transesterification process. However, conventional methods used for oil extraction are not recommended due to their high consumption of energy, time, and generation of toxic volatile organic solvents. Thus, finding a sustainable, economical, and efficient extraction technique is crucial to scale up the process and to ensure more environment-friendly production. Under this perspective, the aim of this work was the statistical study to know an efficient strategy for oil extraction by n-hexane using indirect sonication. The coffee waste mixed Arabica and Robusta, which was used in this work. The temperature effect, sonication time, and solvent-to-solid ratio on the oil yield were statistically investigated as dependent variables by Central Composite Rotatable Design (CCRD) 23. The results were analyzed using STATISTICA 7 StatSoft software. The CCRD showed the significance of all the variables tested (P < 0.05) on the process output. The validation of the model by analysis of variance (ANOVA) showed good adjustment for the results obtained for a 95% confidence interval, and also, the predicted values graph vs. experimental values confirmed the satisfactory correlation between the model results. Besides, the identification of the optimum experimental conditions was based on the study of the surface response graphs (2-D and 3-D) and the critical statistical values. Based on the CCDR results, 29 ºC, 56.6 min, and solvent-to-solid ratio 16 were the better experimental conditions defined statistically for coffee waste oil extraction using n-hexane as solvent. In these conditions, the oil yield was >9% in all cases. The results confirmed the efficiency of using an ultrasound bath in extracting oil as a more economical, green, and efficient way when compared to the Soxhlet method.

Keywords: coffee waste, optimization, oil yield, statistical planning

Procedia PDF Downloads 119

Authors: N. Kaneva, A. Bojinova, K. Papazova

Abstract:

Thin ZnO films are deposited on glass substrates via sol–gel method and dip-coating. The films are prepared from zinc acetate dehydrate as a starting reagent. After that the as-prepared ZnO sol is aged for different periods (0, 1, 3, 5, 10, 15, and 30 days). Nanocrystalline thin films are deposited from various sols. The effect ZnO sols aging time on the structural and photocatalytic properties of the films is studied. The films surface is studied by Scanning Electron Microscopy. The effect of the aging time of the starting solution is studied inrespect to photocatalytic degradation of Reactive Black 5 (RB5) by UV-vis spectroscopy. The experiments are conducted upon UV-light illumination and in complete darkness. The variation of the absorption spectra shows the degradation of RB5 dissolved in water, as a result of the reaction acurring on the surface of the films, and promoted by UV irradiation. The initial concentrations of dye (5, 10 and 20 ppm) and the effect of the aging time are varied during the experiments. The results show, that the increasing aging time of starting solution with respect to ZnO generally promotes photocatalytic activity. The thin films obtained from ZnO sol, which is aged 30 days have best photocatalytic degradation of the dye (97,22%) in comparison with the freshly prepared ones (65,92%). The samples and photocatalytic experimental results are reproducible. Nevertheless, all films exhibit a substantial activity in both UV light and darkness, which is promising for the development of new ZnO photocatalysts by sol-gel method.

Keywords: ZnO thin films, sol-gel, photocatalysis, aging time

Procedia PDF Downloads 382

Authors: Mohd Yusri Ibrahim

Abstract:

Although it is known that interpersonal skills are essential for personal development, the debate however continues as to how to measure those skills, especially in youths. This study was conducted to develop a measurement model of interpersonal skills by suggesting three construct namely personal, skills and relationship; six function namely self, perception, listening, conversation, emotion and conflict management; and 30 behaviours as indicators. This cross-sectional survey by questionnaires was applied in east side of peninsula of Malaysia for 150 respondents, and analyzed by structural equation modelling (SEM) by AMOS. The suggested constructs, functions and indicators were consider accepted as measurement elements by observing on regression weight for standard loading, average variance extracted (AVE) for convergent validity, square root of AVE for discriminant validity, composite reliability (CR), and at least three fit indexes for model fitness. Finally, a measurement model of interpersonal skill for youth was successfully developed.

Keywords: interpersonal communication, interpersonal skill, youth, communication skill

Procedia PDF Downloads 314

Authors: Daniel Nieto, Ramiro Couceiro

Abstract:

Microfluidic chips have demonstrated their significant application potentials in microbiological processing and chemical reactions, with the goal of developing monolithic and compact chip-sized multifunctional systems. Heat generation and thermal control are critical in some of the biochemical processes. The paper presents a laser direct-write technique for rapid prototyping and manufacturing of microheater chips and its applicability for perfusion cell culture outside a cell incubator. The aim of the microheater is to take the role of conventional incubators for cell culture for facilitating microscopic observation or other online monitoring activities during cell culture and provides portability of cell culture operation. Microheaters (5 mm × 5 mm) have been successfully fabricated on soda-lime glass substrates covered with aluminum layer of thickness 120 nm. Experimental results show that the microheaters exhibit good performance in temperature rise and decay characteristics, with localized heating at targeted spatial domains. These microheaters were suitable for a maximum long-term operation temperature of 120ºC and validated for long-time operation at 37ºC. for 24 hours. Results demonstrated that the physiology of the cultured SW480 adenocarcinoma of the colon cell line on the developed microheater chip was consistent with that of an incubator.

Keywords: laser microfabrication, microheater, bioengineering, cell culture

Procedia PDF Downloads 297

Authors: Deepika Christopher, Garima Anand

Abstract:

To determine the best model for churn prediction in the telecom industry, this paper compares 11 machine learning algorithms, namely Logistic Regression, Support Vector Machine, Random Forest, Decision Tree, XGBoost, LightGBM, Cat Boost, AdaBoost, Extra Trees, Deep Neural Network, and Hybrid Model (MLPClassifier). It also aims to pinpoint the top three factors that lead to customer churn and conducts customer segmentation to identify vulnerable groups. According to the data, the Logistic Regression model performs the best, with an F1 score of 0.6215, 81.76% accuracy, 68.95% precision, and 56.57% recall. The top three attributes that cause churn are found to be tenure, Internet Service Fiber optic, and Internet Service DSL; conversely, the top three models in this article that perform the best are Logistic Regression, Deep Neural Network, and AdaBoost. The K means algorithm is applied to establish and analyze four different customer clusters. This study has effectively identified customers that are at risk of churn and may be utilized to develop and execute strategies that lower customer attrition.

Keywords: attrition, retention, predictive modeling, customer segmentation, telecommunications

Procedia PDF Downloads 57

Authors: Tasneem Firdous Islam, G. D. Kedar

Abstract:

The aim of this paper is to study the effect of internal heat generation in a transient infinitely long annular cylinder subjected to hygrothermal loadings. The linear dependence theory of moisture and temperature is derived based on Dufour and Soret effect. The meticulous solutions of temperature, moisture, and thermal stresses are procured by using the Hankel transform technique. The influence of the internal heat source on the radial aspect is examined for coupled and uncoupled cases. In the present study, the composite material T300/5208 is considered, and the coupled and uncoupled cases are analyzed. The results obtained are computed numerically and illustrated graphically.

Keywords: temperature, moisture, hygrothermoelasticity, internal heat generation, annular cylinder

Procedia PDF Downloads 115

Authors: Anton G. Akulichev, Avinash Tiwari, Ben Alcock, Andreas Echtermeyer

Abstract:

Low temperatures are known to pose a major threat for polymers; many are prone to excessive stiffness or even brittleness. There is a technology gap between the properties of existing elastomeric sealing materials and the properties needed for service in extremely cold regions. Moreover, some aspects of low temperature behaviour of rubber are not thoroughly studied and understood. The paper presents results of laboratory testing of a conventional oilfield HNBR (hydrogenated nitrile butadiene rubber) elastomer at low climatic temperatures above and below its glass transition point, as well as the performance of some filled HNBR formulations. Particular emphasis in the experiments is put on rubber viscoelastic characteristics studied by Dynamic Mechanical Analysis (DMA) and quasi-static mechanical testing results at low temperatures. As demonstrated by the stress relaxation and DMA experiments the transition region near Tg of the studied compound has the most striking features, like rapid stress relaxation, as compared to the glassy and rubbery plateau. In addition the quasi-static experiments show that molecular movement below Tg is not completely frozen, but rather evident and manifested in a certain stress decay as well. The effect of temperature and filler additions on typical mechanical and other properties of the materials is also discussed.

Keywords: characterization, filled elastomers, HNBR, low temperature

Procedia PDF Downloads 313

Authors: Isha Rathore, Peeyush Jain, Elangovan Rajasekar

Abstract:

The thermal capacity of the envelope impacts the cooling and heating demand of a building and modulates the peak electricity demand. This paper presents the thermal capacity tuning of a building envelope to minimize peak electricity demand for space cooling. We consider a 40 m² residential testbed located in Hyderabad, India (Composite Climate). An EnergyPlus model is validated using real-time data. A Parametric simulation framework for thermal capacity tuning is created using the Honeybee plugin. Diffusivity, Thickness, layer position, orientation and fenestration size of the exterior envelope are parametrized considering a five-layered wall system. A total of 1824 parametric runs are performed and the optimum wall configuration leading to minimum peak cooling demand is presented.

Keywords: thermal capacity, tuning, peak demand reduction, parametric analysis

Procedia PDF Downloads 184

Authors: Selen Muftuoglu, Dilara Kefeli

Abstract:

The present study was conducted by using the cross-sectional study design and to determine the relationship between body image, eating behavior and nutritional status in 80 female athletes who were basketball, volleyball, flag football, indoor soccer, and ice hockey players. This study demonstrated that 70.0% of the female athletes had skipped meal. Also, female athletes had a normal body mass index (BMI), but 65.0% of them indicated that want to be thinner. On the other hand, we analyzed that their daily nutrients intake, so we observed that 43.4% of the energy was from the fatty acids, especially saturated fatty acids, and they had lower fiber, calcium and iron intake. Also, we found that BMI, waist circumference, waist to hip ratio were negatively correlated with Multidimensional Body-Self Relations Questionnaire and The Dutch Eating Behavior Questionnaire score and they were lower in who had meal skipped or not received diet therapy. As a conclusion, nutrition education is frequently neglected in sports programs. There is a paucity of nutrition education interventions among different sports.

Keywords: body image, eating behavior, eating disorders, female athletes, nutritional status

Procedia PDF Downloads 162

Authors: Mukul Kumar Srivastava, Sumit Basu

Abstract:

Carbon fiber reinforced polymer (CFRP) composites find wide use in the space and aerospace industries primarily due to their favourable strength-to-weight ratios. However, in spite of the impressive mechanical properties, their ability to shield sophisticated electronics from electromagnetic interference (EMI) is rather limited. As a result, metallic wire meshes or metal foils are often embedded in CFRP composites to provide adequate EMI shielding. This comes at additional manufacturing cost, increased weight and, particularly in cases of aluminium, increased risk of galvanic corrosion in the presence of moisture. In this work, we will explore ways of enhancing EMI shielding of CFRP laminates in the 8-12 GHz range (the so-called X-band), without compromising their mechanical and fracture properties, through minimal modifications to their current well-established fabrication protocol. The computational-experimental study of EMI shielding in CFRP laminates will focus on the effects of incorporating multiwalled carbon nanotubes (MWCNT) and conducting nanoparticles in different ways in the resin and/or carbon fibers. We will also explore the possibility of utilising the excellent absorbing properties of MWCNT reinforced polymer foams to enhance the overall EMI shielding capabilities.

Keywords: EMI shielding, X-band, CFRP, MWCNT

Procedia PDF Downloads 83

Authors: Constantinos Vayenas, Athanasios Fokas, Dimitrios Grigoriou

Abstract:

We use special relativity to compute the inertial and thus gravitational mass of relativistic electron and muon neutrinos, and we find that, for neutrino kinetic energies above 150 MeV/c2, these masses are in the Planck mass range. Consequently, we develop a simple Bohr-type model using gravitational rather than electrostatic forces between the rotating neutrinos as the centripetal force in order to examine the bound rotational states formed by two or three such relativistic neutrinos. We find that the masses of the composite rotational structures formed, are in the meson and baryon mass ranges, respectively. These models contain no adjustable parameters and by comparing their predictions with the experimental values of the masses of protons and pions, we compute a mass of 0.0437 eV/c2 for the heaviest electron neutrino mass and of 1.1 x10-3 eV/c2 for the heaviest muon neutrino mass.

Keywords: geons, gravitational confinement, neutrino masses, special relativity

Procedia PDF Downloads 263

Authors: Hamid Merzouk, Djahida Touati-Talantikite, Amina Zaabar

Abstract:

New nanosized materials are in huge expansion worldwide. They play a fundamental role in various industrial applications thanks their unique and functional properties. Moreover, in recent years, a great effort has been made to the design and control fabrication of nanostructured semiconductors such zinc sulphide. In recent years, much attention has been accorded in doped and co-doped ZnS to improve the ZnS films quality. We present in this work the preparation and characterization of ZnS and Al doped ZnS thin films. Nanoparticles ZnS and Al doped ZnS films are prepared by chemical bath deposition method (CBD), for various dopant concentrations. Thin films are deposed onto commercial microscope glass slides substrates. Thiourea is used as sulfide ion source, zinc acetate as zinc ion source and manganese acetate as manganese ion source in alkaline bath at 90 °C. X-ray diffraction (XRD) analyses are carried out at room temperature on films and powders with a powder diffractometer, using CuKα radiation. The average grain size obtained from the Debye–Scherrer’s formula is around 10 nm. Films morphology is examined by scanning electron microscopy. IR spectra of representative sample are recorded with the FTIR between 400 and 4000 cm-1.The transmittance (70 %) is performed with the UV–VIS spectrometer in the wavelength range 200–800 nm. This value is enhanced by Al doping.

Keywords: ZnS, nanostructured semiconductors, thin films, chemical bath deposition

Procedia PDF Downloads 524

Authors: Amin Mojiri, Lou Ziyang

Abstract:

Constructed wetland (CW) is a reasonable method to treat waste water. Current study was carried out to co-treat landfill leachate and domestic waste water using a CW system. Typha domingensis was transplanted to CW, which encloses two substrate layers of adsorbents named ZELIAC and zeolite. Response surface methodology and central composite design were employed to evaluate experimental data. Contact time (h) and leachate to waste water mixing ratio (%; v/v) were selected as independent factors. Phenols and manganese removal were selected as dependent responses. At optimum contact time (48.7 h) and leachate to waste water mixing ratio (20.0%), removal efficiencies of phenols and manganese removal efficiencies were 90.5%, and 89.4%, respectively.

Keywords: constructed wetland, Manganese, phenols, Thypha domingensis

Procedia PDF Downloads 322

Authors: F. Z. Benabid, S. Kridi, F. Zouai, D. Benachour

Abstract:

The aim of present work is to characterize the PP/TiO2 blends as composites, and study the effect of TiO2 on properties of different compositions and the evaluation of the effectiveness of the method used for filler treatment. Nanocomposite samples were synthesized by molten route in an internal mixer. The TiO2 nanoparticles were treated with stearic acid in order to obtain a good dispersion, and the demonstration of the effectiveness of the treatment on the morphology and roughness of the nanofiller was established by microstructural analysis by FTIR and AFM. The various developed nanocomposite compositions were characterized by different methods; i.e. FTIR, XRD, SEM and optical microscopy. Rheological, dielectric and mechanical studies were also performed. The results showed a remarkable increase in the impact strength results which increased about 39% compared to neat PP. The rheological study showed an increase in the fluidity in all developed composite compositions, involved by the good dispersion of TiO2 particles.

Keywords: composites, PP, TiO2, comixing, mechanical treatment

Procedia PDF Downloads 271

Authors: N. Allouache, O. Rahli

Abstract:

Solar radiation is by far the largest and the most world’s abundant, clean, and permanent energy source. In recent years, many promising technologies have been developed to harness the sun's energy. These technologies help in environmental protection, economizing energy, and sustainable development, which are the major issues of the world. One of these important technologies is the solar refrigerating machines that make use of either absorption or adsorption technologies. In this present work, the adsorbent bed is modelized and optimized using different working pairs, such as zeolite-water, silica gel-water, activated carbon-ammonia, calcium chlorid-ammonia, activated carbon fiber- methanol and activated carbon AC35-methanol. The results show that the enhancement of the heat and mass transfer depends on the properties of the working pair; the performances of the adsorption cycle are essentially influenced by the choice of the adsorbent-adsorbate pair. The system can operate successfully for optimal parameters such as the evaporator, condenser, and generating temperatures. The activated carbon is the best adsorbent due to its high surface area and micropore volume.

Keywords: adsorbent bed, heat and mass transfer, numerical analysis, working pairs

Procedia PDF Downloads 149

Authors: A. Şahin Zaimoglu

Abstract:

A number of studies have been conducted recently to investigate the influence of randomly oriented fibers on some engineering properties of cohesive and cohesionless soils. However, few studies have been carried out on freezing-thawing behavior of fine-grained soils modified with discrete fiber inclusions and additive materials. This experimental study was performed to investigate the effect of randomly distributed polypropylene fibers (PP) and some additive materials [e.g.., borogypsum (BG), fly ash (FA) and cement (C)] on freezing-thawing durability (mass losses) of a fine-grained soil for 6,12 and 18 cycles. The Taguchi method was applied to the experiments and a standard L9 orthogonal array (OA) with four factors and three levels were chosen. A series of freezing-thawing tests were conducted on each specimen. 0-20 % BG, 0-20 % FA, 0-0.25 % PP and 0-3 % of C by total dry weight of mixture were used in the preparation of specimens. Experimental results showed that the most effective materials for the freezing-thawing durability (mass losses) of the samples were borogypsum and fly ash. The values of mass losses for 6, 12 and 18 cycles in optimum conditions were 16.1%, 5.1% and 3.6%, respectively.

Keywords: freezing-thawing, additive materials, reinforced soil, optimization

Procedia PDF Downloads 306

Authors: Somboon Sarasit

Abstract:

This research aims to develop a model small ceramic kiln using burner from a high-pressure household gas stove. The efficiency of the kiln and community technology transfer. The study of history shows that this area used to be a source of pottery on the old capital of Ayutthaya. There is evidence from pottery kilns unearthed many types of wood kiln since 2535 and was assumed that the production will end when the war with Burma in the Ayutthaya period. The result of the research design and performance testing of ceramic kiln using burners by gas cooker and outside from 200-liter steel drums inside with ceramic fiber. It was found that the Graze Firing of the products to be at a temperature of 1230°C. The duration of the burn approximately 5-6 hours and uses only 3-4 kg of LPG products, a coffee can burn up to 40-50 pieces. It is an energy-efficient Kiln. Use safe and appropriate opportunities for entrepreneurs, small ceramic and entrepreneurs with new investments or those who want to produce ceramic products as a hobby. The community interest in the pottery to create a new one to continue the product development and manufacturing in the harshest existence forever.

Keywords: ceramics kiln design and development, ceramic gas kiln, burners application, high-pressure of household gas stove

Procedia PDF Downloads 549

Authors: Fatma Zuhrotun Nisa, Aprilina Ratriany, Agus Wijanarka

Abstract:

Background: Cassava leaves are widely used by the people of Indonesia as a vegetable and treat various diseases, including anticancer believed as food. However, not much research on the anticancer activity of cassava leaves, especially in colon cancer. Objectives: the aim of this study is to investigate anti-cancer activity of cassava leaves (Manihot esculanta C.) against colon cancer (WiDr) cells in vitro. Methods: effect of crude aqueous extract of leaves of cassava and cassava leaves boiled tested in colon cancer cells widr. Determination of Anticancer uses the MTT method with parameters such as the percentage of deaths. Results: raw cassava leaf water extract gave IC50 of 63.1 mg / ml. While the water extract of boiled cassava leaves gave IC50 of 79.4 mg/ml. However, there is no difference anticancer activity of raw cassava leaves or cancer (p> 0.05). Conclusion: Cassava leaves contain a variety of compounds that have previously been reported to have anticancer activity. Linamarin, β-carotene, vitamin C, and fiber were thought to affect the IC50 cassava leaf extract against colon cancer cells WiDr.

Keywords: boiled cassava leaves, cassava leaves raw, anticancer activity, colon cancer, IC50

Procedia PDF Downloads 551

Authors: Mahdi Fakoor, Seyed Mohammad Navid Ghoreishi

Abstract:

Initiation and propagation of cracks may cause catastrophic failures in rotating disks, and hence determination of fracture parameter in rotating disks under the different working condition is very important issue. In this paper, a comprehensive study of stress intensity factors in rotating disks containing 3D semi-elliptical cracks under the different working condition is investigated. In this regard, after verification of modeling and analytical procedure, the effects of mechanical properties, rotational velocity, and orientation of cracks on Stress Intensity Factors (SIF) in rotating disks under centrifugal loading are investigated. Also, the effects of using composite patch in reduction of SIF in rotating disks are studied. By that way, the effects of patching design variables like mechanical properties, thickness, and ply angle are investigated individually.

Keywords: stress intensity factor, semi-elliptical crack, rotating disk, finite element analysis (FEA)

Procedia PDF Downloads 364

Authors: Vadim Allheily, Rudiger Schmitt, Lionel Merlat, Gildas L'Hostis

Abstract:

Inflight devices are nowadays major actors in both military and civilian landscapes. Among others, missiles, mortars, rockets or even drones this last decade are increasingly sophisticated, and it is today of prior manner to develop always more efficient defensive systems from all these potential threats. In this frame, recent High Energy Laser weapon prototypes (HEL) have demonstrated some extremely good operational abilities to shot down within seconds flying targets several kilometers off. Whereas test outcomes are promising from both experimental and cost-related perspectives, the deterioration process still needs to be explored to be able to closely predict the effects of a high-energy laser irradiation on typical structures, heading finally to an effective design of laser sources and protective countermeasures. Laser matter interaction researches have a long history of more than 40 years at the French-German Research Institute (ISL). Those studies were tied with laser sources development in the mid-60s, mainly for specific metrology of fast phenomena. Nowadays, laser matter interaction can be viewed as the terminal ballistics of conventional weapons, with the unique capability of laser beams to carry energy at light velocity over large ranges. In the last years, a strong focus was made at ISL on the interaction process of laser radiation with metal targets such as artillery shells. Due to the absorbed laser radiation and the resulting heating process, an encased explosive charge can be initiated resulting in deflagration or even detonation of the projectile in flight. Drones and Unmanned Air Vehicles (UAVs) are of outmost interests in modern warfare. Those aerial systems are usually made up of polymer-based composite materials, whose complexity involves new scientific challenges. Aside this main laser-matter interaction activity, a lot of experimental and numerical knowledge has been gathered at ISL within domains like spectrometry, thermodynamics or mechanics. Techniques and devices were developed to study separately each aspect concerned by this topic; optical characterization, thermal investigations, chemical reactions analysis or mechanical examinations are beyond carried out to neatly estimate essential key values. Results from these diverse tasks are then incorporated into analytic or FE numerical models that were elaborated, for example, to predict thermal repercussion on explosive charges or mechanical failures of structures. These simulations highlight the influence of each phenomenon during the laser irradiation and forecast experimental observations with good accuracy.

Keywords: composite materials, countermeasure, experimental work, high-energy laser, laser-matter interaction, modeling

Procedia PDF Downloads 263

Authors: Christian Gabriel Mariveles, Darelle Jay Gallardo, Leslie Dayaoen, Laurenz Paul Diaz

Abstract:

True experimental research with descriptive analysis was conducted. Utilizing Quicklime (Calcium Oxide) for self-healing properties of coconut husk fibre concrete brick. There are 2 setups established: the first one has the 1:1:2 ratio of calcium oxide, cement and sand, and the second one has a 2:1:2 ratio of the same variables. The bricks are made from the residences along Barangay Greater Lagro. The mixture of sand and cement is mixed with coconut husk fibers and then molded with different ratios in the molder. After the drying of cement, the researchers tested the bricks in the laboratory for compressive strength. The brick with the highest PSI is picked by the researchers to drop into freefall testing, and it makes remarkable remarks as it is deformed after dropping to different heights with a maximum of 20 feet. Unfortunately, the self-healing capabilities were not observed during the 12 weeks of monitoring. However, the brick was weighed after 12 weeks of monitoring, and it increased in weight by 0.030 kg. from 1.833 kg. to 1.863 kg. meaning that this ratio 2 has the potential to self-heal, but 12 weeks of monitoring by the researchers is not enough to conclude that it has a significant difference.

Keywords: self healing, coconut husk bricks, research, calcium oxide, utilizing quicklime

Procedia PDF Downloads 42

Authors: Samah Benmerbi, Kamal Amroun, Abdelkamel Tari

Abstract:

The increasing number of Web service (WS)providers throughout the globe, have produced numerous Web services providing the same or similar functionality. Therefore, there is a need of tools developing the best answer of queries by selecting and composing services with total transparency. This paper reviews various QoS based Web service selection mechanisms and architectures which facilitate qualitatively optimal selection, in other fact Web service composition is required when a request cannot be fulfilled by a single web service. In such cases, it is preferable to integrate existing web services to satisfy user’s request. We introduce an automatic Web service composition method based on hypergraph decomposition using hypertree decomposition method. The problem of selection and the composition of the web services is transformed into a resolution in a hypertree by exploring the relations of dependency between web services to get composite web service via employing an execution order of WS satisfying global request.

Keywords: web service, web service selection, web service composition, QoS, hypergraph decomposition, BE hypergraph decomposition, hypertree resolution

Procedia PDF Downloads 509

Authors: M. Nerantzaki, I. Koliakou, D. Bikiaris

Abstract:

This study evaluates the hypothesis that the incorporation of fibrous hydroxyapatite nanoparticles (nHA) with high crystallinity and high aspect ratio, synthesized by hydrothermal method, into Poly(butylene succinate) (PBSu), improves the bioactivity of the aliphatic polyester and affects new bone growth inhibiting resorption and enhancing bone formation. Hydroxyapatite nanorods were synthesized using a simple hydrothermal procedure. First, the HPO42- -containing solution was added drop-wise into the Ca2+-containing solution, while the molar ratio of Ca/P was adjusted at 1.67. The HA precursor was then treated hydrothermally at 200°C for 72 h. The resulting powder was characterized using XRD, FT-IR, TEM, and EDXA. Afterwards, PBSu nanocomposites containing 2.5wt% (nHA) were prepared by in situ polymerization technique for the first time and were examined as potential scaffolds for bone engineering applications. For comparison purposes composites containing either 2.5wt% micro-Bioglass (mBG) or 2.5wt% mBG-nHA were prepared and studied, too. The composite scaffolds were characterized using SEM, FTIR, and XRD. Mechanical testing (Instron 3344) and Contact Angle measurements were also carried out. Enzymatic degradation was studied in an aqueous solution containing a mixture of R. Oryzae and P. Cepacia lipases at 37°C and pH=7.2. In vitro biomineralization test was performed by immersing all samples in simulated body fluid (SBF) for 21 days. Biocompatibility was assessed using rat Adipose Stem Cells (rASCs), genetically modified by nucleofection with DNA encoding SB100x transposase and pT2-Venus-neo transposon expression plasmids in order to attain fluorescence images. Cell proliferation and viability of cells on the scaffolds were evaluated using fluoresce microscopy and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide) assay. Finally, osteogenic differentiation was assessed by staining rASCs with alizarine red using cetylpyridinium chloride (CPC) method. TEM image of the fibrous HAp nanoparticles, synthesized in the present study clearly showed the fibrous morphology of the synthesized powder. The addition of nHA decreased significantly the contact angle of the samples, indicating that the materials become more hydrophilic and hence they absorb more water and subsequently degrade more rapidly. In vitro biomineralization test confirmed that all samples were bioactive as mineral deposits were detected by X-ray diffractometry after incubation in SBF. Metabolic activity of rASCs on all PBSu composites was high and increased from day 1 of culture to day 14. On day 28 metabolic activity of rASCs cultured on samples enriched with bioceramics was significantly decreased due to possible differentiation of rASCs to osteoblasts. Staining rASCs with alizarin red after 28 days in culture confirmed our initial hypothesis as the presence of calcium was detected, suggesting osteogenic differentiation of rACS on PBSu/nHAp/mBG 2.5% and PBSu/mBG 2.5% composite scaffolds.

Keywords: biomaterials, hydroxyapatite nanorods, poly(butylene succinate), scaffolds

Procedia PDF Downloads 308

Authors: Shalluf Milad

Abstract:

Tomatoes are widely produced and consumed due to their nutritional content and versatility. However, the tomato is a soft fruit liable to damage and flavour deterioration. Hence, the main challenge for the tomato producing industry is to prevent the high loss incurred during harvest, handling and transportation of the crops. The objective of this study was to investigate the overall nutritional implication of controlled storage of tomatoes using ozone on the basic nutritional components of tomatoes. This investigation was also designed to focus on the effect of different ozone doses on the basic components (antioxidant activity). Green, yellow and red stages of ripeness (elegance tomatoes), were harvested at different dates for each experiment. The tomatoes were cleaned and placed inside the glass reactors and ozonated at 0.25, 0.50 and 1 mg O3/g tomatoes and clean air respectively for 5 days at 15°C ± 2 and 90-95 % relative humidity respectively. The fruits were analysed for total antioxidant activity. Analysis of the fruits clearly showed that antioxidant activity in the pericarp tissue was the lowest (P<0.001) compared with the pulp tissue of tomatoes during storage in the red stage of maturity, after being treated with ozone in the atmosphere of storage in a dose of 1.00 mgO3/g tomatoes. It can be concluded from this study that the use of ozone in the atmospheres of storage and handling of fresh products maintains the important compounds of these products while maintaining the nutritional value and health quality.

Keywords: post-harvest treatment, controlled atmosphere storage, ozone, tomatoes, antioxidant activity

Procedia PDF Downloads 327

Authors: Ahmed M. Ashteyat

Abstract:

Artificial Neural Network (ANN) models have been widely used in material modeling, inter-correlations, as well as behavior and trend predictions when the nonlinear relationship between system parameters cannot be quantified explicitly and mathematically. In this paper, ANN was used to predict the residual modulus of elasticity (RME) of self compacted concrete (SCC) damaged by heat. The ANN model was built, trained, tested and validated using a total of 112 experimental data sets, gathered from available literature. The data used in model development included temperature, relative humidity conditions, mix proportions, filler types, and fiber type. The result of ANN training, testing, and validation indicated that the RME of SCC, exposed to different temperature and relative humidity levels, could be predicted accurately with ANN techniques. The reliability between the predicated outputs and the actual experimental data was 99%. This show that ANN has strong potential as a feasible tool for predicting residual elastic modulus of SCC damaged by heat within the range of input parameter. The ANN model could be used to estimate the RME of SCC, as a rapid inexpensive substitute for the much more complicated and time consuming direct measurement of the RME of SCC.

Keywords: residual modulus of elasticity, artificial neural networks, self compacted-concrete, material modeling

Procedia PDF Downloads 534

Authors: Jeffrey Cacho, Sherwin Reyes

Abstract:

The research targeted enhancing energy utilization and reducing waste in roasting processes, particularly in Camarines Norte, where Bounty Agro Ventures Incorporated dominates through brands such as Chooks-to-Go, Uling Roaster, and Reyal. Competitors like Andok’s and Baliwag Lechon Manok also share the market. A staggering 90% of these businesses use traditional glass-type roasting furnaces fueled by wood charcoal, leading to significant energy loss and inefficiency due to suboptimal heat conservation. Only a mere 10% employ electric ovens. Many available furnaces, typically constructed from industrial materials through welding and other metal joining techniques, are not energy-efficient. Cost-prohibitive commercial options compel some micro-enterprises to fabricate their furnaces. The study proposed developing an eco-friendly, cost-effective roasting furnace with excellent heat retention. The distinct design aimed to reduce cooks' heat exposure and overall fuel consumption. The furnace features an angle bar frame, a combustion chute for fuel burning, a heat-retaining clay-walled chamber, and a top cover, all contributing to improved energy savings and user safety.

Keywords: biomass roasting furnace, heat storage, combustion chute, start-up roasting business

Procedia PDF Downloads 53

Authors: Chanunya Fahwan, Supat Chaiyakul

Abstract:

A lactose-free diet is imperative for those with lactose intolerance and experiencing milk intolerance. This entails eliminating milk-based products, which may result in dietary and nutritional challenges and the main problems of Lactose hydrolyzed milk powder during production were the adhesion in the drying chamber and low-yield and low-quality powder. The use of lactose-free milk to produce lactose-free milk powder was studied here. Development of two milk powder formulas from cow's milk and lactose-free cow's milk by using a substitute for maltodextrin, Polydextrose (PDX), Resistant Starch (RS), Cellobiose (CB), and Resistant Maltodextrin (RMD) to improve quality and reduce the glycemic index from maltodextrin, which are carriers that were used in industry at three experimental levels 10%, 15% and 20% the properties of milk powder were studied such as color, moisture content, percentage yield (%yield) and solubility index. The experiment revealed that prebiotic carriers could replace maltodextrin and improve quality, such as solubility and percentage yield, and enriched nutrients, such as dietary fiber. CB, RMD, and PDX are three possible carriers, which are applied to both regular cow's milk formula and lactose-free cow milk.

Keywords: lactose-free milk powder, prebiotic carrier, co-particle, glycemic index

Procedia PDF Downloads 82

Authors: Maiss Razem

Abstract:

The construction sector is considered a major consumer of materials that undergoes processes of extraction, processing, transportation, and maintaining when used in buildings. Several metrics have been devised to capture the environmental impact of the materials consumed during construction using lifecycle thinking. Rarely has the materiality of this sector been explored qualitatively and systemically. This paper aims to explore socio-cultural forces that drive the use of certain materials in the Jordanian construction industry, using practice theory as a heuristic method of analysis, more specifically Shove et al. three-element model. By conducting semi-structured interviews with architects, the results unravel contextually embedded routines when determining qualities of three materialities highlighted herein; stone, glass and spatial openness. The study highlights the inadequacy of only using efficiency as a quantitative metric of sustainable materials and argues for the need to link material consumption with socio-economic, cultural, and aesthetic driving forces. The operationalization of practice theory by tracing materials’ lifetimes as they integrate with competencies and meanings captures dynamic engagements through the analyzed routines of actors in the construction practice. This study can offer policymakers better-nuanced representation to green this sector beyond efficiency rhetoric and quantitative metrics.

Keywords: architects' practices, construction materials, Jordan, practice theory

Procedia PDF Downloads 169