scholarly journals An emerging platform from renewable resources: selection guidelines for human exposure of furfural-related compounds

2014 ◽  
Vol 3 (5) ◽  
pp. 311-314 ◽  
Author(s):  
R. F. M. Frade ◽  
J. A. S. Coelho ◽  
S. P. Simeonov ◽  
C. A. M. Afonso

Toxicity of hydroxymethylfurfural and 21 derivatives was assessed. Important guidelines for selection of more human friendly building blocks were obtained.

1982 ◽  
Vol 35 (7) ◽  
pp. 1391 ◽  
Author(s):  
AJ Liepa

N,N-Dialkyl derivatives of 3-aminoisoquinoline have been prepared by reaction of nitriles with various arylacetic acid tertiary amides in the presence of phosphoryl chloride. The synthesis has been extended to include a benzoisoquinoline and annulated isoquinolines by the selection of appropriate amide and nitrile precursors.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Aleksey E. Kuznetsov

Abstract Various (metallo)porphyrins and related compounds have been intensively investigated by different research groups due to their extremely important role in living organisms along with their versatile applications in technology. The design of novel porphyrinoids by core-modification, or substitution of pyrrole nitrogens, with the elements of other groups of the Periodic Table has been considered as a highly promising methodology for tuning structures and properties of porphyrinoids and thus opening new possible applications for them. Much effort has been given to the modifications of the porphyrin core with elements of the main groups, namely O, S, Se (chalcogens), and the heavier congener of nitrogen, phosphorus. In general, the porphyrin core modification by replacing nitrogens with heteroatoms is a promising and effective strategy for obtaining new compounds with unusual structures and properties (optical, electrochemical, coordinating, etc.) as well as reactivity. These novel molecules can also be employed as promising building or construction blocks in various applications in the nanotechnology area.


Author(s):  
Leezna Saleem ◽  
Imran Ahmad Siddiqui ◽  
Intikhab Ulfat

Pakistan is the world's sixth most populous country, currently facing the worst energy crisis. Although rich in renewable resources, Pakistan's energy system relies mainly on fossil fuels and imported energy for its energy needs. This study aims to use an analytical hierarchy pro-cess to prioritize six renewable technologies for Pakistan, with four criteria and thirteen subcriteria. The results indicate that solar power is particularly well suited for Pakistan, as it gained 42% priority weightage in the final aggregation. Wind energy is ranked second with a priority weight of 24%, followed by hydro 13%, biomass 9%, ocean 8% and geothermal en-ergy 3%. Solar and wind energies accounted for nearly 66% of the total weightage. This result highlighted the significance of economic criteria for the selection of renewable technologies in Pakistan, with around 43% priority weightage. Environmental criteria gained 19% whereas socio-political criteria registered 14% and technical criteria 23% priority weightage. During the potential assessment of the research, it was concluded that although renewable resource development has not been allocated sufficient attention in Pakistan in the past, if the correct decisions are taken regarding the exploitation of these resources, this can remedy the country's hazardous dependence on fossil fuel and imported energy.


1995 ◽  
Vol 31 (1) ◽  
pp. 237-247 ◽  
Author(s):  
Dick B. Janssen ◽  
Wim de Koning

The possibility of obtaining microbial cultures for the degradation of halogenated aliphatic hydrocarbons is mainly determined by the diversity and activity of catabolic enzymes that exist in nature. If a suitable organism is available, applications for the treatment of different waste streams can be developed. The relation between the kinetic parameters of the key enzymes and the properties of the organisms relevant for such applications is discussed, both for growth supporting and cometabolic degradation. When growth on a chlorinated aliphatic compound is possible, development of a biological remediation process is likely to be relatively easy. This is illustrated with the degradation of 1,2-dichloroethane, a synthetic compound that can be mineralized by specific cultures. Closely related compounds may be recalcitrant, which can be understood from an examination of the degradative pathways. The development of biological treatment processes based on cometabolic degradation is more demanding because selection of the proper organisms and maintaining them in the process are not straightforward. The range of compounds that can be degraded cometabolically is significantly larger. The potential of obtaining improved degradation by genetic adaptation and the use of biofilms is discussed.


2019 ◽  
Vol 74 (3-4) ◽  
pp. 91-100 ◽  
Author(s):  
Wissam Farhat ◽  
Arne Stamm ◽  
Maxime Robert-Monpate ◽  
Antonino Biundo ◽  
Per-Olof Syrén

Abstract Accelerated generation of bio-based materials is vital to replace current synthetic polymers obtained from petroleum with more sustainable options. However, many building blocks available from renewable resources mainly contain unreactive carbon-carbon bonds, which obstructs their efficient polymerization. Herein, we highlight the potential of applying biocatalysis to afford tailored functionalization of the inert carbocyclic core of multicyclic terpenes toward advanced materials. As a showcase, we unlock the inherent monomer reactivity of norcamphor, a bicyclic ketone used as a monoterpene model system in this study, to afford polyesters with unprecedented backbones. The efficiencies of the chemical and enzymatic Baeyer–Villiger transformation in generating key lactone intermediates are compared. The concepts discussed herein are widely applicable for the valorization of terpenes and other cyclic building blocks using chemoenzymatic strategies.


Author(s):  
L. Siddharth ◽  
Prabir Sarkar

Design changes are necessary to sustain the product against competition. Due to technical, social, and financial constraints, an organization can only implement a few of many change alternatives. Hence, a wise selection of a change alternative is fundamentally influential for the growth of the organization. Organizations lack knowledge bases to effectively capture rationale for a design change; i.e., identifying the potential effects a design change. In this paper, (1) we propose a knowledge base called multiple-domain matrix that comprises the relationships among different parameters that are building blocks of a product and its manufacturing system. (2) Using the indirect change propagation method, we capture these relationships to identify the potential effects of a design change. (3) We propose a cost-based metric called change propagation impact (CPI) to quantify the effects that are captured from the multiple-domain matrix. These individual pieces of work are integrated into a web-based tool called Vatram. The tool is deployed in a design environment to evaluate its usefulness and usability.


2018 ◽  
Vol 10 (2) ◽  
pp. 84-108
Author(s):  
Philipp Mittnik

*Full text is in GermanNational Socialism in German, Austrian and English Secondary School Textbooks (1980–2017)English AbstractThis article analyzes a selection of German, Austrian and English textbooks dealing with National Socialism. By adopting Waltraud Schreiber’s methodology of categorial textbook analysis, the article presents the surface structure and building blocks as a basis for further analysis. The occurrence (or absence) of the pedagogical historical principle of multiperspectivity is examined with reference to the example of sections concerning “Youth in National Socialism.” Subsequently, the study explores the role of multiperspectivity in the construction of critical historical consciousness. This is followed by a deconstruction of the image of women presented in the textbooks, with particular emphasis on simplifications.German AbstractDie Analyse von Schulbüchern aus Deutschland, Österreich und England zum Themenbereich Nationalsozialismus stehen im Zentrum dieses Artikels. Als Methodologie wird die kategoriale Schulbuchanalyse nach Waltraud Schreiber angewandt. Die Erarbeitung der Oberflächenstruktur und der Bausteine werden als Grundlage für weitere Analyseschritte präsentiert. Das (Nicht-) Vorkommen des bedeutenden geschichtsdidaktischen Prinzips der Multiperspektivität wird am Beispiel des Abschnittes „Jugend im Nationalsozialismus“ beschrieben. Multiperspektivität und deren Bedeutung für den Aufbau eines kritischen Geschichtsbewusstseins wird in einem weiteren Schritt hervorgehoben. Abschließend wird das in den Schulbüchern präsentierte Frauenbild dekonstruiert und auf die problematischen Vereinfachungen hingewiesen.


Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 895
Author(s):  
Aitziber Iriondo ◽  
Ion Agirre ◽  
Nerea Viar ◽  
Jesús Requies

The depletion of fossil resources in the near future and the need to decrease greenhouse gas emissions lead to the investigation of using alternative renewable resources as raw materials. One of the most promising options is the conversion of lignocellulosic biomass (like forestry residues) into bioenergy, biofuels and biochemicals. Among these products, the production of intermediate biochemicals has become an important goal since the petrochemical industry needs to find sustainable alternatives. In this way, the chemical industry competitiveness could be improved as bioproducts have a great potential market. Thus, the main objective of this review is to describe the production processes under study (reaction conditions, type of catalysts, solvents, etc.) of some promising intermediate biochemicals, such as; alcohols (1,2,6-hexanetriol, 1,6-hexanetriol and pentanediols (1,2 and 1,5-pentanediol)), maleic anhydride and 5-alkoxymethylfuran. These compounds can be produced using 5-hydroxymethylfurfural and/or furfural, which they both are considered one of the main biomass derived building blocks.


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