<p>Some molecular complexes exhibiting bistability between two different spin states have been subject to vast investigations. Spin crossover and valence tautomerism interconversion molecular compounds are such examples showing this dynamic switching behavior and are a route toward designing molecular devices with a facile readout due to the change in the spin state that accompanies the change in conductance. Due to their extensive potential applications in industry and research, they are among the most interesting topics in spintronics. Spin state switching processes provide the foundation for applications in molecule-based devices. The main goal is to study the parameters that affect the intramolecular electron transfer between different spin states in spin crossover molecular thin films and the electron transfer between the metal center and redox-active ligands in valence tautomer thin films. </p> <p>Because substrate effects are important for any molecular-based device, there are increasing efforts to study the influence of the substrate on spin state transition. While some non-metallic substrates like graphite seem to be promising from experimental measurements, theoretical and experimental studies indicate that 2D semiconductor surfaces will have minimum interaction with spin crossover molecules.</p> <p>In this work, the functionality of two different spin crossover molecules sublimated on the ferroelectric Polyvinylidene Fluoride Hexafluoropropylene (PVDF-HFP) layer and 2D Ti3C2 MXene thin film is studied. We report the temperature-dependent spin state transition of spin crossover molecules, [Fe{H2B(pz)2}2 (bipy)], thin films, and valance tautomer [Co(sq)(cat)(3-tpp)2] thin films. Using a UV-Vis spectrometer and a specific lab-built sample holder we were able to perform the measurement at temperatures as low as 90 K and as high as 440 K. Temperature-dependent UV-Vis data show that the transition temperature from the high spin state to the low spin state and vice versa is well below the room temperature. However, for isothermal switching purposes, we designed and fabricated a bilayer device with PVDF-HFP thin films as the substrate to facilitate isothermal switching close to room temperature. The retention of voltage-controlled nonvolatile changes to the electronic structure in bilayers of PVDF-HFP/[Fe{H2B(pz)2}2(bipy)] and PVDF-HFP/[Co(sq)(cat)(3-tpp)2] strongly depends on the thickness of the PVDF-HFP layer. </p> <p>While the electric transport measurement revealed that doping the SCO layer with Ti3C2 MXene flakes can significantly improve the conductivity of the spin crossover molecular thin films, the temperature-dependent UV-Vis measurements represent that the adjacent MXene layer can cause a lock in the given spin state or a change in the transition temperature dramatically.</p> <p><br></p>

The Unit Commitment Problem (UCP) poses a significant challenge in optimizing powergeneration schedules within complex and dynamic energy systems. This study explores theapplication of Genetic Algorithms (GAs) as a promising approach to address UCP, their ability tonavigate complex solution spaces and adapt to changing operational conditions. The work provides a broad exploration of their effectiveness, challenges, and future prospects. The objective of UCP is to efficiently optimize power generation schedules within complex energy systems, seeking cost-effective and reliable solutions while accommodating various operational constraints. Various encoding techniques and GA operations are implemented and evaluated incomparison to the solutions obtained from a commercial Mixed-Integer Linear Programming (MILP) solver. The key findings point to the potential for achieving high quality solutions and robustness in the application of these techniques. However, it is important to acknowledge and address challenges such as encoding complexity, extensive computation times, the risk of premature convergence, and the complications of handling complex constraints that continue to exist in this domain. The future scope lies in hybrid approaches, scalability enhancement and incorporation of multi-objective optimization, offering unrealized potential for the efficient andsustainable operation of modern energy systems.

No description available.

This thesis is an ethnomusicological cross-cultural examination of Heavy Metal, Hardcore Punk and Metalcore music-cultures and how the transculturation of two distinct music-cultures, Heavy Metal and Hardcore Punk, have resulted in a third unique music-culture: Metalcore. Attention is given to the evolution of the music-cultures through history, with mention of current trends not covered in any other literature. In addition explanations of key tenets of culture-ways and their importance in forming these cultures as separate and distinct will be included. Topics addressed will include headbanging, the sign of the horns and moshing in Heavy Metal; slam-dancing, Straight Edge, and the do-it-yourself principles of Hardcore Punk; the commercial commoditization and establishment of Metalcore as separate and unique from both Heavy Metal and Hardcore Punk. In addition, a brief assessment of material culture will be included, covering the importance of musical instruments, art, and fashion. Fashion is especially important in forming ties with respective communities, personal interest groups, and establishing personal identity within the music-cultures. Both secondary source, as well as qualitative research will be used. While much of the history and culture-ways of Heavy Metal and Hardcore Punk have been well documented throughout the 1970s there is a lack of literature concerning either culture since the 1990s and 2000s. With the exception of only a few sources, there is little material addressing Metalcore, or Crossover Thrash music-culture. As a participant within Heavy Metal culture I will offer my own personal observations, as well as those of informants, to extend and support the documentary research findings.

Les séries télévisées dramatiques américaines contemporaines (1990-2005) ont développé un mode de communication spécifique avec les téléspectateurs, fondé sur la construction d'une connivence entre le public et le programme, que nous étudierons en utilisant les principes de la rhétorique épidictique. Deux axes sont particulièrement importants et font l'objet d'une attention particulière : les seuils (titres, génériques, épigraphes, etc.) et les phénomènes d'intertextualité et de transtextualité. Les premiers sont devenus des lieux de jeu entre les producteurs du discours (chaînes, créateurs, producteurs exécutifs, scénaristes) et le public : oscillant entre normes industrielles et dynamisme créatif personnel, ils accompagnent les téléspectateurs dans leur entrée et leur sortie de la série et manifestent de forts enjeux marketing. Les phénomènes d'intertextualité et de transtextualité sont d'abord le spin off et le crossover, mais aussi tout le continuum des procédés de citation et de référence qui aboutissent à la constitution d'un texte-centon. Ils finissent par faire de la série télévisée un palimpseste, dans lequel chaque texte est l'écho de mille autres textes, d'événements de notre contemporanéité et nous rappelle les situations de notre vie. La série télévisée devient ainsi un rituel, non seulement de consommation (regarder son épisode chaque semaine), mais aussi au sens que la rhétorique épidictique donne à ce mot : elle permet de créer une communauté réunie autour de valeurs partagées.

本研究始於採訪實務中的觀察：學者在報端發表評論，影響了讀者們對於重要新聞事件或社會議題的解讀，報紙則藉助學者的身分及知識，提高報紙的可信度。根據一份來自媒體內部的非正式排行榜卻顯示，短短數年內，知名的學者或專家見諸報端的次數竟然多達數百次，這份名單被用來提醒記者們少找這些高曝光者。美國媒體界通稱這一群常見諸報端的評論者為Pundit(研究者試譯為「評匠」)，他們擁有「一通電話，快速評論」的本領，甚至自嘲是「評論應召者」。這樣的轉變毋寧是巨大的，研究者試圖追尋知識份子在報紙裡形貌的轉變。 　評論是報紙提供讀者除了資訊之外，得到觀點的重要來源。除了來自學院的知識份子之外，其他評論者還包括來自產業或具有專門知識的專家（例如律師、會計師、醫師或產業專門人士等），包括記者及專欄作家等媒體工作者以及透過投書表達意見的一般民眾。在報導形式上，除了客觀事實之外，摻入專家評論或民眾意見這種混合報導與評論的新聞，出現的頻率越來越多，尤以《蘋果日報》最常使用。研究者將此一報導形式稱為「混搭式報導」(crossover-reporting)，取其將不同性質的訊息及知識拼貼在一起之意，並作為觀察知識份子形貌變化的重要取徑。 本研究採定性及定量雙重取徑，透過內容分析法，選擇1987年（解除報禁）、1989、1997、1999、2003、2009等六個年份，包括：《聯合報》、《中國時報》、《自由時報》(1989年起)、及《蘋果日報》(2003年起)等四份主要報紙，以立意取樣觀察並紀錄評論者出現的次數、所佔面積/字數、位置(如新聞辦面、論壇版面或副刊版面等)、形式(如專文、座談會、受訪、讀者投書)，是否為混搭式報導等。另搭配對報導內容的定性觀察及深入訪談兩位新聞工作者，輔助量化分析所得並進一步進行質性探討。 結果顯示：雖然隨著報禁開放，學院知識份子的評論次數逐漸增加，但在22年間，評論的平均面積卻減少了52%，且從可完整論述的專文，逐漸退卻並轉進到民意論壇。以專文為例，從1987年的每篇平均320cm2，減少到2009年的80cm2。學院知識份子份量減少但次數增加，此一現象自2003年《蘋果日報》創刊後，大量採用混搭式報導就更形明顯。混搭式報導也提供了產業知識份子(專家)們評論的機會，甚至一般民眾都可以表達意見，出現的次數甚至不亞於比學者，但分量更為稀少，平均面積只有10餘平方公分。 至於深入訪談的編輯主管及第一線的記者都坦承在截稿時間壓力下及編輯部門要求下，會趨向選擇採訪口語表達能力好，反應快、可主動提供符合編輯需要的評論意見的學者或專家，與美國的評匠有相當高的同質性。 綜上，研究者認為，知識份子與報紙之間的關係，已從早期的文人報導，論政救國，逐漸退居到作為報導裡眾生喧嘩裡的評論者之一。知識遭到工具化，僅有滿足報紙設定立場的機械式評論。作為獨立意見提供者，知識份子或許應該維持反叛與堅持的態度，基於面向社會的責任感。在面對報業困境及呈現爆炸式成長的新興傳播科技與網路社群的同時，知識份子們應當重新自我書寫、發表並尋回獨立發聲的機會，方能作為社會良知，發聲以震聵 / In order to emphasize the credibility of news reports and offer news analysis to the readers, newspaper as well as other media always quote the comments of experts or scholars. However, an informal ranking list came from a newspaper revealed that the same group of experts always quoted up to several hundred times within years, and the mangers of the this newspaper reminded their reporters to avoid interviewing those experts who were familiar to the public. The American media industry call a group of commentators with different specialties often shown in the newspaper as ‘Pundit,’who are well prepared to answer questions or express their viewpoints for the reporters in a phone call quickly. Thus, this phenomenon seems to be common not only in Taiwan but also in other countries. Comments in the newspaper provide readers different point of views other than objective information. Instead of academic scholars, experts such as lawyers, doctors, accountants, columnists and senior media workers can also play the role of commentators. In this study, we observe a kind of news report which reporters not only provide facts to the readers, but also quote the comments of the intellectuals, as well as that of common people. The study call this type of reports as ‘crossover-reporting,’ which is a new phenomena in Taiwan media industry, and the reporter of which combine different kinds of information in a report. This technique is seemed to be mostly used by Apple Daily. By analyzing how the intellectuals and their comments appears in the newspaper, the study tries to explore the changing roles of the intellectuals in Taiwan printed media. Both quantitative and qualitative analysis are used in this study. We choose four newspaper from 1989 to 2009 as our materials. The properties of the comments were further analyzed by purposively sampling the appearance of intellectuals in the main contents in theses newspapers. We analyze the number of words, the section where the report appears (e.g. in the main reports, forums, or supplements), and the form (e.g. special articles, opinion, symposium, interviews, or letters to editors) to define whether a report is cross-reporting or not, and to observe the change of the role of intellectuals. Besides, we interview two senior media worker to gather qualitative information for our analysis; one of the interviewee is a chief editor and the other one is a senior reporter. The results of the study shows that the number of comments from academic scholars is increasing since 1987 (the year which the Lifting of Martial Law is declared in Taiwan); however, the average area is decreased by 52% within 22 years, and the form they appeared is gradually transformed from integral special article to public opinion forum (e.g. the average area was 320 cm2 in 1987, but remain only 80 cm2 in 2009 in special articles). The study also shows since Apply Daily started publication in 2003 and its massive use of crossover-reporting, the academic scholars’ number of words quoted by reporter has decreased, but the number of academic scholars’ quotation has increased. We also find that the using of crossover-reporting provides the opportunities for other intellectuals and even general public to comment on news issues. The number of their comment is even more than that of the scholars, but number of words of the former (average area is only about 10 cm2) is lesser than that of the latter. By interviewing two senior media workers, both of them agree that, under time pressure and the demand from editors, they prefer to adopt the comments from those intellectuals who can express clearly, response quickly and actively provide information. This situation is very similar to that of American mass media industry of which the media always need ‘Pundit’ to give quick and clear comments for the needs of reporting and editing. In words, this study demonstrates the change of the role of the intellectuals in the newspaper; they used to offered professional opinions for the public and played important role in politics. However, in the recent years, the intellectuals’ role gradually decline and become only one of the commentators appearing in media. Now professional knowledge is used only as tool to support the viewpoint of the newspaper. In our opinion, we still suggest that the intellectuals should remember their social responsibilities, keep their independent and critical roles and resist the present situation which regard them as only tools or materials of reporting. In facing the decline of printed media and the rising of new media technology such as internet and social media, the intellectuals should try to reclaim their position as the conscience of the society and reacquire their influencing role to enlightening the public.

No description available.

De nombreux travaux ont été dédiés ces dernières années aux matériaux à transition de spin qui présentent des potentialités pour le stockage de l’information en raison de leurs propriétés physiques commutables : métastabilité thermique et optique. Ce travail est relatif au mécanisme photo-induit dans les systèmes à transition de spin et, plus précisément, à l’étude des effets de dilution sur la température LIESST. L’objectif principal est de mieux cerner les paramètres qui gouvernent T(LIESST). Diverses études expérimentales ont été réalisées sur des composés mononucléaires 0D, polymériques 1D et polynucléaires. L’analyse de l’ensemble des propriétés photomagnétiques a permis de montrer que T(LIESST) est indépendant de la dilution et suggère que cette grandeur est gérée par la molécule et dépend très peu des interactions intermoléculaires. / In the last few years, many studies have been dedicated to spin-crossover compounds because of their potential application in data-storage systems. In such systems, optical switching is particularly promising. This work deals with the photo-induced phenomenon encountered in spin crossover systems, more specifically, the effects of metal dilution on the LIESST temperature. The main objective is to better define the parameters that govern T (LIESST). Various experimental studies were performed on mononuclear 0D compounds, polymeric 1D systems and polynuclear systems. The analysis of all photomagnetic properties has shown that T(LIESST) is not affected by the dilution and suggests that this parameter is govern at the molecular scale and depends very few of intermolecular interactions.

Thesis (M. Tech.) (Engineering: Electrical, Dept.: Electronic Engineering))--Vaal University of Technology, 2008. / The demand for higher efficiency, sustainability and cleaner power sources increases daily. A Direct Methanol Fuel Cell is a power source that can be applied for small to medium household appliances and office equipment. It can ideally be used for operating appliances like notebook computers on remote sites where no electrical power is available. One of the problems in methanol fuel cells is methanol crossover. Methanol crossover occurs when methanol is not completely used in the process of generating electrons, and a certain percentage of the methanol is wasted. Crossover may damage the proton exchange membrane of the fuel cell and reduce the efficiency of a DMFC. Literature reviews were done and suggestions from other writers are discussed on how to reduce methanol crossover. This research focuses primarily on the fact that crossover can be controlled by controlling the methanol / water concentration. A prototype methanol controller was built with an ultrasonic sensor for detecting the density of the methanol/water mixture and a sensor for the temperature of the mixture; this was done because the density of the mixture is dependant on the temperature and the concentration. The controller was calibrated to determine the amount per volume of water and methanol which enables the controller to control the percentage of methanol in the water. The prototype also had the feature built in to adjust the mixture in order to enable the study on the effects of crossover. A data logger function was added to store collected data on a personal computer for the study on methanol and water. It was observed that the sensor was sensitive enough and was able to produce 1% increments of the level of methanol concentration in the water provided the temperature was stable. A methanol controller was successfully built to ensure the correct volume of methanol. / Telkom Centre of Excellence

Dans cette thèse, nous présentons une approche modélisatrice multi-échelles au sein de la théorie de la fonctionnelle densité (DFT) de différentes classes de complexes à propriétés magnétiques commutables essentiellement à base de Fe(II) (3d6). Le manuscrit est organisé en trois grandes parties : la première a été consacrée à la présentation de la chimie théorique (concepts et méthodes). Le magnétisme moléculaire été examiné au travers du calcul de la constante de couplage et discuté dans la partie II. L’analyse de la constante de couplage, du magnétisme, des structures électroniques et des liaisons chimiques a été présentée. D’autre part, l’étude des valeurs thermodynamiques pour [Fe(btz)2(NCS)2] ainsi que la famille de complexes à transition de spin [Fe(L)2(NCS)2] a formée la troisième partie. De deux approches complémentaires sont utilisées: i-moléculaire où l’entité isolée est examinée en utilisant des codes de calcul ciblés moyennant différentes fonctionnelles d’échange corrélation et bases ; ii-« tout solide » prenant en compte la structure cristalline étendue. Les résultats sont également appuyés par une étude semi-empirique au sein de la dynamique moléculaire / In this thesis, we present an multiscale approaches based on theoretical modeling within density functional (DFT) of different classes of complex magnetic properties switched from predominantly Fe(II) (3d6). The manuscript is organized into three main parts: the first was devoted to the presentation of theoretical chemistry (concepts and methods). The molecular magnetism was examined through the calculation of the coupling constant and discussed in Part II. The analysis of the coupling constant, magnetism, electronic structure and chemical bonds was presented. In the third Part, the study of thermodynamic values for [Fe(btz)2(NCS)2] and the family of spin crossover complexes [Fe(L)2(NCS)2] has formed the third party. Two complementary approaches are used: i-“molecular” which considers a fragment entity or isolated molecule using different computer codes targeted through various exchange correlation functional and basis; ii-"solid state" taking into account the extended crystal structure. The results are also supported by a semi-empirical study through molecular dynamics.