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Design, Synthesis and Applications of Novel Two-Component Gels and Soft-NanocompositesBhattacharjee, Subham January 2014 (has links) (PDF)
No description available.
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Optical Properties and Application Of Template Assisted Electrodeposited Nanowires And NanostructuresAsaduzzaman Mohammad (9159935) 27 July 2020 (has links)
<div>Self-assembled templates allow the creation of many complex arrays of nanostructures, which would be extremely difficult and expensive, if not impossible, to realize using any of the other available fabrication techniques. The complexity of these advanced nanostructures, synthesized using the various template assisted electrodeposition techniques, can be controlled to nanometer scale range by tuning the structural properties of the template, which is achieved by adjusting its various growth parameters during the self-assembly process.</div><div>Electrodeposition allows the creation of arrays of various metallic and semiconducting nanostructures. Monitoring the electrodeposition conditions permit the creation of single crystalline nanostructures of a particular material, or the formation of heterostructures using multiple electrodeposition steps. This work demonstrates the template assisted electrodeposition of vertically aligned nanowire arrays, both straight and branched, of metals, and a direct bandgap, III-V semiconductor, indium antimonide (InSb), which has one of the smallest known bandgap of any material. The template assisted electrodeposition of metallic, and InSb inverse opal (IO) structures is also shown, and the fabrication of a novel zipper shaped nanostructure by laser photomodification of a Ni IO structure is reported.</div><div>The optical characterization of the various nanostructures realized in this work have been examined. The results from this work confirm the ability to tune the optical spectra of nanostructures of the same material with similar volume fill fractions by structural modulation, where the different optical responses can be attributed to the structural differences of the actual structure as opposed to the material properties of the solid.</div>
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Příprava realizace výrobního a administrativního objektu v Moravanech / Construction preparation of production and administrative building in MoravanyVeselý, Martin January 2019 (has links)
The diploma thesis deals with the elaboration of a building-technological project for the construction of a hall in Moravany u Brna. The work includes comprehensive studies of implementation including timetable, financial plans and technological regulations. It also deals with the design of the main building mechanisms, building equipment, control and test plan. There are also three drawings of the construction site equipment for the implementation stages.
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Stavebně technologický projekt haly firmy PP&T / Construction and technology project of the production hall of the company PP&TFindejs, Lukáš January 2015 (has links)
This thesis includes the construction technology project of the production hall of the company PP&T. The work includes technical report object, technological specification for the shell construction, quality control, report site equipment, a report describing the health and safety forth motion of mechanical assemblies, and a report describing the transport relations. The annexes drawings of site equipment, connection details of prefabricated elements, plan of risks, budget and schedule for the main subject and time financial plan for the whole construction.
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Hasičská stanice / FirehouseHladký, Adam January 2017 (has links)
This diploma thesis „Firehouse“ is processed in the form of design documentation for building construction. It´s a new building of firehouse, JPO IV category, P type, for firefighters of Správa železniční dopravní cesty. Object is composed from three parts - administrative and operational part, garage for fire vehicles and maintenance part. Main entrance and exits from the garages are situated on west. Administrative and operational part has two floors and it´s roofed by double-shell roofs. The garage and maintenance have one floor and they are roofed by single-shell roof. Structural system is partly masonry and partly reinforced concrete. Object is located in flat terrain in peripheral locality of the Přerov city.
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Stavebně technologický projekt haly Argos Elektro v Ostravě / Construction technological project of Argos Elektro hall in OstravaVrána, Tomáš January 2017 (has links)
This thesis deals with the construction and technological project for construction of a storage and office buildings Argos Elektro in Ostrava. The thesis contains a technical report object, construction schedule, report building equipment, design mechanical assembly, technological specification for the shell construction, technological prescription for pilots, inspection and test plans, risks and safety measures, structural details and itemized construction budget.
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Spectroelectrochemistry of self-assembled monolayers of 2- and 4-mercaptopyridines: Spectroelectrochemistry of self-assembled monolayersof 2- and 4-mercaptopyridinesHassan, Nazly 20 June 2007 (has links)
Die Elektrochemie und die Spektroelektrochemie von selbst-organisiererten Monoschichten (selfassembled
monolayers, SAMs) gebildet aus 2-Mercaptopyridin (2MP) und 4-Mercaptopyridin
(4MP) wurden an polykristallinen Goldelektroden in wässrigen Elektrolytlösungen untersucht.
Folgende Untersuchungsmethoden wurden angewandt: zyklische Voltammetrie, elektrochemische
Impedanzmessungen (EIM) und oberflächenverstärkte Raman Streuung (surface-enhanced Raman
scattering, SERS).
Die elektrochemischen Untersuchungen von 2MP und 4MP in wässriger saurer Lösung (0.5 M
H2SO4) zeigten, dass 2MP stärker adsorbiert wird als 4MP aufgrund der Bildung eines S-Au-N Chelates,
wobei die S-Au-Interaktionen bei 4MP stärker sind. Die Bildung eines Chelates im Falle
von 2MP verringert die Wahrscheinlichkeit der Bildung eines Dimers. In sauren Lösungen wird
das N-Atom von 2MP protoniert, was zu einer schwächeren Bindung von 2MP-Molekülen zur
Substratoberfläche führt. Die Ergebnisse der SERS-Untersuchungen stimmen mit den Resultaten
aus der zyklischen Voltammetrie überein. Man erhält eine Au-S-Streckschwingungsbande für
2MP zwischen 225 bis 250 cm-1 bei Abscheidung aus wässriger oder saurer Lösung und für 4MP
bei ca. 263 cm-1 in beiden Lösungen. Die SERS-Experimente ergaben eine senkrechte Orientierung
zur Goldoberfläche sowohl für 2MP als auch für 4MP. Die Thion-Thiol-Tautomerie von 2-
Mercaptopyridinen wurde ebenfalls in Betracht gezogen.
Die Unter- und Überpotentialabscheidung von Kupfer auf einer polykristallinen Goldelektrode in
wässriger 0.1 M Schwefelsäure in An- und Abwesenheit von SAMs von 2- und 4-
Mercaptopyridin wurde mit zyklischer Voltammetrie untersucht. Es zeigte sich, daß bei Vorhandensein
der SAMs die Elektrodeposition von Kupfer verhindert wird, was auf starke Wechselwirkungskräfte
zwischen dem Adsorbat (MP) und der Goldoberfläche zurückzuführen ist. 2MP zeigt
eine grössere Inhibierung, was höchstwahrscheinlich auf die Bildung der Chelatstruktur zurückzuführen
ist. Es wurden ebenso Untersuchungen zum Einfluss von 2MP und 4MP auf die abgeschiedene
Kupfermonolage auf der Goldelektrode durchgeführt. Es zeigte sich, daß die Kupfermonolage
teilweise durch 2MP oder 4MP ersetzt wird.
Die Elektronenaustauschgeschwindigkeit für das Fe2+/Fe3+-Redoxsystem in An- und Abwesenheit
von 2MP- oder 4MP-Monolagen wurde mit zyklischer Voltammetrie und elektrochemischen Impedanzmessungen
(EIM) untersucht. Es stellte sich heraus, dass der Elektronenaustausch höchstwahrscheinlich
über Defektstellen in der Monolage (Pinholes) erfolgt. In einer wässrigen Lösung
verringert 4MP den Elektronenaustausch stärker als 2MP. Da die Packungsdichte bei 4MP größer
ist als bei 2MP ist wahrscheinlich auch die Zahl der Pinholes geringer in der 4MP-Monolage. In
saurer Lösung liegen die N-Atome protoniert vor. Man kann davon ausgehen, dass in saurer Lösung
zwei Prozesse gleichzeitig ablaufen, die für den Elektronenaustausch entscheidend sind. Erstens
kommt es zu einer Abstoßung zwischen der positiv geladenen Monolage und den positiv geladenen
Redoxionen. Und zweitens erfolgt eine Abstoßung zwischen den positiv geladenen Molekülen
der SAMs, was zu einer geringeren Packungsdichte führt. Der Ladungsaustausch wird dominiert
durch den zweiten Effekt.
Mit Hilfe von EIM wurden die Elektronenaustauschgeschwindigkeit und der Bedeckungsgrad bestimmt.
Die korrosionshemmende Wirkung von 2MP und 4MP auf Stahl in 3.5 % wässriger NaCl-Lösung
wurde mit Hilfe der EIM untersucht. 2MP zeigte eine grössere Hemmung als 4MP. / The electrochemistry and spectroelectrochemistry of the self-assembled
monolayers (SAMs) prepared of 2-mercaptopyridine (2MP) and 4-mercaptopyridine
(4MP) dissolved either in water or 0.1 M H2SO4 have been investigated at polycrystalline
gold electrodes in aqueous electrolyte solutions using cyclic voltammetry, electrochemical
impedance measurements (EIM) and surface enhanced Raman spectroscopy
(SERS).
Electrochemical studies of 2MP and 4MP monolayers in aqueous acidic solution
(0.5 M H2SO4) suggest that 2MP is adsorbed more strongly than 4MP due to the
formation of S-Au-N chelate. However, the S-Au bond was found to be stronger in
4MP as compared with 2MP. The formation of the chelate in case of 2MP diminishes
the probability of dimer formation. In the acidic solvent, the N-atom of 2MP molecule
will be protonated leading to a weaker interaction of 2MP molecules with the substrate
surface. The SERS results are in good agreement with the cyclic voltammetry
results. The Au-S stretching band was obtained in the region from 215 to 245 cm-1 for
2MP deposited from water and acidic solvent and around 263 cm-1 for 4MP in both
solvents. The SERS measurements showed also a perpendicular orientation of both
2MP and 4MP on the gold surface. In explaining the SERS results, the thione-thiol
tautomerisations of the mercaptopyridines were also taken into consideration.
The under- and overpotential deposition of copper on a polycrystalline gold
electrode in aqueous 0.1 M sulfuric acid in the presence and in the absence of SAMs
of 2- and 4-mercaptopyridine has been studied using cyclic voltammetry. In general,
the presence of these SAMs has been found to inhibit the electrodeposition process of
copper, suggesting very strong interactions between these adsorbates and the Au surface.
2MP shows a higher degree of inhibition, which is due to a stronger interaction
probably due to the formation of the chelate structure. Studies have also been made of
the influence of mercaptopyridines SAMs on the copper monolayer electrodeposited
on the gold surface. The copper adlayer was found to be partially displaced by 2MP
and 4MP monolayers.
The rate of electron transfer for the Fe3+/2+ redox system on the gold electrode
has been probed in the absence and presence of 2MP and 4MP monolayers by cyclic
voltammetry and electrochemical impedance measurements (EIM). The charge transfer
process was suggested to occur through the defects (pinholes) in the monolayer. In
case of aqueous solvent 4MP decreases the electron transfer reaction stronger than
2MP. Since the packing density for 4MP is higher than that of 2MP the number of
pinholes might be lower in 4MP monolayer. In acidic solvent the N-atoms of the mercaptopyridines
will be protonated. It is proposed that two effects, which exist at the
same time, are responsible for the electron transfer process in acidic solution. First,
there will be a repulsive interaction between the positively charged monolayer and the
positively charged redox probe. Second, there is a repulsion among the positively
charged monolayer molecules that results in a less compact monolayer. The charge
transfer is dominated due to the latter effect. With the EIM the rate of electron transfer
and the surface coverage were determined.
2MP and 4MP were examined as steel corrosion inhibitors in 3.5% aqueous
NaCl solution using EIM. 2MP shows higher inhibition efficiency than 4MP.
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Controlled Transfer Of Macroscopically Organized Nanoscopically Patterned Sub–10 nm Features onto 2D Crystalline and Amorphous MaterialsTyson C Davis (9121889) 05 August 2020 (has links)
<div>Surface level molecules act as an interface that mediates between the surface and the environment. In this way, interfacial molecules are responsible for conferring characteristics of relevance to many modern material science problems, such as electrical conductivity and wettability. For many applications, such as organic photovoltaics and nanoelectronics, macroscopic placement of chemical patterns at the sub-10 nm must be achieved to advance next generation device applications.</div><div><br></div><div>In the work presented here, we show that sub-10 nm orthogonal features can be prepared by translating the building principles of the lipid bilayer into striped phase lipids on 2D materials (e.g. highly ordered pyrolytic graphite (HOPG), MoS2). Macroscopic patterning of these nanoscopic elements is achieved via Langmuir Schafer deposition of polymerizable diyne amphiphiles. On the Langmuir trough, amphiphiles at the air water interface are ordered into features that can be observed on the macroscale using Brewster angle microscopy. Upon contact of the 2D material with the air-water interface the macroscopic pattern on the trough is transferred to the 2D material creating a macroscopic pattern consisting of sub-10 nm orthogonal chemistries. We also show here how hierarchical ordering can be accomplished via noncovalent microcontact printing of amphiphiles onto 2D materials. Microcontact printing allows a greater measure of control over the placement and clustering of interfacial molecules.</div><div><br></div><div>The alkyl chain/surface enthalpy has a great deal of influence over the ordering of amphiphiles at the sub-nm scale. Here, we examine this influence by depositing diyne amphiphiles onto MoS2 which has a weaker alkyl adsorption enthalpy compared to HOPG. We found that dual-chain amphiphiles deposited on MoS2 adopt a geometry that maximized the molecule-molecule interaction compared to the geometry adopted on HOPG.</div><div><br></div><div>Finally, we show how the hierarchical pattern of diyne amphiphiles can be transferred off of the 2D material onto an amorphous material. This is done by reacting the amorphous material with the conjugated backbone of the diyne moiety through a hydrosilylation reaction to exfoliate the film from the 2D crystalline material. The resulting polymer ‘skin’ has many applications were controlling interfacial properties of an amorphous material is important.</div>
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Consequences of Interfacial Interactions on Adsorption and AdhesionSingla, Saranshu January 2018 (has links)
No description available.
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NANOSTRUCTURED PRESENTATION OF CARBOHYDRATES AND PROTEINS AT HYDROGEL SURFACESAnamika Singh (16631778) 24 July 2023 (has links)
<p>Extracellular matrix (ECM) creates high-resolution chemical patterns, by assembling simple molecules with nm-scale features (e.g., carbohydrates, nucleotides, amino acids) into complex structures up to micrometers and extending to even larger scales across tissues (e.g., glycans, DNA, proteins), capable of carrying out the diverse and complex cellular functions. Mimicking the complexity of such biological systems requires precise control over the chemical patterning on substrates that exhibit physiochemical properties similar to biological systems (such as hydrogels). Although hydrogels provide tunable physiochemical properties suitable for biological applications; it is a porous material where pore sizes can range from 30 nm to greater than 1000 nm. Due to this structural heterogeneity, chemical patterning below the length scale of this heterogeneity is very challenging.</p>
<p>Here, we demonstrate a new assembly system for generating a nanostructured presentation of carbohydrates on the hydrogel surface. This approach is based on the striped phases assembly of functional alkanes where 1-nm resolution functional patterns are readily assembled on substrates such as highly ordered pyrolytic graphite (HOPG). In this assembly, molecules are stabilized by noncovalent interactions, including alkyl-pi interactions underlying the HOPG, van der Waals interaction between the adjacent alkyl chains, and hydrogen bonding between polar head groups. Topochemical polymerization converts internal diynes into conjugated polydiacetylenes (PDAs). PDAs can also be utilized to covalently attach the striped pattern to polyacrylamide hydrogels through free radical chemistry.</p>
<p>Here, we synthesize new amphiphiles with carbohydrate headgroups (N-acetyl-D-glucosamine (GlcNAc), and D-glucuronic acid (GlcA)), assembled into striped phases on HOPG and covalently transfer to polyacrylamide hydrogels. GlcNAc binds to wheat germ agglutinin (WGA), a lectin that binds specifically in a multivalent fashion (dissociation constant KD in nm range) to GlcNAc. We show that GlcNAc striped phases generate highly selective interactions with wheat germ agglutinin (WGA) but do not induce specific binding with concanavalin A (another lectin molecule that does not target GlcNAc). We further demonstrate that WGA binding affinity can be modulated by shifting the position of diacetylenes that bring the polymer backbone closer to the GlcNAc, increasing the effecting local concentration of carbohydrates.</p>
<p>We investigated the possibility of using sPDA for secondary functionalization with complex biological molecules (such as biotin and cRGD) to mimic the ECM composition closely. The unusual reactivity of the sPDA backbones during the covalent transfer of the striped phase monolayer to hydrogels illustrates the potential of sPDA reactivity azides. In this work, we show that the addition of substituted azide molecules to sPDA-functionalized hydrogels produces a decrease in the fluorescence of the sPDA monolayer. Since these reactions are occurring on porous hydrogel surfaces characterization using techniques such as IR or NMR is difficult. We carried out further solution-phase reactions using a soluble PDA where PDA UV-vis absorption spectra red-shift after the reaction between the PDA backbone and azide. These experiments support the hypothesis of sPDA and azide click reaction.</p>
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