scholarly journals Highly selective generation of vanillin by anodic degradation of lignin: a combined approach of electrochemistry and product isolation by adsorption

2015 ◽  
Vol 11 ◽  
pp. 473-480 ◽  
Author(s):  
Dominik Schmitt ◽  
Carolin Regenbrecht ◽  
Marius Hartmer ◽  
Florian Stecker ◽  
Siegfried R Waldvogel
Keyword(s):  
Driving Forces ◽  
Oxidative Degradation ◽  
Alkaline Electrolyte ◽  
Combined Approach ◽  
Technical Application ◽  
Basic Anion Exchange Resin ◽  
Set Up ◽  
Aroma Chemical ◽  
Exchange Resins ◽  
Work Up

The oxidative degradation of lignin into a variety of valuable products has been under investigation since the first half of the last century. Especially, the chance to claim this cheap, abundant and renewable source for the production of the important aroma chemical vanillin (1) was one of the major driving forces of lignin research. So far most of the developed methods fail in technical application since no viable concept for work-up is included. This work represents a combined approach of electrochemical conversion of Kraft lignin and product recovery by adsorption on a strongly basic anion exchange resin. Electrolysis conditions are optimized regarding reaction temperatures below 100 °C allowing operation of aqueous electrolytes in simple experimental set-up. Employing ion exchange resins gives rise to a selective removal of low molecular weight phenols from the strongly alkaline electrolyte without acidification and precipitation of remaining lignin. The latter represents a significant advantage compared with conventional work-up protocols of lignin solutions.

scholarly journals Heterogeneous acidic catalysts for the tetrahydropyranylation of alcohols and phenols in green ethereal solvents

2018 ◽  
Vol 14 ◽  
pp. 1655-1659 ◽  
Author(s):  
Ugo Azzena ◽  
Massimo Carraro ◽  
Gloria Modugno ◽  
Luisa Pisano ◽  
Luigi Urtis
Keyword(s):  
Organic Chemistry ◽  
Heterogeneous Catalysis ◽  
Important Class ◽  
Green Solvents ◽  
Reaction Products ◽  
Reaction Conditions ◽  
One Pot ◽  
Acidic Catalysts ◽  
Set Up ◽  
Work Up

The application of heterogeneous catalysis and green solvents to the set up of widely employed reactions is a challenge in contemporary organic chemistry. We applied such an approach to the synthesis and further conversion of tetrahydropyranyl ethers, an important class of compounds widely employed in multistep syntheses. Several alcohols and phenols were almost quantitatively converted into the corresponding tetrahydropyranyl ethers in cyclopentyl methyl ether or 2-methyltetrahydrofuran employing NH4HSO4 supported on SiO2 as a recyclable acidic catalyst. Easy work up of the reaction mixtures and the versatility of the solvents allowed further conversion of the reaction products under one-pot reaction conditions.

scholarly journals Procedure to reduce sulphite in wine with anion-exchange resin

2012 ◽  
Vol 60 (8) ◽  
pp. 79-86
Author(s):  
Miroslav Horák ◽  
Pavel Híc ◽  
Eva Tománková ◽  
Josef Balík
Keyword(s):  
Tartaric Acid ◽  
Anion Exchange ◽  
Malic Acid ◽  
Anion Exchanger ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Sodium Bicarbonate Solution ◽  
Basic Anion Exchange Resin ◽  
Basic Anion ◽  
Exchange Resins

The aim of this experiment was to eliminate SO2 ions present in wine using the anion-exchanger resins. To compare the effectiveness, 2 following strongly basic anion-exchange resin were used. When activated, the sodium bicarbonate solution (activation solution I) is used to prevent parallel reduction of sulphites, tartates and malates, so the anion-exchange resins were activated in two-step activation. In the second step, it was immersed into a mixture of malic acid and tartaric acid (1:1). After the application of anex into wine, the content of total SO2 was reduced to 97–201 mg.L−1 (depending on the amount of anex added into the wine sample). According to our expectations, the variants with anion-exchange resin activated only with bicarbonate solution, the tartrates and malates were significantly reduced. If the anion-exchange resin was activated with a two-steps activation, the tartaric acid and malic acid were reduced in the range of ± 0.13 g.L−1. This phenomenon was strongly reflected at the anion-exchanger Aqua Osmotic 02. The changes in antioxidant content were not affected by the type of anion-exchange resin, the method of activation, or an amount of used anion-exchanger. The color parameters of wine, expressed by the L * a * b *, were not significantly affected by the effects of anion-exchange resin use.

Alfred Chaston Chapman, 1869-1932

1933 ◽  
Vol 1 (2) ◽  
pp. 146-148
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Early Education ◽  
Fish Oils ◽  
Early Age ◽  
Grammar School ◽  
Technical Application ◽  
Organic Chemist ◽  
Chemical Knowledge ◽  
Set Up

On the 17th of October, 1932, Alfred Chaston Chapman died at his residence in Hampstead. Born in 1869 he received his early education at Leeds Grammar School, and then, on his father coming to London, he began his chemical training at University College under the instruction of Professors Williamson and Charles Graham. Through the inspiration of Graham he became interested in the fermentation industries, and at a very early age set up in practice as an analytical and consulting chemist, primarily in relation to brewing. On this subject he became the chief authority in this country by his indefatigable study of it in its scientific aspects. Although immersed in the work of a large consulting practice, it was the advancement of chemical knowledge that really held Chapman, so that up to the last researches in pure chemistry came from his laboratory in Duke Street, Aldgate. During the early days of his career he published papers (1895) on the essential oil of hops, a subject to which he returned later.* An excellent organic chemist, he segregated from the oil of hops a number of constituents, indicating the part played by each in the technical application of the oil. Humulene, a sesquiterpene, which he so named after isolating it, is one of these, but he also recovered from hop oil other hydrocarbons, alcohols and ketones, several of them new. Investigations on other essential oils were then published, followed by his work on fish oils.

Thermal Treatment of Historical Radioactive Solid and Liquid Waste Into the CILVA Incinerator

2007 ◽  
Author(s):  
Jan Deckers ◽  
Ludo Mols
Keyword(s):  
Radioactive Waste ◽  
Solid Waste ◽  
Mission Statement ◽  
Organic Liquid ◽  
Liquid Waste ◽  
Volume Reduction ◽  
Air Pollution Control ◽  
Nuclear Facilities ◽  
Set Up ◽  
Exchange Resins

Since the very beginning of the nuclear activities in Belgium, the incineration of radioactive waste was chosen as a suitable technique for achieving an optimal volume reduction of the produced waste quantities. Based on the 35 years experience gained by the operation of the old incinerator, a new industrial incineration plant started nuclear operation in May 1995, as a part of the Belgian Centralized Treatment/Conditioning Facility named CILVA. Up to the end of 2006, the CILVA incinerator has burnt 1660 tonne of solid waste and 419 tonne of liquid waste. This paper describes the type and allowable radioactivity of the waste, the incineration process, heat recovery and the air pollution control devices. Special attention is given to the treatment of several hundreds of tonne historical waste from former reprocessing activities such as alpha suspected solid waste, aqueous and organic liquid waste and spent ion exchange resins. The capacity, volume reduction, chemical and radiological emissions are also evaluated. BELGOPROCESS, a company set up in 1984 at Dessel (Belgium) where a number of nuclear facilities were already installed is specialized in the processing of radioactive waste. It is a subsidiary of ONDRAF/NIRAS, the Belgian Nuclear Waste Management Agency. According to its mission statement, the activities of BELGOPROCESS focus on three areas: treatment, conditioning and interim storage of radioactive waste; decommissioning of shut-down nuclear facilities and cleaning of contaminated buildings and land; operating of storage sites for conditioned radioactive waste.

scholarly journals Smell—Adding a New Dimension to Urinalysis

Biosensors ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 48
Author(s):  
Eva H. Visser ◽  
Daan J. C. Berkhout ◽  
Jiwanjot Singh ◽  
Annemieke Vermeulen ◽  
Niloufar Ashtiani ◽  
...  
Keyword(s):  
High Risk ◽  
Bacterial Growth ◽  
Pediatric Population ◽  
Potential Biomarker ◽  
Volatile Organic ◽  
Dipstick Urinalysis ◽  
Set Up ◽  
Diagnostic Work ◽  
Tract Infections ◽  
Work Up

Background: Urinary tract infections (UTI) are among the most common infections in children. The primary tool to detect UTI is dipstick urinalysis; however, this has limited sensitivity and specificity. Therefore, urine culture has to be performed to confirm a UTI. Urinary volatile organic compounds (VOC) may serve as potential biomarker for diagnosing UTI. Previous studies on urinary VOCs focused on detection of UTI in a general population; therefore, this proof-of-principle study was set up in a clinical high-risk pediatric population. Methods: This study was performed at a tertiary nephro-urological clinic. Patients included were 0–18 years, clinically suspected of a UTI, and had abnormal urinalysis. Urine samples were divided into four groups, i.e., urine without bacterial growth, contamination, colonization, and UTI. VOC analysis was performed using an electronic nose (eNose) (Cyranose 320®) and VOC profiles of subgroups were compared. Results: Urinary VOC analysis discriminated between UTI and non-UTI samples (AUC 0.70; p = 0.048; sensitivity 0.67, specificity 0.70). The diagnostic accuracy of VOCs improved when comparing urine without bacterial growth versus with UTI (AUC 0.80; p = 0.009, sensitivity 0.79, specificity 0.75). Conclusions: In an intention-to-diagnose high-risk pediatric population, UTI could be discriminated from non-UTI by VOC profiling, using an eNose. Since eNose can be used as bed-side test, these results suggest that urinary VOC analysis may serve as an adjuvant in the diagnostic work-up of UTI in children.

Navigated Deep Brain Stimulation Surgery: Evaluating the Combined Use of a Frame-Based Stereotactic System and a Navigation System

2020 ◽  
pp. 1-7
Author(s):  
Marie T. Krüger ◽  
Bálint Várkuti ◽  
Jörg Achinger ◽  
Volker A. Coenen ◽  
Thomas Prokop ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Navigation System ◽  
Phantom Study ◽  
Teaching Tool ◽  
Navigation Systems ◽  
Combined Approach ◽  
Set Up ◽  
Potential Use ◽  
Deep Brain

Deep brain stimulation (DBS) is a complex surgical procedure that requires detailed anatomical knowledge. In many fields of neurosurgery navigation systems are used to display anatomical structures during an operation to aid performing these surgeries. In frame-based DBS, the advantage of visualization has not yet been evaluated during the procedure itself. In this study, we added live visualization to a frame-based DBS system, using a standard navigation system and investigated its accuracy and potential use in DBS surgery. As a first step, a phantom study was conducted to investigate the accuracy of the navigation system in conjunction with a frame-based approach. As a second step, 5 DBS surgeries were performed with this combined approach. Afterwards, 3 neurosurgeons and 2 neurologists with different levels of experience evaluated the potential use of the system with a questionnaire. Moreover, the additional personnel, costs and required set up time were noted and compared to 5 consecutive standard procedures. In the phantom study, the navigation system showed an inaccuracy of 2.1 mm (mean SD 0.69 mm). In the questionnaire, a mean of 9.4/10 points was awarded for the use of the combined approach as a teaching tool, a mean of 8.4/10 for its advantage in creating a 3-dimensional (3-D) map and a mean of 8/10 points for facilitating group discussions. Especially neurosurgeons and neurologists in training found it useful to better interpret clinical results and side effects (mean 9/10 points) and neurosurgeons appreciated its use to better interpret microelectrode recordings (mean 9/10 points). A mean of 6/10 points was awarded when asked if the benefits were worth the additional efforts. Initially 2 persons, then one additional person was required to set up the system with no relevant added time or costs. Using a navigation system for live visualization during frame-based DBS surgery can improve the understanding of the complex 3-D anatomy and many aspects of the procedure itself. For now, we would regard it as an excellent teaching tool rather than a necessity to perform DBS surgeries.

scholarly journals Study on Polishing Method Using Magnetic Levitation Tool in Superconductive-Assisted Machining

2021 ◽  
Vol 15 (2) ◽  
pp. 234-242
Author(s):  
Hidetaka Nakashima ◽  
◽  
Tatsuya Nakasaki ◽  
Tatsuhiro Tanaka ◽  
Yushi Kinoshita ◽  
...  
Keyword(s):  
Driving Forces ◽  
Magnetic Levitation ◽  
Initial Position ◽  
Metal Plate ◽  
Attractive Force ◽  
Average Roughness ◽  
Arithmetic Average ◽  
Pinning Effect ◽  
Tool Interference ◽  
Set Up

Superconductive-assisted machining (SUAM) is a polishing method that employs a magnetic levitation tool, which is based on a superconductive phenomenon called the pinning effect. Since the tool magnetically levitates, the issue of tool interference is eliminated. In this study, in order to set up the polishing conditions of the magnetic levitation tool, we evaluated the relation between the flux density distribution relative to the tool position and the holding force acting on the magnetic levitation tool to maintain its initial position, set by field cooling by the superconducting bulk. For the holding force, we measured the attractive, repulsive, restoring, and driving forces. We found that the greater the holding force, the smaller the initial distance between the superconducting bulk and the magnetic levitation tool. The attractive force was found to peak when the levitated tool was displaced 6 mm from an initial position of 9 mm from the bulk, and it became only the self-weight of the magnetic levitation tool at displacements of 30 mm and above, where the pinning effect broke down. We then evaluated the polishing characteristics for SUS304 and A1100P at a tool displacement that results in the maximum attractive force. In the polishing experiment, we employed a water-based diamond slurry because the temperature of the workpiece was close to room temperature. We found that it was possible to polish SUS304 and A1100P while avoiding the effects of magnetization due to the polishing pressure or induced currents that accompany the rotation of the metal plate. The arithmetic average roughness, Ra, of A1100P was relatively high due to the effect of scratches, while that of SUS304 improved from 92 nm before polishing to 55 nm after polishing when polished with grains with a diameter of 1 μm.

Decolourization of refinery sugar liquors with low environmental impact — a semi industrial trial

2015 ◽  
pp. 36-40
Author(s):  
Luis Bento ◽  
António Alberto Stuchi
Keyword(s):  
Transformation Process ◽  
High Quality ◽  
Industrial Installation ◽  
Anion Exchange Resins ◽  
Start Up ◽  
In Series ◽  
Sugar Plant ◽  
Set Up ◽  
Constant Quality ◽  
Exchange Resins

Amorphous sugar is a white powder sugar with 99% purity, a colour lower than 50 IU and a water content of 0.30%. This sugar is produced through a transformation process, that is, all sucrose contained in fine liquor is incorporated in the final product. There is no residual syrup formation. In consequence, fine liquor must have a high quality, especially with very low colour. Brazil company Raizen produce this kind of sugar, mainly, in two refineries: Barra Bonita and Tarumã. In these refineries, clarified liquor is decolourized with anionic resins, two steps in series. In order to improve the decolourization process in these refineries and obtain a better product with constant quality and, at the same time, to decrease the regeneration effluents and reduce the chemical costs, it was agreed to install a pilot plant in Tarumã refinery to try a combination of anion exchange resins and granular activated carbon, both regenerated chemically. The process was designed in order to send all coloured effluents, from regenerations, into the ethanol distillery. A semi-industrial installation with four 6 m3 columns was set up in the old liquid sugar plant. After start up and initial tests, the installation runs for a first trial. In this paper the decolourization process and the results of the tests are presented.

Learning for and about sustainability in higher education – a regional perspective based on experiences from the Baltic and the Mediterranean

2017 ◽  
Vol 18 (6) ◽  
pp. 877-893 ◽  
Author(s):  
Michael Scoullos ◽  
Vicky Malotidi ◽  
Paula Lindroos ◽  
Sinikka Suomalainen
Keyword(s):  
Higher Education ◽  
Sustainable Development ◽  
Driving Forces ◽  
National Level ◽  
Lessons Learned ◽  
Content Type ◽  
Mediterranean Regions ◽  
The Mediterranean ◽  
Set Up ◽  
The Baltic

Purpose The purpose of the paper is to present and compare collective efforts of higher education institutions working through regional networks in introducing and promoting education for sustainable development (ESD) and environmental education (EE) in two most significant EU boarder regions. Efforts to support EE/ESD in higher education are usually undertaken at individual universities and, in some cases, at national level, still remaining very fragmented; therefore, the examples of University networks in the Baltic and the Mediterranean regions are of particular interest and importance. Both regions have regional conventions, protocols and strategies for the relevant seas, bringing EU and neighbouring countries of the regions together for the protection of the environment and the promotion of sustainable development (SD) within which EE and ESD are embedded. Design/methodology/approach This paper presents the driving forces for the establishment, evolution and design of relevant activities of these two networks, making also a few inter-comparisons and recommendations for further improvements. Findings Both regions, the Baltic and the Mediterranean, have multiple needs and high potential for more efficient linking of SD with higher education. Early enough it was realised that regional networking could stimulate countries and universities towards this task. Two networks were set up: the Baltic University Programme (starting already in 1991) and the Mediterranean Universities Network for SD focusing on ESD (starting in 2007). The paper reviews main activities of the networks together with lessons learned and gives directions for their future operations. Originality/value This paper is one of the rare case studies related to higher education networking on ESD and demonstrates how networking on ESD, apart from enhancing professional development, supports also SD and promotes cooperation and peace in regions that have a history of frequently turbulent relationships.

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