One of the major remaining question about Mars is its habitability - if the requirements necessary to allow for life are presently fulfilled. One of the most relevant ingredients for life, as we know it, is water. Indirect evidence of transient liquid water on Mars has been retrieved from both rover [Martín-Torres et al., 2015] and orbiter [Ojha et al., 2015]. [Martín-Torres et al., 2015] inferred the existence of an active water cycle, driven by chlorate and perchlorate salts, which are commonly found on the Martian surface, and absorb atmospheric water to form stable hydrated compounds and liquid solutions. This happens through a process called deliquescence (absorption of moisture from the atmosphere by the salts and dissolving into a liquid solution). One of the goals of HABIT is to confirm the hypothesis about the water cycle on Mars. HABIT will record the behavior of a selection of salts on Mars, and will also record Martian environmental conditions (UVdose, air and ground temperatures). The Field-Site Prototype for HABIT (FSP-HABIT) was the first prototype of HABIT deployed during field-site campaigns. Three campaigns took place during summer 2016: First, a short preparatory campaign in Abisko, Sweden, was carried out. The second campaign took place in Iceland, within the EU COST Action TD1308 ORIGINS (Origins and evolution of life on Earth and in the Universe), and the third campaign was conducted within the NASA Spaceward Bound India Program in Ladakh. After providing the corresponding background on the mission framework and the scientific background, this document covers the mechanical, electrical, and software design of the instrument. Afterwards, the steps taken to test the instrument and their results are covered, followed by a rating of the instrument and ideas for future improvements. Instruments like FSP-HABIT will enable the characterization of hygroscopic salts by their conductivity as liquid brines are good conductors, hydrated salts are poor conductors, and dehydrated salts are insulators. During the field-site campaigns, the measurements of FSP-HABIT were used to characterize the near surface environment by its temperature, pressure and relative humidity. Now, these measurements are available for comparison with microbiological studies of the water, ice and soils to characterize the habitability of the explored site. The lessons learned while designing and building FSP-HABIT can be used to inform the development of further prototypes for space missions such as HABIT. / Habitability, Brines, Irradition and Temperature (HABIT)

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-05-30T13:01:39Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE DILMO MARQUES_2016.pdf: 3410115 bytes, checksum: ef2c4a31a389b0d7af33d59ec444fa24 (MD5) / Made available in DSpace on 2017-05-30T13:01:39Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE DILMO MARQUES_2016.pdf: 3410115 bytes, checksum: ef2c4a31a389b0d7af33d59ec444fa24 (MD5) Previous issue date: 2016-03-21 / CNPQ / Neste trabalho foram desenvolvidos métodos analíticos, baseados no conceito de multicomutação, para análise de espécies químicas em alimentos. Para isto, foram sintetizados dois materiais: um composto de coordenação usado como fase sólida na determinação de açúcares redutores e uma rede de sílica utilizada como resina de pré-concentração de percloratos. O composto de coordenação cobre (II) - 4,4 '- bipiridina foi usado no desenvolvimento do método para a determinação de açúcares redutores em água de coco e sucos empregando sistema em fluxo multicomutado com detecção espectrofotométrica. A metodologia de análise baseou-se na reação de oxi-redução em meio alcalino entre o reagente sólido e os açúcares redutores. A reação entre a fase sólida (de coloração azul) com (glicose + frutose) resulta em produto de cor amarelada, monitorada em 420 nm. A fase sólida foi fixada em 50 mg e temperatura de 90ºC. Com volume de zona de amostragem de 160 L, que corresponde a 20 ciclos, obtendo resposta linear entre 1,0 e 20,0 g L-1 de AR com RSD de 4,47% (n = 7 ), limite de detecção de 0,2250 g L-1, limite de quantificação de 0,7496 g L-1, freqüência analítica de 75 determinções por hora e geração de efluentes de 320 μL por determinação. Os teores de açúcar redutor encontrados em sucos e água de coco variaram de 38,35 a 98,50 g L-1 e 61,80 a 68,70 g L-1 respectivamente. A rede de sílica, 2,5,8,11,14-pentaoxa-1-silaciclotetradecano, foi empregada num sistema multicomutado como coluna de pré-concentração de perclorato. O sistema foi acoplado a um detector potenciométrico para determinar percloratos em vegetais. Usou-se um eletrodo tubular com membrana constituída por 1% (m/m) de BNIP 4,4 Dapm LC1 solubilizado em 68% (m/m) de 2-nitrodifeniléter, como solvente mediador e 31% (m/m) de poli (cloreto de vinila). Obteve-se limite de detecção de 2,8x10-7 mol L-1, resposta linear no intervalo de 1,0x10-9 a 1,0x10-1 mol L-1, coeficiente de correlação linear de 0,9998 e a coluna apresentou uma capacidade de retenção de 2,86x10-3 mol de perclorato. O sistema foi aplicado às amostras de diferentes vegetais e foram encontradas concentrações de percloratos de 1,30 a 5,08 µg L-1 o teste recuperação variou de 96,5 a 110,8 %. / Two new multicommutation-based analytical methods were developed aiming to the quantification of chemical species in food. The first method is intended to the determination of reducing sugars in coconut water and fruit juices, while the second one is a potentiometric determination of perchlorates in horticultural products. The method eveloped for the determination of reducing sugars uses a multicommuted flow system with spectrophotometric detection employing a (copper (II) - 4,4’ – bipyridyl) coordination compound as the solid-phase reagent. The reaction of the solid blue phase with glucose/fructose resulted in a yellowish solution, which was monitored at 420 nm; 50 mg of the solid phase was used and the temperature was set at 90ºC. The volume of the sample zone was, 160 L, corresponding to 20 cycles, with a linear response of 1.0 e 20.0 g L-1 to the RA and RSD of 4.47% (n = 7), detection limit of 0.2250 g L-1, the limit of quantification was 0.7496 g L-1, analytical frequency of 75 determination per hour and effluent generation of 320 L per determination. The potentiometric method used to determine perchlorates used a tubular electrode formed by a polymeric membrane which showed the best features consisted of 1% (w/w) BNIP Dapm LC1 solubilized in 68% (w/w) of 2-nitrodiphenyl ether as a mediator solvent and 31% (w/w) poly(vinyl chloride) as the polymeric matrix. A limit of detection of 2.8x10-7 mol L-1 was obtained with a linear response in the range of 1.0x10-9 at 1.0x10-1 mol L-1, linear correlation coefficient of 0.9998 and the column retention capacity 2.86x10-3 mol perchlorate. Was applied to samples of different vegetables found perchlorates 1.30 to 5.08 µg L-1 and recovery between 96.5 and 110.8%.

The evaluation of N′-(1-(2-pyridyl)ethylidene)nicotinohydrazide (HL) as a linker for the PbII tagged extended structures is described. The reaction of Pb(ClO4)2 or Pb(OAc)2 with HL in MeOH at 60 °C and room temperature, respectively, leads to heteroleptic complexes {[PbL]ClO4}n·nH2O and [PbL(OAc)]2, while the same reaction of Pb(ClO4)2 with HL at 60 °C in the presence of two equivalents of NaOAc or NaNO2 leads to heteroleptic complexes {[Pb(HL)(OAc)]ClO4}n and [PbL(NO2)]n, respectively. Using Pb(NO3)2 as a source of PbII in the same reaction with HL and two equivalents of NaN3 or NaNCS at room temperature yields [PbLN3]n and [Pb2(HL)2(NO3)2(NCS)2], respectively. The room temperature reaction of Pb(NO3)2 with HL in the presence of two equivalents of NaClO4 leads to the transformation of the parent ligand to its perchlorate salt [H2L]ClO4. In all the obtained PbII structures, HL or its deprotonated form L acts both as a chelating and a bridging ligand. The nature of the inorganic anion also influences the final structure. In all complexes the PbII center exhibits a hemidirected coordination geometry with all the covalent bonds being concentrated on one hemisphere of the coordination sphere with the closest approach of two atoms on the other side varying from 151° to 232°. The sterically available PbII ion participates in tetrel bonding as evidenced from the detailed structural analysis of the described complexes. As a result of tetrel bonding, the structures of all the six compounds can be extended to a higher dimensional framework, which is further stabilized by π⋯π stacking interactions between the aromatic rings. The DFT based charge and energy decomposition (ETS-NOCV) calculations are performed in order to shed light on the nature of non-covalent interactions that determine the stability of the obtained structures.

<p>The performance of solid rocket motors (SRMs) is extremely dependent on propellant formulation, operating pressure, and initial grain geometry. Traditionally, propellant grains are cast into molds, but it is difficult to remove the grains without damage if the geometry is too complex. Cracks or voids in propellant can lead to erratic burning that can break the grain apart and/or potentially overpressurize the motor. Not only is this dangerous, but the payload could be destroyed or lost. Some geometries (i.e. internal voids or intricate structures) cannot be cast and there is no consistent nor economical way to functionally grade grains made of multiple propellant formulations at fines scales (~ mm) without the risk of delamination between layers or the use of adhesives, which significantly lower performance. If one could manufacture grains in such a way, then one would have more control and flexibility over the design and performance of a SRM. However, new manufacturing techniques are required to enable innovation of new propellant grains and new analysis techniques are necessary to understand the driving forces behind the combustion of non-traditionally manufactured propellant.</p> <p>Additive manufacturing (AM) has been used in many industries to enable rapid prototyping and the construction of complex hierarchal structures. AM of propellant is an emerging research area, but it is still in its infancy since there are some large challenges to overcome. Namely, high performance propellant requires a minimum solids loading in order to combust properly and this translates into mixtures with high viscosities that are difficult to 3D print. In addition, it is important to be able to manufacture realistic propellant formulations into grains that do not deform and can be precisely functionally graded without the presence of defects from the printing process. The research presented in this dissertation identifies the effect of a specific AM process called Vibration Assisted Printing (VAP) on the combustion of propellant, as well as the development of binders that enable UV-curing to improve the final resolution of 3D printed structures. In addition, the combustion dynamics of additively manufactured layered propellant is studied with computational and experimental methods. The work presented in this dissertation lays the foundation for progress in the developing research area of additively manufactured energetic materials. </p> <p>The appendices of this dissertation presents some additional data that could also be useful for researchers. A more detailed description of the methods necessary to support the VAP process, additional viscosity measurements and micro-CT images of propellant, the combustion of Al/PVDF filament in windowed propellant at pressure, and microexplosions of propellant with an Al/Zr additive are all provided in this section. </p>

The evaluation of N′-(1-(2-pyridyl)ethylidene)nicotinohydrazide (HL) as a linker for the PbII tagged extended structures is described. The reaction of Pb(ClO4)2 or Pb(OAc)2 with HL in MeOH at 60 °C and room temperature, respectively, leads to heteroleptic complexes {[PbL]ClO4}n·nH2O and [PbL(OAc)]2, while the same reaction of Pb(ClO4)2 with HL at 60 °C in the presence of two equivalents of NaOAc or NaNO2 leads to heteroleptic complexes {[Pb(HL)(OAc)]ClO4}n and [PbL(NO2)]n, respectively. Using Pb(NO3)2 as a source of PbII in the same reaction with HL and two equivalents of NaN3 or NaNCS at room temperature yields [PbLN3]n and [Pb2(HL)2(NO3)2(NCS)2], respectively. The room temperature reaction of Pb(NO3)2 with HL in the presence of two equivalents of NaClO4 leads to the transformation of the parent ligand to its perchlorate salt [H2L]ClO4. In all the obtained PbII structures, HL or its deprotonated form L acts both as a chelating and a bridging ligand. The nature of the inorganic anion also influences the final structure. In all complexes the PbII center exhibits a hemidirected coordination geometry with all the covalent bonds being concentrated on one hemisphere of the coordination sphere with the closest approach of two atoms on the other side varying from 151° to 232°. The sterically available PbII ion participates in tetrel bonding as evidenced from the detailed structural analysis of the described complexes. As a result of tetrel bonding, the structures of all the six compounds can be extended to a higher dimensional framework, which is further stabilized by π⋯π stacking interactions between the aromatic rings. The DFT based charge and energy decomposition (ETS-NOCV) calculations are performed in order to shed light on the nature of non-covalent interactions that determine the stability of the obtained structures.

No description available.

No description available.

The present thesis deals in detail the influence of solvent dynamics and solvation on ion transport in succinonitrile based plastic crystalline electrolytes. The main objective of correlating plastic solvent characteristics with ion transport was achieved by probing the electrolyte using characterization techniques at various length and time scales. Although majority of the results presented in this thesis focus on a prototype succinonitrile electrolyte (succinonitrile-lithium perchlorate, SN-LiClO4), the conclusions drawn from the results on SN-LiClO4 are quite general and can be extended to various types of salts as well as plastic crystalline matrices. Chapters 2-5 demonstrate in a systematic and detailed manner the beneficial influence of solvent dynamics on ion transport in the solid state. The thesis comprises of six chapters. A brief discussion of the contents and highlights of the individual chapters are described below: Chapter 1 briefly reviews the importance of various types of electrolytes for electrochemical applications. The chapter starts with a discussion on different types of liquid and solid crystalline electrolytes and their drawbacks in electrochemical devices such as lithium-ion batteries. Following the discussion on the two extremes of electrolytes viz. liquid and solid electrolytes, various soft matter electrolytes including polymer and plastic crystalline materials are discussed. Aims of the thesis are specified in chapter 1. Chapter 2 discusses plastic crystalline electrolytes as prospective electrolytes for electrochemical applications. In this chapter, we present a detailed study of correlation of ion transport with solvent structure and dynamics in lithium perchlorate (LiClO4)-succinonitrile (SN), a prototype succinonitrile based plastic crystalline electrolyte. Significant influences of the salt on the crystallographic structure, trans-gauche isomerism and solvation properties of succinonitrile (SN) are observed. Ionic conductivity (ac-impedance spectroscopy) and single crystal X-ray studies (in-situ cryo crystallography) reveal the influence of configurational isomerism and ion solvation on ion transport in LiClO4-SN. We quantify the ion association using theoretical analysis of Fuoss-Onsager formalism for various LiX-SN (typically X = ClO4-, CF3SO3-, TFSI-) electrolytes. Thermal (differential scanning caloriemetry) and spectroscopic (Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR)) studies have also been discussed in the chapter to support our proposition. Chapter 3 describes our investigation on issues other than salt that are likely to affect ion transport in Li-salt-SN based plastic crystalline electrolytes such as water in sample and sample thermal history. We investigate here in a detailed manner the influence of water and thermal history on SN configurational isomerism and solvation in LiClO4-SN. LiClO4 in SN electrolyte samples were prepared in various ways for the fulfillment of the objectives of the study of the present chapter. Correlation of water and thermal history on ion transport were studied via ac-impedance spectroscopy and room temperature Fourier transform infrared (FTIR) spectroscopy. The ionic conductivity and infra-red findings were supplemented via differential scanning calorimetry (DSC). Chapter 4 presents dielectric relaxation spectroscopy (DRS) to study the various relaxation processes of the plastic crystalline solvent and ionic species responsible for ion-transport in succinonitrile-based electrolytes. For the DRS study, we select the same system i.e. SN-LiClO4 for which the role of solvent dynamics and ion-association on ion transport was discussed in detail in chapter 2. We supplement the ionic conductivity and various spectroscopic investigations highlighted in chapter 2 via study of the frequency dependence of dielectric function. The permittivity data are further analyzed using Havriliak-Negami (HN) and Kohlrausch-Williams-Watta (KWW) functions for identification of various processes and also for detailed insight on the ion transport mechanism. Chapter 5 comprises of the temperature dependence the bulk acoustic phonons in SN and SN-LiX (X = ClO4-, CF3SO3-, TFSI-, Cl-) electrolytes from (200-300) K. Room temperature Brillouin spectra of SN based plastic crystalline electrolytes with different cationic salts (MClO4-, M = Li+, Na+, Rb+) were also measured. The influences of salt concentration and temperature on solvent dynamics and ion-association effect have been investigated in detail for the SN-LiClO4 electrolyte. The Brillouin data were further analyzed using Lorentzian and Fano resonance function for identification of behavior of various Brillouin modes. An attempt was made to understand ion transport mechanism in SN-LiX plastic crystalline electrolytes based on the concept of molecular liquids as opposed to conventional solid state defect chemistry. The chapter also discusses preliminary results on the relaxational dynamics of SN and SN-LiClO4 in the plastic phase examined using quasi elastic neutron scattering (QENS) facility at ILL-Grenoble IN16 beamline. Chapter 6 provides a brief summary of the work presented in the thesis and discusses how knowledge from the present work (chapters 2-5) can be utilized to generate new electrolytes. The system proposed is a liquid electrolyte based on bis-nitrile (G0-CN) which does not possess majority of the detrimental issues associate with conventional liquids and various improvisations of polymer electrolytes. We also show that the various dendrimer generations obtained from the monomer bis-nitrile (G0-CN) can also be utilized as an alternative solvent for generation of liquid electrolytes for electrochemical devices such as (primary/secondary) batteries. In a way, we discuss a novel liquid electrolyte system whose physical (viscosity, dielectric constant) and solvation properties can be tuned easily to fulfill task of specific objectives. The preliminary ionic conductivity, viscosity and electrochemical studies of the Gn-CN-Li-salt (n=0-2) liquid electrolytes show considerable promise. Though the prospective dendrimer solvent is a liquid, we envisage that in future compounds with similar chemical properties can also be synthesized in the soft matter state.

A new class of treatment processes called Advanced Reduction Processes (ARP) has been proposed. The ARPs combine activation methods and reducing agents to form highly reactive reducing radicals that degrade oxidized contaminants. Batch screening experiments were conducted to identify effective ARP by applying several combinations of activation methods (ultraviolet light, ultrasound, electron beam, microwaves) and reducing agents (dithionite, sulfite, ferrous iron, sulfide) to degradation of five target contaminants (perchlorate, nitrate, perfluorooctanoic acid, 2,4 dichlorophenol, 1,2 dichloroethane) at 3 pH levels (2.4, 7.0, 11.2). These experiments identified the combination of sulfite activated by ultraviolet light produced by a low pressure mercury vapor lamp as an effective ARP. More detailed kinetic experiments were conducted with nitrate and perchlorate as target compounds and nitrate was found to degrade more rapidly than perchlorate. The effects of pH, sulfite concentration, and light intensity on perchlorate and nitrate degradation were investigated. The effectiveness of the sulfite/UV-L treatment process improved with increasing pH for both perchlorate and nitrate.

The present work deals with the properties of suitable electrolytes for lithium-ion batteries. The first part described in the current issue of electrolytes for lithium-ion batteries, types of solvents and their properties and methods of measurement properties. The second part is devoted to the measurement of the properties of solvents and electrolytes such as relative permittivity, density and viscosity. Measurement of relative permittivity was focused on the measurement of the solvent mixture with varying the percentage of the solvent. Viscosity and density were measured on a solvent with a lithium salt added (final electrolyte).