Mirades turístiques a la ciutat. Anàlisi del comportament dels visitants del Barri Vell de Girona

Mirades Turístiques a la ciutat és un estudi sobre el comportament del turisme en les ciutats monumentals, a partir de l'experiència viscuda pels visitants del Barri Vell de Girona. Una recerca que ha pretès determinar, precisament, la forma com els visitants entren en contacte amb el patrimoni monumental de la ciutat medieval. A partir, d'identificar quins factors influeixen (i quins no) en el comportament dels turistes durant la seva visita, tant pel que fa referència als factors ambientals generals (la meteorologia, la congestió, la informació...) com els factors singulars de cada visitant. Per tal d'assolir aquests objectius, en hem plantejat una sèrie d'hipòtesis de treball: 1. Existeix una manera turística d'apropar-se al patrimoni que té les seves pròpies regles, les seves estructures específiques i en conseqüència la necessitat d'uns instruments de gestió particulars. 2. L'aproximació del turista al patrimoni monumental és el resultat de dues forces aparentment contradictòries. D'una banda, el turista tendeix a reproduir pautes de comportament socialment construïdes que prenen la forma d'un ritual. D'altra banda, més enllà d'aquest patró comú, cada visitant viu una experiència singular. Per tant, la relació amb el patrimoni és el resultat d'un subtil equilibri entre experiència i ritual. 3. El consum turístic del patrimoni depèn de la relació entre quatre factors. El primer, la imatge del lloc, és la projecció (sovint idealitzada) de l'espai de visita, una metàfora de la ciutat. El segon, el codi d'interpretació turístic , actua com una mena de ritual, un guió no escrit de la pràctica turística. En tercer lloc, el substrat material que són els components artístics, històrics o culturals de la destinació: la geometria del casc, les visuals, el pes de la història o el valor estètic de les peces condicionen, com és obvi, la mirada turística. Finalment, l'experiència està condicionada per la gestió (pública i privada) del turisme: informació, fluxos, interpretació... L'estudi s'ha sustentat en una metodologia inèdita basada en l'observació directa a partir del seguiment dels visitants durant els seus recorreguts. Hem observat el visitants i hem recollit la informació bàsica de la seva visita: l'itinerari, els monuments visitats, les actituds manifestades, els temps d'estada... Aquesta metodologia ha estat ja implementada en alguns estudis de públic de diversos museus. S'han recollit tres tipus de dades: dades relacionades amb els arcs (segment de carrer entre dues interseccions), dades relacionades amb els nodes (els elements d'interès) i dades relacionades amb el visitant. Les tres fonts estan unides per un identificador comú, que és el codi del turista. Això ens ha permès vincular les dades dels visitants amb el seu recorregut i la seva visita als monuments de la ciutat. Els resultats de l'estudi ens han permès identificar els factors que singularitzen l'apropament dels visitants al patrimoni i que el diferencien d'altres formes de relació o ús. És a dir, els factors que incideixen en el comportament dels visitants de Girona. Així mateix, hem pogut definir models d'itineraris amb una estructura interna molt compacta però molt diferents entre ells; que ens evidencien que, malgrat les regularitats detectades en les visites dels turistes de la ciutat, també existeixen elements diferencials en el seu comportament. Hem detectat quatre models de recorreguts urbans que hem anomenat: itinerari bàsic, comercial, complex i de les muralles, que a l'hora es poden subdividir en varies categories. Finalment, els estadístics multivariants ens han permès demostrar que la relació entre el turista i el patrimoni respon almenys a quatre formes de consum diferenciades, que hem anomenat "no turistes", "rituals", "interessats" i "erudits".

Corrosion behaviour and hardness of in situ consolidated nanostructured Al and Al-Cr alloys produced via high-energy ball milling

This paper presents a hypothesis and its experimental validation that simultaneous improvement in the hardness and corrosion resistance of aluminium can be achieved by the combination of suitable processing route and alloying additions. More specifically, the corrosion resistance and hardness of Al- xCr (x= 0-10 wt.%) alloys as produced via high-energy ball milling were significantly higher than pure Al and AA7075-T651. The improved properties of the Al- xCr alloys were attributed to the Cr addition and high-energy ball milling, which caused nanocrystalline structure, extended solubility of Cr in Al, and uniformly distributed fine intermetallic phases in the Al-Cr matrix.

Synthesis, X-ray crystal structure and theoretical calculations of antileishmanial neolignan analogues

A síntese e a estrutura cristalina por difração de raios-X de dois análogos de neolignanas, 2-(4-clorofenil)-1-feniletanona (20) e 2-[tio(4-clorofenil)]-1-(3,4-dimetoxifenil)propan-1-ona (12) são descritas. O composto 12 apresenta atividade intracelular contra Leishmania donovani e Leishmania amazonensis de amastigotas que causam a leishmaniose tegumentar e visceral. Além disso, a teoria do funcional de densidade (DFT) com o funcional híbrido B3LYP foi empregado para calcular um conjunto de descritores moleculares para dezenove análogos sintéticos de neolignanas com atividades antileishmaniose. Posteriormente, a análise discriminante stepwise foi realizada para investigar possíveis relações entre a estrutura molecular e atividades biológicas. Por meio dessa análise os compostos foram classificados em dois grupos ativos e inativos de acordo com seu grau de atividade biológica, e as propriedades mais importantes foram as cargas de alguns átomos, a afinidade eletrônica e o ClogP.

Isolation, X-ray crystal structure and theoretical calculations of the new compound 8-Eepicordatin and identification of others terpenes and steroids from the bark and leaves of Croton palanostigma Klotzsch

Estudos fitoquímicos com as cascas do caule e com as folhas de Croton palanostigma Klotzsch (Euphorbiaceae) levaram ao isolamento do novo diterpeno clerodânico 8-epicordatina (2), além de éster metílico do ácido 12-oxohardwickiico (3), aparisthmano, cordatina (1), ácido ent-trachiloban-18-óico, óxido de ent-13-epimanoila, óxido de ent-3-oxo-13-epimanoila, óxido de ent-3β-hidroxi-13-epimanoila, sitosterol, estigmasterol, estigmastan-3-ona, 6β-hidroxiestigmast-4-en-3-ona, 6β-hidroxiestigmasta-4,22-dien-3-ona, estigmast-4-en-3-ona, estigmasta-4,22-dien-3-ona, ácido 3-O-acetilaleuritolico, 11α-hidroxiurs-12-en-3-ona, α-amirenona, 24-metilenocicloartenona e lupenona. Estas substâncias foram isoladas através de procedimentos fitoquímicos usuais e suas estruturas foram deduzidas por estudos espectroscópicos, incluindo experimentos em 2D. Adicionalmente, a estrutura cristalina de 8-epicordatina (2) foi determinada por difração de raios-X. Cálculos teóricos de RMN ao nível B3PW91/DGDZVP foram usados para confirmação dos assinalamentos dos deslocamentos químicos dos hidrogênios H-7α e H-7β de 8-epicordatina.

Balanço hídrico, crescimento e produtividade de genótipos RB de cana-de-açúcar em cultivo de sequeiro na região de Rio Largo-AL

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Semantic change and intersubjectification: The origin of reprise evidential conditional in Old Catalan

The reprise evidential conditional (REC) is nowadays not very usual in Catalan: it is restricted to journalistic language and to some very formal genres (such as academic or legal language), it is not present in spontaneous discourse. On the one hand, it has been described among the rather new modality values of the conditional. On the other, the normative tradition tended to reject it for being a gallicism, or to describe it as an unsuitable neologism. Thanks to the extraction from text corpora, we surprisingly find this REC in Catalan from the beginning of the fourteenth century to the contemporary age, with semantic and pragmatic nuances and different evidence of grammaticalization. Due to the current interest in evidentiality, the REC has been widely studied in French, Italian and Portuguese, focusing mainly on its contemporary uses and not so intensively on the diachronic process that could explain the origin of this value. In line with this research, that we initiated studying the epistemic and evidential future in Catalan, our aim is to describe: a) the pragmatic context that could have been the initial point of the REC in the thirteenth century, before we find indisputable attestations of this use; b) the path of semantic change followed by the conditional from a ‘future in the past’ tense to the acquisition of epistemic and evidential values; and c) the role played by invited inferences, subjectification and intersubjectification in this change.

High fidelity probe and mitigation of mirror thermal fluctuations

Thermal noise arising from mechanical loss in high reflective dielectric coatings is a significant source of noise in precision optical measurements. In particular, Advanced LIGO, a large scale interferometer aiming to observed gravitational wave, is expected to be limited by coating thermal noise in the most sensitive region around 30–300 Hz. Various theoretical calculations for predicting coating Brownian noise have been proposed. However, due to the relatively limited knowledge of the coating material properties, an accurate approximation of the noise cannot be achieved. A testbed that can directly observed coating thermal noise close to Advanced LIGO band will serve as an indispensable tool to verify the calculations, study material properties of the coating, and estimate the detector’s performance.

This dissertation reports a setup that has sensitivity to observe wide band (10Hz to 1kHz) thermal noise from fused silica/tantala coating at room temperature from fixed-spacer Fabry–Perot cavities. Important fundamental noises and technical noises associated with the setup are discussed. The coating loss obtained from the measurement agrees with results reported in the literature. The setup serves as a testbed to study thermal noise in high reflective mirrors from different materials. One example is a heterostructure of Al_xGa_1−xAs (AlGaAs). An optimized design to minimize thermo–optic noise in the coating is proposed and discussed in this work.

Polaron effects on the optical absorptions in asymmetrical semi-parabolic quantum wells

The linear and nonlinear optical absorptions considering the weak-coupling electron-LO-phonon interaction in asymmetrical semiparabolic quantum wells are theoretically investigated. The numerical results for the typical GaAs/AlxGa1-xAs material show that the factors of Al content x, the relaxation time and the photon energy have great influence on the optical absorption coefficients. Moreover, the theoretical values of the optical absorptions are more than a factor of 2-3 higher than the one in the structure without considering the electron-LO-phonon interaction by calculating. (C) 2007 Elsevier B.V. All rights reserved.

New optoelectronic devices using GaAs-GaAlAs epitaxy

Three subjects related to epitaxial GaAs-GaAlAs optoelectronic devices are discussed in this thesis. They are:

1. Embedded Epitaxy

This is a technique of selective multilayer growth of GaAs- Ga_1-xAl_xAs single crystal structures through stripe openings in masking layers on GaAs substrates. This technique results in prismatic layers of GaAs and Ga_1-xAl_xAs "embedded" in each other and leads to controllable uniform structures terminated by crystal faces. The dependence of the growth habit on the orientation of the stripe openings has been studied. Room temperature embedded double heterostructure lasers have been fabricated using this technique. Threshold current densities as low as 1.5 KA/cm² have been achieved.

2. Barrier Controlled PNPN Laser Diode

It is found that the I-V characteristics of a PNPN device can be controlled by using potential barriers in the base regions. Based on this principle, GaAs-GaAlAs heterostructure PNPN laser diodes have been fabricated. GaAlAs potential barriers in the bases control not only the electrical but also the optical properties of the device. PNPN lasers with low threshold currents and high breakover voltage have been achieved. Numerical calculations of this barrier controlled structure are presented in the ranges where the total current is below the holding point and near the lasing threshold.

3. Injection Lasers on Semi-Insulating Substrates

GaAs-GaAlAs heterostructure lasers fabricated on semi-insulating substrates have been studied. Two different laser structures achieved are: (1) Crowding effect lasers, (2) Lateral injection lasers. Experimental results and the working principles underlying the operation of these lasers are presented. The gain induced guiding mechanism is used to explain the lasers' far field radiation patterns. It is found that Zn diffusion in Ga_1-xAl_xAs depends on the Al content x, and that GaAs can be used as the diffusion mask for Zn diffusion in Ga_1-xAl_xAs. Lasers having very low threshold currents and operating in a stable single mode have been achieved. Because these lasers are fabricated on semi-insulating substrates, it is possible to integrate them with other electronic devices on the same substrate. An integrated device, which consists of a crowding effect laser and a Gunn oscillator on a common semi-insulating GaAs substrate, has been achieved.

化学法高效载体钛催化剂的乙烯/α-烯烃共聚合

研究了化学反应催化剂制备及其乙烯/α-烯烃共聚反应规律与机理，探讨了共聚活性增大的原因，提出了α烯烃存在下活性中心浓度增大这一基本论点，并对所得共聚物进行了表征。用WAXD、IR等方法研究了化学反应催化剂制备过程，结果表明原料MgCl_2、n-BuOH、i-Bu_3 Al、TiCl_4之间通过①醇解②解醇③载钛，三步反应最后得到了活性组分高度分散在X射线衍射无定形的MgCl_2微晶上而形成的高效载体催化剂。讨论其乙烯/α-烯烃共聚合的基本规律。提出了α-烯烃促进共聚速率较乙烯均聚速率增大这一实验结果。动力学研究结果表明，催化剂系的非均匀性和多活性中心的存在及α-烯烃分子使活性中心浓度增大是共聚速率增大的根本原因。催化体系及其聚合过程的ESCA与ESR研究 证明了α-烯烃存在下催化活性中心浓度的增大，并得出了ESR信号所反应的Ti~3离子中，也有没有活性的Ti~3离子。同时ESR还从乙烯与乙烯/丙烯共聚合不同的共振吸收峰提出了多活性中心存在的初步证据。从不同侧面探讨了多活性中心存在的证据。指出酯不仅可影响共聚反应的催化效率，而且可以影响共聚物的组成及序列分布。共聚物的形态随α-烯烃加入逐渐变为非晶性无定形。不同α-烯烃对共聚物结晶性能有显著影响。不同α-烯烃共聚物具有不同的临界结晶序列长度。乙烯/丙烯/辛烯三无共聚合催化效率比乙烯/丙烯及乙烯/辛烯二元共聚全催化效率进一步增大，反映了α-烯烃促活作用具有迭加性。从取代基效应理论求得了乙烯/丙烯和乙烯/辛烯共聚物取代基效应参数，以很好地对其~(13)C NMR谱图进行归属。成功地对乙烯/丙烯/辛烯三元共聚物~(13)C NMR结果进行了处理，并指出了文献中的两处错误。

Electronic properties of zinc-blende GaN, AlN, and their alloys Ga1-xAlxN

The electronic properties of wide-energy gap zinc-blende structure GaN, A1N, and their alloys Ga(1-x)A1(x)N are investigated using the empirical pseudopotential method. Electron and hole effective mass parameters, hydrostatic and shear deformation potential constants of the valence band at Gamma and those of the conduction band at Gamma and X are obtained for GaN and AIN, respectively. The energies of Gamma, X, L conduction valleys of Ga(1-x)A1(x)N alloy versus Al fraction x are also calculated. The information will be useful for the design of lattice mismatched heterostructure optoelectronic devices based on these materials in the blue light range application. (C) 1995 American Institute of Physics.

Band structure parameters of zinc-blende GaN, AlN and their alloys Ga1-xAlxN

The electronic properties of wide energy gap zinc-blende structure GaN, AlN and their alloys Ga1-xAlxN are investigated using the empirical pseudopotential method. Electron and hole Effective mass parameters, hydrostatic and shear deformation potential constants of the valence band at Gamma and those of the conduction band at Gamma and X are obtained. The energies of Gamma, X, L conduction valleys of Ga1-xAlxN alloy versus Al fraction x are also calculated. The information will be useful for the design of lattice mismatched heterostructure optoelectronic devices in the blue light range.

~(40)Ar~(16+)入射金属表面的近红外光谱线发射

速度小于Bohr速度(vBhor=2.9×106m/s)的高电荷态离子40Ar16+(动能EK=150keV,速度v=8.5×105m/s)入射金属(Ni,Mo,Au和Al)表面,同时测量产生的Ar原子近红外光谱线和X射线谱.实验结果表明,低速高电荷态离子在金属表面俘获电子中性化,形成多激发态的Ar空心原子,空心原子退激辐射从近红外光谱线到X射线波段谱线,近红外光谱线辐射强度说明,低速高电荷态离子在金属表面中性化过程中,金属的功函数起着重要作用,进而验证了经典过垒模型.

非完全深部非弹的简单模型分析 多参数大面积电离室

根据~(16)O+~(27)AL反应α粒子和类弹碎片符合实验中的一些特殊现象，提出了一个弹核先碎裂，然后碎裂余核与靶核进一步发生深部非弹的非完全深部非弹模型，计算的结果和实验的能谱，角分布和维率斯基图进行了对比和分析。 多参数大面积电离室结合放在电离室前的PPAC，能对重离子反应产物进行全运动学参数测量（x,y,A,Z,E），本工作进行了这种探测器的制做和测试，用PLO气体在气压的290mbar下，对Thc-α粒子，电离室ΔE_1,ΔE_2,ΔE_3,ΔE_4及E_k得到的分辩为6.1%、5.7%、4.8%、4.6%及1.5%。对252cf源，y位置分辩为3.65mm，另外还设计，制做和测试了螺旋阴极位置灵敏正比室探测量，其位置分辩为0.94mm、ΔE分辩为16%，并对这种探测器进行电离室x位置测量的可能性进行了探讨