Search results for: biphasic hydrothermal synthesis

Authors: Maricarmen Herrera, Pierre Chymkowitch, Joe Robertson, Jens Eriksson, Jorrit Enserink

Abstract:

tRNA genes are transcribed by RNA polymerase III. During recent years, it has become clear that tDNA transcription fluctuates during the cell cycle. However, the mechanism by which the cell cycle controls the amplitude of tDNA transcription remains unknown. We found that the cyclin Clb5 recruits the cyclin dependent kinase Cdk1 to tRNA genes to sharply increase tRNA synthesis during a brief interval in the cell cycle. We show that Cdk1 promotes the interaction of TFIIIB with TFIIIC, that it stimulates the recruitment of TFIIIC to tRNA genes, that it prevents the formation of an overly stable TFIIIB-tDNA complex and that it augments the dynamics of RNA polymerase III. Furthermore, we identify Bdp1 as a novel Cdk1 substrate, and phosphorylation of Bdp1 is required for the cell cycle-dependent increase in tDNA transcription. In addition, we show that phosphorylation of the Cdk1 substrate Nup60 mediates formation of a Nup60-Nup2 complex at tRNA genes, which is also required for cell cycle-dependent tDNA transcription. Together, our findings indicate that Cdk1 activity gates tRNA synthesis by regulating the dynamics of the TFIIIB-TFIIIC-RNAPIII complex, and that it may promote the formation of a nuclear pore microenvironment conducive to efficient tDNA transcription.

Keywords: Cdk1, cell cycle, RNAPIII machinery, tRNA

Procedia PDF Downloads 176

Authors: Petri Solanti, Russell Klein

Abstract:

Many designers are asking for an automated path from an abstract mathematical MATLAB model to a high-quality Register-Transfer Level (RTL) hardware description. Manual transformations of MATLAB or intermediate code are needed, when the design abstraction is changed. Design conversion is problematic as it is multidimensional and it requires many different design steps to translate the mathematical representation of the desired functionality to an efficient hardware description with the same behavior and configurability. Yet, a manual model conversion is not an insurmountable task. Using currently available design tools and an appropriate design methodology, converting a MATLAB model to efficient hardware is a reasonable effort. This paper describes a simple and flexible design methodology that was developed together with several design teams.

Keywords: design methodology, high-level synthesis, MATLAB, verification

Procedia PDF Downloads 133

Authors: Gabor Varga, Krisztina Karadi, Zoltan Konya, Akos Kukovecz, Pal Sipos, Istvan Palinko

Abstract:

Nickel can efficiently replace palladium in the Heck, Suzuki and Negishi reactions. This study focuses on the synthesis and catalytic application of Ni(II)-containing layered double hydroxides (LDHs) and layered triple hydroxides (LTHs). Our goals were to incorporate Ni(II) ions among the layers of LDHs or LTHs, or binding it to their surface or building it into their layers in such a way that their catalytic activities are maintained or even increased. The LDHs and LTHs were prepared by the co-precipitation method using ethylene glycol as co-solvent. In several cases, post-synthetic modifications (e.g., thermal treatment) were performed. After optimizing the synthesis conditions, the composites displayed good crystallinity and were free of byproducts. The success of the syntheses and the post-synthetic modifications was confirmed by relevant characterization methods (XRD, SEM, SEM-EDX and combined IR techniques). Catalytic activities of the produced and well-characterized solids were investigated through the Heck reaction. The composites behaved as efficient, recyclable catalysts in the Heck reaction between 4-bromoanisole and styrene. Through varying the reaction parameters, we were able to obtain acceptable conversions under mild conditions. Our study highlights the possibility of the application of Ni(II)-containing composites as efficient catalysts in coupling reactions.

Keywords: layered double hydroxide, layered triple hydroxide, heterogeneous catalysis, heck reaction

Procedia PDF Downloads 168

Authors: Sumara Khursheed, Jitendra Sharma

Abstract:

The present work reports synthesis of nanocomposites (NCs) of phosphor (KCaVO4:Sm3+) embedded poly(methylmethacrylate) (PMMA) using solution casting method and their optical properties measurements for their possible application in making flexible luminescent films. X-ray diffraction analyses were employed to obtain the structural parameters as crystallinity, shape and size of the obtained NCs. The emission and excitation spectra were obtained using Photoluminescence spectroscopy to quantify the spectral properties of these fluorescent polymer/phosphor films. Optical energy gap has been estimated using UV-VIS spectroscopy while differential scanning calorimetry (DSC) was exploited to measure the thermal properties of the NC films in terms of their thermal stability, glass transition temperature and degree of crystallinity etc.

Keywords: nanocomposites, luminescence, XRD, differential scanning calorimetry, PMMA

Procedia PDF Downloads 160

Authors: Mutiara Effendi

Abstract:

Nunukan Island is located on North Kalimantan of Indonesia. The region is one of Indonesia’s cross-border with Malaysia. In conjunction with its strategic geographic location, its potential as the new oil and gas resources has brought many researchers to do their studies here. The research area consists of claystone which criss-crossed with quarts sandstone. There are also rocks claystone-grained which are the weathering product of basaltic volcanic rocks. In some places, there are argillic clays which are the hydrothermal-altered product of Sei Apok ancient volcano. Geochemical study was established to learn the origin of the claystones, whether it came from weathering, hydrothermal alteration, or both. The samples used in this research are fresh rock, weathering rocks, hydrothermally-altered rock, and claystones. Chemical compositions of each sample were determined and their relations was studied. The studies encompass major and minor elements analysis using X-Ray Fluoresence (XRF) method and trace elements analysis, specifically rare earth elements, using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) method. The results were plotted on certain graphics to learn about the trend and the relations of each sample and element. Any changes in chemical compositions, like increase and decrease of elements or species, was analysed to learn about geological phenomenon that happens during the formation of claystones. The result of this study shows that claystones of Nunukan Island have relation with volcanic rocks of its surrounding area. Its chemical composition profile corresponds to weathering product of volcanic rocks rather than hydrothermally-altered product. The general profile also resembles claystone minerals of illite or montmorillonite, especially in the existence of aluminum, iron, potassium, and magnesium. Both minerals are formed in basic condition and commonly happen to shales. It is consistent with the fact that claystone was found mixing with shales and silt to clay grained mudstones in field exploration. Even though the general profile is much alike, the amount of each elements is not precisely the same as theoretically claystone mineral compositions because the mineral have not formed completely yet.

Keywords: claystone, geochemistry, ICP-MS, XRF

Procedia PDF Downloads 229

Authors: M. Bahgat, F. M. Awan, H. A. Hanafy, O. N. Alzeghaibi

Abstract:

Strontium hexaferrite (SrFe12O19; Sr-ferrite) is one of the well-known materials for permanent magnets. In this study, M-type strontium ferrite was prepared by following the conventional ceramic method from steelmaking by-product. Initial materials; SrCO3 and by-product, were mixed together in the composition of SrFe12O19 in different Sr/Fe ratios. The mixtures of these raw materials were dry-milled for 6h. The blended powder was pre-sintered (i.e. calcination) at 1000°C for different times periods, then cooled down to room temperature. These pre-sintered samples were re-milled in a dry atmosphere for 1h and then fired at different temperatures in atmospheric conditions, and cooled down to room temperature. The produced magnetic powder has a dense hexagonal grain shape structure. The calculated energy product values for the produced samples ranged from 0.3 to 2.4 MGOe.

Keywords: hard magnetic materials, ceramic route, strontium ferrite, synthesis

Procedia PDF Downloads 318

Authors: Siddhant Srivastav, Shilpa Singh, Sumanta Kumar Meher

Abstract:

Innovative renewable energy sources for energy storage/conversion is the demand of the current scenario in electrochemical machinery. In this context, choosing suitable organic precipitants for tuning the crystal characteristics and microstructures is a challenge. On the same note, herein we report broccoli flower-like porous Mn3O4/NiSe2−MnSe2 composite synthesized using a simple two step hydrothermal synthesis procedure assisted by sluggish precipitating agent and an effective cappant followed by intermediated anion exchange. The as-synthesized material was exposed to physical and chemical measurements depicting poly-crystallinity, stronger bonding and broccoli flower-like porous arrangement. The material was assessed electrochemically by cyclic voltammetry (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS) measurements. The Electrochemical studies reveal redox behavior, supercapacitive charge-discharge shape and extremely low charge transfer resistance. Further, the fabricated Mn3O4/NiSe2−MnSe2 composite based solid-state hybrid supercapacitor (Mn3O4/NiSe2−MnSe2 ||N-rGO) delivers excellent rate specific capacity, very low internal resistance, with energy density (~34 W h kg–1) of a typical rechargeable battery and power density (11995 W kg–1) of an ultra-supercapacitor. Consequently, it can be a favorable contender for supercapacitor applications for high performance energy storage utilizations. A definitive exhibition of the supercapacitor device is credited to electrolyte-ion buffering reservior alike behavior of broccoli flower like Mn3O4/NiSe2−MnSe2, enhanced by upgraded electronic and ionic conductivities of N- doped rGO (negative electrode) and PVA/KOH gel (electrolyte separator), respectively

Keywords: electrolyte-ion buffering reservoir, intermediated-anion exchange, solid-state hybrid supercapacitor, supercapacitive charge-dischargesupercapacitive charge-discharge

Procedia PDF Downloads 70

Authors: Mayuri Gandhi, Nayan Agrawal, Harshita Bhatia

Abstract:

In the present work, cerium fluoride (CeF3) was selected as the host material because of its high density, fast response and high radiation resistance, efficient absorption and energy transfer by host (to activator). For the synthesis of CeF3 nanoparticles doped with Sm3+ ion, co-precipitation route was employed. Thus for optimum results, concentration dependent studies of the fluorescence of Sm3+ was carried out. The photoluminescence gave emissions in both visible as well as the NIR region and therefore it can have its application in solar cells, where it can absorb a large spectrum of energy. CeF3:Sm3+ nanoparticles were carefully incorporated in a suitable polymer matrix in order to demonstrate a variety of applications to improve the performance of the polymer materials and use it to develop high grade optoelectronic devices such as LEDs, security labelling, lasers, displays, biological imaging, etc.

Keywords: bioimaging, cerium fluoride, NIR emission, samarium

Procedia PDF Downloads 401

Authors: Kanti Sapkota, Do Hyun Lee, Sung Soo Han

Abstract:

Nanocomposites have been widely used in various fields such as electronics, catalysis, and in chemical, biological, biomedical and optical fields. They display broad biomedical properties like antidiabetic, anticancer, antioxidant, antimicrobial and antibacterial activities. Moreover, nanomaterials have been used for wastewater treatment. Particularly, bimetallic hybrid nanocomposites exhibit unique features as compared to their monometallic components. Hybrid nanomaterials not only afford the multifunctionality endowed by their constituents but can also show synergistic properties. In addition, these hybrid nanomaterials have noteworthy catalytic and optical properties. Notably, Au−Ag based nanoparticles can be employed in sensor and catalysis due to their characteristic composition-tunable plasmonic properties. Due to their importance and usefulness, various efforts were developed for their preparation. Generally, chemical methods have been described to synthesize such bimetallic nanocomposites. In such chemical synthesis, harmful and hazardous chemicals cause environmental contamination and increase toxicity levels. Therefore, ecologically benevolent processes for the synthesis of nanomaterials are highly desirable to diminish such environmental and safety concerns. In this regard, here we disclose a simple, cost-effective, external additive free and eco-friendly method for the synthesis of Au-Ag@AgCl nanocomposites using Nephrolepis cordifolia root extract. Au-Ag@AgCl NCs were obtained by the simultaneous reduction of cationic Ag and Au into AgCl in the presence of plant extract. The particle size of 10 to 50 nm was observed with the average diameter of 30 nm. The synthesized nanocomposite was characterized by various modern characterization techniques. For example, UV−visible spectroscopy was used to determine the optical activity of the synthesized NCs, and Fourier transform infrared (FT-IR) spectroscopy was employed to investigate the functional groups present in the biomolecules that were responsible for both reducing and capping agents during the formation of nanocomposites. Similarly, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and energy-dispersive X-ray (EDX) spectroscopy were used to determine crystallinity, size, oxidation states, thermal stability and weight loss of the synthesized nanocomposites. As a synthetic application, the synthesized nanocomposite exhibited excellent catalytic activity for the multicomponent synthesis of biologically interesting quinoline molecules via domino annulation-aromatization reaction of aniline, arylaldehyde, and phenyl acetylene derivatives. Interestingly, the nanocatalyst was efficiently recycled for five times without substantial loss of catalytic properties.

Keywords: nanoparticles, catalysis, multicomponent, quinoline

Procedia PDF Downloads 121

Authors: Chi Man Luk, Ming Kiu Tsang, Chi Fan Chan, Shu Ping Lau

Abstract:

Nitrogen-doped graphene quantum dots (N-GQDs) were fabricated by microwave-assisted hydrothermal technique. The optical properties of the N-GQDs were studied. The luminescence of the N-GQDs can be tuned by varying the excitation wavelength. Furthermore, two-photon luminescence of the N-GQDs excited by near-infrared laser can be obtained. It is shown that N-doping play a key role on two-photon luminescence. The N-GQDs are expected to find application in biological applications including bioimaging and sensing.

Keywords: graphene quantum dots, nitrogen doping, photoluminescence, two-photon fluorescence

Procedia PDF Downloads 626

Authors: Sarra Boughaba

Abstract:

α-aminophosphonates have found a wide range of applications in organic and medicinal chemistry; they are considered as pharmacological agents, anti-inflammatory antitumor agents, and antibiotics. A number of procedures have been developed for their synthesis. However, many of these methods suffer from some disadvantages such as long reaction times, environmental pollution, utilization of organic solvents, and expensive catalysts. In the past few years, heteropolyacids have received great attention as environmentally benign catalysts for organic synthetic processes, they possess unique physicochemical properties, such as super-acidity, high thermal and chemical stability, ability to accept and release electrons and high proton mobility, and the possibility of varying their acidity and oxidizing potential. In this context, an efficient and eco-friendly protocol has been described for the synthesis of α-aminophosphonates via one pot, three component reaction catalyzed by H₆P₂W₁₈O₆₂.14H₂O as reusable catalyst, by condensation of amino acids esters, various aromatic aldehydes and triethylphosphite under solvent-free conditions, the corresponding α-aminophosphonates were formed in good yields as racemic or diastereomericmixture. All the new products were systematically characterized by IR, MS, and ¹H, ¹³C-³¹P-NMR analyses. This method offers advantages such as simplicity workup with the green aspects by avoiding expensive catalysts and toxic solvents, good yields, short reaction times.

Keywords: amino acids esters, α-aminophosphonates, H₆P₂W₁₈O₆₂.14H₂O catalyst, green chemistry

Procedia PDF Downloads 121

Authors: Gülşah Çelik Gül, Figen Kurtuluş

Abstract:

Magnesium containing boron compounds with hexagonal structure have been drawn much attention due to their superconductive nature. The main target of this work is new modified microwave oven by on our own has an ability about passing through a gas in the oven medium for attainment of oxygen-free compounds such as c-BN.  Mg containing boride was synthesized by modified-microwave method under nitrogen atmosphere using amorphous boron and magnesium source in appropriate molar ratio. Microwave oven with oxygen free environment has been modified to aimed to obtain magnesium boride without oxygen. Characterizations were done by powder X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Mg containing boride, generally named magnesium boride, with amorphous character without oxygen is obtained via designed microwave oven system.

Keywords: magnesium containing boron compounds, modified microwave synthesis, powder X-ray diffraction, FTIR

Procedia PDF Downloads 365

Authors: Hye Kyung Kim, Myung-Gyou Kim, Kang-Hyun Leem

Abstract:

It has been reported that deer antler extract has bone-strengthening activity and effectively used in bone diseases therapy. However, little is known about the cellular and molecular mechanism of this effect. The upper section, mid section, and base of the antler has been known to exhibit different biological properties. Present study investigated the effects of these three parts of deer antler extracts on bone formation and resorption. The effects of deer antler extracts (DH) on bone formation were determined by cell proliferation, alkaline phosphatase (ALP) activity, collagen synthesis, and mineralization in human osteoblastic MG-63 cells. The effect on bone resorption was determined by osteoclastogenesis from bone marrow-derived precursor cells driven by RANKL. Ethanol extracts of DH (50 ~ 100 µg/ml) dose-dependently increased cell proliferation, and upper part increased the cell proliferation by 118.4% while mid and base parts increased proliferation by 107.8% and 102.3%, respectively. ALP activity was significantly increased by upper part of the DH treatment. After enhancement of ALP activity, significant augmentation of collagen synthesis and calcification assessed by Sirus red and Alzarin red staining, respectively, was observed in upper part of the DH treatment. The effect of DH on bone resorption was not observed in all three parts of the DH. These results could provide a mechanistic explanation for the bone-strengthening effects of DH.

Keywords: alkaline phosphatase, collagen synthesis, deer antler, osteoblastic MG-63 cells

Procedia PDF Downloads 307

Authors: Adrien Cornille, Marine Blain, Bernard Boutevin, Sylvain Caillol

Abstract:

Generally, linear polyurethanes (PUs) are obtained by the reaction between an oligomeric diol, a short diol as chain extender and a diisocyanate. However the use of diisocyanate should be avoided since they are generally very harmful for human health. Therefore the synthesis of NIPUs (non isocyanate PUs) from step growth polymerization of dicyclocarbonates and diamines should be favoured. This method is particularly interesting since no hazardous isocyanates are used. Thus, this reaction, extensively studied by Endo et al. is currently gaining a lot of attention as a substitution route for the synthesis of NIPUs, both from industrial and academic community. However, the reactivity of reaction between amine and cyclic carbonate is a major scientific issue, since cyclic carbonates are poorly reactive. Thus, our team developed several synthetic ways for the synthesis of various di-cyclic carbonates based on C5-, C6- and dithio- cyclic carbonates, from different biobased raw materials (glycerin isosorbide, vegetable oils…). These monomers were used to synthesize NIPUs with various mechanical and thermal properties for various applications. We studied the reactivity of reaction with various catalysts and find optimized conditions for room temperature reaction. We also studied the radical copolymerization of cyclic carbonate monomers in styrene-acrylate copolymers for coating applications. We also succeeded in the elaboration of biobased NIPU flexible foams. To the best of our knowledge, there is no report in literature on the preparation of non-isocyanate polyurethane foams.

Keywords: foam, nonisocyanate polyurethane, cyclic carbonate, blowing agent, scanning electron microscopy

Procedia PDF Downloads 225

Authors: Adhitya Mangala, Yobel

Abstract:

Bittuang geothermal prospect area located at Tana Toraja district, South Sulawesi. The geothermal system of the area related to Karua Volcano eruption product. This area has surface manifestation such as fumarole, hot springs, sinter silica and mineral alteration. Those prove that there are hydrothermal activities in the subsurface. However, the project and development of the area have not implemented yet. One of the important elements in geothermal exploration is to determine upflow and outflow zone. This information very useful to identify the target for geothermal wells and development which it is a risky task. The methods used in this research were Mercury (Hg) anomalies in soil, soil and manifestation temperature distribution and fault fracture density from 93 km² research area. Hg anomalies performed to determine the distribution of hydrothermal alteration. Soil and manifestation temperature distribution were conducted to estimate heat distribution. Fault fracture density (FFD) useful to determine fracture intensity and trend from surface observation. Those deliver Hg anomaly map, soil and manifestation temperature map that combined overlayed to fault fracture density map and geological map. Then, the conceptual model made from north – south, and east – west cross section to delineate upflow and outflow zone in this area. The result shows that upflow zone located in northern – northeastern of the research area with the increase of elevation and decrease of Hg anomalies and soil temperature. The outflow zone located in southern - southeastern of the research area which characterized by chloride, chloride - bicarbonate geothermal fluid type, higher soil temperature, and Hg anomalies. The range of soil temperature distribution from 16 – 19 °C in upflow and 19 – 26.5 °C in the outflow. The range of Hg from 0 – 200 ppb in upflow and 200 – 520 ppb in the outflow. Structural control of the area show northwest – southeast trend. The boundary between upflow and outflow zone in 1550 – 1650 m elevation. This research delivers the conceptual model with innovative methods that useful to identify a target for geothermal wells, project, and development in Bittuang geothermal prospect area.

Keywords: Bittuang geothermal prospect area, Hg anomalies, soil temperature, upflow and outflow zone

Procedia PDF Downloads 314

Authors: S. M. Abd-Altwab, M. R. Noor El-Din

Abstract:

This paper aims to the synthesis of new ethoxylated amide as bactericides to prevent the growth of Gram +ve and –ve bacteria of water-in-diesel fuel nanoemulsions over a long period of time as three months. To realize it, eight kinetically stable water-in-diesel fuel nanoemulsions differing in surfactant concentrations and water contents ranging from 4 to 8 and 5 to 8 wt.,wt.,% of total weight of the nanoemulsions, respectively were formed at a temperature of 20 °C. The performance of this ethoxylated amide as bactericides agents against two strains of Gram-negative bacteria, namely, Pseudomonas aeruginosa and Escherichia coli, and two strains of Gram-positive bacteria namely, Staphylococcus aureus and Bacillus subtilis, were evaluated as antimicrobial agents. The maximum and minimum antimicrobial activities were 85 and 71 % against S. aureus and E. coli, respectively, at a concentration of 5 mg/l, pH 7, and 37 °C.

Keywords: nanoemulsion, bacteriocide, diesel fuel, emulsifier

Procedia PDF Downloads 357

Authors: Nabil Majd Alawi, Gia Hung Pham, Ahmed Barifcani

Abstract:

Dry reforming of methane that converts two greenhouses gases (CH₄ and CO₂) to synthesis gas (a mixture of H₂ and CO) was studied in a commercial bench scale microwave (MW) plasma reactor system at atmospheric pressure. The CO₂, CH₄ and N₂ conversions; H₂, CO selectivities and yields, and syngas ratio (H₂/CO) were investigated in a wide range of total feed flow rate (0.45 – 2.1 L/min), MW power (700 – 1200 watt) and CO₂/CH₄ molar ratio (2 – 5). At the feed flow rates of CH₄, CO₂ and N₂ of 0.2, 0.4 and 1.5 L/min respectively, and the MWs input power of 700 W, the highest conversions of CH₄ and CO₂, selectivity and yield of H₂, CO and H₂/CO ratio of 79.35%, 44.82%, 50.12, 58.42, 39.77%, 32.89%, and 0.86, respectively, were achieved. The results of this work show that the product ratio increases slightly with the increasing total feed flow rate, but it decreases significantly with the increasing MW power and feeds CO₂/CH₄ ratio.

Keywords: dry reforming of methane, microwave discharge, plasma technology, synthesis gas production

Procedia PDF Downloads 263

Authors: Álvaro Ramírez Vidal, Martín Muñoz Morales, Francisco Jesús Fernández Morales, Luis Rodríguez Romero, José Villaseñor Camacho, Javier Llanos López

Abstract:

In recent times, environmental problems have led to the extensive use of biological systems to solve them. Among the different types of biological systems, the use of plants such as aquatic macrophytes in constructed wetlands and terrestrial plant species for treating polluted soils and sludge has gained importance. Though the use of constructed wetlands for wastewater treatment is a well-researched domain, the slowness of pollutant degradation and high biomass production pose some challenges. Plants used in CW participate in different mechanisms for the capture and degradation of pollutants that also can retain some pharmaceutical and personal care products (PPCPs) that are very persistent in the environment. Thus, these systems present advantages in line with the guidelines published for the transition towards friendly and ecological procedures as they are environmentally friendly systems, consume low energy, or capture atmospheric CO₂. However, the use of CW presents some drawbacks, as the slowness of pollutant degradation or the production of important amounts of plant biomass, which need to be harvested and managed periodically. Taking this opportunity in mind, it is important to highlight that this residual biomass (of lignocellulosic nature) could be used as the feedstock for the generation of carbonaceous materials using thermochemical transformations such as slow pyrolysis or hydrothermal carbonization to produce high-value biomass-derived carbons through sustainable processes as adsorbents, catalysts…, thereby improving the circular carbon economy. Thus, this work carried out the analysis of some PPCPs commonly found in urban wastewater, as salicylic acid or ibuprofen, to evaluate the remediation carried out for the Phragmites Australis. Then, after the harvesting, this biomass can be used to synthesize electrodes through hydrothermal carbonization (HTC) and produce high-value biomass-derived carbons with electrocatalytic activity to remove heavy metals and persistent pollutants, promoting circular economy concepts. To do this, it was chosen biomass derived from the natural environment in high environmental risk as the Daimiel Wetlands National Park in the center of Spain, and the rest of the biomass developed in a CW specifically designed to remove pollutants. The research emphasizes the impact of the composition of the biomass waste and the synthetic parameters applied during HTC on the electrocatalytic activity. Additionally, this parameter can be related to the physicochemical properties, as porosity, surface functionalization, conductivity, and mass transfer of the electrodes lytic inks. Data revealed that carbon materials synthesized have good surface properties (good conductivities and high specific surface area) that enhance the electro-oxidants generated and promote the removal of PPCPs and the chemical oxygen demand of polluted waters.

Keywords: constructed wetlands, carbon materials, heavy metals, pharmaceutical and personal care products, hydrothermal carbonization

Procedia PDF Downloads 84

Authors: Longtao He, Han Wu

Abstract:

Summary: As the need for elder care increases in China due to a growing aging population and, in particular, rising cancer rates, it becomes increasingly important to also support family caregivers, who are often the main source of care. We used a qualitative meta-synthesis to systematically evaluate and integrate the caregiving experiences of family caregivers of elderly cancer patients as revealed by articles published in Chinese journals. Findings: Nine studies are included in the final analysis. The caregiver experiences they describe are synthesized into three primary themes: care needs, care burden, and care gains, with numerous secondary themes. Besides the findings that seem to align with other findings across cultures, we have highlighted three main discoveries from the synthesis that may be quite specific to the Chinese context: 1. more sub-themes related to specific caregiving skills caregivers of cancer patients; 2. a call for health professionals to improve their communication skills with family caregivers; 3. the important role of filial piety. Applications: Our findings can be used to help health social workers and relevant policymakers in China support family caregivers by identifying the education and training required for caregivers, ways to make the most of potential care gains, and ways to ease care burdens.

Keywords: cancer, Chinese family caregivers, caregiving skills, care burden, care gains, health social work

Procedia PDF Downloads 180

Authors: Niharul Alam

Abstract:

The development of energy efficient, economic and eco-friendly synthetic protocols for metal nanoparticles (NPs) with tailor-made structural properties and biocompatibility is a highly cherished goal for researchers working in the field of nanoscience and nanotechnology. In this context, green chemistry is highly relevant and the 12 principles of Green Chemistry can be explored to develop such synthetic protocols which are practically implementable. One of the most promising green chemical synthetic methods which can serve the purpose is biogenic synthetic protocol, which utilizes non-toxic multifunctional reactants derived from natural, biological sources ranging from unicellular organisms to higher plants that are often characterized as “medicinal plants”. Over the past few years, a plethora of medicinal plants have been explored as the source of this kind of multifunctional green chemical agents. In this presentation, we focus on the syntheses of stable monometallic Au and Ag NPs and also bimetallic Au/Ag alloy NPs with highly efficient catalytic property using aqueous extract of leaves of Indian Curry leaf plat (Murraya koenigii Spreng.; Fam. Rutaceae) as green multifunctional agents which is extensively used in Indian traditional medicine and cuisine. We have also studied the interaction between the synthesized metal NPs and surface-adsorbed fluorescent moieties, quercetin and quercetin glycoside which are its chemical constituents. This helped us to understand the surface property of the metal NPs synthesized by this plant based biogenic route and to predict a plausible mechanistic pathway which may help in fine-tuning green chemical methods for the controlled synthesis of various metal NPs in future. We observed that simple experimental parameters e.g. pH and temperature of the reaction medium, concentration of multifunctional agent and precursor metal ions play important role in the biogenic synthesis of Au NPs with finely tuned structures.

Keywords: green multifunctional agent, metal nanoparticles, biogenic synthesis

Procedia PDF Downloads 425

Authors: Nur Sulihatimarsyila Abd Wafti, Harrison Lik Nang Lau, Nabilah Kamaliah Mustaffa, Nur Azreena Idris

Abstract:

The use of biolubricant has gained its popularity over the last decade. Base stock produced using methyl ester and trimethylolethane (TME) can be potentially used for biolubricant production due to its biodegradability, non-toxicity and good thermal stability. The synthesis of biolubricant base stock e.g. triester (TE) via transesterification of palm methyl ester and TME in the presence of sodium methoxide as the catalyst was conducted. Factors influencing the reaction conditions were investigated including reaction time, temperature and pressure. The palm-based biolubricant base stock produced was analysed for its monoester (ME), diester (DE) and TE contents using gas chromatography as well as its lubricating properties such as viscosity, viscosity index, oxidation stability, and density. The resulting base stock containing 90 wt% TE was successfully synthesized.

Keywords: biolubricant, methyl ester, triester transesterification, lubricating properties

Procedia PDF Downloads 438

Authors: Abdenour Achour, Kan Chen, Mike Reece, Zhaorong Huang

Abstract:

Here we report the synthesis of pure and cost effective of BiCuSeO by a flux method in air, and the enhancement of the thermoelectric performance by Cs doping. The comparison between our synthesis and the usual vacuum furnace method has been studied for the pristine oxyselenides BiCuSeO. We report for very high Seebeck coefficients up to 516 μV K⁻¹ at room temperature with the electrical conductivity of 5.20 S cm⁻¹ which lead to a high power factor of 140 µWm⁻¹K⁻². We also report at the high temperatures the lowest thermal conductivity value of 0.42 µWm⁻¹K⁻¹. Upon doping with Cs, enhanced electrical conductivity coupled with a moderate Seebeck coefficient lead to a power factor of 338 µWm⁻¹K⁻² at 682 K. Moreover, it shows a very low thermal conductivity in the temperature range of 300 to 682 K (0.75 to 0.35 Wm⁻¹K⁻¹). By optimizing the power factor and reducing the thermal conductivity, this results in a high ZT of ~ 0.66 at 682 K for Bi0.995Cs0.005CuSeO.

Keywords: BiCuSeO, Cs doping, thermoelectric, oxyselenide

Procedia PDF Downloads 292

Authors: Majdi Abid

Abstract:

During the last few decades, great efforts have been made for the development of innovative materials using vegetal biomass. This strategy is understandable for different reasons including the predictable dwindling of the petrochemical feedstock and their price increase as well as the counterbalancing of the environmental problems. As novel bio-based monomers used in polyesters synthesis, two families, namely 1,4:3,6-dianhydrohexitols and furanics were prepared for saccharidic renewable resources. The present work deals with a detail investigation on the synthesis of poly(ethylene-co-isosorbide terephthalate-co-furoate) (PEITF) by melt polycondensation of dimethylterephtalate (DMT), 5,5’-isopropylidene-bis (ethyl 2-furoate) (DEF) ethan-1,2-diol (ED) and isosorbide (IS). Polycondensationwas achieved in two steps: (i) the formation of a hydroxyethylterminated oligomer by reaction of starting diester mixture with excess ED and, (ii) a polycondensation step with elimination of ED was used to obtain high molar mass copolyesters. Copolymers of various compositions were synthesized and characterized by 1H NMR, SEC, DSC and TGA. The resulting materials are amorphous polymers (Tg = 104–127 °C) with good thermal stability.

Keywords: bio-based monomers, furan, isosrbide, polycondensation

Procedia PDF Downloads 280

Authors: Afrah E. Mohammed, Mudawi M. Nour

Abstract:

Environmentally friendly green synthesis of nanomaterial has a very significant part in nanotechnology. In the present research, the synthesis of silver nanoparticles (AgNPs) was established by treating silver ions with the aqueous extract of Calligonum comosum green shoots at room temperature. AgNPs formation was firstly detected by the colour change of mixed extract (plant extract and AgNO3). Further characterization was done by ultraviolet (UV)-Vis spectrophotometer, transmission electron microscopy (TEM), scanning electron microscopy (SEM), zeta potential and fourier transform infrared spectroscopy (FTIR). The peak values for UV-VIS- spectroscopy were in the range of 440 nm, TEM micrograph showed a spherical shape for the particles and zeta potential showed the formation of negative charged nanoparticles with an average size of about 105.8 nm. 1635.41 and 3249.83 cm−1 are the peaks detected from the FTIR analysis. In this study, biosynthesized silver nanoparticles mediated by C. comosum were tested for their antimycotic activity using a well diffusion method against fungal species; Aspergillus flavus, Penicillium sp, Fusarium oxysporum. Our findings indicated that biosynthesized AgNPs showed an efficient antimycotic activity against tested species. The antimycotic action of AgNPs varied according to different fungal species. Results confirmed the ability of C. comosum green shoot extract to act as an reducing and stabilizing agent during the synthesis of AgNPs.

Keywords: AGNPS, zeta potential, TEM, SEM

Procedia PDF Downloads 69

Authors: G. Çelik Gül, F. Kurtuluş

Abstract:

Colemanite is the most common borate mineral, and the main source of the boron required by plants, human, and earth. Transition metals exhibit optical and physical properties such as; non-linear optical character, structural diversity, thermal stability, long cycle life and luminescent radiation. The doping of colemanite with a transition metal, bring it very interesting and attractive properties which make them applicable in industry. Iron doped calcium borate was synthesized by conventional solid state method at 1200 °C for 12 h with a systematic pathway. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy/energy dispersive analyze (SEM/EDS) were used to characterize structural and morphological properties. Also, thermal properties were recorded by thermogravimetric-differential thermal analysis (TG/DTA). 

Keywords: colemanite, conventional synthesis, powder x-ray diffraction, borates

Procedia PDF Downloads 325

Authors: Ana Tsokilauri

Abstract:

The uppermost factor in the regulation of lignin-cellulose activity of decaying white rot or free rot are the substances serving as carbon and nitrogen nutrition of microorganisms and are considered as the most important factor of generative activity of white rot. The research object was Basidiomycete Fungi, peculiar and common in Georgia, and the separation of 10 of them as pure crops. The unidentified pure crops have tasted in order to be determined the potential of synthesis of lignin-degrading enzymes and the substrate of optimal lignocellulose growth. One of the most important aspects of the research conducted on Basidiomycetes was the use of specific lignocellulosic residues for selecting Fungi as a substrate of their growth. In order to increase lignocellulose with the help of substrate, crops were selected from the screening stage that showed good laccase activity. (Dusheti 1; Dusheti 10; Fshavi 5; Fshavi1; Fshavi 8; Fshavi 32; Manglisi 26; Sabaduri20; Dusheti 7; Sabaduri 1 ), Among the selected cultures, the crops with good laccase activity against the following substances, in particular: Dusheti 1- in this case, the rate of enzymatic activity on bran substrate was -105,6 u/ml, mandarin-96,4 u/ml. In case of corn - 102,9 u/ml. In case of Dusheti 7- the indicators were as follows: bananas-121,7 u/ml, mandarin-125,4 u/ml, corn - 117,1 u/ml. In the case of Sanaduri 32, the laccase activity was as follows: pomegranate- 101,2 u/ml. As a result of conducted experiments, the synthesis and activity rates of enzymes depending on plant substrates varied within a fairly wide range, which is still being under research.

Keywords: Lignocellulosic substrate, Basidiomycetes, white-rot basidiomycetes, Laccase

Procedia PDF Downloads 192

Authors: Roman Khanferyan

Abstract:

Endurance exercises and strenuous muscle activity are accompanied by multiple immune dysfunctions due to the activation of cytokines and chemokines synthesis. This study assesses changes in the synthesis of immune regulatory mediators in elite athletes during endurance sports activity. The concentrations of cytokines/chemokines (IL-2, IL-6, IL-8, IL-10, IL-18, MIP-1 beta, GRO-alpha, RANTES, SDF-1a, VEGF) in sera of hockey athletes (n=33) and in supernatants of 24-h cultivated peripheral blood mononuclear cells (PBMC) of boxers (n=6) assayed by ELISA and Luminex xMAP multiplex assays. Estimation of body composition studied by using bioimpedance technology. The dietary energy consumption per person has been estimated using an album of different sizes of portions of the most frequently consumed foods. It has been demonstrated that endurance sports activity enhances the secretions of most pro- and anti-inflammatory cytokines and chemokines in more than 2-6 fold. The study demonstrated that the high increase of more than 3-4 times in the concentration of IL-18 in sera of athletes (327.86 + 45.67 pg/ml) didn’t correlate with BMI (p=0.040) but demonstrated a low correlation with MMI (p=0.234) and BMR (p=0,231). The opposite impact on the concentration of IL-10 has been demonstrated in athletes. It has been shown a negative correlation between its concentration and BMI (p= - 0.251), MMI (p= - 0.327), and BMR (p= - 0.301). In vitro studies in boxers showed greater amounts of chemokines in the PBMC supernatants, including MIP-1β, GRO-α, RANTES, SDF-1α, and IL-8 (P<0.05). At the same time, healthy controls had greater supernatant levels of MCP-1, Eotaxin, and MIP-1α. The study demonstrated a high correlation between physical activity, usual athletes' diet, and consumption of specialized sports nutrition products.

Keywords: sport nutrition, cytokines, chemokines, endurace exercises

Procedia PDF Downloads 36

Authors: Sophio Kobauri, Vladimir P. Torchilin, David Tugushi, Ramaz Katsarava

Abstract:

Nanotherapy is an actual newest mode of treatment numerous diseases using nanoparticles (NPs) loading with different pharmaceuticals. NPs of biodegradable polymeric micelles (PMs) are gaining increased attention for their numerous and attractive abilities to be used in a variety of applications in the various fields of medicine. The present paper deals with the synthesis of a class of biodegradable micelle-forming polymers, namely ABA triblock-copolymer in which A-blocks represent amino-poly(ethylene glycol) (H₂N-PEG) and B-block is biodegradable amino acid-based poly(ester amide) constituted of α-amino acid – L-phenylalanine. The obtained copolymer formed micelles of 70±4 nm size at 10 mg/mL concentration.

Keywords: amino acids, biodegradable poly (ester amide), amphiphilic triblock-copolymer, micelles

Procedia PDF Downloads 186

Authors: Schirin Hanf, Carlos Lizandara-Pueyo, Timmo P. Emmert, Ivana Jevtovikj, Roger Gläser, Stephan A. Schunk

Abstract:

Metal alkoxides are very versatile precursors for a broad array of complex functional materials. However, metal alkoxides, especially transition metal alkoxides, tend to form oligomeric structures due to the very strong M–O–M binding motif. This fact hinders their facile application in sol-gel-processes and complicates access to complex carbonate or oxidic compounds after hydrolysis of the precursors. Therefore, the development of a synthetic alternative with the aim to grant access to carbonates and hydroxycarbonates from simple metal alkoxide precursors via hydrolysis is key to this project. Our approach involves the reaction of metal alkoxides with unsaturated isoelectronic molecules, such as carbon dioxide. Subsequently, a stoichiometric insertion of the CO₂ into the alkoxide M–O bond takes place and leads to the formation of soluble metal alkyl carbonates. This strategy is a very elegant approach to solubilize metal alkoxide precursors to make them accessible for sol-gel chemistry. After hydrolysis of the metal alkyl carbonates, crystalline metal carbonates, and hydroxycarbonates can be obtained, which were then utilized for the synthesis of Cu/Zn based bulk catalysts for methanol synthesis. Using these catalysts, a comparable catalytic activity to commercially available MeOH catalysts could be reached. Based on these results, a complement for traditional precipitation techniques, which are usually utilized for the synthesis of bulk methanol catalysts, have been found based on an alternative solubilization strategy.

Keywords: metal alkoxides, metal carbonates, metal hydroxycarbonates, CO₂ insertion, solubilization

Procedia PDF Downloads 179

Authors: Belete B. Beyene, Ayenew M. Mihirteu, Misganaw T. Ayana, Amogne W. Yibeltal

Abstract:

Modification of synthetic porphyrins is one of the promising strategies in an attempt to get molecules with desired properties and applications. Here in, we report synthesis, photophysical characterization and antibacterial activity of 5, 10, 15, 20-tetrakis-(4- methoxy carbonyl phenyl) porphyrin M(II); where M = Co, Fe, Ni, Zn. Metallation of the ligand was confirmed by using UV–Vis spectroscopy and ESI-Ms measurement, in which the number of Q bands in absorption spectra of the ligand decreased from four to one or two as a result of metal insertion to the porphyrin core. The antibacterial activity study of the complexes toward two Gram-positive (Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (s. pyogenes)) and two Gram-negative (Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae)) bacteria by disc diffusion method showed a promising inhibitory activity. The complexes exhibited highest activities at highest concentration and were better than the activity of free base ligand, the salts, and blank solution. This could be explained on the basis of Overton's concept of cell permeability and Tweed's Chelation theory. An increased lipo-solubility enhances the penetration of the complexes into the lipid membrane and interferes with the normal activities of the bacteria. Our study, therefore, showed that the growth inhibitory effect of these metalloporphyrins is generally in order of ZnTPPCOOMe > NiTPPCOOMe > CoTPPCOOMe> FeTPPCOOMe, which may be attributed to the better lipophilicity and binding of the complex with the cellular components.

Keywords: porphyrins, metalloporphyrins, spectral property, antibacterial activity, synthesis

Procedia PDF Downloads 60