340 resultados para Shift-and
Resumo:
Raman and Fourier transform infrared (FT-IR) spectroscopy have been applied to a systematic investigation of the adsorption and decomposition of dichlorodifluoromethane (CCl2F2, CFC-12), fluorotrichloromethane (CCl3F, CFC-11), chlorodifluoromethane (CHClF2, HCFC-22) and molecular chlorine on oxide surfaces. Additionally, the effects of heating and ultraviolet photolysis of the CFC and HCFCs adsorbed on the oxide surfaces have been investigated. Spectral features for these species indicated a small wavenumber shift (1-6 cm-1) associated with the adsorbed phase. Some evidence, specifically the appearance of the Raman band at 507 cm-1, is presented to show that chlorine decomposition species are associated with these oxide surfaces. It was concluded that the new spectral feature (at ca. 507 cm-1) related with the decomposition of the CFC and HCFC molecules was an important indicator of the extent to which the reaction between the adsorbed CFC and HCFC and oxide surface has taken place. The extent of CFC-surface interaction has been quantified in terms of a maximum (Raman) frequency shift parameter (AM). Wavenumber shifts suggest both cation-adsorbate and non-specific adsorption interactions are occurring in the internal channels of the zeolites. Slow decomposition of the adsorbed CFCs under ultraviolet-visible photolysis (at ? > 300 nm) and/or thermal treatment was observed spectroscopically. Using FT-IR spectroscopy, the formation of gas-phase products (CO, CO2, HCl) both onyn photolysis and heating was evident. Results of these measurements are compared with the observed atmospheric reactivity of these compounds.
Resumo:
Three long chain cationic surfactants were intercalated into Ca-montmorillonite through ion exchangeand the obtained organoclays were characterized by X-ray diffraction (XRD), high resolution thermo-gravimetric analysis (TG) and Raman spectroscopy. The intercalation of surfactants not only changes thesurface properties of clay from hydrophilic to hydrophobic but also greatly increases the basal spacing ofthe interlayers based on XRD analysis. The thermal stability of organoclays intercalated with three sur-factants (TTAB, DTAB and CTAB) and the different arrangements of the surfactant molecules intercalatedinto Ca-montmorillonite were determined by TG-DTG analysis. A Raman spectroscopic study on the Ca-montmorillonite modified by three surfactants prepared at different concentrations provided the detailedconformational ordering of different intercalated long-chain surfactants under different conditions. Thewavenumber of the antisymmetric stretching mode is more sensitive than that of the symmetric stretch-ing mode to the mobility of the tail of the amine chain. At room temperature, the conformational orderingis more easily affected by the packing density in the lateral model. With the increase of the temperature,the positions of both the antisymmetric and symmetric stretching bands shift to higher wavenumbers,which indicates a decrease of conformational ordering. This study offers new insights into the struc-ture and properties of Ca-montmorillonite modified with different long chain surfactants. Moreover, theexperimental results confirm the potential applications of organic Ca-montmorillonites for the removalof organic impurities from aqueous media.
Resumo:
This study is an inquiry into early childhood teacher professional identities. In Australia, workforce reforms in early childhood include major shifts in qualification requirements that call for a university four-year degree-qualified teacher to be employed in child care. This marks a shift in the early years workforce, where previously there was no such requirement. At the same time as these reforms to quality measures are being implemented, and requiring a substantive up skilling of the workforce, there is a growing body of evidence through recent studies that suggests these same four-year degree-qualified early childhood teachers have an aversion to working in child care. Their preferred employment option is to work in the early years of more formal schooling, not in before-school contexts. This collision of agendas warrants investigation. This inquiry is designed to investigate the site at which advocacy for higher qualification requirements meets early childhood teachers who are reluctant to choose child care as a possible career pathway. The key research question for this study is: How are early childhood teachers’ professional identities currently produced? The work of this thesis is to problematise the early childhood teacher in child care through a particular method of discourse analysis. There are two sets of data. The first was a key early childhood political document that read as a "moment of arising" (Foucault, 1984a, p. 83). It is a political document which was selected for its current influence on the early childhood field, and in particular, workforce reforms that call for four-year degree-qualified teachers to work in before-school contexts, including child care. The second data set was generated through four focus group discussions conducted with preservice early childhood teachers. The document and transcripts of the focus groups were both analysed as text, as conceptualised by Foucault (1981). Foucault’s work spans a number of years and a range of philosophical matters. This thesis draws particularly on Foucault’s writings on discourse, power/knowledge, regimes of truth and resistance. In order to consider the production of early childhood teachers’ professional identities, the study is also informed by identity theorists, who have worked on gender, performativity and investment (Davies, 2004/2006; McNay, 1992; Osgood, 2012; Walkerdine, 1990; Weedon, 1997). The ways in which discourses intersect, compete and collide produce the subject (Foucault, 1981) and, in the case of this inquiry, there are a number of competing discourses at play, which produce the early childhood teacher. These particular theories turn particular lenses on the question of professional identities in early childhood, and such a study calls for the application of particular methodologies. Discourse analysis was used as the methodological framework, and the analysis was informed by Foucauldian concepts of discourse. While Foucault did not prescribe a form of discourse analysis as a method, his writings nonetheless provide a valuable framework for illuminating discursive practices and, in turn, how people are affected, through the shifts and distribution of power (Foucault, 1980a). The treatment used with both data sets involved redescription. For the policy document, a technique for reading document-as-text applied a genealogical approach (Foucault, 1984a). For the focus groups, the process of redescription (Rorty, 1989) involved reading talk-as-text. As a method, redescription involves describing "lots and lots of things in new ways until you have created a pattern of linguistic behaviour which will tempt the new generation to adopt it" (Rorty, 1989, p. 9). The development and application of categories (Davies, 2004/2006) built on a poststructuralist theoretical framework and the literature review informed the data analysis method of discourse analysis. Irony provided a rhetorical and playful tool (Haraway, 1991; Rorty, 1989), to look to how seemingly opposing discourses are held together. This opens a space to collapse binary thinking and consider seemingly contradictory terms in a way in which both terms are possible and both are true. Irony resists the choice of one or the other being right, and holds the opposites together in tension. The thesis concludes with proposals for new, ironic categories, which work to bring together seemingly opposing terms, located at sites in the field of early childhood where discourses compete, collide and intersect to produce and maintain early childhood teacher professional identities. The process of mapping these discourses goes some way to investigating the complexities about identities and career choices of early childhood teachers. The category of "the cost of loving" captures the collision between care/love, inherent in child care, and new discourses of investment/economics. Investment/economics has not completely replaced care/love, and these apparent opposites were not read as a binary because both are necessary and both are true (Haraway, 1991). They are held together in tension to produce early childhood teacher professional identities. The policy document under scrutiny was New Directions, released in 2007 by the then opposition ALP leader, Kevin Rudd. The claim was made strongly that the "economic prosperity" of Australia relies on investment in early childhood. The arguments to invest are compelling and the neuroscience/brain research/child development together with economic/investment discourses demand that early childhood is funding is increased. The intersection of these discourses produces professional identities of early childhood teachers as a necessary part of the country’s economy, and thus, worthy of high status. The child care sector and work in child care settings are necessary, with children and the early childhood teacher playing key roles in the economy of the nation. Through New Directions it becomes sayable (Foucault, 1972/1989) that the work the early childhood teacher performs is legitimated and valued. The children are produced as "economic units". A focus on what children are able to contribute to the future economy of the nation re-positions children and produces these "smart productive citizens", making future economic contribution. The early childhood teacher is produced through this image of a child and "the cost of loving" is emphasised. A number of these categories were produced through the readings of the document-as text and the talk-as-text. Two ironic categories were read in the analysis of the transcripts of the focus group discussions, when treated as talk-as-text data: the early childhood teacher as a "heroic victim"; and the early childhood teacher as a "glorified babysitter". This thesis raises new questions about professional identities in early childhood. These new questions might go some way to prompt re-thinking of some government policy, as well as some aspects of early childhood teacher education course design. The images of children and images of child care provide provocations to consider preservice teacher education course design. In particular, how child care, as one of the early childhood contexts, is located, conceptualised and spoken throughout the course. Consideration by course designers and teacher educators of what discourses are privileged in course content —what discourses are diminished or silenced—would go some way to reconceptualising child care within preservice teacher education and challenging dominant ways of speaking child care, and work in child care. This inquiry into early childhood teachers’ professional identities has gone some way to exploring the complexities around the early childhood teacher in child care. It is anticipated that the significance of this study will thus have immediate applicably and relevance for the Australian early childhood policy landscape. The early childhood field is in a state of rapid change, and this inquiry has examined some of the disconnects between policy and practice. Awareness of the discourses that are in play in the field will continue to allow space for conversations that challenge dominant assumptions about child care, work in child care and ways of being an early childhood teacher in child care.
Resumo:
Immigration to Australia has long been the focus of negative political interest. In recent times, the proposal of exclusionary policies such as the Malaysia Deal in 2011 has fuelled further debate. In these debates, Federal politicians often describe asylum seekers and refugees as ‘illegal’, ‘queue jumpers’, and ‘boat people’. This paper investigates how the political discourse constructs asylum seekers and refugees during debates surrounding the Malaysia Deal in the Federal Parliament of Australia in 2011. Hansard Parliamentary debates were analysed to identify the underlying themes and constructions that permeate political discourse about asylum seekers and refugees. This paper argues that a dichotomous characterisation of legitimacy pervades their construction with this group constructed either as legitimate humanitarian refugees or as illegitimate ‘boat arrivals’. These constructions result in the misrepresentation of asylum seekers as illegitimate, undermining their right to protection under Australia’s laws and international obligations. This construction also represents a shift in federal political discourse from constructing asylum seekers as a border or security threat, towards an increasing preoccupation with this categorisation of people as legitimate, or illegitimate.
Resumo:
Residential dissonance refers to the mismatch in land-use patterns between individuals’ preferred residential neighbourhood type and the type of neighbourhood in which they currently reside. Current knowledge regarding the impact of residential dissonance is limited to short-term travel behaviours in urban vs. suburban, and rural vs. urban areas. Although the prevailing view is that dissonants adjust their orientation and lifestyle around their surrounding land use over time, empirical evidence is lacking to support this proposition. This research identifies both short-term mode choice behaviour and medium-term mode shift behaviour of dissonants in transit oriented development (TODs) vs. non-TOD areas in Brisbane, Australia. Natural groupings of neighbourhood profiles (e.g. residential density, land use diversity, intersection density, cul-de-sac density, and public transport accessibility levels) of 3957 individuals were identified as living either in a TOD (510 individuals) or non-TOD (3447 individuals) areas in Brisbane using the TwoStep cluster analysis technique. Levels of dissonance were measured based on a factor analysis of 16 items representing the travel attitudes/preferences of individuals. Two multinomial logistic (MNL) regression models were estimated to understand mode choice behaviour of (1) TOD dissonants, and (2) non-TOD dissonants in 2009, controlling for socio-demographics and environmental characteristics. Two additional MNL regression models were estimated to investigate mode shift behaviour of (3) TOD dissonants, and (4) non-TOD dissonants between 2009 and 2011, also controlling for socio-demographic, changes in socio-demographic, and built environmental factors. The findings suggest that travel preference is relatively more influential in transport mode choice decisions compared with built environment features. Little behavioural evidence was found to support the adjustment of a dissonant orientation toward a particular land use feature and mode accessibility they represent (e.g. a modal shift to greater use of the car for non-TOD dissonants). TOD policies should focus on reducing the level of dissonance in TODs in order to enhance transit ridership.
Resumo:
This article argues that a semantic shift in the crowd in Vietnam over the last decade has allowed public space to become a site through which transgressive ideologies and desires may have an outlet. At a time of accelerating social change, the state has effectively delimited public criticism yet a fragile but assertive form of Vietnamese democratic practice has arisen in public space, at the margins of official society, in sites previously equated with state control. Official state functions attract only small audiences, and rather than celebrating the dominance of the party, reveal the disengagement of the populace in the party's activities. Where crowds were always a component of state (stage)-managed events, now public spaces are attracting large numbers of people for supposedly non-political activities which may become transgressive acts condemned by the regime. In support of the notion that crowding is an opening up of the possibility of more subversive political actions, the paper presents an analysis of recent crowd formations and the state's reaction to them. The analysis reveals the modalities through which popular culture has provided the public with the means to transcend the constraints of official, authorized, and legitimate codes of behaviour in public space. Changes in the use of public space, it is argued, map the sets of relations between the public and the state, making these transforming relationships visible, although fraught with contradictions and anomalies.
Resumo:
This study investigates travel behaviour and wait-time activities as a component of passenger satisfaction with public transport in Brisbane, Australia. Australian transport planners recognise a variety of benefits to encouraging a mode shift away from automobile travel in favour of active and public transport use. Efforts to increase public transport ridership have included introducing state of the art passenger information systems, improving physical station access, and integrating system pricing, routes and scheduling for train, bus and ferry. Previous research regarding satisfaction with public transport emphasizes technical dimensions of service quality, including the timing and reliability of service. Those factors might be especially significant for frequent (commuting) travellers who look to balance the cost and efficiency of their travel options. In contrast, infrequent (leisure) passengers may be more concerned with way finding and the sensory experience of the journey. Perhaps due to the small relative proportion of trips made by river ferry compared to bus and rail, this mode of public transport has not received as much attention in travel-behaviour research. This case study of Brisbane’s river ferry system examines ferry passengers at selected terminals during peak and off-peak travel times to find out how travel behaviours and activities correlate to satisfaction with ferry travel. Data include 416 questionnaires completed by passengers intercepted during wait times at seven CityCat terminals in Brisbane. Descriptive statistical analysis revealed associations between specific wait time activities and satisfaction levels that could inform planners seeking to increase ridership and quality of life through ferry-oriented development.
Resumo:
Streamciphers are common cryptographic algorithms used to protect the confidentiality of frame-based communications like mobile phone conversations and Internet traffic. Streamciphers are ideal cryptographic algorithms to encrypt these types of traffic as they have the potential to encrypt them quickly and securely, and have low error propagation. The main objective of this thesis is to determine whether structural features of keystream generators affect the security provided by stream ciphers.These structural features pertain to the state-update and output functions used in keystream generators. Using linear sequences as keystream to encrypt messages is known to be insecure. Modern keystream generators use nonlinear sequences as keystream.The nonlinearity can be introduced through a keystream generator's state-update function, output function, or both. The first contribution of this thesis relates to nonlinear sequences produced by the well-known Trivium stream cipher. Trivium is one of the stream ciphers selected in a final portfolio resulting from a multi-year project in Europe called the ecrypt project. Trivium's structural simplicity makes it a popular cipher to cryptanalyse, but to date, there are no attacks in the public literature which are faster than exhaustive keysearch. Algebraic analyses are performed on the Trivium stream cipher, which uses a nonlinear state-update and linear output function to produce keystream. Two algebraic investigations are performed: an examination of the sliding property in the initialisation process and algebraic analyses of Trivium-like streamciphers using a combination of the algebraic techniques previously applied separately by Berbain et al. and Raddum. For certain iterations of Trivium's state-update function, we examine the sets of slid pairs, looking particularly to form chains of slid pairs. No chains exist for a small number of iterations.This has implications for the period of keystreams produced by Trivium. Secondly, using our combination of the methods of Berbain et al. and Raddum, we analysed Trivium-like ciphers and improved on previous on previous analysis with regards to forming systems of equations on these ciphers. Using these new systems of equations, we were able to successfully recover the initial state of Bivium-A.The attack complexity for Bivium-B and Trivium were, however, worse than exhaustive keysearch. We also show that the selection of stages which are used as input to the output function and the size of registers which are used in the construction of the system of equations affect the success of the attack. The second contribution of this thesis is the examination of state convergence. State convergence is an undesirable characteristic in keystream generators for stream ciphers, as it implies that the effective session key size of the stream cipher is smaller than the designers intended. We identify methods which can be used to detect state convergence. As a case study, theMixer streamcipher, which uses nonlinear state-update and output functions to produce keystream, is analysed. Mixer is found to suffer from state convergence as the state-update function used in its initialisation process is not one-to-one. A discussion of several other streamciphers which are known to suffer from state convergence is given. From our analysis of these stream ciphers, three mechanisms which can cause state convergence are identified.The effect state convergence can have on stream cipher cryptanalysis is examined. We show that state convergence can have a positive effect if the goal of the attacker is to recover the initial state of the keystream generator. The third contribution of this thesis is the examination of the distributions of bit patterns in the sequences produced by nonlinear filter generators (NLFGs) and linearly filtered nonlinear feedback shift registers. We show that the selection of stages used as input to a keystream generator's output function can affect the distribution of bit patterns in sequences produced by these keystreamgenerators, and that the effect differs for nonlinear filter generators and linearly filtered nonlinear feedback shift registers. In the case of NLFGs, the keystream sequences produced when the output functions take inputs from consecutive register stages are less uniform than sequences produced by NLFGs whose output functions take inputs from unevenly spaced register stages. The opposite is true for keystream sequences produced by linearly filtered nonlinear feedback shift registers.
Resumo:
Expert searchers engage with information as information brokers, researchers, reference librarians, information architects, faculty who teach advanced search, and in a variety of other information-intensive professions. Their experiences are characterized by a profound understanding of information concepts and skills and they have an agile ability to apply this knowledge to interacting with and having an impact on the information environment. This study explored the learning experiences of searchers to understand the acquisition of search expertise. The research question was: What can be learned about becoming an expert searcher from the learning experiences of proficient novice searchers and highly experienced searchers? The key objectives were: (1) to explore the existence of threshold concepts in search expertise; (2) to improve our understanding of how search expertise is acquired and how novice searchers, intent on becoming experts, can learn to search in more expertlike ways. The participant sample drew from two population groups: (1) highly experienced searchers with a minimum of 20 years of relevant professional experience, including LIS faculty who teach advanced search, information brokers, and search engine developers (11 subjects); and (2) MLIS students who had completed coursework in information retrieval and online searching and demonstrated exceptional ability (9 subjects). Using these two groups allowed a nuanced understanding of the experience of learning to search in expertlike ways, with data from those who search at a very high level as well as those who may be actively developing expertise. The study used semi-structured interviews, search tasks with think-aloud narratives, and talk-after protocols. Searches were screen-captured with simultaneous audio-recording of the think-aloud narrative. Data were coded and analyzed using NVivo9 and manually. Grounded theory allowed categories and themes to emerge from the data. Categories represented conceptual knowledge and attributes of expert searchers. In accord with grounded theory method, once theoretical saturation was achieved, during the final stage of analysis the data were viewed through lenses of existing theoretical frameworks. For this study, threshold concept theory (Meyer & Land, 2003) was used to explore which concepts might be threshold concepts. Threshold concepts have been used to explore transformative learning portals in subjects ranging from economics to mathematics. A threshold concept has five defining characteristics: transformative (causing a shift in perception), irreversible (unlikely to be forgotten), integrative (unifying separate concepts), troublesome (initially counter-intuitive), and may be bounded. Themes that emerged provided evidence of four concepts which had the characteristics of threshold concepts. These were: information environment: the total information environment is perceived and understood; information structures: content, index structures, and retrieval algorithms are understood; information vocabularies: fluency in search behaviors related to language, including natural language, controlled vocabulary, and finesse using proximity, truncation, and other language-based tools. The fourth threshold concept was concept fusion, the integration of the other three threshold concepts and further defined by three properties: visioning (anticipating next moves), being light on one's 'search feet' (dancing property), and profound ontological shift (identity as searcher). In addition to the threshold concepts, findings were reported that were not concept-based, including praxes and traits of expert searchers. A model of search expertise is proposed with the four threshold concepts at its core that also integrates the traits and praxes elicited from the study, attributes which are likewise long recognized in LIS research as present in professional searchers. The research provides a deeper understanding of the transformative learning experiences involved in the acquisition of search expertise. It adds to our understanding of search expertise in the context of today's information environment and has implications for teaching advanced search, for research more broadly within library and information science, and for methodologies used to explore threshold concepts.
Resumo:
Research and practice has observed a shift toward service-oriented approaches that depend on input from users and community as co-producers of services. Yet, in delivering public infrastructure the focus is still on assets rather than services. The contribution of external stakeholders in the co-production of public services is still limited. Using the Policy Delphi with a panel of experts, we found that although practitioners understand the need for asset management to follow the service approach, guidelines and policies still lack that service-centric perspective. Findings revealed a range of obstacles to effective service delivery, related to the sub-optimal involvement of stakeholders’, asymmetric levels of power, the lack of accountability, transparency and availability of government, and the lack of genuine consultations between government and stakeholder groups. The paper concludes by offering directions and strategies for asset managers and policymakers to support and reconnect disengaged government-citizen relations for optimal service delivery outcomes in asset management.
Resumo:
Problem-solving courts appear to achieve outcomes that are not common in mainstream courts. There are increasing calls for the adoption of more therapeutic and problem-solving practices by mainstream judges in civil and criminal courts in a number of jurisdictions, most notably in the United States and Australia. Currently, a judge who sets out to exercise a significant therapeutic function is likely to be doing so in a specialist court or jurisdiction, outside the mainstream court system, and arguably, outside the adversarial paradigm itself. To some extent, this work is tolerated but marginalised. However, do therapeutic and problem-solving functions have the potential to help define, rather than simply complement, the role of judicial officers? The core question addressed in this thesis is whether the judicial role could evolve to be not just less adversarial, but fundamentally non-adversarial. In other words, could we see—or are we seeing—a juristic paradigm shift not just in the colloquial, casual sense of the word, but in the strong, worldview changing sense meant by Thomas Kuhn? This thesis examines the current relationship between adversarialism and therapeutic jurisprudence in the context of Kuhn’s conception of the transition from periods of ‘normal science’, through periods of anomaly and disciplinary crises to paradigm shifts. It considers whether therapeutic jurisprudence and adversarialism are incommensurable in the Kuhnian sense, and if so, what this means for the relationship between the two, and for the agenda to mainstream therapeutic jurisprudence. The thesis asserts that Kuhnian incommensurability is, in fact, a characteristic of the relationship between adversarialism and therapeutic jurisprudence, but that the possibility of a therapeutic paradigm shift in law can be reconciled with many adversarial and due process principles by relating this incommensurability to a broader disciplinary matrix.
Resumo:
The microstructures of the quenched melts of samples of Y123 and Y123+15-20 mol% Y211 with PtO2 and CeO2 additives have been examined with optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectrometry (EDS) and X-ray Diffractometry (XRD). Significantly higher temperatures are required for the formation of dendritic or lamellar eutectic patterns throughout the samples with PtO2 and CeO2 additives as compared to samples without additives. The BaCuO2 (BCl) phase appears first in solid form and, instead of rapidly melting, is slowly dissolving or decomposing in the oxygen depleted melt. PtO2 and CeO2 additives slow down or shift to higher temperatures the dissolution or decomposition process of BCl. A larger fraction of BCl in solid form explains why samples with additives have higher viscosities and hence lower diffusivities than samples without additives. There is also a reduction in the Y solubility to about half the value in samples without additives. The mechanism that limits the Ostwald ripening of the Y211 particles is correlated to the morphology of the quenched partial melt. It is diffusion controlled for a finely mixed morphology and interface-controlled when the melt quenches into dendritic or lamellar eutectic patterns. The change in the morphology of the Y211 particles from blocky to acicular is related to an equivalent undercooling of the Y-Ba-Cu-O partial melt, particularly through the crystallization of BCl.
Resumo:
Childbirth is an extraordinary, everyday experience; in 2011, 301 617 infants were born in Australia [1], resulting in countless potential occurrences of sleep disturbance and subsequent daytime sleepiness. While the relationship between sleep and sleepiness has been heavily investigated in the vulnerable sub-populations of shift workers and patients with sleep disorders, comparatively postpartum women have been overlooked. Previous research has reported slower reaction times to the Psychomotor Vigilance Task [2] and shorter sleep onset in the multiple sleep latency test [3] in new mothers compared with control women. However little is known about change in sleep and sleepiness over time or potential interactions with infant care behaviour choices, such as co-sleeping (mother and infant sharing a bed). This study aims to investigate change in new mothers sleep quantity, sleep quality and resulting daytime sleepiness over postpartum weeks 6, 12 and 18, while evaluating the impact of co-sleeping.
Resumo:
This chapter gives an overview of the smartphone app economy and its various constituent ecosystems. It examines the role of the app store model and the proliferation of mobile apps in the shift from value chains controlled by network operators and handset manufacturers, to value networks – or ecosystems – focused around operating systems and apps. It outlines some of the benefits and disadvantages for developers of the app store model for remuneration and distribution. The chapter concludes with a discussion of recent research on the size and employment effects of the app economy.
Resumo:
Relationships between LGBT people and police have been turbulent for some time now, and have been variously characterized as supportive (McGhee, 2004) and antagonistic (Radford, Betts, & Ostermeyer, 2006). These relationships were, and continue to be, influenced by a range of political, legal, cultural, and social factors. This chapter will examine historical and social science accounts of LGBT-police histories to chart the historical peaks and troughs in these relationships. The discussion demonstrates how, in Western contexts, we oscillate between historical moments of police criminalizing homosexual perversity and contemporary landscapes of partnership between police and LGBT people. However, the chapter challenges the notion that it is possible to trace this as a lineal progression from a painful past to a more productive present. Rather, it focuses on specific moments, marked by pain or pleasure or both, and how these moments emerge and re-emerge in ways that shaped LGBT-police landscapes in potted, uneven ways. The chapter concludes noting how, although certain ideas and police practices may shift towards more progressive notions of partnership policing, we cannot just take away the history that emerged out of mistrust and pain.