jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Youssef El Ouardi
Source: SPIRE - Sciences Po Institutional REpository (preprint, 2020-11-10)
Field: Chemistry — Analytical Chemistry

Bentonite et diatomite modifiées versus polymères à empreintes ioniques : vers de nouveaux matériaux pour l'extraction du nickel et de l'argent d'effluents contaminés The brassware manufacturing of Fez city produces effluents that are very contaminated by metals such as nickel, silver, lead, copper and zinc. These effluents are directly discharged into the environment with a negative impact on the ecosystems and nearby wastewater treatment plant. Therefore, there is an urgent need for decontaminating these effluents before their treatment. In this context, the objectives of this work were the valorisation of natural mineral substances, bentonite and diatomite, widespread minerals in Moroccan soil although little exploited, for their use as adsorbent phases for nickel and silver extraction. A considerable part of this work has been directed toward modifying the physicochemical properties of these natural materials to maximize their adsorption capacity. In a first step, the modification of the diatomite was carried out by heating treatment at different temperatures (550 to 950 °C). The diatomite calcined at 550 °C showed the best adsorbing capacity towards nickel and silver. The second step was dedicated to the modification of the bentonite by heating treatment (550 °C and 750 °C) and chemical activation by sodium carbonate and by a combined chemical and thermal activation at 450 °C. Bentonites modified by chemical activation with sodium carbonate and by combined chemical and thermal activations at 450 ° C showed the best results. In addition, Ion Imprinted Polymers (IIPs) have been considered as alternative materials to replace these natural materials to improve the selectivity. The last part of this study consisted in comparing the performance of these materials, in order to select the best material for a future application in the remediation of contaminated effluents before their depollution by the treatment plant of Fez city. The nickel and silver concentrations become negligible in the natural samples after adsorption by the studied materials, which perfectly meets the Environmental Quality Standards. These results successfully validated the use of natural and synthetic materials for the extraction of nickel and silver from contaminated effluents. Bentonite ; Extraction (chemistry) ; Nickel ; Effluent ; Materials science ; Contamination ; Polymer ; Environmental chemistry ; Chemical engineering ; Chemistry ; Metallurgy ; Environmental science ; Chromatography ; Environmental engineering ; Composite material ; Engineering ; Ecology Analytical chemistry methods development ; Adsorption and biosorption for pollutant removal
Authors: Nuri Öztürk
Source: Karadeniz Fen Bilimleri Dergisi (article, 2020-12-12)
Field: Materials Science — Electronic, Optical and Magnetic Materials

n-Tolilürenin (n= o, m, p) Yapısal, Spektroskopik ve Elektronik Özellikleri Üzerine DFT Analizleri n-tolilüre (n = o, m ve p) moleküllerinin spektroskopik ve elektronik özellikleri titreşim (FT-IR ve Raman), 1H ve 13C NMR ve UV-Vis. spektroskopileri kullanılarak karakterize edilmiştir. Teorik geometri parametreleri (bağ uzunlukları ve açıları), titreşim dalgasayıları, NMR kimyasal kaymaları, sınır orbital enerjileri ve UV-Vis. parametreleri (dalgaboyları, uyarılma enerjileri, osilatör şiddeti), literatürden elde edilen deneysel sonuçlarla karşılaştırmak için DFT/B3LYP kuantum kimyasal yöntemi kullanılarak 6-311++G(d,p) baz setiyle hesaplanmıştır. VEDA 4 yazılımı kullanılarak Potansiyel Enerji Dağılımı analizi ile titreşim dalgasayılarının atamaları yapılmıştır. En yüksek işgal edilen moleküler orbital ve en düşük boş moleküler orbital analizleri, UV-Vis. elektronik absorpsiyon parametreleri ve Moleküllerin Moleküler Elektrostatik Potansiyel yüzeyi, elektronik geçişleri, molekül içi yük transferini ve moleküldeki etkileşim bölgelerini açıklamak için incelenmiştir. Elektrofilik ve nükleofilik bölgeler üre grubundaki oksijen atomu ve amin hidrojenleri üzerinde görülmüştür. N-aril bağlarının deneysel ve hesaplanmış burulma açıları arasındaki fark, moleküller arası ve molekül içi etkileşimlerin varlığını göstermiştir. Physics ; Chemistry Nonlinear Optical Materials Research ; Free Radicals and Antioxidants ; Organic Chemistry Cycloaddition Reactions
Authors: Salima El Yakhlifi - El Hadouchi
Source: SPIRE - Sciences Po Institutional REpository (preprint, 2020-09-17)
Field: Materials Science — Surfaces, Coatings and Films

Control of the structure and the properties of polydopamine in suspensions, in films and in gels for biomedical applications Because of the dynamics of the oceans, several marine organisms have had to adapt and develop adhesive strategies in order to survive. In particular, marine mussels are known for their extraordinary ability to attach to a wide variety of surfaces, and even in wet conditions. This feat has opened the door to intense research efforts over the past decade to attempt to understand and be inspired by this property. Studies have shown the presence in the adhesive substance of the mussels, a large amount of L-Lysine, 3,4-dihydroxy-L-phenylalanine (DOPA) and 3-4-hydroxyproline (1). The combination of catechols and primary and secondary amines has been shown to contribute to this strong adhesion (2). Based on this hypothesis, researchers have succeeded in developing a simple synthesis of polydopamine (PDA) by oxidation of dopamine, which is a molecule with precisely these two chemical functions (3). However, even today, there is no consensus on the mechanisms of formation of this material. This complexity stems from the many possible reaction pathways after the initial oxidation step. In addition, PDA shares physicochemical characteristics with eumelanin, the black-brown pigment responsible for the coloring of the skin. The structural similarity between these two entities gives PDA interesting properties, the most remarkable being its antioxidant properties. Although the molecular structure and the stages of formation of PDA are not yet fully understood, its ability to adhere to any kind of substrate makes it a material of choice in many applications in medicine, cosmetics, industry… It is therefore in our interest to continue research efforts in this area. It is in this context that this thesis fits, which can be divided into three axes: a first part consisted in optimizing the method of PDA synthesis and in training and developing a technique for controlling PDA nanoparticles. Using the advances of this step, interest was given to the physicochemical study of PDA films in order to better understand its formation mechanisms in order to then be able to better control them. Finally, special attention was given to the study of an application of gel formed from PDA based on the findings of the first two axes... Materials science ; Nanotechnology ; Chemical engineering ; Polymer science ; Engineering Polymer Surface Interaction Studies ; Hydrogels: synthesis, properties, applications
Authors: Lilian Forsgren
Source: Chalmers Research (Chalmers University of Technology) (article, 2020-01-01)
Field: Materials Science — Biomaterials

Processing and properties of thermoplastic composites containing cellulose nanocrystals or wood-based cellulose fibres Cellulose nanocrystals (CNC) were surface modified with dialkylamines to increase the compatibility between the CNC and the polymeric matrix, and promising results were obtained, with a 300 % stiffness increase when the mixed dispersion was compression moulded on a laboratory scale. The manufacturing process was up-scaled using water-assisted mixing in a twin-screw extruder (TSE) followed by a second compounding step and injection moulding (IM). The composites were successfully produced using conventional melt-processing techniques but these did not show the same improvement in mechanical performance, probably due to the formation of CNC aggregates. There were indications of network formation when CNC was added, especially in the case of surface-modified CNC. Cellulose fibres and thermomechanical pulp were used as reinforcement in similar types of polymer matrices and the mixtures were similarly processed by TSE and IM. These materials were characterized with regard to appearance and durability. The discoloration of the composites due to excessive heat during processing did not significantly affect their mechanical properties, and the addition of the cellulose-based reinforcement to the polymer did not reduce its resistance to thermo-oxidative degradation compared to that of the pure matrix. In fact, the resistance to degradation was increased when lignin was present in the reinforcing element, showing a synergistic effect together with the added anti-oxidant.Superior properties were expected for the CNC composites compared to those of the larger cellulose fibre reinforcements, but in continuous production the stiffening effects were similar regardless of reinforcement type. These results confirm that the processing method and properties strongly affect the final properties of the composite. Materials science ; Composite material ; Cellulose ; Plastics extrusion ; Compounding ; Pulp (tooth) ; Extrusion ; Thermoplastic ; Polymer ; Compression molding ; Chemical engineering Advanced Cellulose Research Studies ; Natural Fiber Reinforced Composites ; Lignin and Wood Chemistry
Authors: Selahattin Yılmaz | Sahin Demirci | Betül Arı | Saliha B. Kurt | Suzan Yanık
Source: Çanakkale Onsekiz Mart University AVESIS (article, 2020-11-01)
Field: Chemistry — Electrochemistry

DEVELOPMENT OF ELECTROCHEMICAL SENSORS FOR QUANTITATIVE ANALYSIS OF METHYLDOPA AT MODIFIED-GCE AND PGE ELECTRODES BY VOLTAMMETRY Quantitative analysis (chemistry) ; Electrode ; Electrochemistry ; Voltammetry ; Methyldopa ; Cyclic voltammetry Electrochemical Analysis and Applications ; Advanced Chemical Sensor Technologies ; Gas Sensing Nanomaterials and Sensors
Authors: Souradip Guha | Ankan Mullick | Jatin Agrawal | Swetarekha Ram | Samir Ghui | Seung‐Cheol Lee | Satadeep Bhattacharjee | Pawan Goyal
Source: arXiv (Cornell University) (preprint, 2020-09-14)
Field: Materials Science — Materials Chemistry

MatScIE: An automated tool for the generation of databases of methods\n and parameters used in the computational materials science literature The number of published articles in the field of materials science is growing\nrapidly every year. This comparatively unstructured data source, which contains\na large amount of information, has a restriction on its re-usability, as the\ninformation needed to carry out further calculations using the data in it must\nbe extracted manually. It is very important to obtain valid and contextually\ncorrect information from the online (offline) data, as it can be useful not\nonly to generate inputs for further calculations, but also to incorporate them\ninto a querying framework. Retaining this context as a priority, we have\ndeveloped an automated tool, MatScIE (Material Scince Information Extractor)\nthat can extract relevant information from material science literature and make\na structured database that is much easier to use for material simulations.\nSpecifically, we extract the material details, methods, code, parameters, and\nstructure from the various research articles. Finally, we created a web\napplication where users can upload published articles and view/download the\ninformation obtained from this tool and can create their own databases for\ntheir personal uses.\n Computer science ; Upload ; Field (mathematics) ; Context (archaeology) ; Database ; Usability ; Download ; Code (set theory) ; Information retrieval ; World Wide Web ; Data science ; Human–computer interaction Machine Learning in Materials Science ; X-ray Diffraction in Crystallography ; Metallurgical Processes and Thermodynamics
Authors: Jacob Porter
Source: Florida International University Digital Commons (Florida International University) (article, 2020-01-01)
Field: Chemistry — Spectroscopy

Structural Characterization of Biomolecules Using Tandem Non- Linear and Linear Ion Mobility, Action Spectroscopy, Mass Spectrometry and Molecular Dynamics The following thesis comprises the use of novel gas-phase spectroscopic and spectrometric techniques complemented with molecular dynamics for the structural characterization of biomolecules: from small model systems to large proteins. In particular, complementary linear and non-linear ion mobility, mass spectrometry and action spectroscopy has been applied to the separation and characterization of native and kinetic intermediate states of biomolecular ions. This suite of tools, comprising ion mobility in tandem with non-ergodic fragmentation and action spectroscopy, provided unique information on the conformational space, folding and binding dynamics of single stranded DNA, peptides, peptide-cofactor and protein systems. Theoretical modeling provided candidate structures filtered by measurements of molecular ion-neutral collision cross section, fragmentation patterns and infrared spectroscopy data. In addition, this work covers the development of higher power analytical separations with increased peak capacity, reduced chemical noise and reduced analysis time for the characterization of complex biological mixtures (e.g., cell digests). Characterization (materials science) ; Tandem mass spectrometry ; Mass spectrometry ; Chemistry ; Biomolecule ; Tandem ; Spectroscopy ; Ion ; Analytical Chemistry (journal) ; Materials science ; Nanotechnology ; Chromatography ; Physics ; Biochemistry Mass Spectrometry Techniques and Applications ; Analytical Chemistry and Chromatography
Authors: Gamze D. Tetik | Jumageldiyeva, Ejebay | Ayşe Ebru Tayyar
Source: DergiPark (Istanbul University) (article, 2020-06-30)
Field: Materials Science — Biomaterials

Production of nanofiber textile surfaces with β-arbutin via electrospinning method Bu çalışmada, cilt lekeleri azaltıcı etkisi bilinen β-arbutin ilave edilmiş polimer çözeltisinden nanoliflerin elektrolif çekim yöntemi ile üretimi amaçlanmıştır. Bu amaçla %2, %5 ve %10 (w/v) oranlarında β-arbutin, formik asit ile hazırlanmış poliamid 6 çözeltisine ilave edilerek, çözeltilerin elektrolif çekimleri gerçekleştirilmiş ve gerçekleştirilen taramalı elektron mikroskobu (SEM) analizi ile optimum elektrolif çekim parametreleri belirlenmeye çalışılmıştır. SEM görüntüleri, en düzgün morfolojili nanoliflerin %2 (w/v)’lik β-arbutin içeren çözelti ile elde edilebildiğini göstermiştir. %2 (w/v) konsantrasyon değeri ile çalışılırken denenen 3 farklı voltajdan 30 kV’un en iyi sonucu verdiği gözlemlenmiştir. Ortalama lif çapları için gerçekleştirilen istatistiksel analizde, nanoliflerin çaplarının konsantrasyon değerlerine göre değiştiği belirlenmiştir. Bu çalışmada, cilt lekeleri azaltıcı madde içeren nanolifli tekstil yüzeylerinin hafif ve oldukça ince formda bir kozmetik tekstil ürünü olarak kullanılmak üzere elektrolif çekim yöntemi ile üretilebileceği gözler önüne serilmiştir. Electrospinning ; Nanofiber ; Textile ; Arbutin ; Materials science ; Pulp and paper industry ; Composite material ; Chemistry ; Engineering ; Chromatography ; Polymer Electrospun Nanofibers in Biomedical Applications ; Catalysis for Biomass Conversion ; Supercapacitor Materials and Fabrication
Authors: Victor Henri
Source: theses.fr (ABES) (article, 2020-10-08)
Field: Materials Science — Materials Chemistry

Identification and analysis of ageing markers in insulating materials under thermal stress in aeronautics Ces travaux s'inscrivent dans une problématique de détermination de marqueurs du vieillissement de polymères hautes performances pour des applications d'isolation électrique dans l'industrie aéronautique. La majorité des câbles de puissance est composée d'un enroulement successif de poly(tétrafluoroéthylène) PTFE et de poly(imide) PI. Ces recherches sont focalisées sur l'analyse des effets d'un vieillissement thermo-oxydatif sur la structure physico-chimique de ces polymères pour interpréter les modifications des propriétés thermomécaniques et électriques. Dans le cas du PTFE, les relaxations enthalpiques et mécaniques sont fortement impactées par l'évolution de la structure chimique due à un mécanisme de dégradation par dépolymérisation. Les valeurs de l'enthalpie de cristallisation et de l'amplitude du mode de relaxation mécanique ß associé à la transition cristal/cristal, peuvent être utilisés comme des marqueurs du vieillissement pour le PTFE. Pour le PI, les modifications de la structure chimique par un mécanisme de scission - recombinaison mettent en évidence la formations d'hétérogénéités impactant la sorption et le transport de charges électriques en spectroscopie diélectrique dynamique. L'évolution du mécanisme de diffusion ainsi que l'énergie d'activation de la conductivité électrique constituent des marqueurs pertinents du vieillissement pour le PI. Stress relaxation ; Stress (linguistics) ; Relaxation (psychology) ; Solid-state High voltage insulation and dielectric phenomena ; Polymer crystallization and properties ; Thermal properties of materials
Authors: Moktar M. Aburzeza | Khaled A. AlFalous
Source: مجلة الجامعة الأسمرية (article, 2020-12-30)
Field: Chemistry — Organic Chemistry

Utilization derivatives of 4 - [4-(acetylamino)phenyl]-2 - (3,5 dimethyl - 1 H-pyrzol -1-yl)-3-hydroxy-4-oxobutanoic acid in Heterocyclic Synthesis and Study of Their Biological Activities The aim of this research the derivatives of 4- [4-(acetylamino) phenyl]- 2 -(3,5dimethyl- 1 H-pyrzol -1-yl)-3-hydroxy-4-oxobutanoic acid was used synthesize heterocyclic compounds. These heterocyclic compounds could be used as the main feedstock to prepare heterocyclic compounds (6,5 membred ring) including thiadiazolo, imidazole and pyridazinone derivatives. The effect of nucleophilic and electrophilic reagents on the resulting pyridazinones compounds was studied. Through preliminary analyzes of the compounds prepared in the research and spectroscopic data which obtained their structures were proved, and it have biological activities. Chemistry ; Imidazole ; Electrophile ; Reagent ; Ring (chemistry) ; Heterocyclic compound ; Nucleophile ; Organic chemistry ; Combinatorial chemistry ; Catalysis Synthesis and Reactions of Organic Compounds ; Chemical synthesis and pharmacological studies ; Synthesis and Biological Evaluation
Authors: Dalel El-Marrouki
Source: theses.fr (ABES) (preprint, 2020-12-10)
Field: Chemistry — Organic Chemistry

Contribution to the study of the reactivity of some cyclic Michael acceptors and applications Ce mémoire de thèse se concentre sur la synthèse d’hétérocycles azotés à partir d’une même famille de précurseurs : les 1,4-dicétones. Ces dernières ont été obtenues à travers deux voies de synthèse dont la première consiste en une réaction de Nef permettant la conversion des composés nitrés en cétones. La deuxième est une réaction de Wittig en utilisant divers ylures de Wittig et la cyclohexanedione. Ces intermédiaires réactionnels ont été utilisés par la suite pour la synthèse de dérivés indoliques via une réaction d’addition-1,2. Nous avons également pu orienter la sélectivité de la réaction vers la synthèse des indolones à partir d’une réaction d’addtion-1,4. En présence d’hydrazine monohydrate, les 1,4-dicétones ont aussi permis l’accès à des cinnolines avec d’excellents rendements. Michael reaction ; Reactivity (psychology) ; Chemistry ; Organic chemistry ; Medicine Synthesis and Reactions of Organic Compounds ; Synthesis and Biological Evaluation ; Chemical Synthesis and Analysis
Authors: Hülya Kuduğ Ceylan | Rızvan İmamoğlu | İ̇sa Gökçe
Source: European Journal of Science and Technology (article, 2020-02-29)
Field: Chemistry — Spectroscopy

Siyan (mavi) Fluoresan Protein Aquamarine’nin Biyoreaktörde Üretilmesi ve Saflaştırılması Aquamarine proteini siyan (mavi ) floresan protein ailesinin bir üyesi olup ve Aequorea victoria'dan elde edilen GFP (yeşil floresan protein) türevi floresan bir proteindir. Aquamarine benzeri floresan proteinler genetik mühendisliği teknikleri ile geliştirilmiş özellikleri sayesinde canlı hücrelerin biyolojik olarak görüntülenmesi ve hücre içerisinde lokalizasyon çalışmaları için sıklıkla kullanılmaktadır. Bu çalışmada Escherichia coli BL21(AI) hücreleri pROEX Aqua plasmid DNA’sı ile transforme edilmiş ve % 0.04 konsantrasyonda arabinoz ilavesi ile protein ekspresyonu indüklenmiştir. 3L kültür hacimli biyoreaktörde yüksek ekspresyon seviyesinde üretilen Histidin etiketli hedef protein Ni+2 afinite kromotografisi ile saflaştırılmıştır. Saflaştırılan protein konsantrasyonu bir litre bakteri kültürü için 80 mg olarak belirlenmiştir. Rekombinant Aquamarine’ne ait fotolüminesans özellikler florometre ile analiz edilmiştir. SDS-PAGE analizi rekombinant Aquamarine proteine ait tek bir bandın olduğunu ve saflaştırılan proteinin ileri çalışmalarda kullanılmak üzere yüksek verimde ve saflıkta (>%95) elde edildiğini göstermektedir. Molecular biology ; Chemistry ; Physics ; Biology Advanced Proteomics Techniques and Applications ; Animal Genetics and Reproduction ; Molecular Biology Techniques and Applications
Authors: Nicolas Felines
Source: theses.fr (ABES) (preprint, 2020-11-06)
Field: Chemistry — Inorganic Chemistry

Ligands optiquement purs pour l'extraction d'actinides Les travaux présentés lors de cette thèse s’inscrivent dans le cadre des études sur le retraitement des combustibles nucléaires usés. Cette étude se concentre majoritairement sur la famille des N,N dialkylamides (ou monoamides) qui est une famille prometteuse pour le remplacement du TBP, ligand actuellement utilisé dans le procédé PUREX pour le recyclage de l’uranium et du plutonium. Le but est de montrer que la stéréochimie du ligand monoamide utilisé influence les performances d’extraction.Lors de ces dernières années, l’importance de la chiralité dans l’industrie s’est confirmée. Des écrits bibliographiques ont montré que la stéréochimie des molécules peut influencer les performances d’extractions, ce comportement a déjà été observé sur un certain nombre d’extractant (ter-pyridine, éther couronnes ou bien aussi des diglycolamides). Le but de la présente étude était de confirmer que les molécules monoamides sont elles aussi assujetties à ce genre de phénomène. Des méthodologies de synthèses ont été mises en œuvre afin d’obtenir différentes molécules énantiopures possédant des chaines –(2-éthylehexyle). Ainsi deux monoamides le DEHBA et le M(2-EH)EHA ont été étudiés en conditions d’extraction afin d’évaluer l’impact de la chiralité sur l’extraction de l’uranium et du plutonium. Tous deux ont montré une influence de la chiralité sur les performances d’extraction du plutonium. Cependant, il est apparu que cette influence peut dépendre du type de coordination ayant lieu lors de la complexation du métal. Actinide ; Extraction (chemistry) ; Radiochemistry ; Nuclear engineering ; Chemistry ; Nuclear chemistry ; Engineering ; Chromatography Radioactive element chemistry and processing