Search results for: post-translational modification
974 White Light Emitting Carbon Dots- Surface Modification of Carbon Dots Using Auxochromes
Authors: Manasa Perikala, Asha Bhardwaj
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Fluorescent carbon dots (CDs), a young member of Carbon nanomaterial family, has gained a lot of research attention across the globe due to its highly luminescent emission properties, non-toxic behavior, stable emission properties, and zero re-absorption lose. These dots have the potential to replace the use of traditional semiconductor quantum dots in light-emitting devices (LED’s, fiber lasers) and other photonic devices (temperature sensor, UV detector). However, One major drawback of Carbon dots is that, till date, the actual mechanism of photoluminescence (PL) in carbon dots is still an open topic of discussion among various researchers across the globe. PL mechanism of CDs based on wide particle size distribution, the effect of surface groups, hybridization in carbon, and charge transfer mechanisms have been proposed. Although these mechanisms explain PL of CDs to an extent, no universally accepted mechanism to explain complete PL behavior of these dots is put forth. In our work, we report parameters affecting the size and surface of CDs, such as time of the reaction, synthesis temperature and concentration of precursors and their effects on the optical properties of the carbon dots. The effect of auxochromes on the emission properties and re-modification of carbon surface using an external surface functionalizing agent is discussed in detail. All the explanations have been supported by UV-Visible absorption, emission spectroscopies, Fourier transform infrared spectroscopy and Transmission electron microscopy and X-Ray diffraction techniques. Once the origin of PL in CDs is understood, parameters affecting PL centers can be modified to tailor the optical properties of these dots, which can enhance their applications in the fabrication of LED’s and other photonic devices out of these carbon dots.Keywords: carbon dots, photoluminescence, size effects on emission in CDs, surface modification of carbon dots
Procedia PDF Downloads 127973 Enhanced of Corrosion Resistance of Carbon Steel C1018 with Nano-Tio2 Films Using Dip-Coating Method
Authors: Mai M. Khalaf, Hany M. Abd El-Lateef
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A new good application for the sol gel method is to improve the corrosion inhibition properties of carbon steel by the dip coating method of Nano TiO2 films and its modification with Poly Ethylene Glycol (PEG). The prepared coating samples were investigated by different techniques, X-ray diffraction, Scanning Electron Microscopy (SEM), transmission electron microscopy and Energy Dispersive X-ray Spectroscopy (EDAX). The corrosion inhibition performance of the blank carbon steel and prepared coatings samples were evaluated in 0.5 M H2SO4 by using Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization measurements. The results showed that corrosion resistance of carbon steel increases with increasing the number of coated layers of both nano–TiO2 films and its modification of PEG. SEM-EDAX analyses confirmed that the percentage atomic content of iron for the carbon steel in 0.5 M H2SO4 is 83% and after the deposition of the steel in nano TiO2 sol and that with PEG are 94.3% and 93.7% respectively.Keywords: dip-coatings, corrosion protection, sol gel, TiO2 films, PEG
Procedia PDF Downloads 419972 Process Modified Geopolymer Concrete: A Sustainable Material for Green Construction Technology
Authors: Dibyendu Adak, Saroj Mandal
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The fly ash based geopolymer concrete generally requires heat activation after casting, which has been considered as an important limitation for its practical application. Such limitation can be overcome by a modification in the process at the time of mixing of ingredients (fly and activator fluid) for geopolymer concrete so that curing can be made at ambient temperature. This process modified geopolymer concrete shows an appreciable improvement in structural performance compared to conventional heat cured geopolymer concrete and control cement concrete. The improved durability performance based on water absorption, sulphate test, and RCPT is also noted. The microstructural properties analyzed through Field Emission Scanning Electron Microscope (FESEM) with Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD) techniques show the better interaction of fly ash and activator solution at early ages for the process modified geopolymer concrete. This accelerates the transformation of the amorphous phase of fly ash to the crystalline phase.Keywords: fly ash, geopolymer concrete, process modification, structural properties, durability, micro-structures
Procedia PDF Downloads 157971 Fly Ash Derived Zeolites as Potential Sorbents for Elemental Mercury Removal from Simulated Gas Stream
Authors: Piotr Kunecki, Magdalena Wdowin
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The fly ash produced as waste in the process of conventional coal combustion was utilized in the hybrid synthesis of zeolites X and A from Faujasite (FAU) and Linde Type A (LTA) frameworks, respectively. The applied synthesis method included modification together with the crystallization stage. The sorbent modification was performed by introducing metals into the zeolite structure in order to create an ability to form stable bonds with elemental mercury (Hg0). The use of waste in the form of fly ash as a source of silicon and aluminum, as well as the proposed method of zeolite synthesis, fits the circular economy idea. The effect of zeolite modification on Hg0 removal from a simulated gas stream was studied empirically using prototype installation designed to test the effectiveness of sorption by solid-state sorbents. Both derived zeolites X and A modified with silver nitrate revealed significant mercury uptake during a 150-minute sorption experiment. The amount of elemental mercury removed in the experiment ranged from 5.69 to 6.01 µg Hg0/1g of sorbent for zeolites X and from 4.47 to 4.86 µg Hg0/1g of sorbent for zeolites A. In order to confirm the effectiveness of the sorbents towards mercury bonding, the possible re-emission effect was tested as well. Derived zeolites X and A did not show mercury re-emission after the sorption process, which confirms the stable bonding of Hg0 in the structure of synthesized zeolites. The proposed hybrid synthesis method possesses the potential to be implemented for both fly ash utilization as well as the time and energy-saving production of aluminosilicate, porous materials with high Hg0 removal efficiency. This research was supported by National Science Centre, Poland, grant no 2021/41/N/ST5/03214.Keywords: fly ash, synthetic zeolites, elemental mercury removal, sorption, simulated gas stream
Procedia PDF Downloads 78970 Surface Modification of Polyethylene Terephthalate Substrates via Direct Fluorination to Promote the Ag+ Ions Adsorption
Authors: Kohei Yamamoto, Jae-Ho Kim, Susumu Yonezawa
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The surface of polyethylene terephthalate (PET) was modified with fluorine gas at 25 ℃ and 100 Torr for one h. Moreover, the effect of ethanol washing on surface modification was investigated in this study. The surface roughness of the fluorinated and washed PET samples was approximately six times larger than that (0.6 nm) of the untreated thing. The results of Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy showed that the bonds such as -C=O and -C-Hx derived from raw PET decreased and were converted into fluorinated bonds such as -CFx after surface fluorination. Even after washing with ethanol, the fluorinated bonds stably existed on the surface. These fluorinated bonds showed higher electronegativity according to the zeta potential results. The negative surface charges were increased by washing the ethanol, and it caused to increase in the number of polar groups such as -CHF- and -C-Fx. The fluorinated and washed surface of PET could promote the adsorption of Ag+ ions in AgNO₃ solution because of the increased surface roughness and the negatively charged surface.Keywords: Ag+ ions adsorption, polyethylene terephthalate, surface fluorination, zeta potential
Procedia PDF Downloads 118969 Induction of HIV-1 Resistance: The New Approaches Based on Gene Modification and Stem Cell Engineering
Authors: Alieh Farshbaf
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Introduction: Current anti-retroviral drugs have some restrictions for treatment of HIV-1 infection. The efficacy of retroviral drugs is not same in different infected patients and the virus rebound from latent reservoirs after stopping them. Recently, the engineering of stem cells and gene therapy provide new approaches to eliminate some drug problems by induction of resistance to HIV-1. Literature review: Up to now, AIDS-restriction genes (ARGs) were suitable candidate for gene and cell therapies, such as cc-chemokine receptor-5 (CCR5). In this manner, CCR5 provide effective cure in Berlin and Boston patients by inducing of HIV-1 resistance with allogeneic stem cell transplantation. It is showed that Zinc Finger Nuclease (ZFN) could induce HIV-1 resistance in stem cells of infected patients by homologous recombination or non-end joining mechanism and eliminate virus loading after returning the modified cells. Then, gene modification by HIV restriction factors, as TRIM5, introduced another gene candidate for HIV by interfering in infection process. These gene modifications/editing provided by stem cell futures that improve treatment in refractory disease such as HIV-1. Conclusion: Although stem cell transplantation has some complications, but in compare to retro-viral drugs demonstrated effective cure by elimination of virus loading. On the other hand, gene therapy is cost-effective for an infected patient than retroviral drugs payment in a person life-long. The results of umbilical cord blood stem cell transplantation showed that gene and cell therapy will be applied easier than previous treatment of AIDS with high efficacy.Keywords: stem cell, AIDS, gene modification, cell engineering
Procedia PDF Downloads 295968 Stabilization of Pb, Cr, Cd, Cu and Zn in Solid Waste and Sludge Pyrolysis by Modified Vermiculite
Authors: Yuxuan Yang, Zhaoping Zhong
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Municipal solid waste and sludge are important sources of waste energy and their proper disposal is of great importance. Pyrolysis can fully decompose solid wastes and sludge, and the pyrolysis products (charcoal, oil and gas) have important recovery values. Due to the complex composition of solid wastes and sludge, the pyrolysis process at high temperatures is prone to heavy metal emissions, which are harmful to humans and the environment and reduce the safety of pyrolysis products. In this paper, heavy metal emissions during pyrolysis of municipal sewage sludge, paper mill sludge, municipal domestic waste, and aged refuse at 450-650°C were investigated and the emissions and hazards of heavy metals (Pb, Cr, Cd, Cu and Zn) were effectively reduced by adding modified vermiculite as an additive. The vermiculite was modified by intercalation with cetyltrimethylammonium bromide, which resulted in more than twice the original layer spacing of the vermiculite. Afterward, the interpolated vermiculite was made into vermiculite flakes by exfoliation modification. After that, the expansion rate of vermiculite flakes was increased by Mg2+ modification and thermal activation. The expanded vermiculite flakes were acidified to improve the textural characteristics of the vermiculite. The modified vermiculite was analysed by XRD, FT-IR, BET and SEM to clarify the modification effect. The incorporation of modified vermiculite resulted in more than 80% retention of all heavy metals at 450°C. Cr, Cu and Zn were better retained than Pb and Cd. The incorporation of modified vermiculite effectively reduced the risk of heavy metals, and all risks were low for Pb, Cr, Cu and Zn. The toxicity of all heavy metals was greatly reduced by the incorporation of modified vermiculite and the morphology of heavy metals was transformed from Exchangeable and acid-soluble (F1) and Reducible (F2) to Oxidizable (F3) and Residual (F4). In addition, the increase in temperature favored the stabilization of heavy metal forms. This study provides a new insight into the cleaner use of energy and the safe management of solid waste.Keywords: heavy metal, pyrolysis, vermiculite, solid waste
Procedia PDF Downloads 59967 Experimental Study of Nucleate Pool Boiling Heat Transfer Characteristics on Laser-Processed Copper Surfaces of Different Patterns
Authors: Luvindran Sugumaran, Mohd Nashrul Mohd Zubir, Kazi Md Salim Newaz, Tuan Zaharinie Tuan Zahari, Suazlan Mt Aznam, Aiman Mohd Halil
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With the fast growth of integrated circuits and the trend towards making electronic devices smaller, the heat dissipation load of electronic devices has continued to go over the limit. The high heat flux element would not only harm the operation and lifetime of the equipment but would also impede the performance upgrade brought about by the iteration of technological updates, which would have a direct negative impact on the economic and production cost benefits of rising industries. Hence, in high-tech industries like radar, information and communication, electromagnetic power, and aerospace, the development and implementation of effective heat dissipation technologies were urgently required. Pool boiling is favored over other cooling methods because of its capacity to dissipate a high heat flux at a low wall superheat without the usage of mechanical components. Enhancing the pool boiling performance by increasing the heat transfer coefficient via surface modification techniques has received a lot of attention. There are several surface modification methods feasible today, but the stability and durability of surface modification are the greatest priority. Thus, laser machining is an interesting choice for surface modification due to its low production cost, high scalability, and repeatability. In this study, different patterns of laser-processed copper surfaces are fabricated to investigate the nucleate pool boiling heat transfer performance of distilled water. The investigation showed that there is a significant enhancement in the pool boiling heat transfer performance of the laser-processed surface compared to the reference surface due to the notable increase in nucleation frequency and nucleation site density. It was discovered that the heat transfer coefficients increased when both the surface area ratio and the ratio of peak-to-valley height of the microstructure were raised. It is believed that the development of microstructures on the surface as a result of laser processing is the primary factor in the enhancement of heat transfer performance.Keywords: heat transfer coefficient, laser processing, micro structured surface, pool boiling
Procedia PDF Downloads 77966 Effect of TEOS Electrospun Nanofiber Modified Resin on Interlaminar Shear Strength of Glass Fiber/Epoxy Composite
Authors: Dattaji K. Shinde, Ajit D. Kelkar
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Interlaminar shear strength (ILSS) of fiber reinforced polymer composite is an important property for most of the structural applications. Matrix modification is an effective method used to improve the interlaminar shear strength of composite. In this paper, EPON 862/w epoxy system was modified using Tetraethyl orthosilicate (TEOS) electrospun nanofibers (ENFs) which were produced using electrospinning method. Unmodified and nanofibers modified resins were used to fabricate glass fiber reinforced polymer composite (GFRP) using H-VARTM method. The ILSS of the Glass Fiber Reinforced Polymeric Composites (GFRP) was investigated. The study shows that introduction of TEOS ENFs in the epoxy resin enhanced the ILSS of GFRPby 15% with 0.6% wt. fraction of TEOS ENFs.Keywords: electrospun nanofibers, H-VARTM, interlaminar shear strength, matrix modification
Procedia PDF Downloads 214965 Extraction, Synthesis, Characterization and Antioxidant Properties of Oxidized Starch from an Abundant Source in Nigeria
Authors: Okafor E. Ijeoma, Isimi C. Yetunde, Okoh E. Judith, Kunle O. Olobayo, Emeje O. Martins
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Starch has gained interest as a renewable and environmentally compatible polymer due to the increase in its use. However, starch by itself could not be satisfactorily applied in industrial processes due to some inherent disadvantages such as its hydrophilic character, poor mechanical properties, its inability to withstand processing conditions such as extreme temperatures, diverse pH, high shear rate, freeze-thaw variation and dimensional stability. The range of physical properties of parent starch can be enlarged by chemical modification which invariably enhances their use in a number of applications found in industrial processes and food manufacture. In this study, Manihot esculentus starch was subjected to modification by oxidation. Fourier Transmittance Infra- Red (FTIR) and Raman spectroscopies were used to confirm the synthesis while Scanning Electron Microscopy (SEM) and X- Ray Diffraction (XRD) were used to characterize the new polymer. DPPH (2, 2-diphenyl-1-picryl-hydrazyl-hydrate) free radical assay was used to determine the antioxidant property of the oxidized starch. Our results show that the modification had no significant effect on the foaming capacity as well as on the emulsion capacity. Scanning electron microscopy revealed that oxidation did not alter the predominantly circular-shaped starch granules, while the X-ray pattern of both starch, native and modified were similar. FTIR results revealed a new band at 3007 and 3283cm-1. Differential scanning calorimetry returned two new endothermic peaks in the oxidized starch with an improved gelation capacity and increased enthalpy of gelatinization. The IC50 of oxidized starch was notably higher than that of the reference standard, ascorbic acid.Keywords: antioxidant activity, DPPH, M. esculentus, oxidation, starch
Procedia PDF Downloads 293964 Type 2 Diabetes Mellitus Among a St. Lucian Population: What We Know about Lifestyle Modification
Authors: Bradley Fevrier
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Background: Type 2 diabetes mellitus, a non-communicable metabolic disorder, is a fast-growing problem for health, as it presents numerous complications and death worldwide. St. Lucia, much like most other emerging nation in the Caribbean, struggles with the management of type 2 diabetes mellitus (T2DM) among its populace. Good knowledge, attitude, and practices [KAP] of T2DM are essential in the prevention and management of this disease.Lifestyle adaptation, including increased knowledge, positive attitude, and efficient practice towards lifestyle modifications, can avert the advancement of difficulties associated with diabetes. Methods: An institutional-based cross-sectional study was conducted during the period June 15, 2022, to July15 2022. Data were collected by using the self-administered questionnaire designed to collect the required information from participants, and the data wasanalyzed using the statistical package for social science (SPSS) version 26. Knowledge, attitude, and practice of lifestyle modification among participants were determined using descriptive statistics. Results: A total of 402 participants completed the study, fully yielding an 84% response rate. Overall, the assessed levels of KAP relating to the life-threatening complications of T2DM were moderate. Results further indicated that women outnumbered men 68.4% to 31.6%, respectively. Significant positive correlation (r= 0.244, p<0.001) and (r=.203, p<0.001) were found between the knowledge level as well as the attitude level of study respondents. Conclusion: The overall study findings regarding the level of knowledge and attitude concerning lifestyle modifications among study participants were interpreted as generally high. However, the practice of healthy lifestyle modification habits was poor. The current findings suggest a need for structured educational campaigns prioritizing the importance of lifestyle modifications (weight loss, smoking cessation, physical exercise) to the general population.Keywords: Diabetes, knowledge, lifestyle, survey
Procedia PDF Downloads 124963 Influence of Pier Modification Techniques for Reducing Scour around Bridge Piers
Authors: Rashid Farooq, Abdul Razzaq Ghumman, Hashim Nisar Hashmi
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Bridge piers often fail all over the world and the whole structure may be endangered due to scouring phenomena. Scouring has been linked to catastrophic failures that lead into the loss of human lives. Various techniques have been employed to extenuate the scouring process in order to assist the bridge designs. Pier modifications plays vital role to control scouring at the vicinity of the pier. This experimental study aims at monitoring the effectiveness of pier modification and temporal development of scour depth around a bridge pier by providing a collar, a cable or openings under the same flow conditions. Provision of a collar around the octagonal pier reduced more scour depth than that for other two configurations. Providing a collar around the octagonal pier found to be the best in reducing scour. The scour depth in front of pier was found to be 19.5% less than that at the octagonal pier without any modifications. Similarly, the scour depth around the octagonal pier having provision of a cable was less than that at pier with provision of openings. The scour depth around an octagonal pier was also compared with a plain circular pier and found to be 9.1% less.Keywords: Scour, octagonal pier, collar, cable
Procedia PDF Downloads 261962 Preparation of New Organoclays and Applications for Adsorption of Telon Dyes in Aqueous Solutions
Authors: Benamar Makhoukhi
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Clay ion-exchange using bismidazolium salts (MBIM) could provide organophilic clays materials that allow effective retention of polluting dyes. The present investigations deal with bentonite (Bt) modification using (ortho, meta and para) bisimidazolium cations and attempts to remove a synthetic textile dyes, such as (Telon-Orange, Telon-Red and Telon-Blue) by adsorption, from aqueous solutions. The surface modification of MBIM–Bt was examined using infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Adsorption tests applied to Telon dyes revealed a significant increase of the maximum adsorption capacity from ca. 21-28 to 88-108 mg.g-1 after intercalation. The highest adsorption level was noticed for Telon-Orange dye on the p-MBIM–Bt, presumably due higher interlayer space and better diffusion. The pseudo-first order rate equation was able to provide the best description of adsorption kinetics data for all three dyestuffs. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were also determined. The results show that MBIM–Bt could be employed as low-cost material for the removal of Telon dyes from effluents.Keywords: Bentonite, Organoclay, Bisimidazolium, Dyes, Isotherms, Adsorption
Procedia PDF Downloads 438961 Development of Surface Modification Technology for Control Element Drive Mechanism Nozzle and Fatigue Enhancement of Ni-Based Alloys
Authors: Auezhan Amanov, Inho Cho, Young-Sik Pyun
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Control element drive mechanism (CEDM) nozzle is manufactured as welded on the reactor vessel and currently uses Alloy 690 material. The top of the reactor is equipped with about 100 CEDM nozzles with an internal diameter of about 70 mm. Relatively large Inlet/Outlet nozzles are equipped with two outlet nozzles and four inlet nozzles on the reactor wall. The inner diameter of the nozzle is vulnerable to stress corrosion cracking (SCC), and in order to solve this problem, an ultrasonic nanocrystal surface modification (UNSM) treatment is performed on the inner diameter of the nozzle and the weld surface. The ultimate goal is to improve the service life of parts by applying compressive residual stress and suppressing primary water stress corrosion cracking (PWSCC). The main purpose is to design and fabricate a UNSM treatment device for the internal diameter processing of CEDM nozzles and inlet/outlet nozzles. In order to develop the system, the basic technology such as the development of UNSM tooling is developed and the mechanical properties and fatigue performance of before and after UNSM treatment of reactor nozzle material made of Ni-based alloys using the specimen are compared and evaluated. The inner diameter of the nozzle was treated by a newly developed UNSM treatment under the optimized treatment parameters. It was found that the mechanical properties and fatigue performance of nozzle were improved in comparison with the untreated nozzle, which may be attributed to the increase in hardness, induced compressive residual stress.Keywords: control element drive mechanism nozzle, fatigue, Ni-based alloy, ultrasonic nanocrystal surface modification, UNSM
Procedia PDF Downloads 106960 Superhydrophobic Behavior of SnO₂-TiO₂ Composite Thin Films
Authors: Debarun Dhar Purkayastha, Talinungsang
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SnO₂-TiO₂ nanocomposite thin films were prepared by the sol-gel method on borosilicate glass substrate. The films were annealed at a temperature of 300ᵒC, 400ᵒC, and 500ᵒC respectively for 2h in the air. The films obtained were further modified with stearic acid in order to decrease the surface energy. The X-ray diffraction patterns for the SnO₂-TiO₂ thin films after annealing at different temperatures can be indexed to the mixture of TiO₂ (rutile and anatase) and SnO₂ (tetragonal) phases. The average crystallite size calculated from Scherrer’s formula is found to be 6 nm. The SnO₂-TiO₂ thin films were hydrophilic which on modification with stearic acid exhibit superhydrophobic behavior. The increase in hydrophobicity of SnO₂ film with stearic acid modification is attributed to the change in surface energy of the film. The films exhibit superhydrophilic behavior under UV irradiation for 1h. Thus, it is observed that stearic acid modified surfaces are superhydrophobic but convert into superhydrophilic on being subjected to UV irradiation. SnO₂-TiO₂ thin films have potential for self-cleaning applications because of photoinduced hydrophilicity under UV irradiation.Keywords: nanocomposite, self-cleaning, superhydrophobic, surface energy
Procedia PDF Downloads 176959 Study Properties of Bamboo Composite after Treatment Surface by Chemical Method
Authors: Kiatnarong Supapanmanee, Ekkarin Phongphinittana, Pongsak Nimdum
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Natural fibers are readily available raw materials that are widely used as composite materials. The most common problem facing many researchers with composites made from this fiber is the adhesion between the natural fiber contact surface and the matrix material. Part of the problem is due to the hydrophilic properties of natural fibers and the hydrophobic properties of the matrix material. Based on the aforementioned problems, this research selected bamboo fiber, which is a strong natural fiber in the research study. The first step was to study the effect of the mechanical properties of the pure bamboo strip by testing the tensile strength of different measurement lengths. The bamboo strip was modified surface with sodium hydroxide (NaOH) at 6wt% concentrations for different soaking periods. After surface modification, the physical and mechanical properties of the pure bamboo strip fibers were studied. The modified and unmodified bamboo strips were molded into a composite material using epoxy as a matrix to compare the mechanical properties and adhesion between the fiber surface and the material with tensile and bending tests. In addition, the results of these tests were compared with the finite element method (FEM). The results showed that the length of the bamboo strip affects the strength of the fibers, with shorter fibers causing higher tensile stress. Effects of surface modification of bamboo strip with NaOH, this chemical eliminates lignin and hemicellulose, resulting in the smaller dimension of the bamboo strip and increased density. From the pretreatment results above, it was found that the treated bamboo strip and composite material had better Ultimate tensile stress and Young's modulus. Moreover, that results in better adhesion between bamboo fiber and matrix material.Keywords: bamboo fiber, bamboo strip, composite material, bamboo composite, pure bamboo, surface modification, mechanical properties of bamboo, bamboo finite element method
Procedia PDF Downloads 85958 Impact of Heat Moisture Treatment on the Yield of Resistant Starch and Evaluation of Functional Properties of Modified Mung Bean (Vigna radiate) Starch
Authors: Sreejani Barua, P. P. Srivastav
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Formulation of new functional food products for diabetes patients and obsessed people is a challenge for food industries till date. Starch is a certainly happening, ecological, reasonable and profusely obtainable polysaccharide in plant material. In the present scenario, there is a great interest in modifying starch functional properties without destroying its granular structure using different modification techniques. Resistant starch (RS) contains almost zero calories and can control blood glucose level to prevent diabetes. The current study focused on modification of mung bean starch which is a good source of legumes carbohydrate for the production of functional food. Heat moisture treatment (HMT) of mung starch was conducted at moisture content of 10-30%, temperature of 80-120 °C and time of 8-24 h.The content of resistant starch after modification was significantly increased from native starches containing RS 7.6%. The design combinations of HMT had been completed through Central Composite Rotatable Design (CCRD). The effects of HMT process variables on the yield of resistant starch was studied through Rapid Surface Methodology (RSM). The highest increase of resistant starch was found up to 34.39% when treated the native starch with 30% m.c at 120 °C temperature for 24 h.The functional properties of both native and modified mung bean starches showed that there was a reduction in the swelling power and swelling volume of HMT starches. However, the solubility of the HMT starches was higher than that of untreated native starch and also observed change in structural (scanning electron microscopy), X-Ray diffraction (XRD) pattern, blue value and thermal (differential scanning calorimetry) properties. Therefore, replacing native mung bean starch with heat-moisture treated mung bean starch leads to the development of new products with higher resistant starch levels and functional properties.Keywords: Mung bean starch, heat moisture treatment, functional properties, resistant starch
Procedia PDF Downloads 196957 Dietary Modification and Its Effects in Overweight or Obese Saudi Women with or without Type 2 Diabetes Mellitus
Authors: Nasiruddin Khan, Nasser M. Al-Daghri, Dara A. Al-Disi, Asim Al-Fadda, Mohamed Al-Seif, Gyanendra Tripathi, A. L. Harte, Philip G. Mcternan
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For the last few decades, the prevalence of type 2 diabetes mellitus (T2DM) in the Kingdom of Saudi Arabia (KSA) is increasing alarmingly high and is unprecedented at 31.6 %. Preventive measures should be taken to curb down the increasing incidence. In this prospective, 3-month study, we aimed to determine whether dietary modification program would confer favorable affects among overweight and obese adult Saudi women with or without T2DM. A total of 92 Saudi women [18 healthy controls, 24 overweight subjects and 50 overweight or obese patients with early onset T2DM were included in this prospective study. Baseline anthropometrics and fasting blood samples were taken at baseline and after 3 months. Fasting blood sugar and lipid profile were measured routinely. A 500 Kcal deficit energy diet less than their daily recommended dietary allowances were prescribed to all participants. After 3 months of follow-up visit, significant improvements were observed in both the overweight and DMT2 group as compared to baseline with decreased mean BMI [Overweight Group 28.54±1.49 versus 27.95±2.25, p<0.05; DMT2 group 35.24±7.67 versus 35.04±8.07, p<0.05] and hip circumference [Overweight group 109.67±5.01 versus 108.07±4.07, p<0.05; DMT2 group 112.3±13.43 versus 109.21±12.71, p<0.01]. Moreover, in the overweight group, baseline HDL-cholesterol was significantly associated with protein intake and inversely associated with carbohydrate intake in controls. In the DMT2 group, carbohydrate intake at baseline was significantly associated with BMI. A 3-month 500kcal/day deficit dietary modification alone is probably effective among adult overweight or obese Saudi females without or with T2DM. Longer prospective studies are to determine whether the dietary intervention alone can reduce progression of T2DM among high-risk adult Arabs.Keywords: diet, lipid, obesity, T2DM
Procedia PDF Downloads 465956 Seismic Assessment of Old Existing RC Buildings with Masonry Infill in Madinah as Per ASCE
Authors: Tarek M. Alguhane, Ayman H. Khalil, Nour M. Fayed, Ayman M. Ismail
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An existing RC building in Madinah is seismically evaluated with and without infill wall. Four model systems have been considered i. e. model I (no infill), model IIA (strut infill-update from field test), model IIB (strut infill- ASCE/SEI 41) and model IIC (strut infill-Soft storey-ASCE/SEI 41). Three dimensional pushover analyses have been carried out using SAP 2000 software incorporating inelastic material behavior for concrete, steel and infill walls. Infill wall has been modeled as equivalent strut according to suggested equation matching field test measurements and to the ASCE/SEI 41 equation. The effect of building modeling on the performance point as well as capacity and demand spectra due to EQ design spectrum function in Madinah area has been investigated. The response modification factor (R) for the 5 story RC building is evaluated from capacity and demand spectra (ATC-40) for the studied models. The results are summarized and discussed.Keywords: infill wall, pushover analysis, response modification factor, seismic assessment
Procedia PDF Downloads 391955 Modification Effect of CeO2 on Pt-Pd Nano Sized Catalysts for Formic Acid Oxidation
Authors: Ateeq Ur Rehman
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This article deals with the promotional effects of CeO2 on PtPd/CeO2-OMC electrocatalysts. The synthesized catalysts are characterized using different physicochemical techniques and evaluated in a formic acid oxidation fuel cell. N2 adsorption/desorption analysis shows that CeO2 modification increases the surface area of OMC from 1005 m2/g to 1119 m2/g. SEM, XRD and TEM analysis reveal that the presence of CeO2 enhances the active metal(s) dispersion on the CeO2-OMC surface. The average particle size of the dispersed metal decreases with the increase of Pt/Pd ratio on CeO2-OMC support. Cyclic voltametry measurement of Pd/CeO2-OMC gives 12 % higher anodic current activity with 83 mV negative shift of the peak potential as compared to unmodified Pd/OMC. In bimetallic catalysts, the addition of Pt improves the activity and stability of the catalysts significantly. Among the bimetallic samples, Pd3Pt1/CeO2-OMC displays superior current density (74.6 mA/cm2), which is 28.3 times higher than that of Pt/CeO2-OMC. It also shows higher stability in extended period of runs with least indication of CO poisoning effects.Keywords: CeO2, ordered mesoporous carbon (OMC), nano particles, formic acid fuel cell
Procedia PDF Downloads 305954 Optimization of Adsorption Performance of Lignocellulosic Waste Pretreatment and Chemical Modification
Authors: Bendjelloul Meriem, Elandaloussi El Hadj
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In this work, we studied the effectiveness of a lignocellulosic waste (wood sawdust) for the removal of cadmium Cd (II) in aqueous solution. The adsorbent material SBO-CH2-CO2Na has been prepared by alkaline pretreatment of wood sawdust followed by a chemical modification with sodium salt of chloroacetic acid. The characterization of the as-prepared material by FTIR has proven that the grafting of acetate spacer took actually place in the lignocellulosic backbone by the appearance of characteristic band of carboxylic groups in the IR spectrum. The removal study of Cd2+ by SBO-CH2-CO2Na material at the solid-liquid interface was carried out by kinetics, sorption isotherms, effect of temperature and thermodynamic parameters were evaluated. The last part of this work was dedicated to assess the regenerability of the adsorbent material after three reuse cycles. The results indicate that SBO-CH2-CO2Na matrix possesses a high effectiveness in removing Cd (II) with an adsorption capacity of 222.22 mg/g, yet a better value that those of many low-cost adsorbents so far reported in the literature. The results found in the course of this study suggest that ionic exchange is the most appropriate mechanism involved in the removal of cadmium ions.Keywords: adsorption, cadmium, isotherms, lignocellulosic, regenerability
Procedia PDF Downloads 328953 Awareness of Genetically Modified Products Among Malaysian Consumers
Authors: Muhamad Afiq Faisal, Yahaya, Mohd Faizal, Hamzah
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Genetic modification technology allows scientists to alter the genetic information of a particular organism. The technology allows the production of genetically modified organism (GMO) that has the enhanced property compared to the unmodified organism. The application of such technology is not only in agriculture industry, it is now has been applied extensively in biopharmaceutical industry such as transgenic vaccines. In Malaysia, Biosafety Act 2007 has been enacted in which all GMO-based products must be labeled with adequate information before being marketed. This paper aims to determine the awareness level amongst Malaysian consumers on the GM products available in the market and the efficiency of information supplied in the GM product labeling. The result of the survey will serve as a guideline for Malaysia government agency bodies to provide comprehensive yet efficient information to consumers for the purpose of GM product labeling in the near future. In conclusion, the efficiency of information delivery plays a vital role in ensuring that the information is being conveyed clearly to Malaysian consumers during the selection process of GM products available in the market.Keywords: genetic modification technology, genetically modified organisms, genetically modified organism products labeling, Biosafety Act 2007
Procedia PDF Downloads 354952 The Effect of Ambient Temperature on the Performance of the Simple and Modified Cycle Gas Turbine Plants
Authors: Ogbe E. E., Ossia. C. V., Saturday. E. G., Ezekwe M. C.
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The disparity in power output between a simple and a modified gas turbine plant is noticeable when the gas turbine functions under local environmental conditions that deviate from the standard ISO specifications. Extensive research and literature have demonstrated a well-known direct correlation between ambient temperature and the power output of a gas turbine plant. In this study, the Omotosho gas turbine plant was modified into three different configurations. The reason for the modification is to improve its performance and reduce the fuel consumption and emission rate. Aspen Hysys software was used to simulate both the simple (Omotosho) and the three modified gas turbine plants. The input parameters considered include ambient temperature, air mass flow rate, fuel mass flow rate, water mass flow rate, turbine inlet temperature, compressor efficiency, and turbine efficiency, while the output parameters considered are thermal efficiency, specific fuel consumption, heat rate, emission rate, compressor power, turbine power and power output. The three modified gas turbine power plants incorporate an inlet air cooling system and a heat recovery steam generator. The variations between the modifications are due to additional components or enhancements alongside the inlet air cooling system and heat recovery steam generator incorporated; the first modification has an additional turbine, the second modification has an additional combustion chamber, and the third modification has an additional turbine and combustion chamber. This paper clearly shows ambient temperature effects on both the simple and three modified gas turbine plants. for every 10-degree kelvin increase in ambient temperature, there is an approximate reduction of 3977 kW, 4795 kW, 4681 kW, and 4793 kW of the power output for the simple gas turbine, first, second, and third modifications, respectively. Also, for every 10-degree kelvin increase in temperature, there is a thermal efficiency decrease of 1.22%, 1.45%, 1.43%, and 1.44% for the simple gas turbine, first, second, and third modifications respectively. Low ambient temperature will help save fuel; looking at the high price of fuel presently in Nigeria for every 10 degrees kelvin increase in temperature, there is a specific fuel consumption increase of 0.0074 kg/kWh, 0.0051 kg/kWh, 0.0061 kg/kWh, and 0.0057 kg/kWh for the simple gas turbine, first, second, and third modifications respectively. These findings will aid in accurately evaluating local power generating plants, particularly in hotter regions, for installing gas turbine inlet air cooling (GTIAC) systems.Keywords: Aspen HYSYS software, Brayton Cycle, modified gas turbine, power plant, simple gas turbine, thermal efficiency.
Procedia PDF Downloads 17951 Aesthetic Modification with Combined Orthognathic Surgery and Closed Rhinoplasty
Authors: Alessandro Marano
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Aim: The author describes the aesthetic modification using orthognathic surgery and closed rhinoplasty. Methods: Series of case study. After orthognathic surgery we can observe a dramatical change of aesthetic especially in the mid-face and nose projection. The advancement of maxillary bone through Le Fort I osteotomy will change the nasal tip projection and lips roundness; combining orthognathic surgery with closed approach rhinoplasty will manage both function and aesthetic of all mid face district. Results: Combining Le Fort I osteotomy with closed approach rhinoplasty resulted in good objective results with high patient satisfaction. Le Fort I osteotomy will increase projection of mid face and the closed approach rhinoplasty will modify the nasal shape to be more harmonic with the new maxillary district. The scars are not visible because hidden inside the mouth and nose. Conclusions: The orthognathic surgery combined with closed approach rhinoplasty are very effective for changing the aesthetic of the mid face. The results illustrate the difference between the use of orthognathic surgery only and to use it in association of closed approach rhinoplasty. Using both will allow to obtain a long lasting and pleasing results.Keywords: orthognathic, rhinoplasty, aesthetic, face
Procedia PDF Downloads 94950 Evaluation of Response Modification Factors in Moment Resisting Frame Buildings Considering Soil Structure Interaction
Authors: K. Farheen, A. Munir
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Seismic response of the multi-storey buildings is created by the interaction of both the structure and underlying soil medium. The seismic design philosophy is incorporated using response modification factor 'R'. Current code based values of 'R' factor does not reflect the SSI problem as it is based on fixed base condition. In this study, the modified values of 'R' factor for moment resisting frame (MRF) considering SSI are evaluated. The response of structure with and without SSI has been compared using equivalent linear static and nonlinear static pushover analyses for 10-storied moment resisting frame building. The building is located in seismic zone 2B situated on different soils with shear wave velocity (Vₛ) of 300m/sec (SD) and 1200m/s (SB). Code based 'R' factor value for building frame system has been taken as 5.5. Soil medium is modelled using identical but mutually independent horizontal and vertical springs. It was found that the modified 'R' factor values have been decreased by 47% and 43% for soil SD and SB respectively as compared to that of code based 'R' factor.Keywords: buildings, SSI, shear wave velocity, R factor
Procedia PDF Downloads 206949 Properties Modification of Fiber Metal Laminates by Nanofillers
Authors: R. Eslami-Farsani, S. M. S. Mousavi Bafrouyi
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During past decades, increasing demand of modified Fiber Metal Laminates (FMLs) has stimulated a strong trend towards the development of these structures. FMLs contain several thin layers of metal bonded with composite materials. Characteristics of FMLs such as low specific mass, high bearing strength, impact resistance, corrosion resistance and high fatigue life are attractive. Nowadays, increasing development can be observed to promote the properties of polymer-based composites by nanofillers. By dispersing strong, nanofillers in polymer matrix, modified composites can be developed and tailored to individual applications. On the other hand, the synergic effects of nanoparticles such as graphene and carbon nanotube can significantly improve the mechanical, electrical and thermal properties of nanocomposites. In present paper, the modifying of FMLs by nanofillers and the dispersing of nanoparticles in the polymers matrix are discussed. The evaluations have revealed that this approach is acceptable. Finally, a prospect is presented. This paper will lead to further work on these modified FML species.Keywords: fiber metal laminate, nanofiller, polymer matrix, property modification
Procedia PDF Downloads 200948 Nanoprofiling of GaAs Surface in a Combined Low-Temperature Plasma for Microwave Devices
Authors: Victor S. Klimin, Alexey A. Rezvan, Maxim S. Solodovnik, Oleg A. Ageev
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In this paper, the problems of existing methods of profiling and surface modification of nanoscale arsenide-gallium structures are analyzed. The use of a combination of methods of local anodic oxidation and plasma chemical etching to solve this problem is considered. The main features that make this technology one of the promising areas of modification and profiling of near-surface layers of solids are demonstrated. In this paper, we studied the effect of formation stress and etching time on the geometrical parameters of the etched layer and the roughness of the etched surface. Experimental dependences of the thickness of the etched layer on the time and stress of formation were obtained. The surface analysis was carried out using atomic force microscopy methods, the corresponding profilograms were constructed from the obtained images, and the roughness of the etched surface was studied accordingly. It was shown that at high formation voltage, the depth of the etched surface increased, this is due to an increase in the number of active particles (oxygen ions and hydroxyl groups) formed as a result of the decomposition of water molecules in an electric field, during the formation of oxide nanostructures on the surface of gallium arsenide. Oxide layers were used as negative masks for subsequent plasma chemical etching by the STE ICPe68 unit. BCl₃ was chosen as the chlorine-containing gas, which differs from analogs in some parameters for the effect of etching of nanostructures based on gallium arsenide in the low-temperature plasma. The gas mixture of reaction chamber consisted of a buffer gas NAr = 100 cm³/min and a chlorine-containing gas NBCl₃ = 15 cm³/min at a pressure P = 2 Pa. The influence of these methods modes, which are formation voltage and etching time, on the roughness and geometric parameters, and corresponding dependences are demonstrated. Probe nanotechnology was used for surface analysis.Keywords: nanostructures, GaAs, plasma chemical etching, modification structures
Procedia PDF Downloads 141947 Enhanced Modification Effect of CeO2 on Pt-Pd Binary Catalysts for Formic Acid Oxidation
Authors: Azeem Ur Rehman, Asma Tayyaba
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This article deals with the promotional effects of CeO2 on PtPd/CeO2-OMC electro catalysts. The synthesized catalysts are characterized using different physico chemical techniques and evaluated in a formic acid oxidation fuel cell. N2 adsorption/desorption analysis shows that CeO2 modification increases the surface area of OMC from 1005 m2/g to 1119 m2/g. SEM, XRD and TEM analysis reveal that the presence of CeO2 enhances the active metal(s) dispersion on the CeO2-OMC surface. The average particle size of the dispersed metal decreases with the increase of Pt/Pd ratio on CeO2-OMC support. Cyclic voltametry measurement of Pd/CeO2-OMC gives 12 % higher anodic current activity with 83 mV negative shift of the peak potential as compared to unmodified Pd/OMC. In bimetallic catalysts, the addition of Pt improves the activity and stability of the catalysts significantly. Among the bimetallic samples, Pd3Pt1/CeO2-OMC displays superior current density (74.6 mA/cm2), which is 28.3 times higher than that of Pt/CeO2-OMC. It also shows higher stability in extended period of runs with least indication of CO poisoning effects.Keywords: CeO2, ordered mesoporous carbon (OMC), electro catalyst, formic acid fuel cell
Procedia PDF Downloads 485946 Analysis of the Spatial Distribution of Public Girls’ and Boys’ Secondary Schools in Riyadh
Authors: Nasser Marshad Alzeer
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This study examines the spatial distribution of secondary schools in Riyadh. It considers both public girls and boys sector provision and assesses the efficiency of the spatial distribution of secondary schools. Since the establishment of the Ministry of Education (MOE) in 1953 and General Presidency for Female Education, (GPFE) in 1960, there has been a great expansion of education services in Saudi Arabia, particularly during the 1980s. However, recent years have seen much slower rates of increase in the public education sector but the population continues to grow rapidly. This study investigates the spatial distribution of schools through the use of questionnaire surveys and applied GIS. Overall, the results indicate a shortage of public secondary schools, especially in the north of the city. It is clear that there is overcrowding in the majority of secondary schools. The establishment of new schools has been suggested to solve the problem of overcrowding. A number of socio-economic and demographic factors are associated with differences in the utilization of the public secondary schools. A GIS was applied in this study in order to assess the spatial distribution of secondary schools including the modification of existing catchment area boundaries and locating new schools. This modification could also reduce the pupil pressure on certain schools and further benefits could probably be gained.Keywords: analysis, distribution, Saudi, GIS, schools
Procedia PDF Downloads 546945 Characterization and Detection of Cadmium Ion Using Modification Calixarene with Multiwalled Carbon Nanotubes
Authors: Amira Shakila Razali, Faridah Lisa Supian, Muhammad Mat Salleh, Suriani Abu Bakar
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Water contamination by toxic compound is one of the serious environmental problems today. These toxic compounds mostly originated from industrial effluents, agriculture, natural sources and human waste. These study are focused on modification of multiwalled carbon nanotube (MWCNTs) with nanoparticle of calixarene and explore the possibility of using this nanocomposites for the remediation of cadmium in water. The nanocomposites were prepared by dissolving calixarene in chloroform solution as solvent, followed by additional multiwalled carbon nanotube (MWCNTs) then sonication process for 3 hour and fabricated the nanocomposites on substrate by spin coating method. Finally, the nanocomposites were tested on cadmium ion (10 mg/ml). The morphology of nanocomposites was investigated by FESEM showing the formation of calixarene on the outer walls of carbon nanotube and cadmium ion also clearly seen from the micrograph. This formation was supported by using energy dispersive x-ray (EDX). The presence of cadmium ions in the films, leads to some changes in the surface potential and Fourier Transform Infrared spectroscopy (FTIR).This nanocomposites have potential for development of sensor for pollutant monitoring and nanoelectronics devices applicationsKeywords: calixarene, multiwalled carbon nanotubes, cadmium, surface potential
Procedia PDF Downloads 474