Search results for: green nano zero valent iron

Authors: Yogita Patil-Sen

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Magnetic nanoparticles such as those made of iron oxide have been widely explored as biocatalysts, contrast agents, and drug delivery systems. However, some of the challenges associated with these particles are agglomeration and biocompatibility, which lead to concern of toxicity of the particles, especially for drug delivery applications. Coating the particles with biocompatible materials such as lipids and peptides have shown to improve the mentioned issues. Thus, these core-shell type nanoparticles are emerging as the new class of nanomaterials for targeted drug delivery applications. In this study, various types of core-shell magnetic nanoparticles are prepared and characterized using techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM) and Thermogravimetric Analysis (TGA). The heating ability of nanoparticles is tested under oscillating magnetic field. The efficacy of the nanoparticles as drug carrier is also investigated. The loading of an anticancer drug, Doxorubicin at 18 °C is measured up to 48 hours using UV-visible spectrophotometer. The drug release profile is obtained under thermal incubation condition at 37 °C and compared with that under the influence of oscillating field. The results suggest that the core-shell nanoparticles exhibit superparamagnetic behaviour, although, coating reduces the magnetic properties of the particles. Both the uncoated and coated particles show good heating ability, again it is observed that coating decreases the heating behaviour of the particles. However, coated particles show higher drug loading efficiency than the uncoated particles and the drug release is much more controlled under the oscillating magnetic field. Thus, the results strongly indicate the suitability of the prepared core-shell type nanoparticles as drug delivery vehicles and their potential in magnetic hyperthermia applications and for hyperthermia cancer therapy.

Keywords: core-shell, hyperthermia, magnetic nanoparticles, targeted drug delivery

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Authors: Disha Gupta

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The aim of this research is to conduct X-ray and e-beam characterization techniques on lithium-ion battery materials for the improvement of battery performance. The key characterization techniques employed are the synchrotron X-ray Absorption Spectroscopy (XAS) combined with X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to obtain a more holistic approach to understanding material properties. This research effort provides additional battery characterization knowledge that promotes the development of new cathodes, anodes, electrolyte and separator materials for batteries, hence, leading to better and more efficient battery performance. Both ex-situ and in-situ synchrotron experiments were performed on LiFePO₄, one of the most common cathode material, from different commercial sources and their structural analysis, were conducted using Athena/Artemis software. This analysis technique was then further extended to study other cathode materials like LiMnxFe(₁₋ₓ)PO₄ and even some sulphate systems like Li₂Mn(SO₄)₂ and Li₂Co0.5Mn₀.₅ (SO₄)₂. XAS data were collected for Fe and P K-edge for LiFePO4, and Fe, Mn and P-K-edge for LiMnxFe(₁₋ₓ)PO₄ to conduct an exhaustive study of the structure. For the sulphate system, Li₂Mn(SO₄)₂, XAS data was collected at both Mn and S K-edge. Finite Difference Method for Near Edge Structure (FDMNES) simulations were also conducted for various iron, manganese and phosphate model compounds and compared with the experimental XANES data to understand mainly the pre-edge structural information of the absorbing atoms. The Fe K-edge XAS results showed a charge compensation occurring on the Fe atom for all the differently synthesized LiFePO₄ materials as well as the LiMnxFe(₁₋ₓ)PO₄ systems. However, the Mn K-edge showed a difference in results as the Mn concentration changed in the materials. For the sulphate-based system Li₂Mn(SO₄)₂, however, no change in the Mn K-edge was observed, even though electrochemical studies showed Mn redox reactions.

Keywords: li-ion batteries, electrochemistry, X-ray absorption spectroscopy, XRD

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Authors: Muna Khushaim

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Aluminum-based alloys play a key role in modern engineering, especially in the aerospace industry. Introduction of solute atoms such as Li and Cu is the main approach to improve the strength in age-hardenable Al alloys via the precipitation hardening phenomenon. Knowledge of the decomposition process of the microstructure during the precipitation reaction is particularly important for future technical developments. The objective of this study is to investigate the nano-scale chemical composition in the Al-Cu, Al-Li and Al-Li-Cu during the early stage of the precipitation sequence and to describe whether this compositional difference correlates with variations in the observed precipitation kinetics. Comparing the random binomial frequency distribution and the experimental frequency distribution of concentrations in atom probe tomography data was used to investigate the early stage of decomposition in the different binary and ternary alloys which were experienced different heat treatments. The results show that an Al-1.7 at.% Cu alloy requires a long ageing time of approximately 8 h at 160 °C to allow the diffusion of Cu atoms into Al matrix. For the Al-8.2 at.% Li alloy, a combination of both the natural ageing condition (48 h at room temperature) and a short artificial ageing condition (5 min at 160 °C) induces increasing on the number density of the Li clusters and hence increase number of precipitated δ' particles. Applying this combination of natural ageing and short artificial ageing conditions onto the ternary Al-4 at.% Li-1.7 at.% Cu alloy induces the formation of a Cu-rich phase. Increasing the Li content in the ternary alloy up to 8 at.% and increasing the ageing time to 30 min resulted in the precipitation processes ending with δ' particles. Thus, the results contribute to the understanding of Al-alloy design.

Keywords: aluminum alloy, atom probe tomography, early stage, decomposition

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Authors: Vijay H. Ingole, Efthimia Lioliou

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Indirubin, a key bioactive component of traditional Chinese medicine, has gained increasing recognition for its potential in modern biomedical applications, particularly in pharmacology and therapeutics. The present work aimed to harness the potential by engineering an Escherichia coli strain capable of high-yield indirubin production. Through meticulous genetic engineering, we optimized the metabolic pathways in E. coli to enhance indirubin synthesis. Further, to explored the optimization of culture media and indirubin yield via batch and fed-batch fermentation techniques. By fine-tuning upstream process (USP) parameters, including nutrient composition, pH, temperature, and aeration, we established conditions that maximized both cell growth and indirubin production. Additionally, significant efforts were dedicated to refining downstream process (DSP) conditions for the extraction, purification, and quantification of indirubin. Utilizing advanced biochemical methods and analytical techniques such as UHPLC, we ensured the production of high purity indirubin. This approach not only improved the economic viability of indirubin bioproduction but also aligned with the principles of green production and sustainability.

Keywords: indirubin, bacterial strain, fermentation, HPLC

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Authors: Jiani Gao, Qingping Luo, Xinlei Fang

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In order to try to achieve better rights and interests for both doctors and patients in the new medical environment, the paper will focus on the renewal and development of medical buildings. In today's highly developed society, many factors have a profound guiding significance for the development of medical buildings. By doing social research, the paper has found that these factors come from all aspects. These factors include the optimization of traditional medical model, rapid alternation of medical technology and equipment, the reform of the social, medical security system, changes in the age structure of the population, the birth of intelligent medical care under the Internet, and the deepening of the concept of green sustainable building development, etc. The purpose of this paper is to capture sensitively these various factors that may affect the evolution of medical buildings in the context of the current era, and to put forward, by using an adaptable development strategy, some feasible suggestions on the design of medical buildings when facing these changes and challenges. Specifically speaking, the adaptable development strategy includes some basic principles and methods, such as using modular design, adopting scalable streamline, selecting a long-span structural system and using replaceable materials and components, etc.

Keywords: medical architecture, adaptable development, medical model, space design

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Authors: Adrita Banerjee, Ajeet Kumar Singh

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Antenatal care (ANC) from a skilled provider is important to monitor the pregnancy and reduce the risk of morbidity for mother and baby during pregnancy and delivery. The quality of antenatal care can be monitored through the content of services received and the kind of information mothers are given during their visit. Objective: The paper tries to examine the association between ANC check-ups and size/ birth weight. It also focuses on investigating the relationship between utilization of recommended prenatal care for mothers and its effect on infant survival in Nepal. Data and methods: This paper uses data from Nepal demographic Health Survey 2011. To understand the relationship bi-variate statistical analysis and logistic regressions has been done. Maternal health care utilization include ANC check-ups i.e. the type of ante-natal care providers, the number and timing of the visit. The various components of the check-ups include intake of iron tablets/syrups, intestinal parasitic drugs, etc. Results: The results show that women who had no antenatal care visits about 40% had small sized babies at the time of birth compared to women to had at least 3 ANC check up. Women who had at least 3 check-ups 17% of the babies have a small size. It has also been found that about 50 % of the women prefer ANC check-ups during pregnancies which have resulted in lowering the infant mortality by about 40% during 1996-2011. Conclusion: Ante natal care check is care and monitoring of the pregnant woman and her foetus throughout pregnancy. ANC checks have an effect on the infant health and child survival. A woman who had at least three check-ups the possibilities of adverse effect on infant health and infant survival was significantly lower. The findings argue for a more enhanced focus on ANC check-ups for improving the maternal and child health in Nepal.

Keywords: maternal, health, pregnancy, outcome

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Authors: Weiyao Zhu, Qian Qi, Ming Yue, Dongxu Ma

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Due to the nano-micro pore structures and the massive multi-stage multi-cluster hydraulic fracturing in shale gas reservoirs, the multi-scale seepage flows are much more complicated than in most other conventional reservoirs, and are crucial for the economic development of shale gas. In this study, a new multi-scale non-linear flow model was established and simplified, based on different diffusion and slip correction coefficients. Due to the fact that different flow laws existed between the fracture network and matrix zone, a three-zone composite model was proposed. Then, according to the conformal transformation combined with the law of equivalent percolation resistance, the productivity equation of a horizontal fractured well, with consideration given to diffusion, slip, desorption, and absorption, was built. Also, an analytic solution was derived, and the interference of the multi-cluster fractures was analyzed. The results indicated that the diffusion of the shale gas was mainly in the transition and Fick diffusion regions. The matrix permeability was found to be influenced by slippage and diffusion, which was determined by the pore pressure and diameter according to the Knudsen number. It was determined that, with the increased half-lengths of the fracture clusters, flow conductivity of the fractures, and permeability of the fracture network, the productivity of the fractured well also increased. Meanwhile, with the increased number of fractures, the distance between the fractures decreased, and the productivity slowly increased due to the mutual interference of the fractures. In regard to the fractured horizontal wells, the free gas was found to majorly contribute to the productivity, while the contribution of the desorption increased with the increased pressure differences.

Keywords: multi-scale, fracture network, composite model, productivity

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Authors: Norhidayah Suleiman, Afza Zulfaka

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Zingiber officinale var. Bentong has been identified as the source of high added value compound specifically gingerol-related compounds. The extraction of the high-value compound using conventional method resulted in low yield and time consumption. Hence, the motivation for this work is to investigate the effect of the extraction technique on the essential oil from Zingiber officinale var. Bentong rhizome for commercialization purpose in many industries namely, functional food, pharmaceutical, and cosmeceutical. The investigation begins with a pre-treatment using ultrasound assisted in order to enhance the recovery of essential oil. It was conducted at a fixed frequency (20 kHz) of ultrasound with various time (10, 20, 40 min). The extraction using supercritical carbon dioxide (scCO2) were carried out afterward at a specific condition of temperature (50 °C) and pressure (30 MPa). scCO2 extraction seems to be a promising sustainable green method for the extraction of essential oil due to the benefits that CO2 possesses. The expected results demonstrated the ultrasound-assisted-scCO2 produces a higher yield of essential oil compared to solely scCO2 extraction. This research will provide important features for its application in food supplements or phytochemical preparations.

Keywords: essential oil, scCO2, ultrasound assisted, Zingiber officinale Var. Bentong

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Authors: Dixit Garg, S. Luthra, A. Haleem

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During recent years, the natural environment has become a challenging topic that business organizations must consider due to the economic and ecological impacts and increasing awareness of environment protection among society. Organizations are trying to achieve the goals of improvement in environment, low cost, high quality, flexibility and more customer satisfaction. Performance measurement frameworks are very useful to monitor the performance of any organization. The basic goal of this paper is to identify performance measures and ranking of these performance measures of GSCM performance measurement towards sustainability framework. Five perspectives (Environment, Economic, Social, Operational and Cost performances) and nineteen performance measures of GSCM performance towards sustainability have been have been identified from extensive literature review. Analytical Hierarchy Process (AHP) technique has been utilized for ranking of these performance perspectives and measures. All pair comparisons in AHP have been made on the basis on the experts’ opinions (selected from academia and industry). Ranking of these performance perspectives and measures will help to understand the importance of environmental, economic, social, operational performances, and cost performances in the supply chain.

Keywords: analytical hierarchy process, green supply chain management, performance measures, sustainability

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Authors: S. Boudali, A. M. Soliman, B. Abdulsalam, K. Ayed, D. E. Kerdal, S. Poncet

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This study investigates the potential of using crushed concrete as aggregates to produce green and sustainable concrete. Crushed concrete was sieved to powder fine recycled aggregate (PFRA) less than 80 µm and coarse recycled aggregates (CRA). Physical, mechanical, and microstructural properties for PFRA and CRA were evaluated. The effect of the additional rates of PFRA and CRA on strength development of recycled aggregate concrete (RAC) was investigated. Additionally, the characteristics of interfacial transition zone (ITZ) between cement paste and recycled aggregate were also examined. Results show that concrete mixtures made with 100% of CRA and 40% PFRA exhibited similar performance to that of the control mixture prepared with 100% natural aggregate (NA) and 40% natural pozzolan (NP). Moreover, concrete mixture incorporating recycled aggregate exhibited a slightly higher later compressive strength than that of the concrete with NA. This was confirmed by the very dense microstructure for concrete mixture incorporating recycled concrete aggregates compared to that of conventional concrete mixture.

Keywords: compressive strength, recycled concrete aggregates, microstructure, interfacial transition zone, powder fine recycled aggregate

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Authors: Jaan Lellep, Shahid Mubasshar

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A numerical solution is developed for simply supported nanoarches based on the non-local theory of elasticity. The nanoarch under consideration has a step-wise variable cross-section and is weakened by crack-like defects. It is assumed that the cracks are stationary and the mechanical behaviour of the nanoarch can be modeled by Eringen’s non-local theory of elasticity. The physical and thermal properties are sensitive with respect to changes of dimensions in the nano level. The classical theory of elasticity is unable to describe such changes in material properties. This is because, during the development of the classical theory of elasticity, the speculation of molecular objects was avoided. Therefore, the non-local theory of elasticity is applied to study the vibration of nanostructures and it has been accepted by many researchers. In the non-local theory of elasticity, it is assumed that the stress state of the body at a given point depends on the stress state of each point of the structure. However, within the classical theory of elasticity, the stress state of the body depends only on the given point. The system of main equations consists of equilibrium equations, geometrical relations and constitutive equations with boundary and intermediate conditions. The system of equations is solved by using the method of separation of variables. Consequently, the governing differential equations are converted into a system of algebraic equations whose solution exists if the determinant of the coefficients of the matrix vanishes. The influence of cracks and steps on the natural vibration of the nanoarches is prescribed with the aid of additional local compliance at the weakened cross-section. An algorithm to determine the eigenfrequencies of the nanoarches is developed with the help of computer software. The effects of various physical and geometrical parameters are recorded and drawn graphically.

Keywords: crack, nanoarches, natural frequency, step

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Authors: T. Zaki, Fathi S. Soliman

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Desulfurization process is required by most, if not all refineries, to achieve ultra-low sulfur fuel, that contains less than 10 ppm sulfur. A lot of research works and many effective technologies have been studied to achieve deep desulfurization process in moderate reaction environment, such as adsorption desulfurization (ADS), oxidative desulfurization (ODS), biodesulfurization and extraction desulfurization (EDS). Extraction desulfurization using deep eutectic solvents (DESs) is considered as simple, cheap, highly efficient and environmentally friend process. In this work, four DESs were designed and synthesized. Choline chloride (ChCl) was selected as typical hydrogen bond acceptors (HBA), and ethylene glycol (EG), glycerol (Gl), urea (Ur) and thiourea (Tu) were selected as hydrogen bond donors (HBD), from which a series of deep eutectic solvents were synthesized. The experimental data showed that the synthesized DESs showed desulfurization affinities towards the thiophene species in cyclohexane solvent. Ethylene glycol molecules showed more affinity to create hydrogen bond with thiophene instead of choline chloride. Accordingly, ethylene glycol choline chloride DES has the highest extraction efficiency.

Keywords: DES, desulfurization, green solvent, extraction

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Authors: Gopal Ji, Priyanka Dwivedi, Shanthi Sundaram, Rajiv Prakash

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Inhibition effect of aqueous Argemone Mexicana root extract (AMRE) on mild steel corrosion in 1 M HCl has been studied by weight loss, Tafel polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. Results indicate that inhibition ability of AMRE increases with the increasing amount of the extract. A maximum corrosion inhibition of 94% is acknowledged at the extract concentration of 400 mg L-1. Polarization curves and impedance spectra reveal that both cathodic and anodic reactions are suppressed due to passive layer formation at metal-acid interface. It is also confirmed by SEM micro graphs and FTIR studies. Furthermore, the effects of acid concentration (1-5 M), immersion time (120 hours) and temperature (30-60˚C) on inhibition potential of AMRE have been investigated by weight loss method and electrochemical techniques. Adsorption mechanism is also proposed on the basis of weight loss results, which shows good agreement with Langmuir isotherm.

Keywords: mild steel, polarization, SEM, acid corrosion, EIS, green inhibition

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Authors: Javier Menéndez, Jorge Loredo

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Large scale energy storage systems (LSESS) such as pumped-storage hydro-power (PSH) are required in the current energy transition towards a low carbon economy by using green energies that produce low levels of greenhouse gas (GHG) emissions. Coal mines are currently being closed in the European Union and their underground facilities may be used to build PSH plants. However, the development of this projects requires the excavation of a network of tunnels and a large cavern that would be used as a powerhouse to install the Francis turbine and motor-generator. The technical feasibility to excavate the powerhouse cavern has been analyzed in the North of Spain. Three-dimensional numerical models have been conducted to analyze the stability considering shale and sandstone rock mass. Total displacements and thickness of plastic zones were examined considering different support systems. Systematic grouted rock bolts and fibre reinforced shotcrete were applied at the cavern walls and roof. The results obtained show that the construction of the powerhouse is feasible applying proper support systems.

Keywords: closed mines, mine water, numerical model, pumped-storage, renewable energies

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Authors: Hesham Moustafa, Ahmed M. Youssef

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The demand for green packagingin the food field has been gained increasing attention in recent decades because of its degradability and safely. Thus, this study revealed that the by-product bagasse papers (BPs) derived from sugarcane waste can be decorated with a thin layer of polystyrene (PS) nanocomposites using the spreading approach.Three variable concentrations of TiO2 nanoparticles (i.e. 0.5, 1.0, 1.5 wt.%) were used to fabricate PS nanocomposites. The morphology of coated BP-PS biofilms was examined by X-ray diffraction, Fourier transferred Infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Moreover, other measurements such as mechanical, thermal stability, flammability, wettability by the contact angle, water vapor, and gas barrier properties were carried out on the fabricated BP-PS biofilms. Most outcomes showed that the major properties were enhanced when the PS nanocomposites were implemented. The use of 1.5 wt.% TiO2 in PS nanocomposite for coated BP-PS biofilm increased the tensile stress by ~ 217 % compared to uncoated BP film. Furthermore, the rate of burning for BP-PS-1.5% film was reduced to ~ 33 mm/min because of the crystallinity of PS and the barrier effect provided by TiO₂ NPs. These coated sheets provide a promising candidate for use in advanced packaging applications.

Keywords: bagasse paper, polystyrene nanocomposites, TiO2 nanoparticles, active packaging, mechanical properties, flammability

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Authors: O. Baghriche, A. Zertal, C. Pulgarin, J. Kiwi, R. Sanjines

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High-Power Impulse Magnetron Sputtering (HIPIMS) is a technology that belongs to the field of Ionized PVD of thin films. This study shows the first complete report on ultrathin TiO2/Ag nano-particulate films sputtered by highly ionized pulsed plasma magnetron sputtering (HIPIMS) leading to fast bacterial loss of viability. The Ag and the TiO2/Ag sputtered films induced complete Escherichia coli inactivation in the dark, which was not observed in the case of TiO2. When Ag was present, the bacterial inactivation was accelerated under low intensity solar simulated light and this has implications for a potential for a practical technology. The design, preparation, testing and surface characterization of these innovative films are described in this study. The HIPIMS sputtered composite films present an appreciable savings in metals compared to films obtained by conventional sputtering methods. HIPIMS sputtering induces a strong interaction with the rugous polyester 3-D structure due to the higher fraction of the Ag-ions (M+) attained in the magnetron chamber. The immiscibility of Ag and TiO2 in the TiO2/Ag films is shown by High Angular Dark Field (HAADF) microscopy. The ionization degree of the film forming species is significantly increased and film growth is assisted by an intense ion flux. Reports have revealed the significant enhancement of the film properties as the HIPIMS technology is used. However, a decrease of the deposition rate, as compared to the conventional DC magnetron sputtering Pulsed (DCMSP) process is commonly observed during HIPIMS.

Keywords: E. coli, HIPIMS, inactivation bacterial, sputtering

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Authors: Cimen Ozburak

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Pollution and the consumption of natural resources are significant global concerns. These problems have to be resolved in order to create a cleaner environment for the world. It is believed that sustainable building designs may reduce environmental problems throughout the world. It is known that if children receive environmental education in early childhood, they will be more likely to construct sustainable living systems and environment when they are older. School buildings can be used as educational material for teaching the natural and artificial environment in environmental education. In this study, the effect of school buildings on environmental education is examined by using the literature review method along with various examples. The selected examples in the study were analyzed according to 4 main criteria of LEED green building certification systems. These are the use of sustainable utilization of land, efficient utilization of water, efficient utilization of energy and efficient utilization of materials. According to the literature review, children who are educated in buildings designed according to these criteria, they will be environmentally sensitive individuals when they are older.

Keywords: clean future, educational sustainable pre-schools, environmental education, sustainable systems

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Authors: Nasim Abuali Galehdari, Venkat Mani, Ajit D. Kelkar

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Space Radiation has become one of the major factors in successful long duration space exploration. Exposure to space radiation not only can affect the health of astronauts but also can disrupt or damage materials and electronics. Hazards to materials include degradation of properties, such as, modulus, strength, or glass transition temperature. Electronics may experience single event effects, gate rupture, burnout of field effect transistors and noise. Presently aluminum is the major component in most of the space structures due to its lightweight and good structural properties. However, aluminum is ineffective at blocking space radiation. Therefore, most of the past research involved studying at polymers which contain large amounts of hydrogen. Again, these materials are not structural materials and would require large amounts of material to achieve the structural properties needed. One of the materials to alleviate this problem is polymeric composite materials, which has good structural properties and use polymers that contained large amounts of hydrogen. This paper presents steps involved in fabrication of multi-functional hybrid sandwich panels that can provide beneficial radiation shielding as well as structural strength. Multifunctional hybrid sandwich panels were manufactured using vacuum assisted resin transfer molding process and were subjected to radiation treatment. Study indicates that various nanoparticles including Boron Nano powder, Boron Carbide and Gadolinium nanoparticles can be successfully used to block the space radiation without sacrificing the structural integrity.

Keywords: multi-functional, polymer composites, radiation shielding, sandwich composites

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Authors: Mohamad Ahrari, Kayvan Sadri, Mahmoud Reza Jafari

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PEGylated liposomes have a smaller volume of distribution and decreased clearance, consequently, due to their more prolonged presence in bloodstream and maintaining their stability during this period, these liposomes can be applied for imaging tumoral sites. The purpose of this study is to develop an appropriate radiopharmaceutical agent in long-term imaging for improved diagnosis and evaluation of tumors. In this study, liposomal formulations encapsulating albumin is synthesized by solvent evaporation method along with homogenization, and their characteristics were assessed. Then these liposomes labeled by Philips method and the rate of stability of labeled liposomes in serum, and ultimately the rate of biodistribution and gamma scintigraphy in C26-colon carcinoma tumor-bearing mice, were studied. The result of the study of liposomal characteristics displayed that capable of accumulating in tumor sites based of EPR phenomenon. these liposomes also have high stability for maintaining encapsulated albumin in a long time. In the study of biodistribution of these liposomes in mice, they accumulated more in the kidney, liver, spleen, and tumor sites, which, even after clearing formulations in the bloodstream, they existed in high levels in these organs up to 96 hours. In gamma scintigraphy also, organs with high activity accumulation from early hours up to 96 hours were visible in the form of hot spots. concluded that PEGylated liposomal formulation encapsulating albumin can be labeled with In-Oxine, and obtained stabilized formulation for long-term imaging, that have more favorable conditions for the evaluation of tumors and it will cause early diagnosis of tumors.

Keywords: nano liposome, 111In-oxine, imaging, biodistribution, tumor

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Authors: R. Vasireddi, J. Kruse, M. Vakili, M. Trebbin

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Here we present a gas dynamic virtual nozzle (GDVN) based microfluidic jetting devices for spinning of nano/microfibers. The device is fabricated by soft lithography techniques and is based on the principle of a GDVN for precise three-dimensional gas focusing of the spinning solution. The nozzle device is used to produce micro/nanofibers of a perfluorinated terpolymer (THV), which were collected on an aluminum substrate for scanning electron microscopy (SEM) analysis. The influences of air pressure, polymer concentration, flow rate and nozzle geometry on the fiber properties were investigated. It was revealed that surface properties are controlled by air pressure and polymer concentration while the diameter and shape of the fibers are influenced mostly by the concentration of the polymer solution and pressure. Alterations of the nozzle geometry had a negligible effect on the fiber properties, however, the jetting stability was affected. Round and flat fibers with differing surface properties from craters, grooves to smooth surfaces could be fabricated by controlling the above-mentioned parameters. Furthermore, the formation of surface roughness was attributed to the fast evaporation rate and velocity (mis)match between the polymer solution jet and the surrounding air stream. The diameter of the fibers could be tuned from ~250 nm to ~15 µm. Because of the simplicity of the setup, the precise control of the fiber properties, access to biocompatible nanofiber fabrication and the easy scale-up of parallel channels for high throughput, this method offers significant benefits compared to existing solution-based fiber production methods.

Keywords: gas dynamic virtual nozzle (GDVN) principle, microfluidic device, spinning, uniform nanofibers

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Authors: Abhimanyu Thakur, Youngjin Lee

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Glioma is a lethal brain cancer whose early diagnosis and prognosis are limited due to the dearth of a suitable technique for its early detection. Current approaches, including magnetic resonance imaging (MRI), computed tomography (CT), and invasive biopsy for the diagnosis of this lethal disease, hold several limitations, demanding an alternative method. Recently, extracellular vesicles (EVs) have been used in numerous biomarker studies, majorly exosomes and microvesicles (MVs), which are found in most of the cells and biofluids, including blood, cerebrospinal fluid (CSF), and urine. Remarkably, glioma cells (GMs) release a high number of EVs, which are found to cross the blood-brain-barrier (BBB) and impersonate the constituents of parent GMs including protein, and lncRNA; however, biophysical properties of EVs have not been explored yet as a biomarker for glioma. We isolated EVs from cell culture conditioned medium of GMs and regular primary culture, blood, and urine of wild-type (WT)- and glioma mouse models, and characterized by nano tracking analyzer, transmission electron microscopy, immunogold-EM, and differential light scanning. Next, we measured the biophysical parameters of GMs-EVs by using atomic force microscopy. Further, the functional constituents of EVs were examined by FTIR and Raman spectroscopy. Exosomes and MVs-derived from GMs, blood, and urine showed distinction biophysical parameters (roughness, adhesion force, and stiffness) and different from that of regular primary glial cells, WT-blood, and -urine, which can be attributed to the characteristic functional constituents. Therefore, biophysical features can be potential diagnostic biomarkers for glioma.

Keywords: glioma, extracellular vesicles, exosomes, microvesicles, biophysical properties

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Authors: Shun-Tong Chen, Wei-Ping Huang, Hong-Ye Yang, Ming-Chieh Yeh, Chih-Wei Du

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This study presents a novel versatile high-precision integrated micromachining system that combines contact and non-contact micromachining techniques to machine intricate micro-parts precisely. Two broad methods of micro fabrication-1) volume additive (micro co-deposition), and 2) volume subtractive (nanometric flycutting, ultrafine w-EDM (wire Electrical Discharge Machining), and micro honing) - are integrated in the developed micromachining system, and their effectiveness is verified. A multidirectional headstock that supports various machining orientations is designed to evaluate the feasibility of multifunctional micromachining. An exchangeable working-tank that allows for various machining mechanisms is also incorporated into the system. Hence, the micro tool and workpiece need not be unloaded or repositioned until all the planned tasks have been completed. By using the designed servo rotary mechanism, a nanometric flycutting approach with a concentric rotary accuracy of 5-nm is constructed and utilized with the system to machine a diffraction-grating element with a nano-metric scale V-groove array. To improve the wear resistance of the micro tool, the micro co-deposition function is used to provide a micro-abrasive coating by an electrochemical method. The construction of ultrafine w-EDM facilitates the fabrication of micro slots with a width of less than 20-µm on a hardened tool. The hardened tool can thus be employed as a micro honing-tool to hone a micro hole with an internal diameter of 200 µm on SKD-11 molded steel. Experimental results prove that intricate micro-parts can be in-situ manufactured with high-precision by the developed integrated micromachining system.

Keywords: integrated micromachining system, in-situ micromachining, nanometric flycutting, ultrafine w-EDM, micro honing

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Authors: Gopalu Karunakaran, Matheswaran Jagathambal, Nguyen Van Minh, Evgeny Kolesnikov, Denis Kuznetsov

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This work investigated the use of Beijerinckia indica extracellular extract for the synthesis of silver nanoparticles using AgNO₃. The formation of nanoparticles was confirmed by different methods, such as UV-Vis absorption spectroscopy, XRD, FTIR, EDX, and TEM analysis. The formation of silver nanoparticles (AgNPs) was confirmed by the change in color from light yellow to dark brown. The absorbance peak obtained at 430 nm confirmed the presence of silver nanoparticles. The XRD analysis showed the cubic crystalline phase of the synthesized nanoparticles. FTIR revealed the presence of groups that acts as stabilizing and reducing agents for silver nanoparticles formation. The synthesized silver nanoparticles were generally found to be spherical in shape with size ranging from 5 to 20 nm, as evident by TEM analysis. These nanoparticles were found to inhibit pathogenic bacterial strains. This work proved that the bacterial extract is a potential eco-friendly candidate for the synthesis of silver nanoparticles with promising antibacterial and antioxidant properties. 

Keywords: antioxidant activity, antimicrobial activity, Beijerinckia indica, characterisation, extracellular extracts, silver nanoparticles

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Authors: Alafara A. Baba, Kuranga I. Ayinla, Folahan A. Adekola, Rafiu B. Bale

Abstract:

Due to increasing demands and diverse applications of copper oxide as pigment in ceramics, cuprammonium hydroxide solution for rayon, p-type semi-conductor, dry cell batteries production and as safety disposal of hazardous materials, a study on the hydrometallurgical operations involving leaching, solvent extraction and precipitation for the recovery of copper for producing high grade copper oxide from a Nigerian chalcopyrite ore in chloride media has been examined. At a particular set of experimental parameter with respect to acid concentration, reaction temperature and particle size, the leaching investigation showed that the ore dissolution increases with increasing acid concentration, temperature and decreasing particle diameter at a moderate stirring. The kinetics data has been analyzed and was found to follow diffusion control mechanism. At optimal conditions, the extent of ore dissolution reached 94.3%. The recovery of the total copper from the hydrochloric acid-leached chalcopyrite ore was undertaken by solvent extraction and precipitation techniques, prior to the beneficiation of the purified solution as copper oxide. The purification of the leach liquor was firstly done by precipitation of total iron and manganese using Ca(OH)2 and H2O2 as oxidizer at pH 3.5 and 4.25, respectively. An extraction efficiency of 97.3% total copper was obtained by 0.2 mol/L Dithizone in kerosene at 25±2ºC within 40 minutes, from which ≈98% Cu from loaded organic phase was successfully stripped by 0.1 mol/L HCl solution. The beneficiation of the recovered pure copper solution was carried out by crystallization through alkali addition followed by calcination at 600ºC to obtain high grade copper oxide (Tenorite, CuO: 05-0661). Finally, a simple hydrometallurgical scheme for the operational extraction procedure amenable for industrial utilization and economic sustainability was provided.

Keywords: chalcopyrite ore, Nigeria, copper, copper oxide, solvent extraction

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Authors: Lu Yanru, Handojo Djati Utomo, Yin Xi Jiang, Li Xiaodong

Abstract:

Insulation plays a key role in the sustainable building due to the contribution of energy consumption reduction. Without sufficient insulation, a great amount of the energy used to heat or cool a building will be lost to the outdoors. In this study, we developed a highly efficient thermal insulation paint with the incorporation of silica aerogel. Silica aerogel, with a low thermal conductivity of 0.01 W/mK, has been successfully prepared from the solid waste from the incineration plants. It has been added into water-based paints to increase its thermal insulation properties. To investigate the thermal insulation performance of silica aerogel additive, the paint samples were mixed with silica aerogel at different sizes and with various portions. The thermal conductivity, water resistance, thermal stability and adhesion strength of the samples were tested and evaluated. The thermal diffusivity measurements proved that adding silica aerogel additive could improve the thermal insulation properties of the paint significantly. Up to 5 ˚C reductions were observed after applying paints with silica aerogel additive compare to the one without it. The results showed that the developed thermal insulation paints have great potential for an application in green and sustainable building.

Keywords: silica aerogel, thermal insulation, water-based paints, water resistant

Procedia PDF Downloads 175

Authors: E. Locatelli, I. Monaco, R. C. Martin, Y. Li, R. Pini, M. Chiariello, M. Comes Franchini

Abstract:

Despite the many advantages of application of nanomaterials in the field of nanomedicine, increasing concerns have been expressed on their potential adverse effects on human health. There is urgency for novel green strategies toward novel materials with enhanced biocompatibility using safe reagents. Photothermal ablation therapy, which exploits localized heat increase of a few degrees to kill cancer cells, has appeared recently as a non-invasive and highly efficient therapy against various cancer types; anyway new agents able to generate hyperthermia when irradiated are needed and must have precise biocompatibility in order to avoid damage to healthy tissues and prevent toxicity. Recently, there has been increasing interest in magnesium as a biomaterial: it is the fourth most abundant cation in the human body, and it is essential for human metabolism. However magnesium nanoparticles (Mg NPs) have had limited diffusion due to the high reduction potential of magnesium cations, which makes NPs synthesis challenging. Herein, we report the synthesis of Mg NPs and their surface functionalization for the obtainment of a stable and biocompatible nanomaterial suitable for photothermal ablation therapy against cancer. We synthesized the Mg crystals by reducing MgCl2 with metallic lithium and exploiting naphthalene as an electron carrier: the lithium–naphthalene complex acts as the real reducing agent. Firstly, the nanocrystal particles were coated with the ligand 12-ethoxy ester dodecanehydroxamic acid, and then entrapped into water-dispersible polymeric micelles (PMs) made of the FDA-approved PLGA-b-PEG-COOH copolymer using the oil-in-water emulsion technique. Lately, we developed a more straightforward methodology by introducing chitosan, a highly biocompatible natural product, at the beginning of the process, simultaneously using lithium–naphthalene complex, thus having a one-pot procedure for the formation and surface modification of MgNPs. The obtained MgNPs were purified and fully characterized, showing diameters in the range of 50-300 nm. Notably, when coated with chitosan the particles remained stable as dry powder for more than 10 months. We proved the possibility of generating a temperature rise of a few to several degrees once MgNPs were illuminated using a 810 nm diode laser operating in continuous wave mode: the temperature rise resulted significant (0-15 °C) and concentration dependent. We then investigated potential cytotoxicity of the MgNPs: we used HN13 epithelial cells, derived from a head and neck squamous cell carcinoma and the hepa1-6 cell line, derived from hepatocellular carcinoma and very low toxicity was observed for both nanosystems. Finally, in vivo photothermal therapy was performed on xenograft hepa1-6 tumor bearing mice: the animals were treated with MgNPs coated with chitosan and showed no sign of suffering after the injection. After 12 hours the tumor was exposed to near-infrared laser light. The results clearly showed an extensive damage to tumor tissue after only 2 minutes of laser irradiation at 3Wcm-1, while no damage was reported when the tumor was treated with the laser and saline alone in control group. Despite the lower photothermal efficiency of Mg with respect to Au NPs, we consider MgNPs a promising, safe and green candidate for future clinical translations.

Keywords: chitosan, magnesium nanoparticles, nanomedicine, photothermal therapy

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Authors: S. Potgieter-Vermaak, N. Bain, A. Brown, K. Shaw

Abstract:

It is well-known from public news media that air pollution is a health hazard and is responsible for early deaths. The quantification of the relationship between air quality and health is a probing question not easily answered. It is known that airborne particulate matter (APM) <2.5µm deposits in the tracheal and alveoli zones and our research probes the possibility of quantifying pulmonary injury by linking reactive oxygen species (ROS) in these particles to DNA damage. Currently, APM mass concentration is linked to early deaths and limited studies probe the influence of other properties on human health. To predict the full extent and type of impact, particles need to be characterised for chemical composition and structure. APMs are routinely analysed for their bulk composition, but of late analysis on a micro level probing single particle character, using micro-analytical techniques, are considered. The latter, single particle analysis (SPA), permits one to obtain detailed information on chemical character from nano- to micron-sized particles. This paper aims to provide a snapshot of studies using data obtained from chemical characterisation and its link with in-vitro studies to inform on personal health risks. For this purpose, two studies will be compared, namely, the bioaccessibility of the inhalable fraction of urban road dust versus total suspended solids (TSP) collected in the same urban environment. The significant influence of metals such as Cu and Fe in TSP on DNA damage is illustrated. The speciation of Hg (determined by SPA) in different urban environments proved to dictate its bioaccessibility in artificial lung fluids rather than its concentration.

Keywords: air pollution, human health, in-vitro studies, particulate matter

Procedia PDF Downloads 220

Authors: Yun Zhang

Abstract:

Urban housing in China is typified by residential districts that occupy 25 to 40 percentage of the urban land. In residential districts, squares, roads, and building facades, as well as plants, usually form a four-grade spatial structure: district entrances, central landscapes, housing cluster entrances, green spaces between dwellings. This spatial structure and its elements not only compose the visible residential landscape but also play a major role of carrying rain water. These elements, therefore, imply ecological significance to urban fitness. Based upon theories of landscape ecology, residential landscape can be understood as a pattern typified by minor soft patch of planted area and major hard patch of buildings and squares, as well as hard corridors of roads. Use five landscape districts in Hangzhou as examples; this paper finds that the size, shape and slope direction of soft patch, the bend of roads, and the form of the four-grade spatial structure are influential for adapting to natural rainwater circulation.

Keywords: Hangzhou China, rainwater, residential landscape, spatial character, urban housing

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Authors: Konstantinos G. Dassios, Guillaume Bonnefont, Gilbert Fantozzi, Theodore E. Matikas, Costas Galiotis

Abstract:

We report herein the development and preliminary mechanical characterization of fully-dense multi-wall carbon nanotube (MWCNT)-reinforced ceramics and glasses based on a completely new methodology termed High Shear Compaction (HSC). The tubes are introduced and bound to the matrix grains by aid of polymeric binders to form flexible green bodies which are sintered and densified by spark plasma sintering to unprecedentedly high densities of 100% of the pure-matrix value. The strategy was validated across a PyrexTM glass / MWCNT composite while no identifiable factors limit application to other types of matrices. Non-destructive evaluation, based on ultrasonics, of the dynamic mechanical properties of the materials including elastic, shear and bulk modulus as well as Poisson’s ratio showed optimum property improvement at 0.5 %wt tube loading while evidence of nanoscale-specific energy dissipative characteristics acting complementary to nanotube bridging and pull-out indicate a high potential in a wide range of reinforcing and multifunctional applications.

Keywords: ceramic matrix composites, carbon nanotubes, toughening, ultrasonics

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Authors: B. E. Adeyanju, M. K. Bolade, V. N. Enijuigha

Abstract:

This work examined the nutritional composition of maize-based snack (kango) fortified with kidney beans (Phaseolus vulgaris) and alligator pepper (Aframomum melegueta). The snack is essentially traditional food being consumed by all ages in the southwestern part of Nigeria. Three varieties of maize were obtained from the Institute of Agricultural Research and Training (IAR&T), Ibadan, Nigeria, namely: ART-98-SW06-W, Br 9943-DMR-SR-W and SUWAN-1-SR-Y. Flour blends were obtained using the Response Surface Methodology (RSM) which resulted in appropriate blending ratios of maize, kidney beans and alligator pepper. Kango was prepared by milling maize grain into flour; ingredients such as pepper, onion, salt and water were added to the maize flour, mixed together to make a slurry. The slurry was fried in hot groundnut oil at a temperature of 126°C for 8 minutes. The incorporation of kidney bean and alligator pepper in maize flour was observed to increase the water and oil absorption capacities of the resultant blends thereby giving 109.21 to 156.90 ml/mg and 110.68 to 136.67 ml/mg respectively for kango. The pasting properties of the maize flour blends were also enhanced due to the incorporation of kidney bean and alligator pepper. The peak viscosity of the flour blends ranged from 3.24 to 7.67 RVU. The incorporation of kidney bean and alligator pepper in the production of the snacks increased the protein contents from 9.63 to 16.37%. The mineral contents (sodium, potassium, calcium, magnesium, iron and zinc) of the snacks were equally increased due to the incorporation of kidney bean and alligator pepper. A general increase was observed for vitamin B1 (0.69- 1.25 mg/100g), B2 (0.09 - 0.46 mg/100g) and B3 (0.11 - 0.72 mg/100g) in the snacks due to the incorporation of kidney bean and alligator pepper. This research work showed that kango produced from the composited maize flour, kidney bean and alligator pepper had better functional properties and higher nutritional contents.

Keywords: functional properties, kango, nutritional composition, snack

Procedia PDF Downloads 155