Search results for: Hong Hoi formation
3385 Oxidosqualene Cyclase: A Novel Inhibitor
Authors: Devadrita Dey Sarkar
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Oxidosqualene cyclase is a membrane bound enzyme in which helps in the formation of steroid scaffold in higher organisms. In a highly selective cyclization reaction oxidosqualene cyclase forms LANOSTEROL with seven chiral centres starting from the linear substrate 2,3-oxidosqualene. In humans OSC in cholesterol biosynthesis it represents a target for the discovery of novel anticholesteraemic drugs that could complement the widely used statins. The enzyme oxidosqualene: lanosterol cyclase (OSC) represents a novel target for the treatment of hypercholesterolemia. OSC catalyzes the cyclization of the linear 2,3-monoepoxysqualene to lanosterol, the initial four-ringed sterol intermediate in the cholesterol biosynthetic pathway. OSC also catalyzes the formation of 24(S), 25-epoxycholesterol, a ligand activator of the liver X receptor. Inhibition of OSC reduces cholesterol biosynthesis and selectively enhances 24(S),25-epoxycholesterol synthesis. Through this dual mechanism, OSC inhibition decreases plasma levels of low-density lipoprotein (LDL)-cholesterol and prevents cholesterol deposition within macrophages. The recent crystallization of OSC identifies the mechanism of action for this complex enzyme, setting the stage for the design of OSC inhibitors with improved pharmacological properties for cholesterol lowering and treatment of atherosclerosis. While studying and designing the inhibitor of oxidosqulene cyclase, I worked on the pdb id of 1w6k which was the most worked on pdb id and I used several methods, techniques and softwares to identify and validate the top most molecules which could be acting as an inhibitor for oxidosqualene cyclase. Thus, by partial blockage of this enzyme, both an inhibition of lanosterol and subsequently cholesterol formation as well as a concomitant effect on HMG-CoA reductase can be achieved. Both effects complement each other and lead to an effective control of cholesterol biosynthesis. It is therefore concluded that 2,3-oxidosqualene cyclase plays a crucial role in the regulation of intracellular cholesterol homeostasis. 2,3-Oxidosqualene cyclase inhibitors offer an attractive approach for novel lipid-lowering agents.Keywords: anticholesteraemic, crystallization, statins, homeostasis
Procedia PDF Downloads 3453384 Biogenic Amines Production during RAS Cheese Ripening
Authors: Amr Amer
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Cheeses are among those high-protein-containing foodstuffs in which enzymatic and microbial activities cause the formation of biogenic amines from amino acids decarboxylation. The amount of biogenic amines in cheese may act as a useful indicator of the hygienic quality of the product. In other words, their presence in cheese is related to its spoilage and safety. Formation of biogenic amines during Ras cheese (Egyptian hard cheese) ripening was investigated for 4 months. Three batches of Ras cheese were manufactured using Egyptian traditional method. From each batch, Samples were collected at 1, 7, 15, 30, 60, 90 and 120 days after cheese manufacture. The concentrations of biogenic amines (Tyramine, Histamine, Cadaverine and Tryptamine) were analyzed by high performance liquid chromatography (HPLC). There was a significant increased (P<0.05) in Tyramine levels from 4.34± 0.07 mg|100g in the first day of storage till reached 88.77± 0.14 mg|100g at a 120-day of storage. Also, Histamine and Cadaverine levels had the same increased pattern of Tyramine reaching 64.94± 0.10 and 28.28± 0.08 mg|100g in a 120- day of storage, respectively. While, there was a fluctuation in the concentration of Tryptamine level during ripening period as it decreased from 3.24± 0.06 to 2.66± 0.11 mg|100g at 60-day of storage then reached 5.38±0.08 mg|100g in a 120- day of storage. Biogenic amines can be formed in cheese during production and storage: many variables, as pH, salt concentration, bacterial activity as well as moisture, storage temperature and ripening time, play a relevant role in their formation. Comparing the obtained results with the recommended standard by Food and Drug Administration "FDA" (2001), High levels of biogenic amines in various Ras cheeses consumed in Egypt exceeded the permissible value (10 mg%) which seemed to pose a threat to public health. In this study, presence of high concentrations of biogenic amines (Tyramine, Histamine, cadaverine and Tryptamine) in Egyptian Ras cheeses reflects the bad hygienic conditions under which they produced and stored. Accordingly, the levels of biogenic amines in different cheeses should be come in accordance with the safe permissible limit recommended by FDA to ensure human safety.Keywords: Ras cheese, biogenic amines, tyramine, histamine, cadaverine
Procedia PDF Downloads 4303383 Investigating Geopolymerization Process of Aluminosilicates and its Impact on the Compressive Strength of the Produced Geopolymers
Authors: Heba Fouad, Tarek M. Madkour, Safwan A. Khedr
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This paper investigates multiple factors that impact the formation of geopolymers and their compressive strength to be utilized in construction as an environmentally-friendly material. Bentonite and Kaolinite were thermally calcinated at 750 °C to obtain Metabentonite and Metakaolinite with higher reactivity. Both source materials were activated using a solution of sodium hydroxide (NaOH). Thereafter, samples were cured at different temperatures. The samples were analyzed chemically using a host of spectroscopic techniques. The bulk density and compressive strength of the produced Geopolymer pastes were studied. Findings indicate that the ratio of NaOH solution to source material affects the compressive strength, being optimal at 0.54. Moreover, controlled heat curing was proven effective to improve compressive strength. The existence of characteristic Fourier Transform Infrared Spectroscopy (FTIR) peaks at approximately 1020 cm-1 and 460 cm-1 which corresponds to the asymmetric stretching vibration of Si-O-T and bending vibration of Si-O-Si, hence, confirming the formation of the target geopolymer.Keywords: calcination of metakaolinite, compressive strength, FTIR analysis, geopolymer, green cement
Procedia PDF Downloads 1573382 Surface Acoustic Waves Nebulisation of Liposomes Manufactured in situ for Pulmonary Drug Delivery
Authors: X. King, E. Nazarzadeh, J. Reboud, J. Cooper
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Pulmonary diseases, such as asthma, are generally treated by the inhalation of aerosols that has the advantage of reducing the off-target (e.g., toxicity) effects associated with systemic delivery in blood. Effective respiratory drug delivery requires a droplet size distribution between 1 and 5 µm. Inhalation of aerosols with wide droplet size distribution, out of this range, results in deposition of drug in not-targeted area of the respiratory tract, introducing undesired side effects on the patient. In order to solely deliver the drug in the lower branches of the lungs and release it in a targeted manner, a control mechanism to produce the aerosolized droplets is required. To regulate the drug release and to facilitate the uptake from cells, drugs are often encapsulated into protective liposomes. However, a multistep process is required for their formation, often performed at the formulation step, therefore limiting the range of available drugs or their shelf life. Using surface acoustic waves (SAWs), a pulmonary drug delivery platform was produced, which enabled the formation of defined size aerosols and the formation of liposomes in situ. SAWs are mechanical waves, propagating along the surface of a piezoelectric substrate. They were generated using an interdigital transducer on lithium niobate with an excitation frequency of 9.6 MHz at a power of 1W. Disposable silicon superstrates were etched using photolithography and dry etch processes to create an array of cylindrical through-holes with different diameters and pitches. Superstrates were coupled with the SAW substrate through water-based gel. As the SAW propagates on the superstrate, it enables nebulisation of a lipid solution deposited onto it. The cylindrical cavities restricted the formation of large drops in the aerosol, while at the same time unilamellar liposomes were created. SAW formed liposomes showed a higher monodispersity compared to the control sample, as well as displayed, a faster production rate. To test the aerosol’s size, dynamic light scattering and laser diffraction methods were used, both showing the size control of the aerosolised particles. The use of silicon superstate with cavity size of 100-200 µm, produced an aerosol with a mean droplet size within the optimum range for pulmonary drug delivery, containing the liposomes in which the medicine could be loaded. Additionally, analysis of liposomes with Cryo-TEM showed formation of vesicles with narrow size distribution between 80-100 nm and optimal morphology in order to be used for drug delivery. Encapsulation of nucleic acids in liposomes through the developed SAW platform was also investigated. In vitro delivery of siRNA and DNA Luciferase were achieved using A549 cell line, lung carcinoma from human. In conclusion, SAW pulmonary drug delivery platform was engineered, in order to combine multiple time consuming steps (formation of liposomes, drug loading, nebulisation) into a unique platform with the aim of specifically delivering the medicament in a targeted area, reducing the drug’s side effects.Keywords: acoustics, drug delivery, liposomes, surface acoustic waves
Procedia PDF Downloads 1183381 Processes of Identities Formation and Transformation among Professional Skilled Mexican Migrants in the United States
Authors: M. Laura Vazquez Maggio, Lilia Dominguez Villalobos, Jan Luka Frey
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This paper contributes to the understanding of the dynamic and the relational nature of identities formation among skilled middle-class migrants. Following the idea that identities are never singular, multifaceted and have a necessarily processual character, the authors specifically analyze three dimensions of the identity of qualified Mexican migrants in the US and the interplay between them. Drawing on semi-structured interviews with skilled Mexican middle-class migrants in the US, the paper explores how skilled Mexican migrants preserve their ethno-national identity (their ‘Mexicanness’) in reaction to a hostile socio-political reception context in the US. It further shows how these migrants recreate their class identity and show tendencies to distance themselves from what they perceive as lower-class Mexican migrants and the dominant popular Mexican and Latin-American cultural expressions. In a final step, it examines how the lived experience of migration itself impacts the migrants’ identities, their concept of self and feelings/modes of being and belonging.Keywords: ethno-national identity, middle class identity, middle-class migration, migrants’ identity, skilled migration
Procedia PDF Downloads 1383380 Chemical Synthesis, Electrical and Antibacterial Properties of Polyaniline/Gold Nanocomposites
Authors: L. N. Shubha, M. Kalpana, P. Madhusudana Rao
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Polyaniline/gold (PANI/Au) nanocomposite was prepared by in-situ chemical oxidation polymerization method. The synthesis involved the formation of polyaniline-gold nanocomposite, by in-situ redox reaction and the dispersion of gold nano particles throughout the polyaniline matrix. The nanocomposites were characterized by XRD, FTIR, TEM and UV-visible spectroscopy. The characteristic peaks in FTIR and UV-visible spectra confirmed the expected structure of polymer as reported in the literature. Further, transmission electron microscopy (TEM) confirmed the formation of gold nano particles. The crystallite size of 30 nm for nanoAu was supported by the XRD pattern. Further, the A.C. conductivity, dielectric constant (€’(w)) and dielectric loss (€’’(w)) of PANI/Au nano composite was measured using impedance analyzer. The effect of doping on the conductivity was investigated. The antibacterial activity was examined for this nano composite and it was observed that PANI/Au nanocomposite could be used as an antibacterial agent.Keywords: AC-conductivity, anti-microbial activity, dielectric constant, dielectric loss, polyaniline/gold (PANI/AU) nanocomposite
Procedia PDF Downloads 3743379 The Effect of Tool Type on Surface Morphology of FSJ Joint
Authors: Yongfang Deng, Dunwen Zuo
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An attempt is made here to join 2024 aluminum alloy plate by friction stir joining (FSJ) using different types of tools. Joint surface morphology was observed, and both arc line spacing and flash were measured. Study is carried out on the effect of pin, shoulder and eccentricity of the tool on the surface topography of the joint and the formation of the joint surface topography is analyzed. It is found that, eccentric squeezing action of the tool is the mainly motive power to form arc lines contour and flash structure. Little flash appears in the advancing side but with severe deformation, while the flash in the retreating side is heavy but with soft deformation. The pin of tool has a deep impact on the flash on the advancing side of the joints. Shoulder can widen the arc lines, refine arcs structure, reduce flash in the retreat side, but will increase the flash in the advancing side. Increasing the amount of eccentricity, it has litter effect on the arc line spacing but will destroy the arc lines morphology in the joint surface and promote the formation of filamentous flash structure in the joint.Keywords: FSJ, surface morphology, tool, joint
Procedia PDF Downloads 3523378 Photochemical Behaviour of Carbamazepine in Natural Waters
Authors: Fanny Desbiolles, Laure Malleret, Isabelle Laffont-Schwob, Christophe Tiliacos, Anne Piram, Mohamed Sarakha, Pascal Wong-Wah-Chung
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Pharmaceuticals in the environment have become a very hot topic in the recent years. This interest is related to the large amounts dispensed and to their release in urine or faeces from treated patients, resulting in their ubiquitous presence in water resources and wastewater treatment plants (WWTP) effluents. Thereby, many studies focused on the prediction of pharmaceuticals’ behaviour, to assess their fate and impacts in the environment. Carbamazepine is a widely consumed psychotropic pharmaceutical, thus being one of the most commonly detected drugs in the environment. This organic pollutant was proved to be persistent, especially with respect to its non-biodegradability, rendering it recalcitrant to usual biological treatment processes. Consequently, carbamazepine is very little removed in WWTP with a maximum abatement rate of 5 % and is then often released in natural surface waters. To better assess the environmental fate of carbamazepine in aqueous media, its photochemical transformation was undertaken in four natural waters (two French rivers, the Berre salt lagoon, Mediterranean Sea water) representative of coastal and inland water types. Kinetic experiments were performed in the presence of light using simulated solar irradiation (Xe lamp 300W). Formation of short-lifetime species was highlighted using chemical trap and laser flash photolysis (nanosecond). Identification of transformation by-products was assessed by LC-QToF-MS analyses. Carbamazepine degradation was observed after a four-day exposure and an abatement of 20% maximum was measured yielding to the formation of many by-products. Moreover, the formation of hydroxyl radicals (•OH) was evidenced in waters using terephthalic acid as a probe, considering the photochemical instability of its specific hydroxylated derivative. Correlations were implemented using carbamazepine degradation rate, estimated hydroxyl radical formation and chemical contents of waters. In addition, laser flash photolysis studies confirmed •OH formation and allowed to evidence other reactive species, such as chloride (Cl2•-)/bromine (Br2•-) and carbonate (CO3•-) radicals in natural waters. Radicals mainly originate from dissolved phase and their occurrence and abundance depend on the type of water. Rate constants between reactive species and carbamazepine were determined by laser flash photolysis and competitive reactions experiments. Moreover, LC-QToF-MS analyses of by-products help us to propose mechanistic pathways. The results will bring insights to the fate of carbamazepine in various water types and could help to evaluate more precisely potential ecotoxicological effects.Keywords: carbamazepine, kinetic and mechanistic approaches, natural waters, photodegradation
Procedia PDF Downloads 3713377 Simulation Approach for Analyzing Transportation Energy System in South Korea
Authors: Sungjun Hong, Youah Lee, Jongwook Kim
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In the last COP21 held in Paris on 2015, Korean government announced that Intended Nationally Determined Contributions (INDC) was 37% based on BAU by 2030. The GHG reduction rate of the transportation sector is the strongest among all sectors by 2020. In order to cope with Korean INDC, Korean government established that 3rd eco-friendly car deployment national plans at the end of 2015. In this study, we make the energy system model for estimating GHG emissions using LEAP model.Keywords: INDC, greenhouse gas, LEAP, transportation
Procedia PDF Downloads 2023376 The Comparison of Safety Factor in Dry and Rainy Condition at Coal Bearing Formation. Case Study: Lahat Area South Sumatera Province, Indonesia
Authors: Teguh Nurhidayat, Nurhamid, Dicky Muslim, Zufialdi Zakaria, Irvan Sophian
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This paper presents the role of climate change as the factor that induces landslide. Case study is located at Lahat Regency, South Sumatera Province, Indonesia. Study area has high economic value of coal reserves (mostly subbituminous – bituminous), which is developable for open pit coal mining in the future. Seams are found in Muara Enim Formation. This formation is at south Sumatera basin which is formed at Tertiary as a result of collision between the indian plate and eurasian plate. South Sumatera basin which is a basin located in back arc basin. This study aims to unravel the relationship between slope stability with different season condition in tropical climate. Undisturbed soil samples were obtained in the field along with other geological data. Laboratory works were carried out to obtain physical and mechanical properties of soils. Methodology to analyze slope stability is bishop method. Bishop methods are used to identify safety factor of slope. Result shows that slopes in rainy season conditions are more prone to landslides than in dry season. In the dry seasons with moisture content is 22.65%, safety factor is 1.28 the slope in stable condition. If rain is approaching with moisture content increasing to 97.8%, the slope began to be critical. On wet condition groundwater levels is increased, followed by γ (unit weight), c (cohesion), and φ (angle of friction) at 18.04, 5,88 kN/m2, and 28,04°, respectively, which ultimately determines the security factor FS to be 1.01 (slope in unstable conditions).Keywords: rainfall, moisture content, slope analysis, landslide prone
Procedia PDF Downloads 3083375 Study of Machinability for Titanium Alloy Ti-6Al-4V through Chip Formation in Milling Process
Authors: Moaz H. Ali, Ahmed H. Al-Saadi
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Most of the materials used in the industry of aero-engine components generally consist of titanium alloys. Advanced materials, because of their excellent combination of high specific strength, lightweight, and general corrosion resistance. In fact, chemical wear resistance of aero-engine alloy provide a serious challenge for cutting tool material during the machining process. The reduction in cutting temperature distributions leads to an increase in tool life and a decrease in wear rate. Hence, the chip morphology and segmentation play a predominant role in determining machinability and tool wear during the machining process. The result of low thermal conductivity and diffusivity of this alloy in the concentration of high temperatures at the tool-work-piece and tool-chip interface. Consequently, the chip morphology is very important in the study of machinability of metals as well as the study of cutting tool wear. Otherwise, the result will be accelerating tool wear, increasing manufacturing cost and time consuming.Keywords: machinability, titanium alloy (ti-6al-4v), chip formation, milling process
Procedia PDF Downloads 4413374 Field Efficacy Evaluation and Synergistic Effect of Two Rodenticides Zinc Phosphide and Brodifacoum against Field Rats of the Pothwar Region, Pakistan
Authors: Nadeem Munawar, David Galbraith, Tariq Mahmood
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Rodenticides are often included as part of an integrated pest management approach for managing rodent species since they are relatively quick and inexpensive to apply. The current field study was conducted to evaluate the effectiveness of formulated baits of zinc phosphide (2%) and the second generation anticoagulant brodifacoum (0.005%) against field rats inhabiting a wheat-groundnut cropping system. Burrow baiting was initiated at the early flowering stages of the respective crops, and continued through three growth stages (tillering / peg formation, flowering, and maturity). Three treatments were done at equal time intervals, with the final baiting being about 2 weeks before harvest. Treatment efficacy of the trials was assessed through counts of active rodent burrows before and after treatments at the three growth stages of these crops. The results indicated variable degrees of reduction in burrow activities following the three bait applications. The reductions in rodent activity in wheat were: 88.8% (at tillering), 92%, (at flowering/grain formation), and 95.5% (at maturity). In groundnut, the rodent activities were reduced by 91.8%, 93.5% and 95.8% at sowing, peg formation, and maturity stages, respectively. The estimated mortality at all three growth stages of both wheat and groundnut ranged between 60-85%. We recommend that a field efficacy study should be conducted with zinc phosphide and brodifacoum bait formulations to determine their field performance in the reduction of agricultural damage by rodent pest species. It is a promising alternative approach for use of the most potent second-generation anticoagulant (brodifacoum) in resistance management, particularly with respect to reducing environmental risks and secondary poisoning.Keywords: brodifacoum, burrow baiting, second-generation anticoagulant, synergistic effect
Procedia PDF Downloads 1163373 Broadband Platinum Disulfide Based Saturable Absorber Used for Optical Fiber Mode Locking Lasers
Authors: Hui Long, Chun Yin Tang, Ping Kwong Cheng, Xin Yu Wang, Wayesh Qarony, Yuen Hong Tsang
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Two dimensional (2D) materials have recently attained substantial research interest since the discovery of graphene. However, the zero-bandgap feature of the graphene limits its nonlinear optical applications, e.g., saturable absorption for these applications require strong light-matter interaction. Nevertheless, the excellent optoelectronic properties, such as broad tunable bandgap energy and high carrier mobility of Group 10 transition metal dichalcogenides 2D materials, e.g., PtS2 introduce new degree of freedoms in the optoelectronic applications. This work reports our recent research findings regarding the saturable absorption property of PtS2 layered 2D material and its possibility to be used as saturable absorber (SA) for ultrafast mode locking fiber laser. The demonstration of mode locking operation by using the fabricated PtS2 as SA will be discussed. The PtS2/PVA SA used in this experiment is made up of some few layered PtS2 nanosheets fabricated via a simple ultrasonic liquid exfoliation. The operational wavelength located at ~1 micron is demonstrated from Yb-doped mode locking fiber laser ring cavity by using the PtS2 SA. The fabricated PtS2 saturable absorber offers strong nonlinear properties, and it is capable of producing regular mode locking laser pulses with pulse to pulse duration matched with the round-trip cavity time. The results confirm successful mode locking operation achieved by the fabricated PtS2 material. This work opens some new opportunities for these PtS2 materials for the ultrafast laser generation. Acknowledgments: This work is financially supported by Shenzhen Science and Technology Innovation Commission (JCYJ20170303160136888) and the Research Grants Council of Hong Kong, China (GRF 152109/16E, PolyU code: B-Q52T).Keywords: platinum disulfide, PtS2, saturable absorption, saturable absorber, mode locking laser
Procedia PDF Downloads 1833372 A Study of the Formation, Existence and Stability of Localised Pulses in PDE
Authors: Ayaz Ahmad
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TOPIC: A study of the formation ,existness and stability of localised pulses in pde Ayaz Ahmad ,NITP, Abstract:In this paper we try to govern the evolution deterministic variable over space and time .We analysis the behaviour of the model which allows us to predict and understand the possible behaviour of the physical system .Bifurcation theory provides a basis to systematically investigate the models for invariant sets .Exploring the behaviour of PDE using bifurcation theory which provides many challenges both numerically and analytically. We use the derivation of a non linear partial differential equation which may be written in this form ∂u/∂t+c ∂u/∂x+∈(∂^3 u)/(∂x^3 )+¥u ∂u/∂x=0 We show that the temperature increased convection cells forms. Through our work we look for localised solution which are characterised by sudden burst of aeroidic spatio-temporal evolution. Key word: Gaussian pulses, Aeriodic ,spatio-temporal evolution ,convection cells, nonlinearoptics, Dr Ayaz ahmad Assistant Professor Department of Mathematics National institute of technology Patna ,Bihar,,India 800005 [email protected] +91994907553Keywords: Gaussian pulses, aeriodic, spatio-temporal evolution, convection cells, nonlinear optics
Procedia PDF Downloads 3283371 Relative Navigation with Laser-Based Intermittent Measurement for Formation Flying Satellites
Authors: Jongwoo Lee, Dae-Eun Kang, Sang-Young Park
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This study presents a precise relative navigational method for satellites flying in formation using laser-based intermittent measurement data. The measurement data for the relative navigation between two satellites consist of a relative distance measured by a laser instrument and relative attitude angles measured by attitude determination. The relative navigation solutions are estimated by both the Extended Kalman filter (EKF) and unscented Kalman filter (UKF). The solutions estimated by the EKF may become inaccurate or even diverge as measurement outage time gets longer because the EKF utilizes a linearization approach. However, this study shows that the UKF with the appropriate scaling parameters provides a stable and accurate relative navigation solutions despite the long measurement outage time and large initial error as compared to the relative navigation solutions of the EKF. Various navigation results have been analyzed by adjusting the scaling parameters of the UKF.Keywords: satellite relative navigation, laser-based measurement, intermittent measurement, unscented Kalman filter
Procedia PDF Downloads 3483370 Impact of Different Fuel Inlet Diameters onto the NOx Emissions in a Hydrogen Combustor
Authors: Annapurna Basavaraju, Arianna Mastrodonato, Franz Heitmeir
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The Advisory Council for Aeronautics Research in Europe (ACARE) is creating awareness for the overall reduction of NOx emissions by 80% in its vision 2020. Hence this promotes the researchers to work on novel technologies, one such technology is the use of alternative fuels. Among these fuels hydrogen is of interest due to its one and only significant pollutant NOx. The influence of NOx formation due to hydrogen combustion depends on various parameters such as air pressure, inlet air temperature, air to fuel jet momentum ratio etc. Appropriately, this research is motivated to investigate the impact of the air to fuel jet momentum ratio onto the NOx formation in a hydrogen combustion chamber for aircraft engines. The air to jet fuel momentum is defined as the ratio of impulse/momentum of air with respect to the momentum of fuel. The experiments were performed in an existing combustion chamber that has been previously tested for methane. Premix of the reactants has not been considered due to the high reactivity of the hydrogen and high risk of a flashback. In order to create a less rich zone of reaction at the burner and to decrease the emissions, a forced internal recirculation flow has been achieved by integrating a plate similar to honeycomb structure, suitable to the geometry of the liner. The liner has been provided with an external cooling system to avoid the increase of local temperatures and in turn the reaction rate of the NOx formation. The injected air has been preheated to aim at so called flameless combustion. The air to fuel jet momentum ratio has been inspected by changing the area of fuel inlets and keeping the number of fuel inlets constant in order to alter the fuel jet momentum, thus maintaining the homogeneity of the flow. Within this analysis, promising results for a flameless combustion have been achieved. For a constant number of fuel inlets, it was seen that the reduction of the fuel inlet diameter resulted in decrease of air to fuel jet momentum ratio in turn lowering the NOx emissions.Keywords: combustion chamber, hydrogen, jet momentum, NOx emission
Procedia PDF Downloads 2863369 Surface and Subsurface Characterization of a Fault along Boso-Boso River, Rizal
Authors: Marco Jan Rafael C. Sicam, Maria Daniella C. Yambao
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The Philippines is a tectonically active archipelagic country situated near the Circum-Pacific Belt. Hence, seismic hazard assessments are important in the nation-building. In 2014, the Philippines Institute of Volcanology and Seismology (PHIVOLCS) mapped a 12-km NW-trending unnamed active fault near Boso-Boso River, Rizal. Given the limited nature of their technical report, they would like to further consolidate relevant data about this fault. As such, this study aims to characterize the surface and subsurface expression of the fault along Boso-Boso River using rangefront morphology, structural criteria, and ground penetrating radar. This fault is subdivided into two segments: the first segment located in the city of Antipolo is mainly manifested in the upper Kinabuan Formation and terminating near Mt. Qutago, and the second segment in Baras, Pinugay, Rizal cuts through recent fluvial deposits and to the Guadalupe Formation. IfSAR-derived DTM data reveals the morphological expression of the fault defined by offset streams and ridges, linear sidehill valleys, and linear valleys. Fault gouges, fault breccia, transtentional flower structures, slickensides, and other shear sense markers observed in the units of the upper Cretaceous Kinabuan Formation indicate a sinistral sense of displacement. GPR radargram profiles revealed the presence of displacement in reflectors at 3-5 meters below the surface which may be suggestive of the fault within the area. Finally, the fault in Boso-Boso river may be a segment of the larger sinistral Montalban Fault in the north or largely affected by the movement from the Marikina Valley Fault System.Keywords: NW unnamed fault, range-front morphology, shear sense markers, ground penetrating radar, boso-boso river, antipolo
Procedia PDF Downloads 553368 Comparing the Gap Formation around Composite Restorations in Three Regions of Tooth Using Optical Coherence Tomography (OCT)
Authors: Rima Zakzouk, Yasushi Shimada, Yuan Zhou, Yasunori Sumi, Junji Tagami
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Background and Purpose: Swept source optical coherence tomography (OCT) is an interferometric imaging technique that has been recently used in cariology. In spite of progress made in adhesive dentistry, the composite restoration has been failing due to secondary caries which occur due to environmental factors in oral cavities. Therefore, a precise assessment to effective marginal sealing of restoration is highly required. The aim of this study was evaluating gap formation at composite/cavity walls interface with or without phosphoric acid etching using SS-OCT. Materials and Methods: Round tapered cavities (2×2 mm) were prepared in three locations, mid-coronal, cervical, and root of bovine incisors teeth in two groups (SE and PA Groups). While self-etching adhesive (Clearfil SE Bond) was applied for the both groups, Group PA had been already pretreated with phosphoric acid etching (K-Etchant gel). Subsequently, both groups were restored by Estelite Flow Quick Flowable Composite Resin. Following 5000 thermal cycles, three cross-sectionals were obtained from each cavity using OCT at 1310-nm wavelength at 0°, 60°, 120° degrees. Scanning was repeated after two months to monitor the gap progress. Then the average percentage of gap length was calculated using image analysis software, and the difference of mean between both groups was statistically analyzed by t-test. Subsequently, the results were confirmed by sectioning and observing representative specimens under Confocal Laser Scanning Microscope (CLSM). Results: The results showed that pretreatment with phosphoric acid etching, Group PA, led to significantly bigger gaps in mid-coronal and cervical compared to SE group, while in the root cavity no significant difference was observed between both groups. On the other hand, the gaps formed in root’s cavities were significantly bigger than those in mid-coronal and cervical within the same group. This study investigated the effect of phosphoric acid on gap length progress on the composite restorations. In conclusions, phosphoric acid etching treatment did not reduce the gap formation even in different regions of the tooth. Significance: The cervical region of tooth was more exposing to gap formation than mid-coronal region, especially when we added pre-etching treatment.Keywords: image analysis, optical coherence tomography, phosphoric acid etching, self-etch adhesives
Procedia PDF Downloads 2153367 Callus Induction of Segmented Corm Explant of Gladiolus cv. White Prosperity and Regeneration in vitro Condition
Authors: M. Sepahvand, M. Khorushy
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Gladiolus, being a cormous plant, it is principally propagated by the natural multiplication of new corms and cormels. In order to obtain callus from segmented corm which was obtained from in vitro culture, callus formation media were MS media supplemented with 4 levels of hormones such as 1.0 mg l-1 NAA + 0.5 mg l-1 BAP, 0.5 mg l-1 NAA + 0.25 mg l-1 BAP, 1.0 mg l-1 2, 4-D + 0.5 mg l-1 BAP, and 0.5 mg l-1 2, 4-D + 0.25 mg l-1 BAP. The results showed that the most weight of callus (2.28 g) was produced in MS callus formation media which were supplemented with 1.0 mg l-1 NAA + 0.5 mg l-1 BAP. This experiment was carried out in randomized completely design with 3 replications and each treatment with six jars. In second experiment for regeneration of callus, a factorial experiment in the form of randomized complete design with 12 treatments and 3 replications and each replication with six jars was carried out. The treatments consisted of callus culture media in 4 levels and regeneration culture media in 3 levels [control (no PGRs), MS with 0.2 mg l-1 BAP + 0.1 mg l-1 Kin + 0.01 mg l-1 NAA, and MS with 0.2 mg l-1 BAP + 0.05 mg l-1 Kin + 0.01 mg l-1 NAA]. The results showed that the best regeneration media were MS media which were supplemented with 0.2 mg l-1 BAP + 0.1 mg l-1 Kin. + 0.01 mg l-1 NAA that had the highest number of shoots (7/83 N), and shoot length (7/3 cm).Keywords: regeneration, Segmented corm explant, callus, in vitro, gladiolus cv. white prosperity
Procedia PDF Downloads 4433366 In vitro and in vivo Antiangiogenic Activity of Girinimbine Isolated from Murraya koenigii
Authors: Venoos Iman, Suzita Mohd Noor, Syam Mohan, Mohamad Ibrahim Noordin
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Girinimbine, a carbazole alkaloid was isolated from the stem bark and root of Murraya koenigii and its structure and purity was identified by HPLC and LC-MS. Here we report that Girinimbine strongly inhibit angiogenesis activity both in vitro and in vivo. MTT result showed that girinimbine inhibits cell proliferation of the HUVECS cell line in vitro. Result of endothelial cell invasion, migration, tube formation and wound healing assays also demonstrated significant time and does dependent inhibition by girinimbine. Moreover, girinibine mediates its anti-angiogenic activity through up- and down-regulation of angiogenic and anti-aniogenic proteins. Furthermore, anti-angiogenic potential of girinimbine was evidenced in vivo on zebrafish model. Girinimbine inhibited neo-vessels formation in zebrafish embryos during 24 hours exposure time. Together, these results demonstrated for the first time that girinimbine could effectively suppress angiogenesis and strongly suggest that it might be a novel angiogenesis inhibitor.Keywords: anti-angiogenic, carbazole alkaloid, girinimbine, zebrafish
Procedia PDF Downloads 3713365 Specific Frequency of Globular Clusters in Different Galaxy Types
Authors: Ahmed H. Abdullah, Pavel Kroupa
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Globular clusters (GC) are important objects for tracing the early evolution of a galaxy. We study the correlation between the cluster population and the global properties of the host galaxy. We found that the correlation between cluster population (NGC) and the baryonic mass (Mb) of the host galaxy are best described as 10 −5.6038Mb. In order to understand the origin of the U -shape relation between the GC specific frequency (SN) and Mb (caused by the high value of SN for dwarfs galaxies and giant ellipticals and a minimum SN for intermediate mass galaxies≈ 1010M), we derive a theoretical model for the specific frequency (SNth). The theoretical model for SNth is based on the slope of the power-law embedded cluster mass function (β) and different time scale (Δt) of the forming galaxy. Our results show a good agreement between the observation and the model at a certain β and Δt. The model seems able to reproduce higher value of SNth of β = 1.5 at the midst formation time scale.Keywords: galaxies: dwarf, globular cluster: specific frequency, number of globular clusters, formation time scale
Procedia PDF Downloads 3203364 Formation of the Investment Portfolio of Intangible Assets with a Wide Pairwise Comparison Matrix Application
Authors: Gulnara Galeeva
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The Analytic Hierarchy Process is widely used in the economic and financial studies, including the formation of investment portfolios. In this study, a generalized method of obtaining a vector of priorities for the case with separate pairwise comparisons of the expert opinion being presented as a set of several equal evaluations on a ratio scale is examined. The author claims that this method allows solving an important and up-to-date problem of excluding vagueness and ambiguity of the expert opinion in the decision making theory. The study describes the authentic wide pairwise comparison matrix. Its application in the formation of the efficient investment portfolio of intangible assets of a small business enterprise with limited funding is considered. The proposed method has been successfully approbated on the practical example of a functioning dental clinic. The result of the study confirms that the wide pairwise comparison matrix can be used as a simple and reliable method for forming the enterprise investment policy. Moreover, a comparison between the method based on the wide pairwise comparison matrix and the classical analytic hierarchy process was conducted. The results of the comparative analysis confirm the correctness of the method based on the wide matrix. The application of a wide pairwise comparison matrix also allows to widely use the statistical methods of experimental data processing for obtaining the vector of priorities. A new method is available for simple users. Its application gives about the same accuracy result as that of the classical hierarchy process. Financial directors of small and medium business enterprises get an opportunity to solve the problem of companies’ investments without resorting to services of analytical agencies specializing in such studies.Keywords: analytic hierarchy process, decision processes, investment portfolio, intangible assets
Procedia PDF Downloads 2603363 A Statistical Approach to Rationalise the Number of Working Load Test for Quality Control of Pile Installation in Singapore Jurong Formation
Authors: Nuo Xu, Kok Hun Goh, Jeyatharan Kumarasamy
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Pile load testing is significant during foundation construction due to its traditional role of design validation and routine quality control of the piling works. In order to verify whether piles can take loadings at specified settlements, piles will have to undergo working load test where the test load should normally up to 150% of the working load of a pile. Selection or sampling of piles for the working load test is done subject to the number specified in Singapore National Annex to Eurocode 7 SS EN 1997-1:2010. This paper presents an innovative way to rationalize the number of pile load test by adopting statistical analysis approach and looking at the coefficient of variance of pile elastic modulus using a case study at Singapore Tuas depot. Results are very promising and have shown that it is possible to reduce the number of working load test without influencing the reliability and confidence on the pile quality. Moving forward, it is suggested that more load test data from other geological formations to be examined to compare with the findings from this paper.Keywords: elastic modulus of pile under soil interaction, jurong formation, kentledge test, pile load test
Procedia PDF Downloads 3773362 Calcium Complexing Properties of Isosaccharinate Ion in Highly Alkaline Environment
Authors: Csilla Dudás, Éva Böszörményi, Bence Kutus, István Pálinkó, Pál Sipos
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In this study the behavior of alpha-D-isosaccharinate (2-hydroxymethyl-3-deoxy-D-erythro-pentonate, ISA−) in alkaline medium in the presence of calcium was studied. At first the Ca–ISA system was studied by Ca-ion selective electrode (Ca-ISE) in neutral medium at T = 25 °C and I = 1 M NaCl to determine the formation constant of the CaISA+ monocomplex, which was found to be logK = 1.01 ± 0.01 for the reaction of Ca2+ + ISA– = CaISA+. In alkaline medium pH potentiometric titrations were carried out to determine the composition and stability constant of the complex(es) formed. It was found that in these systems above pH = 12.5 the predominant species is the CaISAOH complex. Its formation constant was found to be logK = 3.04 ± 0.05 for the reaction of Ca2+ + ISA– + H2O = CaISAOH + H+ at T = 25 °C and I = 1 M NaCl. Solubility measurements resulted in data consistent with those of the potentiometric titrations. Temperature dependent NMR spectra showed that the slow exchange range between the complex and the free ligand is below 5 °C. It was also showed that ISA– acts as a multidentate ligand forming macrochelate Ca-complexes. The structure of the complexes was determined by using ab initio quantum chemical calculations.Keywords: Ca-ISE potentiometry, calcium complexes, isosaccharinate ion, NMR spectroscopy, pH potentiometry
Procedia PDF Downloads 2563361 The Exploration Targets of the Nanpu Sag: Insight from Organic Geochemical Characteristics of Source Rocks and Oils
Authors: Lixin Pei, Zhilong Huang, Wenzhe Gang
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Organic geochemistry of source rocks and oils in the Nanpu Sag, Bohai Bay basin was studied on the basis of the results of Rock-Eval and biomarker. The possible source rocks consist of the third member (Es₃) and the first member (Es₁) of Shahejie formation and the third member of Dongying Formation (Ed₃) in the Nanpu Sag. The Es₃, Es₁, and Ed₃ source rock intervals in the Nanpu Sag all have high organic-matter richness and are at hydrocarbon generating stage, which are regarded as effective source rocks. The three possible source rock intervals have different biomarker associations and can be differentiated by gammacerane/αβ C₃₀ hopane, ETR ([C₂₈+C₂₉]/ [C₂₈+C₂₉+Ts]), C₂₇ diasterane/sterane and C₂₇/C₂₉ steranes, which suggests they deposited in different environments. Based on the oil-source rock correlation, the shallow oils mainly originated from the Es₃ and Es₁ source rocks in the Nanpu Sag. Through hydrocarbon generation and expulsion history of the source rocks, trap development history and accumulation history, the shallow oils mainly originated from paleo-reservoirs in the Es₃ and Es₁ during the period of Neotectonism, and the residual paleo-reservoirs in the Es₃ and Es₁ would be the focus targets in the Nanpu Sag; Bohai Bay Basin.Keywords: source rock, biomarker association, Nanpu Sag, Bohai Bay Basin
Procedia PDF Downloads 3683360 The Academic Achievement of Writing via Project-Based Learning
Authors: Duangkamol Thitivesa
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This paper focuses on the use of project work as a pretext for applying the conventions of writing, or the correctness of mechanics, usage, and sentence formation, in a content-based class in a Rajabhat University. Its aim was to explore to what extent the student teachers’ academic achievement of the basic writing features against the 70% attainment target after the use of project is. The organization of work around an agreed theme in which the students reproduce language provided by texts and instructors is expected to enhance students’ correct writing conventions. The sample of the study comprised of 38 fourth-year English major students. The data was collected by means of achievement test and student writing works. The scores in the summative achievement test were analyzed by mean score, standard deviation, and percentage. It was found that the student teachers do more achieve of practicing mechanics and usage, and less in sentence formation. The students benefited from the exposure to texts during conducting the project; however, their automaticity of how and when to form phrases and clauses into simple/complex sentences had room for improvement.Keywords: project-based learning, project work, writing conventions, academic achievement
Procedia PDF Downloads 3293359 The Potential of Southern Malang as Geotourism Site: The Distribution of Geodiversity and Geotrek in Southern Malang, Indonesia
Authors: Arda Bagus M, Yehezkiel Festian P, Budianto Santoso
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The Tourism Area of Southern Malang is administratively located in the Regency of Malang, East Java Province, Indonesia and geographically is in a position between 112o17' - 112o57' E dan 7o44' - 8o26' S. Southern Malang consists of several sub-districts that directly borders with the Indian Ocean, such as Donomulyo, Bantur, Gedangan, Sumbermanjing, Tirto Yudo, and Ampel Gading. This area has a high geotourism potential because of the existence of geodiversity such as beaches, waterfalls, caves, and karst area. However, to the best of the authors’ knowledge, there is still no systematic data that informs the geotourism potentials to the public. The aim of this research is to complete the lack of data and then arrange it systematically so it can be used for both tourism and research purposes. Research methods such as field observation, literature study, and depth interview to local people have been implemented. Aspects reviewed by visiting the field are accommodation, transportation, and the feasibility of a place to be geotourism object. The primary data was taken in Sumbermanjing, Gedangan, Bantur, and Donomulyo sub-district. A literature study is needed to determine the regional geology of Southern Malang and as a comparison to new data obtained in the field. The results of the literature study show that southern Malang consists of three formations: Wonosari Formation, Mandalaka Formation, and River-swamps Sediment Formation with the age range of Oligocene to Quaternary. Depth interviews have been conducted by involving local people with the aim of knowing cultural-history in the research area. From this research, the geotourism object distribution map has been made. The map also includes Geotrek and basic geological information of each object. The results of this research can support the development of geotourism in Southern Malang.Keywords: geodiversity, geology, geotourism, geotrek, southern Malang
Procedia PDF Downloads 1703358 Synthesis, Structure and Properties of NZP/NASICON Structured Materials
Authors: E. A. Asabina, V. I. Pet'kov, P. A. Mayorov, A. V. Markin, N. N. Smirnova, A. M. Kovalskii, A. A. Usenko
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The purpose of this work was to synthesize and investigate phase formation, structure and thermophysical properties of the phosphates M0.5+xM'xZr2–x(PO4)3 (M – Cd, Sr, Pb; M' – Mg, Co, Mn). The compounds were synthesized by sol-gel method. The results showed formation of limited solid solutions of NZP/NASICON type. The crystal structures of triple phosphates of the compositions MMg0.5Zr1.5(PO4)3 were refined by the Rietveld method using XRD data. Heat capacity (8–660 K) of the phosphates Pb0.5+xMgxZr2-x(PO4)3 (x = 0, 0.5) was measured, and reversible polymorphic transitions were found at temperatures, close to the room temperature. The results of Rietveld structure refinement showed the polymorphism caused by disordering of lead cations in the cavities of NZP/NASICON structure. Thermal expansion (298−1073 K) of the phosphates MMg0.5Zr1.5(PO4)3 was studied by XRD method, and the compounds were found to belong to middle and low-expanding materials. Thermal diffusivity (298–573 K) of the ceramic samples of phosphates slightly decreased with temperature increasing. As was demonstrated, the studied phosphates are characterized by the better thermophysical characteristics than widespread fire-resistant materials, such as zirconia and etc.Keywords: NASICON, NZP, phosphate, structure, synthesis, thermophysical properties
Procedia PDF Downloads 1373357 Nanoindentation Behaviour and Microstructural Evolution of Annealed Single-Crystal Silicon
Authors: Woei-Shyan Lee, Shuo-Ling Chang
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The nanoindentation behaviour and phase transformation of annealed single-crystal silicon wafers are examined. The silicon specimens are annealed at temperatures of 250, 350 and 450ºC, respectively, for 15 minutes and are then indented to maximum loads of 30, 50 and 70 mN. The phase changes induced in the indented specimens are observed using transmission electron microscopy (TEM) and micro-Raman scattering spectroscopy (RSS). For all annealing temperatures, an elbow feature is observed in the unloading curve following indentation to a maximum load of 30 mN. Under higher loads of 50 mN and 70 mN, respectively, the elbow feature is replaced by a pop-out event. The elbow feature reveals a complete amorphous phase transformation within the indented zone, whereas the pop-out event indicates the formation of Si XII and Si III phases. The experimental results show that the formation of these crystalline silicon phases increases with an increasing annealing temperature and indentation load. The hardness and Young’s modulus both decrease as the annealing temperature and indentation load are increased.Keywords: nanoindentation, silicon, phase transformation, amorphous, annealing
Procedia PDF Downloads 3603356 Reduplication in Dhiyan: An Indo-Aryan Language of Assam
Authors: S. Sulochana Singha
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Dhiyan or Dehan is the name of the community and language spoken by the Koch-Rajbangshi people of Barak Valley of Assam. Ethnically, they are Mongoloids, and their language belongs to the Indo-Aryan language family. However, Dhiyan is absent in any classification of Indo-Aryan languages. So the classification of Dhiyan language under the Indo-Aryan language family is completely based on the shared typological features of the other Indo-Aryan languages. Typologically, Dhiyan is an agglutinating language, and it shares many features of Indo-Aryan languages like presence of aspirated voiced stops, non-tonal, verb-person agreement, adjectives as different word class, prominent tense and subject object verb word order. Reduplication is a productive word-formation process in Dhiyan. Besides it also expresses plurality, intensification, and distributive. Generally, reduplication in Dhiyan can be at the morphological or lexical level. Morphological reduplication in Dhiyan involves expressives which includes onomatopoeias, sound symbolism, idiophones, and imitatives. Lexical reduplication in the language can be formed by echo formations and word reduplication. Echo formation in Dhiyan is formed by partial repetition from the base word which can be either consonant alternation or vowel alternation. The consonant alternation is basically found in onset position while the alternation of vowel is basically found in open syllable particularly in final syllable. Word reduplication involves reduplication of nouns, interrogatives, adjectives, and numerals which further can be class changing or class maintaining reduplication. The process of reduplication can be partial or complete whether it is lexical or morphological. The present paper is an attempt to describe some aspects of the formation, function, and usage of reduplications in Dhiyan which is mainly spoken in ten villages in the Eastern part of Barak River in the Cachar District of Assam.Keywords: Barak-Valley, Dhiyan, Indo-Aryan, reduplication
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