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

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

https://www.massey.ac.nz/~ychisti/Biodiesel.pdf

Biodiesel from microalgae.

Fast pyrolysis utilizes biomass to produce a product that is used both as an energy source and a feedstock for chemical production. Considerable efforts have been made to convert wood biomass to liquid fuels and chemicals since the oil crisis in mid-1970s. This review focuses on the recent developments in the wood pyrolysis and reports the characteristics of the resulting bio-oils, which are the main products of fast wood pyrolysis. Virtually any form of biomass can be considered for fast pyrolysis. Most work has been performed on wood, because of its consistency and comparability between tests. However, nearly 100 types of biomass have been tested, ranging from agricultural wastes such as straw, olive pits, and nut shells to energy crops such as miscanthus and sorghum. Forestry wastes such as bark and thinnings and other solid wastes, including sewage sludge and leather wastes, have also been studied. In this review, the main (although not exclusive) emphasis has been given to wood. The literature on woo...

Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review

Sustainable economic and industrial growth requires safe, sustainable resources of energy. For the future re-arrangement of a sustainable economy to biological raw materials, completely new approaches in research and development, production, and economy are necessary. The ‘first-generation’ biofuels appear unsustainable because of the potential stress that their production places on food commodities. For organic chemicals and materials these needs to follow a biorefinery model under environmentally sustainable conditions. Where these operate at present, their product range is largely limited to simple materials (i.e. cellulose, ethanol, and biofuels). Second generation biorefineries need to build on the need for sustainable chemical products through modern and proven green chemical technologies such as bioprocessing including pyrolysis, Fisher Tropsch, and other catalytic processes in order to make more complex molecules and materials on which a future sustainable society will be based. This review focus on cost effective technologies and the processes to convert biomass into useful liquid biofuels and bioproducts, with particular focus on some biorefinery concepts based on different feedstocks aiming at the integral utilization of these feedstocks for the production of value added chemicals.

http://staff.cimap.res.in/PublicationFiles/Renew_Sustain_Energ_Rev_14_578.pdf

Production of first and second generation biofuels: A comprehensive review

Industrial hemp hearts were subjected to three different extraction techniques-advanced extraction techniques like microwave and ultrasound extraction and primitive extraction technique like mechanical cold pressing in order to extract oils. The extraction yield varied between 41.0 ± 2.1% (w/w) and 54.0 ± 2.7% (w/w). Linoleic acid (LA) was reported to be the major polyunsaturated fatty acid (PUFA) followed by α−Linolenic acid (ALA). The ratio of LA to ALA was found to be close to 3:1 which is considered optimal for nutrition. The ratio of unsaturated fatty acids (UFA) to saturated fatty acids (SFA) was in the range of 6.7 to 9.1. Several minor compounds like ɣ-Sitosterol, stigmasterol, rhodoxanthin, carotene, and methyl cholate as well as antioxidants like β-Carotene and ɣ-Tocopherol have been identified in the oils. The physicochemical properties of the oils like the acid value, iodine value, and oxidative stability indicated that they have higher quality and that the level of unsaturation was very high. Furthermore, free radical scavenging activity of the oils revealed that the oils exhibited 94% of activity in the first 2 h. A perfect combination of unsaturated fatty acids and saturated fatty acids, an appropriate medley of different antioxidants not only qualifies hemp seed oil as an excellent source of nutrition but also as an important plant-based (vegetable) oil for the higher value nutraceutical and pharmaceutical industries. 

Valorization of hemp hearts oils by advanced extraction techniques and their comparative physicochemical characterization

Design of a renewable catalyst support derived from biomass with optimized textural features for fischer tropsch synthesis

In this report, the effects of pore diameter and structure of iron catalysts supported on carbon nanotubes (CNTs) on Fischer–Tropsch (FT) reaction rates and product selectivities are presented. Two types of CNTs with different average pore sizes (12 and 63 nm) were prepared. The CNTs were chosen in a way to have comparable surface areas so as to eliminate the effects of different surface areas. The iron catalysts (the narrow pore catalyst denoted Fe/np-CNT and wide pore catalyst denoted Fe/wp-CNT) were prepared using incipient wetness impregnation method and characterized by ICP, BET, XRD, TPR, SEM and TEM analyses. The TEM and XRD analysis showed that the iron oxide particles on the Fe/wp-CNT (17 nm) were larger than those on Fe/np-CNT sample (11 nm). TPR analyses of the catalysts showed that the degree of reduction of the Fe/np-CNT catalyst was 17% higher compared to that of the Fe/wp-CNT catalyst. For the FT reactions, it was found that the activity of the np-CNT catalyst (%CO conversion of 31) was much higher than that of the wpCNT catalyst (%CO conversion of 11). Also, the Fe/wp-CNT was more selective toward lighter hydrocarbons with a methane selectivity of 41% whereas, the methane selectivity of the np-CNT catalyst was 14%. It can be concluded that the deposition of the metal particles on the CNT with narrow pore size (in the range of larger than 10 nm) results in more active and selective catalyst due to higher degree of reduction and higher metal dispersion.

/pdf/iron-catalysts-supported-on-carbon-nanotubesfor-fischer-55lda39u4u.pdf

Iron Catalysts Supported On Carbon NanotubesFor Fischer–Tropsch Synthesis:Effect Of Pore Size

Production of Biolubricant Basestocks from Structurally Modified Plant Seed Oils and Their Derivatives

Disinfection by-products (DBPs) such as chloramines, haloacetic acids (HAAs) and trihalomethane (THMs) are frequently detected in water and wastewater systems and their excess concentration can be detrimental to human health and many industrial operations. Therefore, it is imperative to evaluate their formation and speciation and decay kinetics in subsequent disinfection processes like UV treatment. UV Photodecay of monochloramine (NH2Cl), dichloramine (NHCl2) and trichloramine (NCl3) and decay kinetics of these compounds were assessed at different environmental conditions in synthetic and brine solutions. Results showed that the chloramine fractions and speciation were strongly dependent on solution pH and chlorine to ammonia molar ratios. Among the chloramines, NCl3 showed the fastest depletion with a quantum yield of 2.16 mol E−1. Kinetics study showed that the rate of photodecay and quantum yield of NCl3 was 8-times and 13-times higher than NHCl2 and NH2Cl, respectively. Addition of natural organic matter lead to formation of DBPs like THMs and HAAs in reaction mixture and the concentration of DBPs was found to increase post UV irradiation. DBP concentrations in present study were well below the regulatory value provided by US Environmental Protection Agency (US EPA). This investigation provides a better understanding of chloramine decay kinetics and aids in identification of DBPs that can potentially discharged from treatment plants employing UV photolysis.

Ajay K. Dalai

Papers

Valorization of hemp hearts oils by advanced extraction techniques and their comparative physicochemical characterization

Design of a renewable catalyst support derived from biomass with optimized textural features for fischer tropsch synthesis

Iron Catalysts Supported On Carbon NanotubesFor Fischer–Tropsch Synthesis:Effect Of Pore Size

Production of Biolubricant Basestocks from Structurally Modified Plant Seed Oils and Their Derivatives

Photodecay of inorganic chloramines and disinfection by-products in synthetic and brine solution using UV irradiation