In memory of François Diederich. / Nanographenes (NGs) with open-shell character have gained intense attention due to their potential applications in future organic nanoelectronics and spintronics. Among them, NGs bearing a pair of parallel zigzag edges, such as acenes and periacenes (PAs) bestow unique (opto)electronic and magnetic properties owing to their localized non-bonding π-state. However, their reactive zigzag edges impart intrinsic instability, leading to the challenging synthesis. The recent development of synthetic strategies provided access to several π-extended PAs, which were considered unrealistic for decades. Notably, their laterally π-extended structures of zigzag-edged graphene nanoribbons was realised via on-surface synthesis. However, synthesis of π-extended PAs in solution is still in its infancy, more intensive scientific efforts are needed to surpass the existing challenges regarding stability and solubility. This Review provides an overview of recent progress in the synthesis and characterization of PAs through a bottom-up synthetic strategy, including on-surface and solution-phase chemistry. In addition, views on existing challenges and the future prospects are also provided.

Nature based sports and outdoor recreation activities are much appreciated, but continued densification in urban and peri-urban areas may reduce future opportunities to take part in such activities in a desirable way. To be able to consider the needs of these activities, in relation to other competing land use interests, it is essential to understand why people engage in the activities and how the nature landscape contributes and is used. The aim of this degree project is, therefore, to investigate motives and preferences among participants in various nature based activities, and to describe the role of nature and the participants’ relation to the nature landscape. While many previous studies have targeted recreational activities, where participation traditionally is non-competitive and focused on wellbeing, this study mainly targets nature based sports, where activities, in general, are more physical and result-oriented. The study has a descriptive approach where Rudan, a nature reserve in southern Stockholm, is used as a case study. There, data was primarily collected through a questionnaire (N=64), distributed among members of sport clubs in Rudan as well as among visitors on site. Responses were then analysed through cross-tabulations. The results indicate that people have varying, and often several, motives for taking part in their activities and for performing their activities in a particular setting. The results also show that the nature landscape, and the characteristics it holds, has an important role to play in many aspects; it can be a driver of motivation, a stage for the activity, and a generator of human benefits. The relatively small sample size does, however, affect the accuracy of the study, and more research is needed to get a comprehensive understanding. Nevertheless, the findings can be used to raise awareness and communicate the value of nature in nature based sports and outdoor recreation activities. Recognising nature’s multiple roles and values for participants in such activities will be necessary when analysing potential effects of future development plans or interventions in the peri-urban nature landscape. / Utomhusidrott och friluftsliv utgör uppskattade inslag i många människors vardag, men med fortsatt förtätning i städer och i stadsnära grönområden riskerar de framtida möjligheterna att delta i sådana aktiviteter att försämras. För att möta dessa aktiviteters behov, framförallt då de utsätts för konkurrens av andra samhällsintressen, är det nödvändigt att förstå grunderna för deltagande i sådana utomhusaktiviteter, samt hur naturlandskapet används och bidrar till upplevelsen. Syftet med detta examensarbete är därför att undersöka motiv och preferenser bland deltagare i olika naturrelaterade idrotts- och friluftsaktiviteter, och att därutöver beskriva naturens roll och deltagarnas relation till naturlandskapet. Då många tidigare studier har fokuserat på friluftsliv, där deltagande traditionellt sett är inriktat på rekreation och välmående, vänder sig denna studie främst mot idrottsaktiviteter, där deltagande i allmänhet är mer fysiskt och resultatinriktat. Studien har ett beskrivande tillvägagångssätt där Rudan, ett naturreservat i södra Stockholm, används som fallstudie. Flera metoder har använts, men data har främst inhämtats genom en enkätundersökning (N = 64) som besvarades av medlemmar i idrottsföreningar i Rudan samt av besökare på plats. Svaren analyserades sedan med hjälp av pivottabeller. Resultaten visar att det finns olika, och ofta flera, motiv för att delta i aktiviteterna och för att utföra aktiviteterna i ett visst område. Resultaten visar även att naturlandskapet har en viktig roll, sett ur många aspekter. Det kan vara en motiverande faktor, en arena för aktiviteten och bidra till många övriga mervärden. Då antalet respondenter i studien var relativt lågt är studiens resultat dock något osäkert, och mer omfattande undersökningar behövs för att skapa tydligare förståelse. Trots det kan resultaten i studien användas för att öka medvetenheten och tydliggöra naturens värde inom utomhusidrott och friluftsliv. Naturens många olika värden och roller för idrotts- och friluftslivsutövare bör sedan beaktas inom samhällsplaneringen i stort och vid framtida utveckling av stadsnära natur- och rekreationsområden.

Combining solution-based and surface-assisted synthesis, we demonstrate the first synthesis of NBN-doped bis-tetracene (NBN-BT) and peri-tetracene (NBN-PT). The chemical structures are clearly elucidated by high-resolution scanning tunneling microscopy (STM) in combination with noncontact atomic force microscopy (nc-AFM). Scanning tunneling spectroscopy (STS) characterizations reveal that NBN-BT and NBN-PT possess higher energy gaps than bis-tetracene and peri-tetracene. Interestingly, NBN-BT can undergo stepwise one-electron oxidation and convert into its corresponding radical cation and then to its dication. The energy gap of the NBN-BT dication is similar to that of bis-tetracene, indicating their isoelectronic relationship. Moreover, a similar energy gap between the NBN-PT dication and peri-tetracene can be predicted by DFT calculations. This work provides a novel synthesis along with characterizations of multi-NBN-doped zigzag-edged peri-acenes with tunable electronic properties.

The clean reaction of 5-lithio-6-diisopropylphosphinoacenaphthene (1') with dichlorophosphines, RPCl₂ (R = Ph, Fc, NMe₂, iPr), led to the formation of peri-substituted phosphino-phosphonium chloride salts 2-5. The synthetic utility of these salts was demonstrated in a range of reactions. Mixed tertiary/secondary bis(phosphines) (6 and 7) were prepared by the LiAlH₄ reduction of phenyl or ferrocenyl phosphino-phosphoniums (2 and 3), and the bis(borane) adduct of 6 was prepared by reduction of 2 with BH₃•SMe₂. Reaction of 2 and 3 with a large excess of MeOTf at elevated temperature gave 1,2-diphosphoniums (11 and 12), which were subjected to reduction and co-ordination to a molybdenum(0) centre. An investigation into the co-ordination chemistry of 2 revealed three distinct modes of reactivity. In the reaction with [(nor)Mo(CO)₄] the Mo(0) complex [(2)Mo(CO)₄Cl] (18) was isolated, in which monodentate co-ordination was observed. [PtCl₂(cod)] reacts with the chloride and triflate salts of 2 to form [(2Cl)PtCl₂] (19) and [((2Cl)PtCl)₂][TfO]₂ (21) respectively, both of which show co-ordination of 2 as a bidentate phosphine/chlorophosphine ligand. A palladium(II) dimer (22) in which 2 forms a chelating phosphine/phosphide ligand was isolated from the oxidative addition of 2 to a palladium(0) complex. The geminally bis(peri-substituted) tridentate phosphine (27) was prepared by reaction of 1' with half an equivalent of iPrPCl₂. 27 has a rather strained geometry, and displays restricted dynamics on an NMR timescale, which leads to anisochronicity of all three phosphorus nuclei at low temperatures. Strained bis and tris(sulfides) 28 and 29 and the bis(selenide) 30 have been isolated from the reaction of 27 with sulfur and selenium, respectively. A series of co-ordination complexes, [(27)Cu(MeCN)][BF₄] (32), [(27)PtCl][Cl] (33), [(27)FeCl₂] (34) and fac-[(27)Mo(CO)₃] (35), with tetrahedral, square planar, trigonal bipyramidal and octahedral geometries, respectively, were synthesised. In all of these complexes the tris(phosphine) backbone is distorted, but to a significantly smaller extent that in the chalcogenides 28-30.

The majority of research in this thesis uses X-ray crystallography to investigate the structural features of peri-substituted naphthalene compounds. X-ray crystallography is introduced in chapter one, followed by a discussion on modes of distortion peri-substituted naphthalene derivatives can undergo, in chapter two. In chapter three, compounds having non-bonded -SPh and -EPh (E = S, Se, or Te) peri-substituents are compared. These similar compounds react differently when oxidized with bromine. The oxidation products are used to discuss a recently proposed mechanism and a more specific mechanism is suggested. In chapter four, a one-pot synthesis for naphtho[1,8-c,d]-1,2-diselenole (Se₂naph) is reported. Substituents were added to Se₂naph to form two new naphthalene compounds. The substituents are found to distort the Se-Se bond and influence packing. In chapter five, several diselenium-containing compounds are used as ligands in platinum(II)-bisdiphosphine complexes. The preference for platinum(II) to stay square planar dictates the geometry around the metal center, not the rigidity of the naphthalene backbone. Chapter six introduces (8-phenylsulfanylnaphth-1-yl)diphenylphosphine, a peri-substituted naphthalene containing -SPh and -PPh₂ substituents, and several derivatives. This ligand is used in a variety of complexes containing platinum(II), ruthenium(II), and copper(I) metal halides, whose coordination geometries are discussed in chapter 7. The naphthalene-based ligands in Cu(I) and Ru(II) seem to determine the geometry around the metal, whereas the metal center d-orbitals dominate in the Pt(II) examples. Chapters eight and nine deviate from the naphthalene theme. In chapter eight, X-ray analysis of sulfoxide compounds is used to discuss the structural environment around the sulfur. Various intra- and inter-molecular interactions were discovered in crystal packing. Finally, chapter 9 uses STANDARD (St ANDrews Automated Robotic Diffractometer) to statistically analyze numerous E₂Ph₂ (E = S, Se, or Te) crystals to determine chirality. It is intriguing that Te₂Ph₂ shows a preference for one enantiomer over the other.

This study investigates the prevalence of peri-operative anxiety and the effective management of intra-operative anxiety during awake surgery. Plastic and vascular surgical patients were selected for the study as many procedures performed within these specialities are performed under local or regional anaesthesia. The study consists of two distinct stages. The first stage was a postal survey of patients (n=213) who had undergone awake plastic, renal access or carotid surgery up to two weeks previously, in order to determine retrospectively the prevalence of peri-operative anxiety. The second stage of the study was a randomised controlled trial of interventions for the effective management of intra-operative anxiety in patients (n=128) having undergone the same surgical procedures described in stage one. The interventions tested in stage two were handholding and an anxiety management package involving a relaxation technique and a procedural information leaflet, against a 'usual care' control. The findings from stage one of the study suggest that peri-operative anxiety prevalence is low, although unacceptable levels of anxiety are seen to elevate during the intra-operative phase. The RCT in stage two demonstrated that intra-operative anxiety was no more effectively managed by the interventions tested than by usual care alone. The validity and reliability of retrospective anxiety measurement was investigated by comparing anxiety scores from stage one with contemporaneous and post-hoc anxiety scores from stage two and found to be an accurate measure of anxiety experienced at the time of the event.

<p>Den snabba utvecklingen och urbaniseringen i stora delar av Kina har ett flertal konsekvenser för miljön. Yangtzedeltats ytvatten är till stor del eutrofierade, delvis p.g.a. diffusa förluster från jordbruket. I denna studie har kväve- och, till viss del, fosforflöden och förluster från två odlingsrutor i ett intensivt odlat grönsaksfält i ett tätortsnära område i Nanjing, med hög tillförsel av organiskt gödsel, undersökts med hjälp av den fältskaliga simuleringsmodellen GLEAMS. GLEAMS parametriserades och kalibrerades mot mätvärden av jordens vatten- och kväveinnehåll. Ett scenario med minskad kvävetillförsel simulerades sedan.</p><p>Simuleringen av vattenhalten i de olika horisonterna var inte utmärkt. Den simulerade mängden mineralkväve i marken var avsevärt lägre än den uppmätta. Detta kan bero på en felaktig simulering av mineraliseringen av organiskt kväve eller en för långsam nedbrytning av gödsel. Det är också möjligt att felen i vattensimuleringarna bidrog till underskattningen av mängden mineralkväve i marken. Simuleringarna på de båda odlingsrutorna gav liknande resultat, förutom att ruta B hade 20% större förluster av N via simulerad erosion och läckage. För fortsatt simulering av alternativa odlingsmetoder bör modellens parametrisering förbättras, särskilt vad avser parametrar kopplade till gödselns mineralisering.</p> / <p>Many parts of China are going through a rapid development and urbanization resulting in various environmental impairities. The Yangtze Delta Region surface water bodies are affected by eutrophication, partly caused by diffuse losses from agriculture. In this study, nitrogen, and to some extent also phosphorus, flows and losses from two plots in an intensively cultivated vegetable field in a peri-urban area of Nanjing, with a high input of organic fertilizer, were analysed by the use of the field-scale simulation model GLEAMS. The GLEAMS model was parameterized and calibrated against measurements of soil water and nitrogen content in two plots. A scenario with a reduced input of nitrogen was then simulated.</p><p>The resemblance between simulated and measured water content in the different soil layers was quite poor. The simulated inorganic nitrogen content in the soil was significantly lower than the measured during great parts of the simulation period. This could be due to an inappropriate simulation of the mineralization of organic N under these conditions, or an underestimated decomposition rate of manure. It is also possible that the poor water simulations contributed to the underestimated inorganic N content in the soil. There were similar results for the two plots, except for an unexplained 20% increase in leaching and erosion losses of N in Plot B. For simulation of scenarios to find best management practices, the model parameterization should be further refined.</p>

The family of polycyclic aromatic hydrocarbons naphthalene, acenaphthene and acenaphthylene, containing rigid organic backbones, allow the study of non-bonded intramolecular interactions. Due to the rigid framework, heteroatoms that are substituted at the peri-positions (positions 1- and 8- of the naphthalene ring and positions 5- and 6- of the acenaphthene and acenaphthylene rings) are forced to occupy space that is closer than the sum of their van der Waals radii, resulting in severe steric strain and unique interactions. In spite of this, a vast amount of peri-substituted naphthalenes have been prepared, however acenaphthene and acenaphthylene compounds have received much less attention. Preparation of these sterically crowded systems is possible because of the backbones ability to relieve strain as a result of both attractive and repulsive interactions. Attractive interactions relax the backbone via formation of weak or strong bonds between the substituents. Alternatively, repulsive interactions can result in the deformation of the backbone away from its natural geometry by buckling the ring system and causing the peri-bonds to distort in-plane and out-of-plane. Peri-substituted systems can also ease strain by forming compounds with bridging atoms or through bidentate coordination to form metal complexes with, for example, metal bis(phosphine) or bis(thiolate) moieties. The competition between attractive and repulsive forces, the method by which peri-substituted compounds relieve steric strain, is investigated in this thesis using a variety of different peri-moieties and the aforementioned organic backbones. Chapter 2 initially focuses on the formation of a series of platinum bis(phosphine) complexes, constructed from corresponding peri-substituted naphthalenes, 1,8-naphthosultone and 1,8-naphthosultam, the chemistry of which is outlined in Chapter 1. A corresponding study of platinum bis(phosphine) complexes, constructed from analogous 5,6-dihydroacenaphtho[5,6-cd]-1,2-dithiole and 5,6-dihydroacenaphtho[5,6-cd]-1,2-diselenole bidentate ligands is provided in Chapter 6. The chemistry of peri-substituted naphthalenes is well documented and a number of reviews have been written on this subject. Chapter 3, meanwhile, reviews the chemistry of related acenaphthene and acenaphthylenes which have seen increasing use in the literature over the last few years. Chapter 4 investigates the relationship between repulsive and attractive interactions that occur between the peri-substituents in a series of bis-chalcogen, mixed chalcogen-chalcogen and mixed halogen-chalcogen acenaphthylenes. By comparison with their known naphthalene and acenaphthene counterparts, the effect the rigid aromatic ring system has on the molecular geometry is examined. Finally, Chapter 5 looks at a series of acenaphthene and acenaphthylene compounds containing ArTe peri-substituents and explores how repulsive and attractive interactions affect molecular conformation and Te•••Te spin-spin coupling constants.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Thesis (M.M. (Public Policy))--University of the Witwatersrand, Faculty of Commerce, Law and Management, Graduate School of Public and Development Management, 2013. / This research set out to explore the feasibility of developing Urban and Peri-urban Agriculture (UPA) collaborative policy networks in South African metros. The study explored related challenges and barriers, and investigated the role of the state (national, provincial and local/metro) and other sectoral development stakeholders (private sector, research institutions, non-governmental-organisations, development partners, donors, and farmers) in the substantive UPA policy management process in South Africa. The research was conducted against the backdrop of institutional/procedural policy and collaborative policy networks’ theory was used as framework. The research goal was to contribute to and generate new information and knowledge to enhance UPA collaborative governance and procedural policy. This was done through the application of collaborative policy networks as a contemporary procedural policy arrangement framework. Collaborative policy networks in this research are patterned relationships between state and society. These networks link a variety of actors (in the public and private sector) in a set of relatively stable relationships, that are non-hierarchical and interdependent, that share similar policy interests and exchange resources. The purpose is to collaboratively pursue specific policy goals as outlined by Börzel (1997:1). This research applies institutional/procedural theory as formal and legal aspects of government structure and particularly focuses on the way governments are arranged, their legal powers, and their rules and procedures in policy management (Kraft and Furlong, 2004). South Africa’s metros have continuously demonstrated an appreciation of the developmental role of UPA through small and concrete initiatives, including the development and implementation of urban and peri-urban agriculture (UPA) development policies. In line with Mougeot (1994:1), this research however notes that the focus on UPA development in South Africa overemphasises agricultural production as the major component of the UPA definition. According to Dr Jane Battersby-Lennard, Head of the Urban Food Security programme of the African Centre for Cities at the University of Cape Town, the overemphasis on agricultural production can mainly be attributed to the peri-urban agriculture vi (UPA) terminology, which accentuates agriculture – even in metros where agricultural production is not feasible. As a result, this research recommends that the UPA terminology in South Africa be rephrased as ‘Urban Food-security Systems’ (UFS). In this context UFS is defined as a systems approach to develop sustainable and equitable urban food value chains while incorporating a strong focus on elements of urban land-use planning, access to production resources (land and water), food production, safe supply of production inputs, value adding and processing, market development and access. Such an approach also develops responsive institutional/procedural and substantive policy management instruments. The emerging trend noted through this research is that South African metros have not made much progress on the ground in terms of UPS substantive policy management. This also applies to UPA institutional policy in South Africa, which in its current form offers limited opportunities to UFS development in South African metros. This type of development still faces a number of barriers and challenges that relate to institutional ad substantive policy issues. Even with the metros’ demonstrated interest in advancing the sector, UPA policy management capacity and resources (human, social, physical, economic and environmental capital) remain limited. UPA suffers overall limited state attention and commitment and consequently restrictive legislation, bureaucratic red tape and limited institutional, technical and financial support. The research argues that UPA development initiatives could benefit from government’s commitment and prioritisation at all spheres (metro, provincial and national). The research gathers that UPA governance could be enhanced through institutional policy improvements that emphasise wider stakeholder participation through collaborative policy networks. The researcher argues that there is a strong need for state sanctioned interventions that initially focus on developing strategic institutional policy networks as a development foundation for comprehensive, accelerated, equitable and sustainable UFS interventions rather than just agricultural production. This calls for the engagement of multiple stakeholders from social, economic and environmental vii development sectors (including agriculture, food security, natural resources management, social development, political management, climate change, environment and health, etc.) as active UFS development partners in South Africa. This research emphasises collaborative policy networks as an appropriate form of UPA institutional/procedural policy arrangements to help ensure trust, transparency, participation, reciprocity and a good balance of vertical and horizontal power/governance structure (as also defined by Deleon and Varda, 2009:67-71). Here the researcher argues that institutional policy networks articulate very well with the desired objectives of achieving collaborative UPA governance, and that these objectives are key to efficient UPA substantive policy management for South Africa. As a justification for policy networks, the study found that UFS development as a multi-stakeholder and multi-sectoral public policy issue could benefit not only from the distributed intelligence presented as a benefit of policy networks, but also from the distributed human, social, physical, financial, and political capital/resources that can be accessed and utilised collaboratively to pursue overarching and specific substantive UFS policy goals at national, provincial and local levels. The study recommends the establishment of a national level UFS policy network that could be led by the Department of Agriculture, Forestry and Fisheries (DAFF) in partnership with the metros and other strategic state and non-state actors. The research recommends that a national UFS Secretariat be established at part of DAFF, to deal with national UFS policy issues (substantive and institutional) and to provide strategic programming and technical support to metros. The research also notes that developing efficient UFSs would require engaging numerous specialised skills and capacity sources that thus calls for the establishment of smaller specific substantive policy networks within the national UFS policy network. This could be led and constituted by specialist institutions with the required capacity and skills. Potential smaller specific substantive policy networks could include: agricultural production, trade, food/nutrition security and research; trade and marketing and research; environmental management and research; and spatial development and land-use planning and research. The research recommends that such policy networks be institutionalised at national, provincial and local/metro levels and that viii these policy networks are referred to as the Urban Food-security Systems – Community of Practice (UFS-COP). The research also notes that although there is a strong appreciation of the characteristic benefits of policy networks for managing multi-dimensional policy issues such as UFS, it must be noted however, that policy networks are not a panacea and that they do exhibit a hind-side of major challenges (for collaborative governance) that must be continuously addressed in search of efficient collaborative policy governance structures that emphasis the active engagement of multi-sectorial and multi-level policy management stakeholders for collective action.