•Selective B–H functionalization of o-carborane with differing functional groups has reviewed and detailed metal-mediated B–H activation has been elucidated.
Transition metal-mediated B–H ...functionalization of carboranes has drawn increasing interests during the last two decades. This review describes how to incorporate B–H functionalization into the derivation of half-sandwich transition metal complexes containing o-carborane dichalcogenolates. The detailed mechanistic elucidations for metal-induced versatile B–H functionalization are also reviewed. Examples of selective B–H activation, stepwise B–H functionalization, cobalt-mediated B–H functionalization as well as dimetal-mediated B–H activation of o-carborane are discussed.
Let $R$ be a ring and $S$ a multiplicative subset of $R$. An $R$-module $T$ is called $u$-$S$-torsion ($u$-always abbreviates uniformly) provided that $sT=0$ for some $s\in S$. The notion of ...$u$-$S$-exact sequences is also introduced from the viewpoint of uniformity. An $R$-module $F$ is called $u$-$S$-flat provided that the induced sequence $0\rightarrow A\otimes_RF\rightarrow B\otimes_RF\rightarrow C\otimes_RF\rightarrow 0$ is $u$-$S$-exact for any $u$-$S$-exact sequence $0\rightarrow A\rightarrow B\rightarrow C\rightarrow 0$. A ring $R$ is called $u$-$S$-von Neumann regular provided there exists an element $s\in S$ satisfying that for any $a\in R$ there exists $r\in R$ such that $sa=ra^2$. We obtain that a ring $R$ is a $u$-$S$-von Neumann regular ring if and only if any $R$-module is $u$-$S$-flat. Several properties of $u$-$S$-flat modules and $u$-$S$-von Neumann regular rings are obtained. KCI Citation Count: 0
Bioenergy derived from biomass provides a promising energy alternative and can reduce the greenhouse gas (GHG) emissions generated from fossil fuels. Biomass-based thermochemical conversion ...technologies have been acknowledged as apt options to convert bioresources into bioenergy; this bioenergy includes electricity, heat, and fuels/chemicals in solid, liquid, and gaseous phases. In this review, the techno-economic and life cycle assessment of these technologies (combustion, gasification, pyrolysis, liquefaction, carbonization, and co-firing) are summarized. Specific indicators (production costs in a techno-economic analysis, functional units and environmental impacts in a life cycle analysis) for different technologies were compared. Finally, gaps in research and future trends in biomass thermochemical conversion were identified. This review could be used to guide future research related to economic and environmental benefits of bioenergy.
A luminescent Eu-MOF, namely, Eu2(ppda)2(npdc)(H2O)·H2O (1) based on the mixed ligands 4-(pyridin-3-yloxy)-phthalic acid (H2ppda) and naphthalene-1,4-dicarboxylic acid (H2npdc) was synthesized under ...solvothermal conditions. Compound 1 was initially constructed from the 1D binuclear chains of Ln(npdc)2 and further connected by ppda2− ligands, forming a 2D layered structure. It is worth noting that compound 1 exhibited excellent fluorescence stability in the pH range of 2–13 in an aqueous solution. It was found that compound 1 could not only detect trivalent Fe3+, Cr3+ and Al3+ ions with high selectivity and recyclability but also serve as an excellent selective sensing material for PO43− ions among some anions. The detection of NACs demonstrated that compound 1 could also behave as a functional probe with high selectivity, sensitivity, and recyclability, and the detection limit of TNP was 2.97 × 10−6 M. Furthermore, the luminescent sensing mechanisms for different analytes were speculated.
Traditional nitrogen removal relies on the autotrophic nitrification and anaerobic denitrification process. In the system, autotrophic microorganisms achieve nitrification under aerobic condition and ...heterotrophic microorganisms complete the denitrification in anaerobic condition. As the two types of microorganisms have different tolerance on oxygen concentration, nitrification and denitrification are normally set in two compartments for high nitrogen removal. Therefore, large land occupying is required. In fact, there is a special type of microorganism called heterotrophic nitrification & aerobic denitrification microorganisms (HNADMs) which can oxidize ammonium nitrogen, and perform denitrification in the presence of oxygen. HNADMs have been reported in many environments. It was found that HNADMs could simultaneously achieve nitrification and denitrification. In addition, some HNADMs not only have the ability to remove nitrogen, but also have the ability to remove phosphorus. It suggests that HNADMs have great potential for pollution removal from wastewater. So far, individual work on single strain was carried out. Comprehensive summary of the HNADMs would provide a better picture for understanding and directing its application. In this paper, the studies related on HNADMs were reviewed. The nitrogen metabolism pathway of HNADMs was summarized. The impact of pH, DO, carbon source, and C/N on HNADMs growth and metabolism were discussed. In addition, the extracellular polymeric substance (EPS) production, quorum sensing (QS) secretion and P removal by HNADMs were displayed.
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•Heterotrophic nitrification and aerobic denitrification microorganism is reviewed.•Cultivation condition impact on the microorganism is discussed.•Nitrogen and phosphorus metabolism mechanism of the microorganism is proposed.•The EPS and QS of the microorganism are summarized.
Biomass fuels have long been accepted as useful renewable energy sources, especially in mitigating greenhouse gases (GHG), nitrogen oxides, and sulfur oxide emissions. Biomass fuel is carbon neutral ...and is usually low in both nitrogen and sulfur. For the past decade, various forms of biomass fuels have been co-combusted in existing coal-fired boilers and gas-fired power plants. Biomass is used as a supplemental fuel to substitute for up to 10% of the base fuel in most full commercial operations. There are several successful co-firing projects in many parts of the world, particularly in Europe and North America. However, despite remarkable commercial success in Europe, most of the biomass co-firing in North America is limited to demonstration levels. This review takes a detailed look at several aspects of biomass co-firing with a direct focus on North America. It also explores the benefits, such as the reduction of GHG emissions and its implications. This paper shows the results of our studies of the biomass resources available in North America that can be used in coal-fired boilers, their availability and transportation to the power plant, available co-firing levels and technologies, and various technological and environmental issues associated with biomass co-firing. Finally, the paper proffers solutions to help utility companies explore biomass co-firing as a transitional option towards a completely carbon-free power sector in North America.
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•Crude glycerol composition is dependent on trans-esterification process.•Impact of impurities on lipid production is dependent on their concentration and the strain ...tolerance.•Purified glycerol gives better results than crude glycerol.•Choice of glycerol purification technique is dependent on the final usage of glycerol.
Crude glycerol (CG) is a by-product formed during the trans-esterification reaction for biodiesel production. Although crude glycerol is considered a waste stream of the biodiesel industry, it can replace expensive carbon substrates required for lipid production by oleaginous micro-organisms. However, crude glycerol has several impurities, such as methanol, soap, triglycerides, fatty acids, salts and metals, which are created during the trans-esterification process and may affect the cellular metabolism involved in lipid synthesis. This review aims to critically present a variation in crude glycerol composition depending on trans-esterification process and impact of impurities present in the crude glycerol on the cell growth and lipid accumulation by oleaginous microbes. This study also draws comparison between purified and crude glycerol for lipid production. Several techniques for crude glycerol purification (chemical treatment, thermal treatment, membrane technology, ion-exchange chromatography and adsorption) have been presented and discussed with reference to cost and environmental effects.
Virus detection and analysis are of critical importance in biological fields and medicine. Surface‐enhanced Raman scattering (SERS) has shown great promise in small molecule and even single molecule ...detection, and can provide fingerprint signals of molecules. Despite the powerful detection capabilities of SERS, the size discrepancy between the SERS “hot spots” (generally, <10 nm) and viruses (usually, sub‐100 nm) yields poor detection reliability of viruses. Inspired by the concept of molecular imprinting, a volume‐enhanced Raman scattering (VERS) substrate composed of hollow nanocones at the bottom of microbowls (HNCMB) is developed. The hollow nanocones of the resulting VERS substrates serve a twofold purpose: 1) extending the region of Raman signal enhancement from the nanocone surface (e.g., surface “hot spots”) to the hollow area within the cone (e.g., volume “hot spots”)—a novel method of Raman signal enhancement, and 2) directing analyte such as viruses of a wide range of sizes to those VERS “hot spots” while simultaneously increasing the surface area contributing to SERS. Using HNCMB VERS substrates, greatly improved Raman signals of single viruses are demonstrated, an achievement with important implications in disease diagnostics and monitoring, biomedical fields, as well as in clinical treatment.
The size discrepency between surface‐enhanced Raman scattering (SERS) “hot spots” (generally, <10 nm) and viruses (usually, sub‐100 nm) makes reliable SERS detection of viruses very challenging. Inspired by the “molecular imprinting” method, a volume‐enhanced Raman scattering (VERS) technique capable of reliably detecting viruses is developed. The VERS technique has promsing applications in virus‐detection‐related biological and biomedical fields.
Carboranyl aldehydes are among the most useful synthons in derivatization of carboranes. However, compared to the utilization of carboranyl carboxylic acids in selective B–H bond functionalizations, ...the synthetic application of carboranyl aldehydes is limited due to the weakly coordinating nature of the aldehyde group. Herein, the direct arylation of o-carboranyl aldehydes has been developed via Pd-catalyzed cage B–H bond functionalization. With the help of glycine to generate a directing group (DG) in situ, a series of cage B(4,5)-diarylated- and B(4)-monoarylated-o-carboranyl aldehydes were obtained in good to excellent yields with high selectivity. A wide range of functional groups are tolerated. The aldehyde group in the B–H arylated products could be readily removed or transformed into o-carboranyl methanol. A plausible catalytic cycle for B–H arylation was proposed based on control experiments and stoichiometric reactions, including the isolation of a key bicyclic palladium complex.
In recent years, biodiesel production has grabbed significant attention due to the awareness of fossil fuel exhaustion. Microalgae become interested feedstock candidate of biodiesel production as ...they have rapid growth rate and high oil content compared to crops. Efforts have been made to increase microalgae productivity and oil content. To investigate the potential of microalgae for biodiesel production, it is essential to knowledge if the microalgae oil is qualified as possible feedstock oil. Moreover, what would be the energy and environmental effect of the production? And whether the production cost would be reasonable? This paper compared the properties of microalgae oil with traditional biodiesel production oils (vegetable oils); the properties of the biodiesel produced from microalgae and vegetable oils; reviewed the net energy ratio (energy output to energy input), GHG emissions, and economic analysis of the process of biodiesel production from microalgae; as well as discussed the factors which would influent the energy, environment, and cost of the process.
•The energy balance and GHG emission of microalgae for biodiesel production were discussed.•The factors impacting on the cost of microalgae biodiesel production were evaluated.•The strategies for reducing the cost of microalgae biodiesel production were proposed.
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