There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

As the fossil fuels are depleting day by day, there is a need to find out an alternative fuel to fulfill the energy demand of the world. Biodiesel is one of the best available resources that have come to the forefront recently. In this paper, a detailed review has been conducted to highlight different related aspects to biodiesel industry. These aspects include, biodiesel feedstocks, extraction and production methods, properties and qualities of biodiesel, problems and potential solutions of using vegetable oil, advantages and disadvantages of biodiesel, the economical viability and finally the future of biodiesel. The literature reviewed was selective and critical. Highly rated journals in scientific indexes were the preferred choice, although other non-indexed publications, such as Scientific Research and Essays or some internal reports from highly reputed organizations such as International Energy Agency (IEA), Energy Information Administration (EIA) and British Petroleum (BP) have also been cited. Based on the overview presented, it is clear that the search for beneficial biodiesel sources should focus on feedstocks that do not compete with food crops, do not lead to land-clearing and provide greenhouse-gas reductions. These feedstocks include non-edible oils such as Jatropha curcas and Calophyllum inophyllum , and more recently microalgae and genetically engineered plants such as poplar and switchgrass have emerged to be very promising feedstocks for biodiesel production. It has been found that feedstock alone represents more than 75% of the overall biodiesel production cost. Therefore, selecting the best feedstock is vital to ensure low production cost. It has also been found that the continuity in transesterification process is another choice to minimize the production cost. Biodiesel is currently not economically feasible, and more research and technological development are needed. Thus supporting policies are important to promote biodiesel research and make their prices competitive with other conventional sources of energy. Currently, biodiesel can be more effective if used as a complement to other energy sources.

A comprehensive review on biodiesel as an alternative energy resource and its characteristics

Über die Adsorption in Lösungen

World energy demand is expected to increase due to the expanding urbanization, better living standards and increasing population. At a time when society is becoming increasingly aware of the declining reserves of fossil fuels beside the environmental concerns, it has become apparent that biodiesel is destined to make a substantial contribution to the future energy demands of the domestic and industrial economies. There are different potential feedstocks for biodiesel production. Non-edible vegetable oils which are known as the second generation feedstocks can be considered as promising substitutions for traditional edible food crops for the production of biodiesel. The use of non-edible plant oils is very significant because of the tremendous demand for edible oils as food source. Moreover, edible oils’ feedstock costs are far expensive to be used as fuel. Therefore, production of biodiesel from non-edible oils is an effective way to overcome all the associated problems with edible oils. However, the potential of converting non-edible oil into biodiesel must be well examined. This is because physical and chemical properties of biodiesel produced from any feedstock must comply with the limits of ASTM and DIN EN specifications for biodiesel fuels. This paper introduces non-edible vegetable oils to be used as biodiesel feedstocks. Several aspects related to these feedstocks have been reviewed from various recent publications. These aspects include overview of non-edible oil resources, advantages of non-edible oils, problems in exploitation of non-edible oils, fatty acid composition profiles (FAC) of various non-edible oils, oil extraction techniques, technologies of biodiesel production from non-edible oils, biodiesel standards and characterization, properties and characteristic of non-edible biodiesel and engine performance and emission production. As a conclusion, it has been found that there is a huge chance to produce biodiesel from non-edible oil sources and therefore it can boost the future production of biodiesel.

Non-edible vegetable oils: A critical evaluation of oil extraction, fatty acid compositions, biodiesel production, characteristics, engine performance and emissions production

Fogging occurs when moisture condensation takes the form of accumulated droplets with diameters larger than 190 nm or half of the shortest wavelength (380 nm) of visible light. This problem may be effectively addressed by changing the affinity of a material’s surface for water, which can be accomplished via two approaches: i) the superhydrophilic approach, with a water contact angle (CA) less than 5°, and ii) the superhydrophobic approach, with a water CA greater than 150°, and extremely low CA hysteresis. To date, all techniques reported belong to the former category, as they are intended for applications in optical transparent coatings. A well-known example is the use of photocatalytic TiO2 nanoparticle coatings that become superhydrophilic under UV irradiation. Very recently, a capillary effect was skillfully adopted to achieve superhydrophilic properties by constructing 3D nanoporous structures from layer-by-layer assembled nanoparticles. The key to these two “wet”-style antifogging strategies is for micrometer-sized fog drops to rapidly spread into a uniform thin film, which can prevent light scattering and reflection from nucleated droplets. Optical transparency is not an intrinsic property of antifogging coatings even though recently developed antifogging coatings are almost transparent, and the transparency could be achieved by further tuning the nanoparticle size and film thickness. To our knowledge, the antifogging coatings may also be applied to many fields that do not require optical transparency, including, for example, paints for inhibiting swelling and peeling issues and metal surfaces for preventing corrosion. These types of issues, which are caused by adsorption of moisture, are hard to solve by the superhydrophilic approach because of its inherently “wet” nature. Thus, a “dry”-style antifogging strategy, which consists of a novel superhydrophobic technique that can prevent moisture or microscale fog drops from nucleating on a surface, is desired. Recent bionic researches have revealed that the self-cleaning ability of lotus leaves and the striking ability of a water-strider’s legs to walk on water can be attributed to the ideal superhydrophobicity of their surfaces, induced by special microand nanostructures. To date, the biomimetic fabrication of superhydrophobic microand/or nanostructures has attracted considerable interest, and these types of materials can be used for such applications as self-cleaning coatings and stain-resistant textiles. Although a superhydrophobic technique inspired by lotus leaves is expected to be able to solve such fogging problems because the water droplets can not remain on the surface, there are no reports of such antifogging coatings. Very recently, researchers from General Motors have reported that the surfaces of lotus leaves become wet with moisture because the size of the fog drops are at the microscale—so small that they can be easily trapped in the interspaces among micropapillae. Thus, lotuslike surface microstructures are unsuitable for superhydrophobic antifogging coatings, and a new inspiration from nature is desired for solving this problem. In this communication, we report a novel, biological, superhydrophobic antifogging strategy. It was found that the compound eyes of the mosquito C. pipiens possess ideal superhydrophobic properties that provide an effective protective mechanism for maintaining clear vision in a humid habitat. Our research indicates that this unique property is attributed to the smart design of elaborate microand nanostructures: hexagonally non-close-packed (ncp) nipples at the nanoscale prevent microscale fog drops from condensing on the ommatidia surface, and hexagonally close-packed (hcp) ommatidia at the microscale could efficiently prevent fog drops from being trapped in the voids between the ommatidia. We also fabricated artificial compound eyes by using soft lithography and investigated the effects of microand nanostructures on the surface hydrophobicity. These findings could be used to develop novel superhydrophobic antifogging coatings in the near future. It is known that mosquitoes possess excellent vision, which they exploit to locate various resources such as mates, hosts, and resting sites in a watery and dim habitat. To better understand such remarkable abilities, we first investigated the interaction between moisture and the eye surface. An ultrasonic humidifier was used to regulate the relative humidity of the atmosphere and mimic a mist composed of numerous tiny water droplets with diameters less than 10 lm. As the fog was C O M M U N IC A IO N

The dry-style antifogging properties of mosquito compound eyes and artificial analogues prepared by soft lithography: a superhydrophobic state with high adhesive force

Photocatalytic processes are an environmentally friendly technology for treatment of persistent organic pollutants. However, the majority of current photocatalysts cannot utilize sunlight sufficiently to realize fast decomposition of organic pollutants. In this research, a silver oxide nanoparticle aggregation with superb photocatalytic performance under artificial light source and sunlight was prepared and characterized. The results showed that methyl orange (MO) was decomposed completely in 120 s under irradiation of artificial visible light, artificial ultraviolet light, and sunlight, and in 40 min under near-infrared (NIR) light. The superb photocatalytic performance of as-prepared silver oxide remained almost constant after reuse or exposure under sunlight. It was confirmed that the co-working effect of photogenerated hole and ozone anion radicals did play an important role in the process of MO photodegradation with the existence of Ag2O. The narrow band gap of Ag2O, less than 1.3 eV, resulted in the...

Silver Oxide as Superb and Stable Photocatalyst under Visible and Near-Infrared Light Irradiation and Its Photocatalytic Mechanism

Properties of Tung oil biodiesel and its blends with 0# diesel.

Cross-linked poly(vinylbenzyl chloride) (PVBC) microspheres tethered with polymer brushes containing quaternary ammonium ions were developed as an anionic adsorbent for the efficient removal of phenol from aqueous solutions. The terminal alkyl chlorine groups on the PVBC microspheres served as anchor sites for the grafting of poly(dimethylaminopropyl methacrylamide) (PDMAPMA) brushes via surface-initiated atom transfer radical polymerization (ATRP). The pendent tertiary amino groups of the PDMAPMA chains were converted into quaternary ammonium ions by N-alkylation reaction to produce anionic adsorption functionality. Success for each reaction step was ascertained by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Batch adsorption results demonstrated that solution pH values in a wide range of 3.0–11.0 had no evident effect on phenol adsorption by the quaternized PDMAPMA-grafted PVBC (i.e., PVBC-g-QPDMAPMA) microspheres, and that the adsorption capacity of the microspheres increased with the grafting density of the quaternized PDMAPMA brushes within 6 h. The so-synthesized anionic adsorbents had a rapid pseudo-first-order-adsorption kinetic (equilibrium achieved within 60 min), and the Langmuir model-fitted maximum adsorption capacity of phenol was approximately 2.23 mmol g−1 at pH 6.5 with an initial concentration of 1.05–5.31 mmol L−1 (i.e., 100–500 mg L−1). The calculated thermodynamic parameters revealed an exothermic and spontaneous adsorption process of phenol onto the quaternized QPDMAPMA-grafted microspheres. Desorption and adsorption cycle experiments demonstrated that the anionic adsorbents loaded with phenol were found to be readily regenerated in a 0.1 mol L−1 NaOH solution, and that the adsorption capacity decreased by less than 10% upon five cycles.

Purification of phenol-contaminated water by adsorption with quaternized poly(dimethylaminopropyl methacrylamide)-grafted PVBC microspheres

Ag2S has only rarely been investigated as a photocatalyst on its own, although it has been widely used as an important component of composite photocatalysts. We synthesized Ag2S by a facile ion-exchange method at room temperature and used it directly as an effective photocatalyst. Our results confirmed the excellent performance of Ag2S in completely photodegrading methyl orange within 30 min under irradiation with visible light and within 70 min under irradiation with near-infrared light. This good performance is ascribed to the narrow band gap (1.078 eV) of Ag2S and the lower recombination efficiency of the photogenerated electron–hole pairs of Ag2S in the photocatalytic process. The active species in the photo-oxidation process was identified as anioic ozone radicals. This simple preparation method and high photocatalytic performance increases the possible future applications of Ag2S.

Photocatalytic performance of Ag2S under irradiation with visible and near-infrared light and its mechanism of degradation

Engineering the surface structure and constructing a suitable internal conductive network is essential for the electron transfer rate and the active material utilization efficiency of an electrode. Here, high-porosity carbon nanotube (CNT) arrays grown on graphite foam (GNF) are synthesized via the self-sacrificial ZnO nanorod template. Then three-dimensional Co-doped Ni3S2 nanostructures (Co–Ni3S2) are coated on the CNT surface via a simple hydrothermal process. The CNTs/GNF hybrid with a hierarchical conductive network exhibits good electrical conductivity, while the tectorum-like Co–Ni3S2 nanosheet structure may facilitate both the ion and electron transfer in the redox process. Therefore, the Co–Ni3S2@CNTs/GNF composite shows a highest specific capacitance of 4.1 F cm−2, good rate performance (57.8% capacitance retention from 1 to 40 mA cm−2) and cycling stability (89.8% capacitance retention after 1000 cycles). Moreover, the Co–Ni3S2@CNT/GNF electrode also reveals good hydrogen evolution reaction activity in alkaline solution (an overpotential of 155 mV at 10 mA cm−2).

Co-doped Ni3S2@CNT arrays anchored on graphite foam with a hierarchical conductive network for high-performance supercapacitors and hydrogen evolution electrodes

Wei Jiang

Papers

Silver Oxide as Superb and Stable Photocatalyst under Visible and Near-Infrared Light Irradiation and Its Photocatalytic Mechanism

Properties of Tung oil biodiesel and its blends with 0# diesel.

Purification of phenol-contaminated water by adsorption with quaternized poly(dimethylaminopropyl methacrylamide)-grafted PVBC microspheres

Photocatalytic performance of Ag2S under irradiation with visible and near-infrared light and its mechanism of degradation

Co-doped Ni3S2@CNT arrays anchored on graphite foam with a hierarchical conductive network for high-performance supercapacitors and hydrogen evolution electrodes