Search results for: transparent coatings

Authors: Komal Kumar, Sreedevi Upadhyayula

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In this study, a two-stage process was established for the synthesis of HMF esters using ionic liquid acid catalyst. Ionic liquid catalyst with different strength of the Bronsted acidity was prepared in the laboratory and characterized using 1H NMR, FT-IR, and 13C NMR spectroscopy. Solid acid catalyst from the ionic liquid catalyst was prepared using the immobilization method. The acidity of the synthesized acid catalyst was measured using Hammett function and titration method. Catalytic performance was evaluated for the biomass conversion to 5-hydroxymethylfurfural (5-HMF) and levulinic acid (LA) in methyl isobutyl ketone (MIBK)-water biphasic system. A good yield of 5-HMF and LA was found at the different composition of MIBK: Water. In the case of MIBK: Water ratio 10:1, good yield of 5-HMF was observed at ambient temperature 150˚C. Upgrading of 5-HMF into monoesters from the reaction of 5-HMF and reactants using biomass-derived monoacid were performed. Ionic liquid catalyst with -SO₃H functional group was found to be best efficient in comparative of a solid acid catalyst for the esterification reaction and biomass conversion. A good yield of 5-HMF esters with high 5-HMF conversion was found to be at 105˚C using the best active catalyst. In this process, process A was the hydrothermal conversion of cellulose and monomer into 5-HMF and LA using acid catalyst. And the process B was the esterification followed by using similar acid catalyst. All monoesters of 5-HMF synthesized here can be used in chemical, cross linker for adhesive or coatings and pharmaceutical industry. A theoretical density functional theory (DFT) study for the optimization of the ionic liquid structure was performed using the Gaussian 09 program to find out the minimum energy configuration of ionic liquid catalyst.

Keywords: biomass conversion, 5-HMF, Ionic liquid, HMF ester

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Authors: Philipp Stehle, Dragoljub Vrankovic, Montaha Anjass

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Due to its high availability and extremely high specific capacity, silicon (Si) is the most promising anode material for next generation lithium-ion batteries (LIBs). However, Si anodes are suffering from high volume changes during cycling causing unstable solid-electrolyte interface (SEI). One approach for mitigation of these effects is to embed Si particles into a carbon matrix to create silicon/carbon composites (Si/C). These typically show more stable electrochemical performance than bare silicon materials. Nevertheless, the same failure mechanisms mentioned earlier appear in a less pronounced form. In this work, we further improved the cycling performance of two commercially available Si/C materials by coating thin metal oxide films of different thicknesses on the powders via Atomic Layer Deposition (ALD). The coated powders were analyzed via ICP-OES and AFM measurements. Si/C-graphite anodes with automotive-relevant loadings (~3.5 mAh/cm2) were processed out of the materials and tested in half coin cells (HCCs) and full pouch cells (FPCs). During long-term cycling in FPCs, a significant improvement was observed for some of the ALD-coated materials. After 500 cycles, the capacity retention was already up to 10% higher compared to the pristine materials. Cycling of the FPCs continued until they reached a state of health (SOH) of 80%. By this point, up to the triple number of cycles were achieved by ALD-coated compared to pristine anodes. Post-mortem analysis via various methods was carried out to evaluate the differences in SEI formation and thicknesses.

Keywords: silicon anodes, li-ion batteries, atomic layer deposition, silicon-carbon composites, surface coatings

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Authors: G. Gokceli, O. Eksik, E. Ozkan Zayim, N. Karatepe

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Alternative electrode materials for optoelectronic devices have been widely investigated in recent years. Since indium tin oxide (ITO) is the most preferred transparent conductive electrode, producing ITO films by simple and cost-effective solution-based techniques with enhanced optical and electrical properties has great importance. In this study, single- and multi-walled carbon nanotubes (SWCNT and MWCNT) incorporated into the ITO structure to increase electrical conductivity, mechanical strength, and chemical stability. Carbon nanotubes (CNTs) were firstly functionalized by acid treatment (HNO₃:H₂SO₄), and the thermal resistance of CNTs after functionalization was determined by thermogravimetric analysis (TGA). Thin films were then prepared by spin coating technique and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), four-point probe measurement system and UV-Vis spectrophotometer. The effects of process parameters were compared for ITO, MWCNT-ITO, and SWCNT-ITO films. Two factors including CNT concentration and annealing temperature were considered. The UV-Vis measurements demonstrated that the transmittance of ITO films was 83.58% at 550 nm, which was decreased depending on the concentration of CNT dopant. On the other hand, both CNT dopants provided an enhancement in the crystalline structure and electrical conductivity. Due to compatible diameter and better dispersibility of SWCNTs in the ITO solution, the best result in terms of electrical conductivity was obtained by SWCNT-ITO films with the 0.1 g/L SWCNT dopant concentration and heat-treatment at 550 °C for 1 hour.

Keywords: CNT incorporation, ITO electrode, spin coating, thin film

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Authors: Haleden Chiririwa, Sandile S. Gwebu

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The coatings industry is a million dollar business, and it is easy and inexpensive to set-up but it is growing very slowly in developing countries, and this study developed a paint formulation which gives better quality and good application properties. The effect of rheology modifiers, i.e. non-ionic polymers hydrophobically-modified ethoxylated urethanes (HEUR), anionic polymers hydrophobically-modified alkali soluble emulsions (HASE) and hydroxyl ethyl cellulose (HEC) on the quality and properties of water-based paints have been investigated. HEC provides the in-can viscosity and increases open working time while HASE improves application properties like spatter resistance and brush loading and HEUR provides excellent scrub resistance. Four paint recipes were prepared using four different thickeners HEC, HASE (carbopol) and Cellulose nitrate. The fourth formulation was thickened with a combination of HASE and HEC, this aimed at improving quality and at the same time reducing cost. The four samples were tested for quality tests such viscosity, sag resistance, volatile matter, tinter effect, drying times, hiding power, scrub resistance and stability on storage. Environmental factors were incorporated in the attempt to formulate an economic and green product. Hydroxyl ethyl cellulose and cellulose nitrate gave high quality and good properties of the paint. HEC and Cellulose nitrate showed stability on storage whereas carbopol thickener was very unstable.

Keywords: properties, thickeners, rheology modifiers, water based paints

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Authors: Rohini Hariharan, Yazhini R., Blessy Maria Mathew

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The task of detecting email spam is a very important one in the era of digital technology that needs effective ways of curbing unwanted messages. This paper presents an approach aimed at making email spam categorization algorithms transparent, reliable and more trustworthy by incorporating Local Interpretable Model-agnostic Explanations (LIME). Our technique assists in providing interpretable explanations for specific classifications of emails to help users understand the decision-making process by the model. In this study, we developed a complete pipeline that incorporates LIME into the spam classification framework and allows creating simplified, interpretable models tailored to individual emails. LIME identifies influential terms, pointing out key elements that drive classification results, thus reducing opacity inherent in conventional machine learning models. Additionally, we suggest a visualization scheme for displaying keywords that will improve understanding of categorization decisions by users. We test our method on a diverse email dataset and compare its performance with various baseline models, such as Gaussian Naive Bayes, Multinomial Naive Bayes, Bernoulli Naive Bayes, Support Vector Classifier, K-Nearest Neighbors, Decision Tree, and Logistic Regression. Our testing results show that our model surpasses all other models, achieving an accuracy of 96.59% and a precision of 99.12%.

Keywords: text classification, LIME (local interpretable model-agnostic explanations), stemming, tokenization, logistic regression.

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Authors: Carmen M. Gonzalez-Henriquez, Mauricio A. Sarabia-Vallejos, Juan Rodriguez-Hernandez

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DMAEMA, as a monomer, has been widely studied and used in several application fields due to their pH-sensitive capacity (tertiary amine protonation), being relevant in the biomedical area as a potential carrier for drugs focused on the treatment of genetic or acquired diseases (efficient gene transfection), among others. Additionally, the inhibition of bacterial growth and, therefore, their antimicrobial activity, can be used as dual-functional antifogging/antimicrobial polymer coatings. According to their interesting physicochemical characteristics and biocompatible properties, DMAEMA was used as a monomer to synthesize a smart pH-sensitive hydrogel, namely poly(HEMA-co-PEGDA575-co-DMAEMA). Thus, different mole ratios (ranging from 5:1:0 to 0:1:5, according to the mole ratio between HEMA, PEGDA, and DEAEMA, respectively) were used in this research. The surface patterns formed via a two-step polymerization (redox- and photo-polymerization) were first chemically studied via 1H-NMR and elemental analysis. Secondly, the samples were morphologically analyzed by using Field-Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscopy (AFM) techniques. Then, a particular relation between HEMA, PEGDA, and DEAEMA (0:1:5) was also characterized at three different pH (5.4, 7.4 and 8.3). The hydrodynamic radius and zeta potential of the micro-hydrogel particles (emulsion) were carried out as a possible control for morphology, exploring the effect that produces hydrogel micelle dimensions in the wavelength, height, and roughness of the wrinkled patterns. Finally, contact angle and cross-hatch adhesion test was carried out for the hydrogels supported on glass using TSM-silanized surfaces in order to measure their mechanical properties.

Keywords: wrinkled patterns, smart pH-sensitive hydrogels, hydrogel micelle diameter, adhesion tests

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Authors: Mirko Ante, Şeniz Sörgel, Andreas Bund

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Li-S- (Lithium-Sulfur-) battery systems provide very high specific gravimetric energy (2600 Wh/kg) and volumetric energy density (2800Wh/l). Hence, Li-S batteries are one of the key technologies for both the upcoming electromobility and stationary applications. Furthermore, the Li-S battery system is potentially cheap and environmentally benign. However, the technical implementation suffers from cycling stability, low charge and discharge rates and incomplete understanding of the complex polysulfide reaction mechanism. The aim of this work is to develop an effective electrocatalyst for the polysulfide reactions so that the electrode kinetics of the sulfur half-cell will be improved. Accordingly, the overvoltage will be decreased, and the efficiency of the cell will be increased. An enhanced electroactive surface additionally improves the charge and discharge rates. To reach this goal, functionalized electrocatalytic coatings are investigated to accelerate the kinetics of the polysulfide reactions. In order to determine a suitable electrocatalyst, apparent exchange current densities of a variety of materials (Ni, Co, Pt, Cr, Al, Cu, ITO, stainless steel) have been evaluated in a polysulfide containing electrolyte by potentiodynamic measurements and a Butler-Volmer fit including diffusion limitation. The samples have been examined by Scanning Electron Microscopy (SEM) after the potentiodynamic measurements. Up to now, our work shows that cobalt is a promising material with good electrocatalytic properties for the polysulfide reactions and good chemical stability in the system. Furthermore, an electrodeposition from a modified Watt’s nickel electrolyte with a sulfur source seems to provide an autocatalytic effect, but the electrocatalytic behavior decreases after several cycles of the current-potential-curve.

Keywords: electrocatalyst, energy storage, lithium sulfur battery, sulfur electrode materials

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Authors: Mahmoud S. El-Sebaey, Asko Ellman, Ahmed Hegazy, Tarek Ghonim

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Due to population growth, the need for drinkable healthy water is highly increased. Consequently, and since the conventional sources of water are limited, researchers devoted their efforts to oceans and seas for obtaining fresh drinkable water by thermal distillation. The current work is dedicated to the design and fabrication of modified solar still model, as well as conventional solar still for the sake of comparison. The modified still is single slope double basin solar still. The still consists of a lower basin with a dimension of 1000 mm x 1000 mm which contains the sea water, as well as the top basin that made with 4 mm acrylic, was temporarily kept on the supporting strips permanently fixed with the side walls. Equally ten spaced vertical glass strips of 50 mm height and 3 mm thickness were provided at the upper basin for the stagnancy of the water. Window glass of 3 mm was used as the transparent cover with 23° inclination at the top of the still. Furthermore, the performance evaluation and comparison of these two models in converting salty seawater into drinkable freshwater are introduced, analyzed and discussed. The experiments were performed during the period from June to July 2018 at seawater depths of 2, 3, 4 and 5 cm. Additionally, the solar still models were operated simultaneously in the same climatic conditions to analyze the influence of the modifications on the freshwater output. It can be concluded that the modified design of double basin single slope solar still shows the maximum freshwater output at all water depths tested. The results showed that the daily productivity for modified and conventional solar still was 2.9 and 1.8 dm³/m² day, indicating an increase of 60% in fresh water production.

Keywords: freshwater output, solar still, solar energy, thermal desalination

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Authors: Ghadah Abusalim, Suliman Alharbi, Hesham Khalil, Milton Wainwright, Mohammad A. Khiyami

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The use of implantable foreign devices in medicine has recently increased dramatically. Intravascular cannulae and catheters are used to administer fluids, medications, parenteral nutrition, and blood products in order to monitor hemodynamic status and also to provide hemodialysis. The early and late failure of inserted or implanted devices is largely the result of bacterial infection and may lead to the disruption of integration between the device and the tissues which surround it. Staphylococcus aureus and Staphylococcus epidermidis are widely considered to be the most common organisms causing device-related infection. Our study showed that S. aureus and S. epidermidis adhered to intravascular cannulae made up of PTFE, SPTFE and vialon. Adhesion of S. epidermidis and S. aureus to intravascular cannulae varied significantly depending upon the type of material used and the presence of coating materials. Both bacteria adhered less to PTFE followed by Vialon and SPTFE and the adhesion capacity of S. aureus and S. epidermidis increased over time. Coating intravascular cannulae with human serum albumin inhibited the adhesion of S. aureus and S. epidermidis to these cannulae, and pretreatment of cannulae with fibronectin inhibited the adhesion of S. epidermidis but increased the adhesion of S. aureus to all types of cannulae. Pretreatment of cannulae surface with potassium chloride or calcium chloride increased the adhesion of S. aureus and S. epidermidis to cannulae, suggesting a role for electrostatic forces in the mechanism of such adhesion. This study will hopefully clarify the mechanism of adhesion and provide possible means of preventing such adhesion either by the use of better material coatings or by interfering with the process of adhesion by targeting bacterial structures responsible for it. Currently we recommend the use of PTFE cannulae as they exhibit a lower bacterial adhesion capacity compared to the other tested cannulae.

Keywords: Staphylococcus epidermidis, Staphylococcus aureus, adhesion, cannulae, PTFE, Vialon

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Authors: Muhammad Sajid Arshad, Sadaf Bashir

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In this study, the effects of pomegranate peel based edible coating were determined on safety and quality of chicken nuggets. Four treatment groups were prepared as control (without coating), coating with sodium alginate (SA) (1.5%), pomegranate peel powder (PPP) (1.5%), and combination of SA and PPP. There was a significant variation observed with respect to coating treatments and storage intervals. The chicken nuggets were subjected to refrigerated storage (40C) and were analyzed at regular intervals of 0, 7, 14 1 and 21 days. The microbiological quality was determined by total aerobic and coliform counts. Total aerobic (5.09±0.05 log CFU/g) and coliforms (3.91±0.06 log CFU/g) counts were higher in uncoated chicken nuggets whereas lower was observed in coated chicken nuggets having combination of SA and PPP. Likewise, antioxidants potential of chicken nuggets was observed by assessing total phenolic contents (TPC) and DPPH activity. Higher TPC (135.66 GAE/100g) and DPPH (64.65%) were found in combination with SA and PPP, whereas minimum TPC (91.38) and DPPH (41.48) was observed in uncoated chicken nuggets. Regarding the stability analysis of chicken nuggets, thiobarbituric acid reactive substances (TBARS) and peroxide value (POV) were determined. Higher TBARS (1.62±0.03 MDA/Kg) and POV (0.92±0.03 meq peroxide/kg) were found in uncoated chicken nuggets. Hunter color values were also observed in both uncoated and coated chicken nuggets. Sensorial attributes were also observed by the trained panelists. The higher sensory score for appearance, color, taste, texture and overall acceptability were observed in control (uncoated) while in coated treatments, it was found within acceptable limits. In nutshell, the combination of SA and PPP enhanced the overall quality, antioxidant potential, and stability of chicken nuggets.

Keywords: chicken nuggets, edible coatings, pomegranate peel powder, sodium alginate

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Authors: Farbod Behnaminia, Saeed Samet

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The COVID-19 pandemic has paralyzed many lives until a vaccine was available, which caused the so-called “new normal.” According to the World Health Organization (WHO), COVID-19 is an infectious disease. It can cause significant illness or death in anyone. Governments and health officials tried to impose rules and regulations to avoid and slow down transmission. Therefore, software engineers worldwide developed applications to trace and track patients’ movements and notify others, mainly using Bluetooth. In this way, everyone could be informed whether they come in close contact with someone who has COVID-19 and takes proper safety precautions. Because most of the applications use technologies that can potentially reveal the user’s identity and location, researchers have debated privacy preservation and how to improve user privacy during such pandemics. Thanks to Distributed Ledger Technology (DLT), there have been some proposed methods to develop privacy-preserving Patient Tracking Systems in the last two years. As an instance of the DLT, Blockchain is like a decentralized peer-to-peer database that maintains a record of transactions. Transactions are immutable, transparent, and anonymous in this system. We conducted a comprehensive evaluation of the literature by looking for papers in the relevant field and dividing them into pre- and post-pandemic systems. Additionally, we discussed the many uses of blockchain technology in pandemic control. We found that two major obstacles facing blockchain implementation across many healthcare systems are scalability and privacy. The Polkadot platform is presented, along with a review of its efficacy in tackling current concerns. A more scalable healthcare system is achievable in the near future using Polkadot as well as a much more privacy-preserving environment.

Keywords: blockchain, electronic record management, EHR, privacy-preserving, patient tracking, COVID-19, trust and confidence, Polkadot

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Authors: Melanie Macgregor-Ramiasa, Isabel Hopp, Patricia Murray, Krasimir Vasilev

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Stem cells based therapies are one of the greatest promises of new-age medicine due to their potential to help curing most dreaded conditions such as cancer, diabetes and even auto-immune disease. However, establishing suitable in vitro culture materials allowing to control the fate of stem cells remain a challenge. Amongst the factor influencing stem cell behavior, substrate chemistry and nanotopogaphy are particularly critical. In this work, we used plasma assisted surface modification methods to produce model substrates with tailored nanotopography and controlled chemistry. Three different sizes of gold nanoparticles were bound to amine rich plasma polymer layers to produce homogeneous and gradient surface nanotopographies. The outer chemistry of the substrate was kept constant for all substrates by depositing a thin layer of our patented biocompatible polyoxazoline plasma polymer on top of the nanofeatures. For the first time, protein adsorption and stem cell behaviour (mouse kidney stem cells and mesenchymal stem cells) were evaluated on nanorough plasma deposited polyoxazoline thin films. Compared to other nitrogen rich coatings, polyoxazoline plasma polymer supports the covalent binding of proteins. Moderate surface nanoroughness, in both size and density, triggers cell proliferation. In association with polyoxazoline coating, cell proliferation is further enhanced on nanorough substrates. Results are discussed in term of substrates wetting properties. These findings provide valuable insights on the mechanisms governing the interactions between stem cells and their growth support.

Keywords: nanotopography, stem cells, differentiation, plasma polymer, oxazoline, gold nanoparticles

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Authors: Ana Paula Esteves, Diego S. Caetano, Louise L. B. Lomardo

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This paper presents an approach to the performance of the natural lighting, when the use of appropriated solar lighting systems on the roof is applied in cultural buildings such as museums and foundations. The roofs, as a part of contact between the building and the external environment, require special attention in projects that aim at energy efficiency, being an important element for the capture of natural light in greater quantity, but also for being the most important point of generation of photovoltaic solar energy, even semitransparent, allowing the partial passage of light. Transparent elements in roofs, as well as superior protection of the building, can also play other roles, such as: meeting the needs of natural light for the accomplishment of the internal tasks, attending to the visual comfort; to bring benefits to the human perception and about the interior experience in a building. When these resources are well dimensioned, they also contribute to the energy efficiency and consequent character of sustainability of the building. Therefore, when properly designed and executed, a roof light system can bring higher quality natural light to the interior of the building, which is related to the human health and well-being dimension. Furthermore, it can meet the technologic, economic and environmental yearnings, making possible the more efficient use of that primordial resource, which is the light of the Sun. The article presents the analysis of buildings that used zenith light systems in search of better lighting performance in museums and foundations: the Solomon R. Guggenheim Museum in the United States, the Iberê Camargo Foundation in Brazil, the Museum of Fine Arts in Castellón in Spain and the Pinacoteca of São Paulo.

Keywords: natural lighting, roof lighting systems, natural lighting in museums, comfort lighting

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Authors: V. Jelev, P. Petkov, P. Shindov

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Thin films of undoped and As-doped tin oxide (As:SnO2) were obtained on silicon and glass substrates at 450°- 480°C by spray pyrolysis technique. Tin chloride (SnCl4.5H2O) and As oxide (3As2O5.5H2O) were used as a source for Sn and As respectively. The As2O5 concentration was varied from 0 to 10 mol% in the starting water-alcoholic solution. The characterization of the films was provided with XRD, CEM, AFM and UV-VIS spectroscopy. The influence of the synthesis parameters (the temperature of the substrate, solution concentration, gas and solution flow rates, deposition time, nozzle-to substrate distance) on the optical, electrical and structural properties of the films was investigated. The substrate temperature influences on the surface topography, structure and resistivity of the films. Films grown at low temperatures (<300°C) are amorphous whereas this deposited at higher temperatures have certain degree of polycrystallinity. Thin oxide films deposited at 450°C are generally polycrystalline with tetragonal rutile structure. The resistivity decreases with dopant concentration. The minimum resistivity was achieved at dopant concentration about 2.5 mol% As2O5 in the solution. The transmittance greater than 80% and resistivity smaller than 7.5.10-4Ω.cm were achieved in the films deposited at 480°C. The As doped films (SnO2: As) deposited on silicon substrates was used for preparation of a large area position sensitive photodetector (PSD), acting on the base of a lateral photovoltaic effect. The position characteristic of PSD is symmetric to the zero and linear in the 80% of the active area. The SnO2 films are extremely stable under typical environmental conditions and extremely resistant to chemical etching.

Keywords: metal oxide film, SnO2 film, position sensitive photodetectors (PSD), lateral photovoltaic effect

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Authors: Aptullah Karakas, Murat Baydogan

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Hot-dip aluminizing (HDA) is one of the several aluminizing methods to form a wear-, corrosion- and oxidation-resistant aluminide layers on the surface. In this method, the substrate is dipped into a molten aluminum bath, hold in the bath for several minutes, and cooled down to the room temperature in air. A subsequent annealing after the HDA process is generally performed. The main advantage of HDA is its very low investment cost in comparison with other aluminizing methods such as chemical vapor deposition (CVD), pack aluminizing and metalizing. In the HDA process, Al or Al-Si molten baths are mostly used. However, in this study, three different Al alloys such as Al4043 (Al-Mg), Al5356 (Al-Si) and Al7020 (Al-Zn) were used as the molten bath in order to see their effects on morphological and mechanical properties of the resulting aluminide layers. AISI 4140 low alloyed steel was used as the substrate. Parameters of the HDA process were bath composition, bath temperature, and dipping time. These parameters were considered within a Taguchi L9 orthogonal array. After the HDA process and subsequent diffusion annealing, coating thickness measurement, microstructural analysis and hardness measurement of the aluminide layers were conducted. The optimum process parameters were evaluated according to coating morphology, such as cracks, Kirkendall porosity and hardness of the coatings. According to the results, smooth and clean aluminide layer with less Kirkendall porosity and cracks were observed on the sample, which was aluminized in the molten Al7020 bath at 700 C for 10 minutes and subsequently diffusion annealed at 750 C. Hardness of the aluminide layer was in between 1100-1300 HV and the coating thickness was approximately 400 µm. The results were promising such that a hard and thick aluminide layer with less Kirkendall porosity and cracks could be formed. It is, therefore, concluded that Al7020 bath may be used in the HDA process of AISI 4140 steel substrate.

Keywords: hot-dip aluminizing, microstructure, hardness measurement, diffusion annealing

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Authors: F. Z. Tighilt, N. Belhaneche-Bensemra, S. Belhousse, S. Sam, K. Lasmi, N. Gabouze

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Recently, the gold nanoparticles (Au NPs) became an active multidisciplinary research topic. First, Au thin films fabricated by alkylthiol-functionalized Au NPs were found to have vapor sensitive conductivities, they were hence widely investigated as electrical chemiresistors for sensing different vapor analytes and even organic molecules in aqueous solutions. Second, Au thin films were demonstrated to have speciallocalized surface plasmon resonances (LSPR), so that highly ordered 2D Au superlattices showed strong collective LSPR bands due to the near-field coupling of adjacent nanoparticles and were employed to detect biomolecular binding. Particularly when alkylthiol ligands were replaced by thiol-terminated polymers, the resulting polymer-modified Au NPs could be readily assembled into 2D nanostructures on solid substrates. Monolayers of polystyrene-coated Au NPs showed typical dipolar near-field interparticle plasmon coupling of LSPR. Such polymer-modified Au nanoparticle films have an advantage that the polymer thickness can be feasibly controlled by changing the polymer molecular weight. In this article, the effect of tin-doped indium oxide (ITO) coatings on the plasmonic properties of ITO interfaces modified with gold nanostructures (Au NSs) is investigated. The interest in developing ITO overlayers is multiple. The presence of a con-ducting ITO overlayer creates a LSPR-active interface, which can serve simultaneously as a working electrode in an electro-chemical setup. The surface of ITO/ Au NPs contains hydroxyl groups that can be used to link functional groups to the interface. Here the covalent linking of nickel /Au NSs/ITO hybrid LSPR platforms will be presented.

Keywords: conducting polymer, metal nanoparticles (NPs), LSPR, poly (3-(pyrrolyl)–carboxylic acid), polypyrrole

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Authors: Mohammad Reza Fazeli

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Nowadays, the fourth industry, known as the digital transformation of industries, is seen as one of the top subjects in the history of structural revolution, which has led to the high-tech and tactical dominance of the organization. In the face of these profits, the undefined and non-transparent nature of the after-effects of investing in digital transformation has hindered many organizations from attempting this area of this industry. One of the important frameworks in the field of understanding digital transformation in all organizations is the maturity model of digital transformation. This model includes two main parts of digital transformation maturity dimensions and digital transformation maturity stages. Mediating factors of digital maturity and organizational performance at the individual (e.g., motivations, attitudes) and at the organizational level (e.g., organizational culture) should be considered. For successful technology adoption processes, organizational development and human resources must go hand in hand and be supported by a sound communication strategy. Maturity models are developed to help organizations by providing broad guidance and a roadmap for improvement. However, as a result of a systematic review of the literature and its analysis, it was observed that none of the 18 maturity models in the field of digital transformation fully meet all the criteria of appropriateness, completeness, clarity, and objectivity. A maturity assessment framework potentially helps systematize assessment processes that create opportunities for change in processes and organizations enabled by digital initiatives and long-term improvements at the project portfolio level. Cultural characteristics reflecting digital culture are not systematically integrated, and specific digital maturity models for the service sector are less clearly presented. It is also clearly evident that research on the maturity of digital transformation as a holistic concept is scarce and needs more attention in future research.

Keywords: digital transformation, organizational performance, maturity models, maturity assessment

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Authors: Mucahit Unal, Ibrahim Arslan

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The New Turkish Commercial Code (TCC) No. 6102 was published in the Official Gazette on February 14, 2011. As stated in the New Turkish Commercial Code No. 6102 and Law No. 6103 on Validity and Application of the Turkish Commercial Code, TCC came into effect on July 1, 2012. The basic purpose of the TCC is to form corporate governance coherent with the international standards; to provide transparency in company management; to adjust the Turkish Commercial Code rules with European Union legislations and to simplify establishing a company for foreigner investors to move investments to Turkish market. In this context according to TCC, joint stock companies and limited liability companies can establish with only one single shareholder; the one single shareholder can be foreigner; all board of director members can be foreigner, also all shareholders and board of director members can be non-resident foreigners. Additionally, TCC does not require physical participation to the general shareholders and board members meetings. TCC allows that the general shareholders and board members meetings can hold in an electronic form and resolution of these meetings may also be approved via electronic signatures. Through this amendment, foreign investors no longer have to deal with red tapes. This amendment also means the TCC prevents foreign companies from incurring unnecessary travel expenses. In accordance with all this amendments about TCC, to invest in Turkish market is easy, simple and transparent for foreigner investors and also investors can establish a company in Turkey, irrespective of nationality or place of residence. This article aims to analyze ‘Establish a Company in Turkey for Foreigners’ and inform investors about investing (especially establishing a company) in the Turkish market.

Keywords: establish a company, foreigner investors, invest in Turkish market, Turkish commercial code

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Authors: Alae El Fahsi

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This study explores the ‘Tajawob’ app's role in urban development, demonstrating how mobile applications can empower citizens and facilitate urban planning. Tajawob serves as a digital platform for community feedback, engagement, and participatory governance, addressing urban challenges through innovative tech solutions. This research synthesizes data from a variety of sources, including user feedback, engagement metrics, and interviews with city officials, to assess the app’s impact on citizen participation in urban development in Morocco. By integrating advanced data analytics and user experience design, Tajawob has bridged the communication gap between citizens and government officials, fostering a more collaborative and transparent urban planning process. The findings reveal a significant increase in civic engagement, with users actively contributing to urban management decisions, thereby enhancing the responsiveness and inclusivity of urban governance. Challenges such as digital literacy, infrastructure limitations, and privacy concerns are also discussed, providing a comprehensive overview of the obstacles and opportunities presented by mobile app-based citizen engagement platforms. The study concludes with strategic recommendations for scaling the Tajawob model to other contexts, emphasizing the importance of adaptive technology solutions in meeting the evolving needs of urban populations. This research contributes to the burgeoning field of smart city innovations, offering key insights into the role of digital tools in facilitating more democratic and participatory urban environments.

Keywords: smart cities, digital governance, urban planning, strategic design

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Authors: Kwadwo Yeboah

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Background and Aims: The adoption of International Accounting Standards (IAS) is considered to be one of the most significant developments in the accounting profession. The adoption of IAS aims to improve financial reporting quality by ensuring that financial information is transparent and comparable across borders. However, there is a lack of research on the impact of IAS on financial reporting quality in emerging economies. This study aims to fill this gap by evaluating the impact of IAS on financial reporting quality in emerging economies. Methods: This study uses a sample of firms from emerging economies that have adopted IAS. The sample includes firms from different sectors and industries. The financial reporting quality of these firms is measured using financial ratios, such as earnings quality, financial leverage, and liquidity. The data is analyzed using a regression model that controls for firm-specific factors, such as size and profitability. Results: The results show that the adoption of IAS has a positive impact on financial reporting quality in emerging economies. Specifically, firms that adopt IAS exhibit higher earnings quality and lower financial leverage compared to firms that do not adopt IAS. Additionally, the adoption of IAS has a positive impact on liquidity, suggesting that firms that adopt IAS have better access to financing. Conclusions: The findings of this study suggest that the adoption of IAS has a positive impact on financial reporting quality in emerging economies. The results indicate that IAS adoption can improve transparency and comparability of financial information, which can enhance the ability of investors to make informed investment decisions. The study contributes to the literature by providing evidence of the impact of IAS adoption in emerging economies. The findings of this study have implications for policymakers and regulators in emerging economies, as they can use this evidence to support the adoption of IAS and improve financial reporting quality in their respective countries.

Keywords: accounting, international, standards, finance

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Authors: S. Brain, P. J. Storer, H. Strydom, Z. M. Solaiman

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Increasing farmer awareness of soil health, the impact of agricultural management practices, and the requirement for high-quality agricultural produce are major factors driving the rapid adoption of biological seed treatments - currently valued globally at USD 1.5 billion. Biological seed coatings with multistrain plant beneficial microbial technology have the capability to affect plant establishment, growth, and development positively. These beneficial plant microbes can potentially increase soil health, plant yield, and nutrition – acting as bio fertilisers, rhizoremediators, phytostimulators, and stress modulators, and can ultimately reduce the overall use of agrichemicals. A field trial was conducted on MACE wheat in the central wheat belt of Western Australia to evaluate a proprietary seed coating technology (Langleys Bio-EnergeticTM Microbe blend (BMB)) on a conventional program (+/- BMB microbes) and a Regenerative Biomineral fertiliser program (+/- BMB microbes). The Conventional (+BMB) and Biomineral (+BMB) treated plants had no fungicide treatments and had no disease issues. Control (No fertiliser, No microbes), Conventional (No Microbes), and Biomineral (No Microbes) were treated with fungicides (seed dressing and foliar). From the research findings, compared to control and no microbe treatments, both the Conventional (+ BMB) and Biomineral (+ BMB) showed significant increases in Soil Carbon (SOC), Seed germination, nutrient use efficiency (NUE) of nitrogen, phosphate and mineral nutrients, grain mineral nutrient uptake, protein %, hectolitre weight, and fewer screenings, yield, and gross margins.

Keywords: biological seed coating, biomineral fertiliser, plant nutrition, regenerative and conventional agriculture

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Authors: Sanchita Abrol, Kunal Rana, Ankit Dhir, S. K. Gupta

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According to N.R.E.L.’s findings, 700 crore gallons of petrol is used annually to run the air conditioners of passenger vehicles (nearly 6% of total fuel consumption in the USA). Beyond fuel use, the Environmental Protection Agency reported that refrigerant leaks from auto air conditioning units add an additional 5 crore metric tons of carbon emissions to the atmosphere each year. The objective of our project is to deal with this vital issue by carefully modifying the interiors of a car thereby increasing its mileage and the efficiency of its engine. This would consequently result in a decrease in tail emission and generated pollution along with improved car performance. An automatic mechanism, deployed between the front and the rear seats, consisting of transparent thermal insulating sheet/curtain, would roll down as per the requirement of the driver in order to optimize the volume for effective air conditioning, when travelling alone or with a person. The reduction in effective volume will yield favourable results. Even on a mild sunny day, the temperature inside a parked car can quickly spike to life-threatening levels. For a stationary parked car, insulation would be provided beneath its metal body so as to reduce the rate of heat transfer and increase the transmissivity. As a result, the car would not require a large amount of air conditioning for maintaining lower temperature, which would provide us similar benefits. Authors established the feasibility studies, system engineering and primarily theoretical and experimental results confirming the idea and motivation to fabricate and test the actual product.

Keywords: automation, car, cooling insulating curtains, heat optimization, insulation, reduction in tail emission, mileage

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Authors: Ufaith Qadri, M Marouf Wani

Abstract:

In this paper, the performance and emission characteristics of a Single Cylinder Spark Ignition engine have been investigated. The research is based on micro emulsion application as fuel in a gasoline engine. We have analyzed many micro emulsion compositions in various proportions, for predicting the performance of the Spark Ignition engine. This new technology of fuel modifications is emerging very rapidly as lot of research is going on in the field of micro emulsion fuels in Compression Ignition engines, but the micro emulsion fuel used in a Gasoline engine is very rare. The use of micro emulsion as fuel in a Spark Ignition engine is virtually unexplored. So, our main goal is to see the performance and emission characteristics of micro emulsions as fuel, in Spark Ignition engines, and finding which composition is more efficient. In this research, we have used various micro emulsion fuels whose composition varies for all the three blends, and their performance and emission characteristic were predicted in AVL Boost software. Conventional Gasoline fuel 90%, 80% and 85% were blended with co-surfactant Ethanol in different compositions, and water was used as an additive for making it crystal clear transparent micro emulsion fuel, which is thermodynamically stable. By comparing the performances of engines, the power has shown similarity for micro emulsion fuel and conventional Gasoline fuel. On the other hand, Torque and BMEP shows increase for all the micro emulsion fuels. Micro emulsion fuel shows higher thermal efficiency and lower Specific Fuel Consumption for all the compositions as compared to the Gasoline fuel. Carbon monoxide and Hydro carbon emissions were also measured. The result shows that emissions decrease for all the composition of micro emulsion fuels, and proved to be the most efficient fuel both in terms of performance and emission characteristics.

Keywords: AVL Boost, emissions, microemulsions, performance, Spark Ignition (SI) engine

Procedia PDF Downloads 264

Authors: Marco Vinicio Félix Lerma, Efrain Rubio Rosas, Fernando Ricardez Rueda, Victor Manuel Castaño Meneses

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This paper reports a spectral analysis of the exposure levels of radiofrequency electromagnetic fields originating from a wide variety of telecommunications sources present in an urban area of Lagos de Moreno, Jalisco, Mexico. The electromagnetic characterization of the urban zone under study was carried out by measurements in 118 sites. Measurements of TETRA,ISM434, LTE800, ISM868, GSM900, GSM1800, 3G UMTS,4G UMTS, Wlan2.4, LTE2.6, DECT, VHF Television and FM radio signals were performed at distances ranging over 10 to 1000m from 87 broadcasting towers concentrated in an urban area of about 3 hectares. The aim of these measurements is the evaluation of the electromagnetic fields power levels generated by communication systems because of their interaction with the human body. We found that in certain regions the general public exposure limits determined by ICNIRP (International Commission of Non Ionizing Radiation Protection) are overpassed from 5% up to 61% of the upper values, indicating an imminent health public hazard, whereas in other regions we found that these limits are not overpassed. This work proposes an electromagnetic pollution classification for urban zones according with ICNIRP standards. We conclude that the urban zone under study presents diverse levels of pollution and that in certain regions an electromagnetic shielding solution is needed in order to safeguard the health of the population that lives there. A practical solution in the form of paint coatings and fiber curtains for the buildings present in this zone is also proposed.

Keywords: electromagnetic field, telecommunication systems, electropollution, health hazards

Procedia PDF Downloads 393

Authors: Aylin Mohammadalipour Tofighi

Abstract:

Marine-based geoengineering methods, proposed to mitigate climate change, operate primarily through two mechanisms: reducing atmospheric carbon dioxide levels and diminishing solar absorption by the oceans. While these approaches promise beneficial outcomes, they are fraught with environmental, legal, ethical, and political challenges, necessitating robust international governance. This paper underscores the critical role of international cooperation within the governance framework, offering a focused analysis of existing international environmental mechanisms applicable to marine-based geoengineering governance. It evaluates the efficacy and limitations of current international legal structures, including treaties and organizations, in managing marine-based geoengineering, noting significant gaps such as the absence of specific regulations, dedicated international entities, and explicit governance mechanisms such as monitoring. To rectify these problems, the paper advocates for concrete steps to bolster international cooperation. These include the formulation of dedicated marine-based geoengineering guidelines within international agreements, the establishment of specialized supervisory entities, and the promotion of transparent, global consensus-building. These recommendations aim to foster governance that is environmentally sustainable, ethically sound, and politically feasible, thereby enhancing knowledge exchange, spurring innovation, and advancing the development of marine-based geoengineering approaches. This study emphasizes the importance of collaborative approaches in managing the complexities of marine-based geoengineering, contributing significantly to the discourse on international environmental governance in the face of rapid climate and technological changes.

Keywords: climate change, environmental law, international cooperation, international governance, international law, marine-based geoengineering, marine law, regulatory frameworks

Procedia PDF Downloads 72

Authors: Muhammad Zahid, Ilker S. Bayer, Athanassia Athanassiou

Abstract:

Fluorinated polymers having C8 chemistry (chemicals with 8 fluorinated carbon atoms) are well renowned for their excellent low surface tension and water repelling properties. However, these polymers degrade into highly toxic heavy perfluoro acids in the environment. When the C8 chemistry is reduced to C6 chemistry, this environmental concern is eliminated at the expense of reduced liquid repellent performance. In order to circumvent this, in this study, we demonstrate pre-treatment of woven cotton fabrics with a fluorinated acrylic copolymer with C6 chemistry and subsequently with a silicone polymer to render them hydrophobic. A commercial fluorinated acrylic copolymer was blended with silica nanoparticles to form hydrophobic nano-roughness on cotton fibers and a second coating layer of polydimethylsiloxane (PDMS) was applied on the fabric. A static water contact angle (for 5µl) and rolling angle (for 12.5µl) of 147°±2° and 31° were observed, respectively. Hydrostatic head measurements were also performed to better understand the performance with 26±1 cm and 2.56kPa column height and static pressure respectively. Fabrication methods (with rod coater etc.) were kept simple, reproducible, and scalable and cost efficient. Moreover, the robustness of applied coatings was also evaluated by sonication cleaning and abrasion methods. Water contact angle (WCA), water shedding angle (WSA), hydrostatic head, droplet bouncing-rolling off and prolonged staining tests were used to characterize hydrophobicity of materials. For chemical and morphological analysis, various characterization methods were used such as attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM) and scanning electron microscopy (SEM).

Keywords: fluorinated polymer, hydrophobic, polydimethylsiloxane, water contact angle

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Authors: Rishabh Hans, Saksham Sharma

Abstract:

Drying of a sessile droplet imbibed with colloidal solution is a complex process in many aspects. Till now, most of the work revolves around; conditions for buckling onset, post-buckling effects, nature of change of droplet shape etc. In this work, we are determining the shape of daughter cavity (DC) formed during post-buckling onset, a less explored stage, and its relationship with experimental parameters. We have introduced solid angle as a special parameter that can quantify the shape of DC at any instant. It facilitates us to compare the shape while experimenting across different substrate types, droplet sizes and particle concentration. Furthermore, the angular location of ‘weak spot’ on the periphery of droplet, which marks the initiation of cavity growth, varies in different conditions. To solve this problem, we have evaluated the deflection angle of weak spots w.r.t. the vertical axis going through the middle of droplet. Subsequently, the solid angle subtended by DC is analyzed about that inclined axis. Finally, results of analysis allude that increasing colloidal concentration has inverse effect on the growth rate of cavity’s shape. Moreover, the cap radius of DC is observed lower for high PLR which makes the capillary pressure higher and thus tougher to expedite cavity formation relatively. This analysis can be helpful in further studies to relate the shape, deflection angle, growth rate of daughter cavity to the type of droplet crust formed in the end. Examining DC stage shall add another layer to nano-colloidal research which aims to influence many industrial applications like patterning, coatings, drug delivery, food processing etc.

Keywords: buckling of sessile droplets, daughter cavity, droplet evaporation, nanoporous shell formation, solid angle

Procedia PDF Downloads 270

Authors: Hongbo Zhang, Xinlu Tang, Jiangwei Li, Chi Yan

Abstract:

Home zone parking pilot (HPP) is a fast-growing segment in low-speed autonomous driving applications. It requires the car automatically cruise around a parking lot and park itself in a range of up to 100 meters inside a recurrent home/office parking lot, which requires precise parking lot mapping and localization solution. Although Lidar is ideal for SLAM, the car OEMs favor a low-cost fish-eye camera based visual SLAM approach. Recent approaches have employed segmentation models to extract semantic features and improve mapping accuracy, but these AI models are memory unfriendly and computationally expensive, making deploying on embedded ADAS systems difficult. To address this issue, we proposed a new method that utilizes object detection models to extract robust and accurate parking lot features. The proposed method could reduce computational costs while maintaining high accuracy. Once combined with vehicles’ wheel-pulse information, the system could construct maps and locate the vehicle in real-time. This article will discuss in detail (1) the fish-eye based Around View Monitoring (AVM) with transparent chassis images as the inputs, (2) an Object Detection (OD) based feature point extraction algorithm to generate point cloud, (3) a low computational parking lot mapping algorithm and (4) the real-time localization algorithm. At last, we will demonstrate the experiment results with an embedded ADAS system installed on a real car in the underground parking lot.

Keywords: ADAS, home zone parking pilot, object detection, visual SLAM

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Authors: L. Mentar, O. Baka, M. R. Khelladi, A. Azizi

Abstract:

Zinc oxide (ZnO), as a transparent semiconductor with a wide band gap of 3.4 eV and a large exciton binding energy of 60 meV at room temperature, is one of the most promising materials for a wide range of modern applications. With the development of film growth technologies and intense recent interest in nanotechnology, several varieties of ZnO nanostructured materials have been synthesized almost exclusively by thermal evaporation methods, particularly chemical vapor deposition (CVD), which generally require a high growth temperature above 550 °C. In contrast, wet chemistry techniques such as hydrothermal synthesis and electro-deposition are promising alternatives to synthesize ZnO nanostructures, especially at a significantly lower temperature (below 200°C). In this study, the electro-deposition method was used to produce zinc oxide (ZnO) nanostructures on fluorine-doped tin oxide (FTO)-coated conducting glass substrate from chloride bath. We present the influence of KCl concentrations on the electro-deposition process, morphological, structural and optical properties of ZnO nanostructures. The potentials of electro-deposition of ZnO were determined using the cyclic voltammetry. From the Mott-Schottky measurements, the flat-band potential and the donor density for the ZnO nanostructure are determined. Field emission scanning electron microscopy (FESEM) images showed different sizes and morphologies of the nanostructures which depends on the concentrations of Cl-. Very netted hexagonal grains are observed for the nanostructures deposited at 0.1M of KCl. X-ray diffraction (XRD) study confirms the Wurtzite phase of the ZnO nanostructures with a preferred oriented along (002) plane normal to the substrate surface. UV-Visible spectra showed a significant optical transmission (~80%), which decreased with low Cl-1 concentrations. The energy band gap values have been estimated to be between 3.52 and 3.80 eV.

Keywords: Cl-, electro-deposition, FESEM, Mott-Schottky, XRD, ZnO

Procedia PDF Downloads 289

Authors: Meril Kate Mariano, Billy Joel Almarinez Divina Amalin, Jose Isagani Janairo

Abstract:

The scale insects Aspidiotus destructor and Aspidiotus rigidus exhibit notable scale covers made of wax which provides protection against water loss and is capable to resist wetting, thus making them a desirable model for biomimetic designs. Their waxy covers enable them to infest mainly leaves of coconut trees despite the harsh wind and rain. This study aims to describe and compare the micro morphological characters on the surfaces of their scale covers consequently, how these micro structures affect their wetting properties. Scanning electron microscope was used for the surface characterization while an optical contact angle meter was employed in the wetting measurement. The scale cover of A. destructor is composed of multiple overlapping layers of wax that is arranged regularly while that of A. rigidus is composed of a uniform layer of wax with much more prominent wax ribbons irregularly arranged compared to the former. The protrusions found on the two organisms are formed by the wax ribbons that differ in arrangement with their height being A. destructor (3.57+1.29) < A. rigidus (4.23+1.22) and their density A. destructor (15+2.94) < A. rigidus (18.33+2.64). These morphological measurements could affect the contact angle (CA θ) measurement of A. destructor (102.66+9.78°) < A. rigidus (102.77 + 11.01°) wherein the assessment that the interaction of the liquid to the microstructures of the substrate is a large factor in the wetting properties of the insect scales is realized. The calculated surface free energy of A. destructor (38.47 mJ/m²) > A. rigidus (31.02 mJ/m²) shows inverse proportionality with the CA measurement. The dispersive interaction between the surface and liquid is more prevalent compared to the polar interaction for both Aspidiotus species, which was observed using the Fowkes method. The results of this study have possible applications to be a potential biomimetic design for various industries such as textiles and coatings.

Keywords: Aspidiotus spp., biomimetics, contact angle, surface characterization, wetting behavior

Procedia PDF Downloads 121