Search results for: nickel-cermet anodic thin films

Authors: Punit Kumar, Niraj Kumar

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The traction behavior of lubricants with the linear pressure-viscosity response in EHL line contacts is investigated numerically for smooth as well as rough surfaces. The analysis involves the simultaneous solution of Reynolds, elasticity and energy equations along with the computation of lubricant properties and surface temperatures. The temperature modified Doolittle-Tait equations are used to calculate viscosity and density as functions of fluid pressure and temperature, while Carreau model is used to describe the lubricant rheology. The surface roughness is assumed to be sinusoidal and it is present on the nearly stationary surface in near-pure sliding EHL conjunction. The linear P-V oil is found to yield much lower traction coefficients and slightly thicker EHL films as compared to the synthetic oil for a given set of dimensionless speed and load parameters. Besides, the increase in traction coefficient attributed to surface roughness is much lower for the former case. The present analysis emphasizes the importance of employing realistic pressure-viscosity response for accurate prediction of EHL traction.

Keywords: EHL, linear pressure-viscosity, surface roughness, traction, water/glycol

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Authors: T. C. Bera, A. Bansal, D. Nema

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During performing turning operation, cutting force plays a significant role in metal cutting process affecting tool-work piece deflection, vibration and eventually part quality. The present research work aims to develop a mechanistic cutting force model and to study the mechanistic constants used in the force model in case of turning operation. The proposed model can be used for the reliable and accurate estimation of the cutting forces establishing relationship of various force components (cutting force and feed force) with uncut chip thickness. The accurate estimation of cutting force is required to improve thin-walled part accuracy by controlling the tool-work piece deflection induced surface errors and tool-work piece vibration.

Keywords: turning, cutting forces, cutting constants, uncut chip thickness

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Authors: Yael Rieder, Yael Gilboa, S. O. Adva, Efrat Halevi, Ronnie Tepper

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Background: Operation of ultrasound equipment is a core skill for many clinical specialties. As part of the training program at -Simultech- a simulation center for Ob\Gyn at the Meir Medical Center, Israel, teaching how to operate ultrasound equipment requires dealing with misunderstandings of spatial and 3D orientation, failure of the operator to hold a transducer correctly, and limited ability to evaluate the data on the screen. We have developed a platform intended to endow physicians and sonographers with clinical and operational skills of obstetric ultrasound. Simultech's simulations are focused on medical knowledge, risk management, technology operations and physician-patient communication. The simulations encompass extreme work conditions. Setup: Between eight and ten of the eight hundred and fifty physicians and sonographers of the Clalit health services from seven hospitals and eight community centers across Israel, participate in individual Ob/Gyn training sessions each week. These include Ob/Gyn specialists, experts, interns, and sonographers. Innovative teaching and training methodologies: The six-hour training program includes: (1) An educational computer program that challenges trainees to deal with medical questions based upon ultrasound pictures and films. (2) Sophisticated hands-on simulators that challenge the trainees to practice correct grip of the transducer, elucidate pathology, and practice daily tasks such as biometric measurements and analysis of sonographic data. (3) Participation in a video-taped simulation which focuses on physician-patient communications. In the simulation, the physician is required to diagnose the clinical condition of a hired actress based on the data she provides and by evaluating the assigned ultrasound films accordingly. Giving ‘bad news’ to the patient may put the physician in a stressful situation that must be properly managed. (4) Feedback at the end of each phase is provided by a designated trainer, not a physician, who is specially qualified by Ob\Gyn senior specialists. (5) A group exercise in which the trainer presents a medico-legal case in order to encourage the participants to use their own experience and knowledge to conduct a productive ‘brainstorming’ session. Medical cases are presented and analyzed by the participants together with the trainer's feedback. Findings: (1) The training methods and content that Simultech provides allows trainees to review their medical and communications skills. (2) Simultech training sessions expose physicians to both basic and new, up-to-date cases, refreshing and expanding the trainee's knowledge. (3) Practicing on advanced simulators enables trainees to understand the sonographic space and to implement the basic principles of ultrasound. (4) Communications simulations were found to be beneficial for trainees who were unaware of their interpersonal skills. The trainer feedback, supported by the recorded simulation, allows the trainee to draw conclusions about his performance. Conclusion: Simultech was found to contribute to physicians at all levels of clinical expertise who deal with ultrasound. A break in daily routine together with attendance at a neutral educational center can vastly improve performance and outlook.

Keywords: medical training, simulations, ultrasound, Simultech

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Authors: Nikhil Jain, Yang Xu, Bin Yu

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Hexagonal boron nitride (h-BN) has been used as a substrate and gate dielectric for graphene field effect transistors (GFETs). Using a graphene/h-BN/TiN (channel/dielectric/gate) stack, key material properties of h-BN were investigated i.e. dielectric strength and tunneling behavior. Work function difference between graphene and TiN results in spontaneous p-doping of graphene through a multi-layer h-BN flake. However, at high levels of current stress, n-doping of graphene is observed, possibly due to the charge transfer across the thin h-BN multi layer. Neither Direct Tunneling (DT) nor Fowler-Nordheim Tunneling (FNT) was observed in TiN/h-BN/Au hetero structures with h-BN showing two distinct volatile conduction states before breakdown. Hexagonal boron nitride emerges as a material of choice for gate dielectrics in GFETs because of robust dielectric properties and high tunneling barrier.

Keywords: graphene, transistors, conduction, hexagonal boron nitride, dielectric strength, tunneling

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Authors: Aleš Kratochvíl, Svatomír Slavík

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The paper presents an aircraft flutter suppression by active damping of supplementary control surface at trailing edge. The mathematical model of thin oscillation airfoil with control surface driven by pilot is developed. The supplementary control surface driven by control law is added. Active damping of flutter by several control law is present. The structural model of tailplane with an aerodynamic strip theory based on the airfoil model is developed by a finite element method. The optimization process of stiffens parameters is carried out to match the structural model with results from a ground vibration test of a small sport airplane. The implementation of supplementary control surface driven by control law is present. The active damping of tailplane model is shown.

Keywords: active damping, finite element method, flutter, tailplane model

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Authors: Ahbdelfattah M. Khourshid, T. Elabeidi

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Friction Stir Welding (FSW), a solid state joining technique, is widely being used for joining Al alloys for aerospace, marine automotive and many other applications of commercial importance. FSW were carried out using a vertical milling machine on Al 5083 alloy pipe. These pipe sections are relatively small in diameter, 5mm, and relatively thin walled, 2mm. In this study, 5083 aluminum alloy pipe were welded as similar alloy joints using (FSW) process in order to investigate mechanical and microstructural properties .rotation speed 1400 r.p.m and weld speed 10,40,70 mm/min. In order to investigate the effect of welding speeds on mechanical properties, metallographic and mechanical tests were carried out on the welded areas. Vickers hardness profile and tensile tests of the joints as a metallurgical investigation, Optic Microscopy and Scanning Electron Microscopy (SEM) were used for base and weld zones.

Keywords: friction stir welding (FSW), Al alloys, mechanical properties, microstructure

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Authors: Yasmeen F. Pervez, Etesh K. Janghel, Santosh Kumar Sar

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Simple and sensitive analytical thermal gradient-thin layer chromatography technique has been developed for the simultaneous determination of phenolic pesticides like carbaryl, propoxur and carbofuran. It is based on the differential migration of colored derivatives formed by the reaction of hydrolysed phenolic compound with diazotized 3, 4 dimethyl aniline on a silica gel plate. Quantitative evaluation of hydrolyzed phenolic compound is made by visual comparison of intensities of color by spectrophotometry. The color system obeys Beer’s law in the following working range in ppm : carbaryl, 0.5-6.6; propoxur, 0.8-7.2; and carbofuran, 0.2-3.3 respectively. The Molar absorptivity, Sandell’s sensitivity, Correlation coefficient have been determined. The effects of analytical parameters on migration and analysis have been evaluated. The methods are highly reproducible and have been successfully applied to determination of phenolic pesticides in environmental and biological samples.

Keywords: phenolic pesticides (carbaryl, propoxur and carbofuran), 3.4 dimethyl aniline, environmental, biological samples

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Authors: P. Meethum, C. Suvanjumrat

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Many aluminum motorcycle parts produced by a high pressure die casting. Some parts such as fuel caps were a thin and complex shape. This part risked for porosities and blisters on surface if it only depended on an experience of mold makers for mold design. This research attempted to use CAST-DESIGNER software simulated the high pressure die casting process with the same process parameters of a motorcycle fuel cap production. The simulated results were compared with fuel cap products and expressed the same porosity and blister locations on cap surface. An average of absolute difference of simulated results was obtained 0.094 mm when compared the simulated porosity and blister defect sizes on the fuel cap surfaces with the experimental micro photography. This comparison confirmed an accuracy of software and will use the setting parameters to improve fuel cap molds in the further work.

Keywords: aluminum, die casting, fuel cap, motorcycle

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Authors: Farid Amidi Fazli

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Replacement of plastics used in the food industry seems to be a serious issue to overcome mainly the environmental problems in recent years. This study investigates the hydrophilicity and permeability properties of starch biopolymer which ethylene vinyl alcohol (EVOH) (0-10%) and nanocrystalline cellulose (NCC) (1 -15%) were used to enhance its properties. Starch -EVOH nanocomposites were prepared by casting method in different formulations. NCC production by acid hydrolysis was confirmed by scanning electron microscopy. Solubility, water vapor permeability, water vapor transmission rate and moisture absorbance were measured on each of the nanocomposites. The results were analyzed by SAS software. The lowest moisture absorbance was measured in pure starch nanocomposite containing 8% NCC. The lowest permeability to water vapor belongs to starch nanocomposite containing 8% NCC and the sample containing 7.8% EVOH and 13% NCC. Also, the lowest solubility was observed in the composite contains the highest amount of EVOH. Applied Process resulted in production of bio films which have good resistance to water vapor permeability and solubility in water. The use of NCC and EVOH leads to reduced moisture absorbance property of the biofilms.

Keywords: starch, EVOH, nanocrystalline cellulose, hydrophilicity

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Authors: W. Sun, W. Wen, J. Lu, A. A. Becker

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In this work, methods for determining creep properties which can be used to represent the full life until failure from miniature specimen creep tests based on analytical solutions are presented. Examples used to demonstrate the application of the methods include a miniature rectangular thin beam specimen creep test under three-point bending and a miniature two-material tensile specimen creep test subjected to a steady load. Mathematical expressions for deflection and creep strain rate of the two specimens were presented for the Kachanov-Rabotnov creep damage model. On this basis, an inverse procedure was developed which has potential applications for deriving the full life creep damage constitutive properties from a very small volume of material, in particular, for various microstructure constitutive  regions, e.g. within heat-affected zones of power plant pipe weldments. Further work on validation and improvement of the method is addressed.

Keywords: creep damage property, miniature specimen, inverse approach, finite element modeling

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Authors: Samira Naghdi, Kyong Yop Rhee

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Transfer-free synthesis of graphene on dielectric substrates is highly desirable but remains challenging. Here, by using a thin sacrificial platinum layer as a catalyst, graphene was deposited on a silicon substrate through a simple and transfer-free synthesis method. During graphene growth, the platinum layer evaporated, resulting in direct deposition of graphene on the silicon substrate. In this work, different growth conditions of graphene were optimized. Raman spectra of the produced graphene indicated that the obtained graphene was bilayer. The sheet resistance obtained from four-point probe measurements demonstrated that the deposited graphene had high conductivity. Reflectance spectroscopy of graphene-coated silicon showed a decrease in reflectance across the wavelength range of 200-800 nm, indicating that the graphene coating on the silicon surface had antireflection capabilities.

Keywords: antireflection coating, chemical vapor deposition, graphene, the sheet resistance

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Authors: Gülçin Tekin, Fethi Kadıoğlu

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In this study, the dynamic analysis of viscoelastic plates with variable thickness is examined. The solutions of dynamic response of viscoelastic thin plates with variable thickness have been obtained by using the functional analysis method in the conjunction with the Gâteaux differential. The four-node serendipity element with four degrees of freedom such as deflection, bending, and twisting moments at each node is used. Additionally, boundary condition terms are included in the functional by using a systematic way. In viscoelastic modeling, Three-parameter Kelvin solid model is employed. The solutions obtained in the Laplace-Carson domain are transformed to the real time domain by using MDOP, Dubner & Abate, and Durbin inverse transform techniques. To test the performance of the proposed mixed finite element formulation, numerical examples are treated.

Keywords: dynamic analysis, inverse laplace transform techniques, mixed finite element formulation, viscoelastic plate with variable thickness

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Authors: Sira Suren, Soorathep Kheawhom

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This work investigates the development of a high energy density zinc-air battery. Printed and flexible thin film zinc-air battery with an overall thickness of about 350 μm was fabricated by an inexpensive screen-printing technique. Commercial nano-silver ink was used as both current collectors and catalyst layer. Carbon black ink was used to fabricate cathode electrode. Polypropylene membrane was used as the cathode substrate and separator. 9 M KOH was used as the electrolyte. A mixture of Zn powder, ZnO, and Bi2O3 was used to prepare the anode electrode. The suitable concentration of Bi2O3 and types of binders (styrene-butadiene and sodium silicate) were investigated. Results showed that battery using 20% Bi2O3 and sodium silicate binder provided the best performance. The open-circuit voltage and energy density observed were 1.59 V and 690 Wh/kg, respectively. When the battery was discharged at 20 mA/cm2, the potential voltage observed was 1.3 V. Furthermore, the battery was tested for its flexibility. Upon bending, no significant loss in performance was observed.

Keywords: flexible, printed battery, screen printing, Zn-air

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Authors: Yohann R. J. Thomas, Sébastien Solan

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Conventional battery technology includes the assembly of electrode/separator/electrode by standard techniques such as stacking or winding, depending on the format size. In that type of batteries, coating or pasting techniques are only used for the electrode process. The processes are suited for large scale production of batteries and perfectly adapted to plenty of application requirements. Nevertheless, as the demand for both easier and cost-efficient production modes, flexible, custom-shaped and efficient small sized batteries is rising. Thin-film, printable batteries are one of the key areas for printed electronics. In the frame of European BASMATI project, we are investigating the feasibility of a new design of lithium-ion battery: interdigitated planar core design. Polymer substrate is used to produce bendable and flexible rechargeable accumulators. Direct fully printed batteries lead to interconnect the accumulator with other electronic functions for example organic solar cells (harvesting function), printed sensors (autonomous sensors) or RFID (communication function) on a common substrate to produce fully integrated, thin and flexible new devices. To fulfill those specifications, a high resolution printing process have been selected: Aerosol jet printing. In order to fit with this process parameters, we worked on nanomaterials formulation for current collectors and electrodes. In addition, an advanced printed polymer-electrolyte is developed to be implemented directly in the printing process in order to avoid the liquid electrolyte filling step and to improve safety and flexibility. Results: Three different current collectors has been studied and printed successfully. An ink of commercial copper nanoparticles has been formulated and printed, then a flash sintering was applied to the interdigitated design. A gold ink was also printed, the resulting material was partially self-sintered and did not require any high temperature post treatment. Finally, carbon nanotubes were also printed with a high resolution and well defined patterns. Different electrode materials were formulated and printed according to the interdigitated design. For cathodes, NMC and LFP were efficaciously printed. For anodes, LTO and graphite have shown to be good candidates for the fully printed battery. The electrochemical performances of those materials have been evaluated in a standard coin cell with lithium-metal counter electrode and the results are similar with those of a traditional ink formulation and process. A jellified plastic crystal solid state electrolyte has been developed and showed comparable performances to classical liquid carbonate electrolytes with two different materials. In our future developments, focus will be put on several tasks. In a first place, we will synthesize and formulate new specific nano-materials based on metal-oxyde. Then a fully printed device will be produced and its electrochemical performance will be evaluated.

Keywords: high resolution digital printing, lithium-ion battery, nanomaterials, solid-state electrolytes

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Authors: Jeff Letcher, Dennis Tierney, Haider Raad

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Antennas are devices for transmitting and/or receiving signals which make them a necessary component of any wireless system. In this paper, a thermal deposition technique is utilized as a method to fabricate antenna structures on substrates. Thin-film deposition is achieved by evaporating a source material (metals in our case) in a vacuum which allows vapor particles to travel directly to the target substrate which is encased with a mask that outlines the desired structure. The material then condenses back to solid state. This method is used in comparison to screen printing, chemical etching, and ink jet printing to indicate advantages and disadvantages to the method. The antenna created undergoes various testing of frequency ranges, conductivity, and a series of flexing to indicate the effectiveness of the thermal deposition technique. A single band antenna that is operated at 2.45 GHz intended for wearable and flexible applications was successfully fabricated through this method and tested. It is concluded that thermal deposition presents a feasible technique of producing such antennas.

Keywords: thermal deposition, wearable antennas, bluetooth technology, flexible electronics

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Authors: Sumonthip Kongtun Janphuk

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Ten cereal grains that usually used as ingredients in healthy products were studied for phytosteryl glucoside contents. β-sitosteryl glucoside in 10 cereal grains, including Phasecolus vulgaris L. (kidney bean), Sorghum bicolor (sorghum), Moringa oleifera Lam. (drumstick), Nelumbo nucifera (lotus), Vigna radiate L. (mung bean), Coix lacrymajobi (job’tears), Oryza sativa. (red rice), Glycine max L. Merrill. (soybean),Cucurbita maschata Decne (pumpkin) and Helianthas annuus (sunflower seeds), were analyzed using Thin-layer chromatography (TLC) and High-Performance liquid chromatography (HPLC). All grains were extracted with methanol before analysis. Red bean showed the maximum phytosteryl glucoside content of 0.42% w/w. The content of others were as follows: pumpkin seed 0.173%, mung bean 0.099 %, soybean 0.07%, dried moringa seed 0.067%, lotus seed 0.044%, sorghum 0.032%, sunflower seed 0.016%, Job's tears 0.012%, and brown rice 0.006%.

Keywords: cereal grains, phytosterol, β-sitosteryl glucoside, food analysis.

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Authors: Lise Paule Labéjof, Raíza Sales Pereira Bizerra, Galileu Barbosa Costa, Thaísa Barros dos Santos

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Since the beginning of the microscopy, improving the image quality has always been a concern of its users. Especially for transmission electron microscopy (TEM), the problem is even more important due to the complexity of the sample preparation technique and the many variables that can affect the conservation of structures, proper operation of the equipment used and then the quality of the images obtained. Animal tissues being transparent it is necessary to apply a contrast agent in order to identify the elements of their ultrastructural morphology. Several methods of contrastation of tissues for TEM imaging have already been developed. The most used are the “in block” contrastation and “in situ” contrastation. This report presents an alternative technique of application of contrast agent in vivo, i.e. before sampling. By this new method the electromicrographies of the tissue sections have better contrast compared to that in situ and present no artefact of precipitation of contrast agent. Another advantage is that a small amount of contrast is needed to get a good result given that most of them are expensive and extremely toxic.

Keywords: image quality, microscopy research, staining technique, ultra thin section

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Authors: Tian-Fang Kang, Xue Sun

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DNA damage induced by tetrachloro-1,4-benzoquinone (TCBQ), a reactive metabolite of pentachloro-phenol (PCP), was investigated using a glassy carbon electrode (GCE) modified with calf thymus double-stranded DNA (ds-DNA) in this work. DNA modified films were constructed by layer-by-layer adsorption of polycationic poly(diallyldimethyl- ammonium chloride) (PDDA) and negatively charged ds-DNA on the surface of a glassy carbon electrode. The DNA intercalator [Ru(bpy)2(dppz)]2+ (bpy=2, 2′-bipyridine, dppz0dipyrido [3, 2-a: 2′,3′-c] phenazine) was chosen as an electrochemical probe to detect DNA damage. After the sensor was incubated in 0.1 M pH 7.3 phosphate buffer solution (PBS) for 30min, the intact PDDA/DNA film produced a sensitive electrochemiluminescent (ECL) signal. However, after the sensor was incubated in 100 μM TCBQ or a mixed solution of 100 μM TCBQ and 2 mM H2O2, ECL signal decreased significantly. During the incubation of DNA in TCBQ or TCBQ-H2O2 solution, the double-helix of DNA was damaged, which resulted in the decrease of Ru-dppz bound to DNA. Additionally, the results were verified independently by fluorescence experiments. This paper provides a sensitive method to directly screen DNA damage induced by chemicals in the environment.

Keywords: DNA damage, detection, electrochemiluminescence, sensor

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Authors: Cristian Viespe, Dana Miu

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Surface acoustic wave (SAW) sensors with nanoparticles (NPs) of various dimensions and concentrations embedded in different types of polymer sensing films for detecting volatile organic compounds (VOCs) were studied. The sensors were ‘delay line’ type with a center frequency of 69.4 MHz on ST-X quartz substrates. NPs with different diameters of 7 nm or 13 nm were obtained by laser ablation with lasers having 5 ns or 10 ps pulse durations, respectively. The influence of NPs dimensions and concentrations on sensor properties such as frequency shift, sensitivity, noise and response time were investigated. To the best of our knowledge, the influence of NP dimensions on SAW sensor properties with has not been investigated. The frequency shift and sensitivity increased with increasing NP concentration in the polymer for a given NP dimension and with decreasing NP diameter for a given concentration. The best performances were obtained for the smallest NPs used. The SAW sensor with NPs of 7 nm had a limit of detection (LOD) of 65 ppm (almost five times better than the sensor with polymer alone), and a response time of about 9 s for ethanol.

Keywords: surface acoustic wave sensor, nanoparticles, volatile organic compounds, laser ablation

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Authors: Boughedaoui Rachid, Belaidi Idir, Ouali Mohamed

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The formatting by removal of material remains an indispensable means for obtaining different forms of pieces. The objective of this work is to study the influence of parameters of the vibratory regime of the system PTM 'Piece-Tool-Machine, in the case of the machining of the thin pieces on the surface finish. As a first step, an analytical study of essential dynamic models 2D slice will be presented. The stability lobes will be thus obtained. In a second step, a characterization of PTM system will be realized. This system will be instrumented with accelerometric sensors but also a laser vibrometer so as to have the information closer to the cutting area. Dynamometers three components will be used for the analysis of cutting forces. Surface states will be measured and the condition of the cutting edge will be visualized thanks to a binocular microscope coupled to a data acquisition system. This information will allow quantifying the influence of chatter on the dimensional quality of the parts. From lobes stabilities previously determined experimental validation allow for the development a method for detecting of the phenomenon of chatter and so an approach will be proposed.

Keywords: chatter, dynamic, milling, lobe stability

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Authors: Esma Kocaoglu, Oktay Talaz, Huseyin Cavdar, Murat Senturk, Deniz Eki̇nci̇

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Glutathione reductase (GR) is a crucial antioxidant enzyme which is responsible for the maintenance of the antioxidant GSH (glutathione) molecule. Antimalarial effects of some chemical molecules are attributed to their inhibition of GR; thus inhibitors of this enzyme are expected to be promising candidates for the treatment of malaria. In this work, GR inhibitory properties of N-Methylpyrrole derivatives are reported. Firstly, GR was purified by means of affinity chromatography using 2’,5’-ADP-Sepharose 4B as ligand. Enzymatic activity was measured by Beutler’s method. Synthesis of the compounds was approved by thin layer chromatography and column chromatography. Different inhibitor concentrations were used and all compounds were tested in triplicate at each concentration used. It was found that all compounds have better inhibitory activity than the strong GR inhibitor N,N-bis(2-chloroethyl)-N-nitrosourea, especially three molecules, 8m, 8n, and 8q, are the best among them with low micromolar I₅₀ values. Findings of our study indicate that these Schiff base derivatives are strong GR inhibitors which can be used as leads for designation of novel antimalaria candidates.

Keywords: glutathione reductase, antimalaria, inhibitor, enzyme

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Authors: Sankara Rao Gollu, Ramakant Sharma, G. Srinivas, Souvik Kundu, Dipti Gupta

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In recent years, bulk heterojunction organic solar cells (BHJ OSCs) based on polymer–fullerene attracted a large research attention due to their numerous advantages such as light weight, easy processability, eco-friendly, low-cost, and capability for large area roll-to-roll manufacturing. BHJ OSCs usually suffer from insufficient light absorption due to restriction on keeping thin ( < 150 nm) photoactive layer because of small exciton diffusion length ( ~ 10 nm) and low charge carrier mobilities. It is thus highly desirable that light absorption as well as charge transport properties are enhanced by alternative methods so as to improve the device efficiency. In this work, therefore, we have focused on the strategy of incorporating metallic nanostructures in the active layer or charge transport layer to enhance the absorption and improve the charge transport.

Keywords: organic solar cell, efficiency, bulk heterojunction, polymer-fullerene

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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 applications

Keywords: calixarene, multiwalled carbon nanotubes, cadmium, surface potential

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Authors: Annika Agarwal, Sara Baumann

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The urbanization of Mumbai has loosened restrictions placed on Indian women while menstruating, like not praying or entering the kitchen, but it has also introduced sanitary issues. On one hand, residents use community toilets that lack water, electricity, doors, or disposal, making menstruation a communal issue. On the other hand, menstrual taboos perpetuate a culture of a dirty and clandestine menstrual experience. This dichotomy makes India the ideal location for public health research given the complexities of purity and pollution concepts in the Hindu tradition. This study asks: What are the attitudes, practices, and sources of knowledge production around menstrual disposal among men and women of different age groups in Dharavi? Using collaborative filmmaking (CF), researchers cocreated films on menstrual disposal with 20-30 women from 3 slum sites: Dharavi, Kandivali, and Kalwa. Results demonstrate 1) fear and availability issues around sustainable product use, 2) the prominence of certain myths and traditions, 3) lack of disposal facilities and clean toilets, and 4) a lack of discussion around periods with males. These factors jeopardize the health and safety for menstruating women.

Keywords: menstruation, sustainability, sanitation, public health, global health

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Authors: M. Simchi, M. Amiri, E. Rezvani, I. Mirzaei, M. Berahman, A. Simchi, M. Fardmanesh

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Graphene is a single-atomic two-dimensional crystal of carbon atoms that has considerable properties due to its unique structure and physics with applications in different fields. Graphene has sensitive electrical properties due to its atomic-thin structure. Along with the substrate materials and their influence on the transport properties in graphene, design and fabrication of graphene-based devices for biomedical and biosensor applications are challenging. In this work, large-area high-quality graphene nanosheets were prepared by low pressure chemical vapor deposition using methane gas as carbon source on copper foil and transferred on the biocompatible substrates. Through deposition of titanium and gold contacts, current-voltage response of the transferred graphene on four biocompatible substrates, including PDMS, SU-8, Nitrocellulose, and Kapton (Fig. 2) were experimentally determined. The considerable effect of the substrate type on the electrical properties of graphene is shown. The sheet resistance of graphene is changed from 0.34 to 14.5 kΩ/sq, depending on the substrate.

Keywords: biocompatible substrates, electrical properties, graphene, sheet resistance

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Authors: Benjamin Panreck, Manfred Hild

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Strain sensors based on a change in resistance are well established for the measurement of forces, stresses, or material fatigue. Within the scope of this paper, fully additive manufactured strain sensors were produced using an ink of silver nanoparticles. Their behavior was evaluated by periodic tensile tests. Printed strain sensors exhibit two advantages: Their measuring grid is adaptable to the use case and they do not need a carrier-foil, as the measuring structure can be printed directly onto a thin sprayed varnish layer on the aluminum specimen. In order to compare quality characteristics, the sensors have been manufactured using two different technologies, namely aerosoljet-printing and micropipette-dispensing. Both processes produce structures which exhibit continuous features (in contrast to what can be achieved with droplets during inkjet printing). Briefly summarized the results show that aerosoljet-printing is the preferable technology for specimen with non-planar surfaces whereas both technologies are suitable for flat specimen.

Keywords: aerosoljet-printing, micropipette-dispensing, printed electronics, printed sensors, strain gauge

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Authors: Guoheng Liu, Zhilong Huang

Abstract:

For more than the past ten years, oil and gas production from marine shale such as the Barnett shale. In addition, in recent years, major breakthroughs have also been made in lacustrine shale gas exploration, such as the Yanchang Formation of the Ordos Basin in China. Lucaogou Formation shale, which is also lacustrine shale, has also yielded a high production in recent years, for wells such as M1, M6, and ML2, yielding a daily oil production of 5.6 tons, 37.4 tons and 13.56 tons, respectively. Lithologic identification and classification of reservoirs are the base and keys to oil and gas exploration. Lithology and lithofacies obviously control the distribution of oil and gas in lithological reservoirs, so it is of great significance to describe characteristics of lithology and lithofacies of reservoirs finely. Lithofacies is an intrinsic property of rock formed under certain conditions of sedimentation. Fine-grained sedimentary rocks such as shale formed under different sedimentary conditions display great particularity and distinctiveness. Hence, to our best knowledge, no constant and unified criteria and methods exist for fine-grained sedimentary rocks regarding lithofacies definition and classification. Consequently, multi-parameters and multi-disciplines are necessary. A series of qualitative descriptions and quantitative analysis were used to figure out the lithofacies characteristics and its effect on oil accumulation of Lucaogou formation fine-grained sedimentary rocks in Santanghu basin. The qualitative description includes core description, petrographic thin section observation, fluorescent thin-section observation, cathode luminescence observation and scanning electron microscope observation. The quantitative analyses include X-ray diffraction, total organic content analysis, ROCK-EVAL.II Methodology, soxhlet extraction, porosity and permeability analysis and oil saturation analysis. Three types of lithofacies were mainly well-developed in this study area, which is organic-rich massive shale lithofacies, organic-rich laminated and cloddy hybrid sedimentary lithofacies and organic-lean massive carbonate lithofacies. Organic-rich massive shale lithofacies mainly include massive shale and tuffaceous shale, of which quartz and clay minerals are the major components. Organic-rich laminated and cloddy hybrid sedimentary lithofacies contain lamina and cloddy structure. Rocks from this lithofacies chiefly consist of dolomite and quartz. Organic-lean massive carbonate lithofacies mainly contains massive bedding fine-grained carbonate rocks, of which fine-grained dolomite accounts for the main part. Organic-rich massive shale lithofacies contain the highest content of free hydrocarbon and solid organic matter. Moreover, more pores were developed in organic-rich massive shale lithofacies. Organic-lean massive carbonate lithofacies contain the lowest content solid organic matter and develop the least amount of pores. Organic-rich laminated and cloddy hybrid sedimentary lithofacies develop the largest number of cracks and fractures. To sum up, organic-rich massive shale lithofacies is the most favorable type of lithofacies. Organic-lean massive carbonate lithofacies is impossible for large scale oil accumulation.

Keywords: lithofacies classification, tuffaceous shale, oil enrichment, Lucaogou formation

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Authors: Durata Haciu, Ozgur Birer

Abstract:

Zinc acetate solution is sonicated at high power in water and in ethanol in the absence and presence of various peroxides. In the absence of peroxides, the products are zinc oxide and layered hydroxy zinc acetate in water and in ethanol, respectively. Layered basic zinc acetate are prepared for the first time using sonochemical methods. The addition of peroxides alters the reaction mechanisms. In water, insoluble peroxides produce zinc oxides while the water soluble peroxide, i.e.hydrogen peroxide, completely destroyed the structure and casted a doubt on the accepted peroxide initiated mechanism of reactions. In ethanol,peroxide addition caused the reaction mechanism to change and some oxide formation is observed. The reaction mechanism is sensitive to water/ethanol amounts as well as the peroxide to zinc ion mole ratio.Thin zinc oxide wafers (ca. 30 nm) with band gaps of 3.24 eV were obtained.

Keywords: ultrasound, zinc oxide, hydroxy zinc acetate, fenton, peroxide initiation

Procedia PDF Downloads 295

Authors: Jafar Khan Kasi, Ajab Khan Kasi, Muzamil Bokhari

Abstract:

Carbon nanotube is one of the most attractive materials for the potential applications of nanotechnology due to its excellent mechanical, thermal, electrical and optical properties. In this paper we report a supercapacitor made of nickel foil electrodes, coated with multiwall carbon nanotubes (MWCNTs) thin film using electrophoretic deposition (EPD) method. Chemical vapor deposition method was used for the growth of MWCNTs and ethanol was used as a hydrocarbon source. High graphitic multiwall carbon nanotube was found at 750 C analyzing by Raman spectroscopy. We observed the electrochemical performance of supercapacitor by cyclic voltammetry. The electrodes of supercapacitor fabricated from MWCNTs exhibit considerably small equivalent series resistance (ESR), and a high specific power density. Electrophoretic deposition is an easy method in fabricating MWCNT electrodes for high performance supercapacitor.

Keywords: carbon nanotube, chemical vapor deposition, catalyst, charge, cyclic voltammetry

Procedia PDF Downloads 562

Authors: Elahe Moradi, Hossein Ali Khonakdar

Abstract:

In the context of the growing interest in renewable polymers, this study presents an innovative approach to environmental conservation through the development of an eco-friendly structure. The research focused on enhancing the compatibility between two immiscible polymers, poly (lactic acid) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT), using polyhedral oligomeric silsesquioxanes (POSS) nanoparticles with an epoxy functional group (Epoxy-POSS). This was achieved through a solution casting method. The study found that the modulus in the glassy region for blends containing Epoxy-POSS was significantly higher than that of the PLA/PBAT blend without Epoxy-POSS. However, in the transition and rubbery regions, the modulus of the Epoxy-POSS-containing blends was only marginally greater. From a mechanical properties’ perspective, the study demonstrated that the incorporation of POSS-EPOXY at varying concentrations enhanced the tensile strength of the PLA/PBAT blend by 30%, thereby acting as a reinforcement. This finding underscores the potential of this approach in the development of renewable polymers.

Keywords: Polyhedral oligomeric silsesquioxane, mechanical behavior, PLA, PBAT, nanocomposite

Procedia PDF Downloads 61