The move towards a de-carbonized world, driven partly by climate science and partly by the business opportunities it offers, will need the promotion of environmentally friendly alternatives, if an acceptable Stabilization level of atmospheric carbon dioxide is to be achieved. This requires the harnessing and use of natural resources that produce no air pollution or greenhouse gases and provides comfortable coexistence of human, livestock, and plants. This article presents a comprehensive review of energy sources, and the development of sustainable technologies to explore these energy sources. It also includes potential renewable energy technologies, efficient energy systems, energy savings techniques and other mitigation measures necessary to reduce climate changes. There is strong scientific evidence that the average temperature of the earth’s surface is rising. This is a result of the increased concentration of carbon dioxide and other GHGs in the atmosphere as released by burning fossil fuels. This global warming will eventually lead to substantial changes in the world’s climate, which will, in turn, have a major impact on human life and the built environment. Therefore, effort has to be made to reduce fossil energy use and to promote green energy, particularly in the building sector. Energy use reductions can be achieved by minimising the energy demand, rational energy use, recovering heat and the use of more green energy. This study was a step towards achieving this goal. Globally, buildings are responsible for approximately 40% of the total world annual energy consumption. Most of this energy is for the provision of lighting, heating, cooling, and air conditioning. Increasing awareness of the environmental impact of CO2, NOx and CFCs emissions triggered a renewed interest in environmentally friendly cooling, and heating technologies. Under the 1997 Montreal Protocol, governments agreed to phase out chemicals used as refrigerants that have the potential to destroy stratospheric ozone. It was therefore considered desirable to reduce energy consumption and decrease the rate of depletion of world energy reserves and pollution of the environment. This article discusses a comprehensive review of energy sources, environment and sustainable development. This includes all the renewable energy technologies, energy efficiency systems, energy conservation scenarios, energy savings and other mitigation measures necessary to reduce climate change.
The development of nanocomposite membranes for desalination and wastewater treatment has attracted significant interest in recent years. This exceptional growth is owed to the enhanced multi functionalities of the nanocomposite membranes in terms of permselectivity, thermal stability, electrical conductivity, and antifouling propensities. In the present work, we fabricated novel thin film nanocomposite (TFN) polyamide membranes using indium tin oxide (ITO) nanoparticles. The thin film composite (TFC) membranes were synthesized by interfacial polymerization (IP) reaction using m-phenylenediamine (MPD)-aqueous solution and trimesoyl chloride (TMC)-ITO heptane solution. The addition of ITO nanoparticles to the polyamide layer significantly improved the water flux from 25.3 LMH for the pristine TFC membrane to 43.5 LMH for the ITO-modified TFN membrane with a slight reduction in salt rejection from 98% to 97% during the treatment of saline water (2000 ppm NaCl). Also, TFN membranes demonstrated superior antifouling propensity than the pristine and commercial membranes during filtration of oil sands produced water to remove organic matter. The improved fouling resistance of TFN membranes was mainly attributed to their enhanced surface wettability as the contact angle decreased from ~82° for the pristine TFC to ~65° for TFN membranes.
This short commentary mentions some reports of immobilization of enzymes by encapsulation into the structure of metal organic frameworks (MOFs) and adsorption on the surface of the MOFs. Improvements in thermal stability, storage stability, and reusability were also observed. The ability to improve the function of enzymes while maintaining their stability will lead to cost reduction. In addition, there are possible applications in the fields of biosensing and cancer treatment.
With the development of smart materials and the requirement of multifunctional systems, coatings were developed with the aim to improve and optimize many properties and especially in the electrical field (resistivity, conductivity, permittivity,..) Relative to the electrical conductivity, the need is growing in many activity areas with the recent tendencies (green technology and energy). Recently, the sol-gel route to process coatings was investigated for its ability to develop innovative multifunctional coatings. Because the sol-gel matrix is known to be completely insulating, the conductivity can be brought by the development of a composite material, with the incorporation of conductive fillers into the insulating network. The aim of this paper is to present an overview of the sol-gel coatings, dedicated to the electrical conduction, started in the 2000’s. A rapid introduction will set the context including many “standard” applications of sol-gel coatings. Then, studies are gathered according to the fillers incorporated in the sol-gel formulation (Tables 1-3). Each coating is described in detailed. Correlations and tendencies are identified and discussed. The lowest surface electrical resistance is obtained using metallic fillers (145 mΩâ?i), but the carbon fillers are very promising taking benefit of their various form factors. After an exhaustive presentation of the state of the art in this field, some new quantitative examples of coatings recently developed are presented. Various systems and architectures are detailed with associated applications. The major results show a surface electrical resistance comparable to the best values listed in the literature (around 130 mΩâ?i), but with carbon fillers against metallic fillers. Furthermore, the combination of carbon fillers and the capability to develop a sol-gel multi-layer is demonstrated. Finally, a key point is relative to the application of these conductive sol-gel coatings on a complex shape substrate.
In this work, the impact of the substrate annealing temperature on the thickness and roughness of La2Ti2O7 thin films was verified. A group of LTO Thin films was grown on Si (100) substrates successfully via pulsed laser deposition technique (PLD) at various annealing temperatures with a constant numbers of pulses and energy per pulse. Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) were used to investigate the thickness and roughness of the deposited La2Ti2O7 thin films. The average thickness of the thin films was decreased due to the increasing in the annealing temperature linearly; the maximum thickness was found (231 nm) when LTO thin film deposited at 500°C. The root mean square roughness was increased linearly with increasing the substrate Temperatures. The minimum roughness was found (0.254 nm) when LTO deposited at (500°C). From the obtained results, its clear evidence that the annealing temperature has an influence on the thickness and roughness of the LTO thin films.
There is no denying that the future of liquid crystals is in the display industry. The use of the twisted nematic (TN) and the superwisted nematic (STN) is widespread. The twisting in these devices is achieved either by use of optical components such as polarizers or the use of chiral dopants in a guest-host system. The later has gained much more attention. This is because not only are the accompanying optical components not needed, but any desired colour can be achieved by varying the pitch length of the helix formed by the chiral nematic (cholesteric) compound. In such application, the ability to determine the pitches of the resulting helical superstructure accurately and quickly is essential. Currently there are many methods for measuring the pitch of a helical super structure. These methods mostly employ optical or spectroscopic techniques. In this paper, four such methods namely, Fingerprint, Diffraction, Selective Reflection and Cano-wedge, are discussed in terms of their theoretical foundation, suitability to given situations and the validity of the results obtained. The suitability of the method depends among other things on the type of mesophase and the length of the pitch in relation to the wavelengths of the visible light. While the Fingerprint and Selective reflection may be used for both cholesteric and chiral smectic C (SmC*), Diffraction and Cano techniques are most suitable for the cholesterics.
Graphene transparent conductive electrodes are highly attractive for photodetector (PD) applications due to their excellent electrical and optical properties. The emergence of graphene/semiconductor hybrid heterostructures provides a platform useful for fabricating high-performance optoelectronic devices, thereby overcoming the inherent limitations of graphene. Here, we review the studies of PDs based on graphene/semiconductor hybrid heterostructures, including device physics/design, performance, and process technologies for the optimization of PDs. In the last section, existing technologies and future challenges for PD applications of graphene/semiconductor hybrid heterostructures are discussed.
Aluminium metrics based aluminium alloys have numerous applications in the field of modern technology. The aluminium alloys having three platforms of industrial applications which are widely used in electronics goods, ground transportation such as automobile, aerospace engineering and marine as well as military purposes. Aluminium alloys having low density, lightweight, excellent malleability and high strength are the key potency of these alloys. At present, the aluminium alloys are the capability to full fill the current demand of the modern industry. To enhance the mechanical properties of this aluminium alloys can be developed by reinforcing with ceramics such as SiC, MgO, Gr and so on are used to achieve the desirable properties of the materials. The present works investigated on Al 6061/B4C composites have been synthesized with different weight percentages of B4C (0, 1, 5, and 15%) along with varied particulate sizes of 50, 100 and 150 μm were used. The cast composites were produced via stir casting method and the addition of B4C particles in the base matrix has been analysis by SEM. The mechanical property such as Vickers hardness and UTS has been studied and the values of ultimate tensile strength have been optimized using the Taguchi method.
ACF preparation from different materials has been attached with great attention during these years. This study was conducted to prepare activated carbon fiber (ACF) from luffa through the processes i.e pre-treatment, pre-oxidation and carbonization activation. Besides, this study also characterizes the ACF and its effect, i.e effect of pre-oxidation time and temperature also activation time and temperature on the compressive strength of ACF were investigated. The results from SEM, BET, FTIR and XRD show that the ACF is very efficient. The products under the optimum conditions had a specific surface area of 478.441 m2 /g with an average pore diameter of 3.783nm, and a pore volume of 0.193 cm3 /g. The surface of the luffa fiber is degummed and exposed, which is beneficial to the subsequent process and the increase of product properties. The compressive strength of HP-ACF was prepared under the optimum conditions, which can reach 0.2461 MPa. ACF is rich in micro-pores and has a good application prospect in the field of environmental protection.
Multiferroics, materials in which both magnetic and electric fields can induce each other, resulting in a magnetoelectric response, have been attracting increasing attention, although the induced magnetic susceptibility and dielectric constant are usually small and have typically been reported for low temperatures. The magnetoelectric response usually depends on d-electrons of transition metals. Here we report that in [(GeTe)(2)(Sb2Te3)(l)](m) superlattice films (where l and m are integers) with topological phase transition, strong magnetoelectric response may be induced at temperatures above room temperature when the external fields are applied normal to the film surface. By ab initio computer simulations, it is revealed that the multiferroic properties are induced due to the breaking of spatial inversion symmetry when the p-electrons of Ge atoms change their bonding geometry from octahedral to tetrahedral. Finally, we demonstrate the existence in such structures of spin memory, which paves the way for a future hybrid device combining nonvolatile phase-change memory and magnetic spin memory.
Present paper has been done to describe the parameters related to organic device’s process of charge injection and to observe how these parameters get affected by different sized multi walled carbon nanotubes such as 8 nm diameter, 30 nm diameter and 50 nm diameter respectively. Barrier height significantly affects the interfacial charge injection process. Image charge effect also plays a salient role in lowering interfacial barrier. Spin coating technique has been used to form these devices. To estimate the barrier height, the current-voltage characteristics of these devices have been analyzed. Threshold voltage and ideality factor of these devices were also estimated. All the above mentioned parameters were calculated in absence and presence of different sized multi walled carbon nanotubes to observe its effect on these parameters. The barrier height was also estimated by Norde method. Both the methods remained consistent in showing that multi walled carbon nanotubes reduced the interfacial barrier. Effective barrier height considering image charge effect was also decreased due to incorporation of multi walled carbon nanotubes. Lowering of these parameters indicated improved charge flow at the interface. This work will be informative as the lower threshold voltage will cause consumed power to decrease. As the interfacial charge injection process gets improved, device conductivity will be improved which will result in greater efficiency.
This paper discusses a new method to prepare boron doped carbon (CBx) material with some substitutional boron atoms homogeneously distributed in the highly graphitic structure. The chemistry involves a mesophase boron-doped pitch (B-Pitch) prepared by mixing a borane reagent (i.e., dichlorophenylacetylborane) with petroleum pitch at 400°C. The resulting mesophase B-Pitch was further diluted with the starting pitch to adjust its softening temperature and melt viscosity, they are essential during the preparation of C/C composites. A resulting B-Pitch/Pitch blended precursor with 3.3 mol% B content and a softening temperature of 300°C was directly converted to CBx CBx CBx CBx B2O3 surface layer to slow down the oxygen diffusion into the matrix and stability. CBx) CBx at 2300°C under argon atmosphere, showing a char yield of 81%. The presence of a small percentage of B atoms in this B-Pitch/Pitch precursor catalyzes the carbonization/graphitization to form a highly graphitic CBx structure. Compared to synthetic graphite, which is stable in air up to 500°C, the resulting CBx shows higher thermal-oxidative stability. In air at 600°C, no weight loss was observed after 6 hours. At 700°C and 800°C, there was no detectable weight loss for 80 minutes. Evidently, the homogeneous distribution of B atoms in the CBx matrix is essential in continuously providing a protective B2O3 surface layer to slow down the oxygen diffusion into the matrix and delay the thermal/oxidative degradation process. Overall, this new precursor technology may offer the C/C composite manufacturing with reduced pyrolysis cycles and increased thermal/oxidative stability in high temperature applications.
Microbiologically influenced corrosion (MIC) and biofouling both begin with an initial layer of bacteria accumulating on a hard surface exposed to the natural environment. These bacteria quickly form a biofilm which becomes the feeding source for marine life fouling and the root of both of these highly damaging, expensive types of corrosion. Preventative methods for biofilm development is an ongoing field of study due to critical necessity in many industries including healthcare, aerospace, and oil and gas. Today, biofilm inhibitors for the oil and gas industry may include regular cleaning or scraping of the affected surface, electrochemical processes, or biocide injections which have a negative impact on the environment and provide only temporary relief from MIC. This constant need for MIC and fouling remediation creates a great demand and thus market potential for long-term, more environmentally conscious methods to mitigate and control biofilm development. This study investigates the incorporation of well-known biocidal materials as well as one commercial additive into the fabrication process of underwater structures and surfaces. High Density Polyethylene (HDPE) and Fiber Reinforced Plastic (FRP) with antimicrobial additive were processed. Experiments were conducted per ASTM E2149-13a and F895 to evaluate antibacterial efficacy in the laboratory. Field tests were constructed per ASTM D3623 78a for material evaluation in offshore fouling conditions. The manufactured materials were tested against gram-positive and gram-negative bacteria and fouling microorganisms to analyze the effectiveness of biofilm prevention. Results showed positive efficacy of biocidal additives incorporated through the fabrication process in all cases including copper, multiple forms of zinc, and titanium dioxide. The commercially available additive produced the largest zone of inhibition and highest reduction of colony forming units in dynamic flow conditions. Fouling tests show that the incorporation of the additive into HDPE and FRP provides a surface protection and thus serves as an agent for material preservation. Results from this study demonstrate innovative and effective methods for surface protection from MIC and biofouling by incorporating antimicrobial additives into the structural matrix during the manufacturing process.
In today’s world one of the major problems is pollution. In order reduce the pollution we need sustainable solution this sustainability includes socio economical equity. and environmental protection. To achieve sustainable solution, these three issues must be solved. Titanium dioxide blended concrete is the most promising solution for this ever increasing problem. This concrete has the same structural properties to normal concrete but because of the presence of titanium dioxide in the concrete which removes the pollutants effectively. This solution provides a viable option to high traffic volume roads or areas. The smog absorbing or photocatalytic concrete acts as pollution reducer. It means which converts harmful pollutants into harmless pollutants. In our project we are making concrete blocks by replacing the cement with titanium from 0% to 5% and we tested the blocks for compressive strength and smog absorbing test to know the number of pollutants absorbed by the concrete blocks by using Multi Gas Analyser machine and we compare the results with normal concrete.
Materials researchers work with different kinds of materials (e.g., metals, polymers, ceramics, fluid precious stones, composites) for a wide scope of uses (e.g., energy, development, gadgets, biotechnology, nanotechnology) utilizing current preparing and revelation standards (e.g., projecting, added substance producing, covering, dissipation, plasma and radiation handling, man-made brainpower, and programmatic experiences).
Huge amounts of unusable portion of leather and cattle hair from leather industries and chicken feather from poultries are polluting the environmental atmosphere tremendously. To reduce environmental pollution, these discarded parts need to use to produce other products. In this research, cow hair, chicken feather and waste leather were used to prepare useful composites combining with unsaturated polyester resin (UPR) to consider their reinforcement property and chemical property with view to curtail the environmental pollution. One portion of washed fibers was treated with aqueous solution of sodium hydroxide and the left portion was untreated. Then the chemically treated and untreated both portions of fibers were used to unsaturated polyester resin at 2, 5, 7, 10, 12 and 15 wt% fiber loading respectively. The composites were produced by hand lay-up technique and prepared composites were characterized by tensile and bending properties, Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and Thermo Gravimetric Analysis. Obtained all the results revealed best outcomes and significant enhancement in the properties of the composites with the optimum combination by 5 wt% treated cow hair fiber.
