Background: Historically the identification of ACL injuries upon initial presentation is low and considerable diagnostic delays have been reported. However, specific evidence on the individual elements of, and factors which influence delay, is lacking. Aims: The overarching aim was to provide a comprehensive picture of delay to diagnosis and specialist consultation, including factors which influence delay. An additional aim was to determine whether the approach to examining acute knee injuries varied as a consequence of varying patient presentation or experience of the assessing clinician. Methods: Study 1: Cross -sectional survey. Study 2: Non-participant direct observation methodology. Results: Data from 194 patients were analysed in the survey. Only 15.5% of patients were given a correct diagnosis of ACL rupture at the initial consultation. Median delay to diagnosis was 67.5 days (IQR= 15 to 178 days) and specialist consultation 108 days (IQR= 38 to 292 days). The factors most influential on delay were whether a follow-up appointment was arranged after attending A&E, whether the site of attendance operated an acute knee clinic and whether MRI was performed. The direct observation study showed wide variation in approach to injury assessment. Specialist clinicians performed the most comprehensive examination. A&E clinicians were more likely to assess for bony, neurovascular and gross tendon injuries as opposed to ligamentous or meniscal injury. Conclusions: The diagnostic rate of ACL injury at initial presentation remains low. Considerable delays to diagnosis and specialist consultation are apparent following ACL injury, the majority of which is attributable to health system delay.

OBJECTIVES : This work studies the indications, methods, results , satisfaction and partner relationships in immediate (IBR ) and deferred breast reconstruction ( DBR ) to objectively consider the benefits and indications IBR . METHOD : IBR between 1/2002-12/2012 underwent 51 ( 33.33 %) women ( 29-58 years, mean 41.5 , median 40.5 ) ; DBR 102 ( 66.67 %) ( 31-64 , mean 47.5 , median 47 ), data were obtained from medical records , questionnaires interviews and questionnaires , processed by statistical analysis RESULTS : Indications IBR : ≤ pT2N0M0 , low grade tumor ; DBR : ≥ 1 year of remission. Age at IBR was lower than the DBR ( p- 0.0004 ) Statistical differences in the modes of life after reconstruction the IBR a DBR were observed ( p- 0.1935-0.9659 ) predominates full and prevailing contentment. IBR does not burden patients ( 55 to 160 min, average 91.1 and 139.3 min, median 75 and 135 min ) between unilateral and bilateral operations are not statistically significant differences ( p -value 0.1065 ) . Complications prolonging healing rare - IBR 5 ( 8.33 %) , DBR 6 ( 5.8 % ) and mortality generalization low - IBR and 1 ( 1.96 % s ) DBR 1 and 2 ( 0.98 % and 1 , 96%) . Satisfaction with IBR was reported by 84.09 % , with 86.11 % DBR . The DBR was found 4 times greater risk of life or relationship. SUMMARY:...

abstract: Voltage stability is always a major concern in power system operation. Recently Fault Induced Delayed Voltage Recovery (FIDVR) has gained increased attention. It is widely believed that the motor-driven loads of high efficiency, low inertia air conditioners are one of the main causes of FIDVR events. Simulation tools that assist power system operation and planning have been found insufficient to reproduce FIDVR events. This is because of their inaccurate load modeling of single-phase motor loads. Conventionally three-phase motor models have been used to represent the aggregation effect of single-phase motor load. However researchers have found that this modeling method is far from an accurate representation of single-phase induction motors. In this work a simulation method is proposed to study the precise influence of single-phase motor load in context of FIDVR. The load, as seen the transmission bus, is replaced with a detailed distribution system. Each single-phase motor in the distribution system is represented by an equipment-level model for best accuracy. This is to enable the simulation to capture stalling effects of air conditioner compressor motors as they are related to FIDVR events. The single phase motor models are compared against the traditional three phase aggregate approximation. Also different percentages of single-phase motor load are compared and analyzed. Simulation result shows that proposed method is able to reproduce FIDVR events. This method also provides a reasonable estimation of the power system voltage stability under the contingencies. / Dissertation/Thesis / M.S. Electrical Engineering 2012

Esta tese versa sobre a síntese de compensadores antiwindup para sistemas lineares contínuos invariantes no tempo, com restrições no atuador e atraso no tempo. Baseados em um funcional Liapunov-Krasovskii e uma condição de setor para a função zona-morta já existentes na literatura, são propostas condições suficientes expressas em LMIs para a existência de compensadores antiwindup para duas classes de sistemas: sistemas com atraso nos estados, e sistemas com atraso na entrada. Em ambos os casos, considera-se a síntese de um compensador de ordem plena para um sistema com um controlador dado a priori desprezando limites do atuador. A síntese dos compensadores antiwindup considera um atuador restrito em amplitude e o sistema sujeito a perturbações limitadas em norma L2. A verificação das condições enunciadas garante a estabilidade da origem em malha fechada, e um conjunto de inicialização dos estados do sistema tolerante à perturbação com norma L2 inferior a um máximo, determinado juntamente com a síntese do compensador antiwindup. Na ausência de perturbação a origem é garantida assintoticamente estável. Para sistemas com atraso no estado, primeiro propõe-se um método para a síntese de compensadores dinâmicos racionais de ordem plena. Este método é baseado no Lema de Projeção. Em seguida, estende-se o resultado, propondo-se um framework genérico que permite a síntese de compensadores racionais e não racionais. Este método é baseado em uma transformação de variáveis linearizante. Para sistemas com atraso na entrada, propõe-se três resultados de síntese de compensadores antiwindup: compensadores estáticos, dinâmicos racionais, e dinâmicos não racionais. Estes métodos são novamente baseados no Lema de Projeção. Em todos os casos, as condições obtidas que garantem a existência de um compensador antiwindup são expressas em forma de LMIs e garantem a estabilidade local da origem. Em seguida, estende-se os resultados para garantir a estabilidade global da origem, nos casos em que a planta é estável em malha aberta. Problemas de otimização são propostos para ambos os métodos para maximizar a tolerância à perturbação e a minimização do ganho L2 da perturbação à saída regulada. Exemplos numéricos ilustram cada método na solução dos problemas de máxima tolerância à perturbação, e minimização do ganho L2 da perturbação à saída regulada. / This thesis verses about antiwindup compensator synthesis for linear time invariant continuous systems, presenting constraints in actuator and time delay. Based on a Liapunov-Krasovskii functional and a sector condition for the dead-zone nonlinearity already castign in literature, it is proposed sufficient conditions expressed in LMI to the existance of an antiwindup compensator for two classes of systems: systems with state delay, and systems with input delay. In both cases it is considered the synthesis of a full order antiwindup compensator for a system with a controller a priori given that disregards the actuator bounds. The synthesis of antiwindup compensators considers an actuator constrained in amplitude and a system subjected to norm-L2 bounded disturbances. Once the casted conditions are verified, it is assured the closed loop origin stability; a set for the initial states of the system tolerating disturbances up to a maximum L2 norm, which is also determined along the antiwindup compensator synthesis procedure. In the absence of disturbance the origin is assuredly asymptotically stable. For state delay systems, first it is proposed a method for designing full order rational antiwindup compensators. This method is based on the Projection Lemma. Afterwards, results are extended proposing a generic framework allowing the synthesis of rational and nonrational compensators of different topologies. This method is based on a linearizing variable transformation. For input delay systems, it is proposed three synthesis results: static, rational dynamic and nonrational dynamic compensators. These methods are based on the Projection Lemma. In all cases, the conditions obtained assuring the existance of an antiwindup compensator are expressed by means of LMIs that, once verified, assure the origin local stability. Then, the conditions are extended for the global stability case, when the system is open loop stable. Optimization problems are proposed for both methods to maximize the disturbance tolerance and the minimization of the L2-gain of the disturbance to the regulated output. Numerical examples are presented to illustrate each method in the solution of the problems of maximum disturbance tolerance, and minimization of L2-gain from the disturbance to the regulated output.

In this study of causal decision-making, a video game was adapted to explore factors affecting causal judgment in a dynamic setting. In the experiment, participants were presented with groups of potential targets. Causal delay and number of alternatives were varied. The participants were tasked with discriminating which one of the potential targets was producing a secondary event in the form of distal explosions on objects that the participant was instructed to preserve. Choice accuracies and latencies were recorded for each participant. For the analysis, choice accuracies were converted into discriminability metrics using signal detection theory. The experiment revealed a main effect of delay on discriminability but no effect of the number of alternatives. There were main effects of the number of alternatives, sex, as well as a Delay × Number of alternatives interaction on latency. The results suggest that discriminability is maintained across different numbers of targets by compensating with longer observation times.

The current study sought to add to the literature on applying interdependent group-oriented contingency systems with randomized components to academic performance. This study expanded previous work, which has only examined effects on elementary classrooms and students with disabilities, by implementing a similar intervention within a general education, secondary classroom. Given the restricted time that teachers have to learn and implement interventions, while simultaneously carrying out all their additional responsibilities in the classroom, it is necessary for school psychologists to consider these limitations when recommending interventions. In previous work involving interdependent group-oriented contingencies, the delivery of reinforcement has been relatively immediate. While this is an ideal arrangement, it may be infeasible for middle and high school teachers to ensure reinforcement of academic performance occurs immediately within the class period. This study examined whether the delivery of reinforcement can be delayed within an interdependent group-oriented contingency system and still improve the academic performance of students in the classroom, which will allow the teacher more time for evaluating the quality of student work and, in turn, impact the acceptability of the intervention. One middle school, general education classroom served as the setting for this study. Academic performance data, including in-class work completion and accuracy rates, were collected class-wide and data on social behavior variables were gathered for 3 students exhibiting moderate to high levels of off-task behavior, based on teacher perception. An alternating treatments design was employed with two intervention conditions: one condition included immediate reinforcement and the other involved delivering reinforcement to students a day later. The interdependent group-oriented contingency intervention implemented included procedures for randomly selecting target behaviors, criteria, and reinforcers.

Esta tese versa sobre a síntese de compensadores antiwindup para sistemas lineares contínuos invariantes no tempo, com restrições no atuador e atraso no tempo. Baseados em um funcional Liapunov-Krasovskii e uma condição de setor para a função zona-morta já existentes na literatura, são propostas condições suficientes expressas em LMIs para a existência de compensadores antiwindup para duas classes de sistemas: sistemas com atraso nos estados, e sistemas com atraso na entrada. Em ambos os casos, considera-se a síntese de um compensador de ordem plena para um sistema com um controlador dado a priori desprezando limites do atuador. A síntese dos compensadores antiwindup considera um atuador restrito em amplitude e o sistema sujeito a perturbações limitadas em norma L2. A verificação das condições enunciadas garante a estabilidade da origem em malha fechada, e um conjunto de inicialização dos estados do sistema tolerante à perturbação com norma L2 inferior a um máximo, determinado juntamente com a síntese do compensador antiwindup. Na ausência de perturbação a origem é garantida assintoticamente estável. Para sistemas com atraso no estado, primeiro propõe-se um método para a síntese de compensadores dinâmicos racionais de ordem plena. Este método é baseado no Lema de Projeção. Em seguida, estende-se o resultado, propondo-se um framework genérico que permite a síntese de compensadores racionais e não racionais. Este método é baseado em uma transformação de variáveis linearizante. Para sistemas com atraso na entrada, propõe-se três resultados de síntese de compensadores antiwindup: compensadores estáticos, dinâmicos racionais, e dinâmicos não racionais. Estes métodos são novamente baseados no Lema de Projeção. Em todos os casos, as condições obtidas que garantem a existência de um compensador antiwindup são expressas em forma de LMIs e garantem a estabilidade local da origem. Em seguida, estende-se os resultados para garantir a estabilidade global da origem, nos casos em que a planta é estável em malha aberta. Problemas de otimização são propostos para ambos os métodos para maximizar a tolerância à perturbação e a minimização do ganho L2 da perturbação à saída regulada. Exemplos numéricos ilustram cada método na solução dos problemas de máxima tolerância à perturbação, e minimização do ganho L2 da perturbação à saída regulada. / This thesis verses about antiwindup compensator synthesis for linear time invariant continuous systems, presenting constraints in actuator and time delay. Based on a Liapunov-Krasovskii functional and a sector condition for the dead-zone nonlinearity already castign in literature, it is proposed sufficient conditions expressed in LMI to the existance of an antiwindup compensator for two classes of systems: systems with state delay, and systems with input delay. In both cases it is considered the synthesis of a full order antiwindup compensator for a system with a controller a priori given that disregards the actuator bounds. The synthesis of antiwindup compensators considers an actuator constrained in amplitude and a system subjected to norm-L2 bounded disturbances. Once the casted conditions are verified, it is assured the closed loop origin stability; a set for the initial states of the system tolerating disturbances up to a maximum L2 norm, which is also determined along the antiwindup compensator synthesis procedure. In the absence of disturbance the origin is assuredly asymptotically stable. For state delay systems, first it is proposed a method for designing full order rational antiwindup compensators. This method is based on the Projection Lemma. Afterwards, results are extended proposing a generic framework allowing the synthesis of rational and nonrational compensators of different topologies. This method is based on a linearizing variable transformation. For input delay systems, it is proposed three synthesis results: static, rational dynamic and nonrational dynamic compensators. These methods are based on the Projection Lemma. In all cases, the conditions obtained assuring the existance of an antiwindup compensator are expressed by means of LMIs that, once verified, assure the origin local stability. Then, the conditions are extended for the global stability case, when the system is open loop stable. Optimization problems are proposed for both methods to maximize the disturbance tolerance and the minimization of the L2-gain of the disturbance to the regulated output. Numerical examples are presented to illustrate each method in the solution of the problems of maximum disturbance tolerance, and minimization of L2-gain from the disturbance to the regulated output.

Orientador: Maria Regina Wolf Maciel / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-12T16:55:11Z (GMT). No. of bitstreams: 1 Fregolente_LeonardoVasconcelos_D.pdf: 1867297 bytes, checksum: 6a22c8c7c525474c0864d4df237dce16 (MD5) Previous issue date: 2009 / Resumo: Neste trabalho, a técnica de planejamento de experimentos foi aplicada em diferentes estudos de otimização realizados na Refinaria de Paulínia (Replan). O trabalho abrange aplicações da técnica em escala laboratorial, em ferramenta computacional, até a utilização da técnica em diferentes plantas industriais. Os estudos de laboratórios consistiram na avaliação da dependência da lubricidade do diesel metropolitano em relação à sua composição e no desenvolvimento de uma nova metodologia para determinação do ponto de fulgor de frações leves de petróleo. Através de planejamentos fatoriais aplicados a um simulador do processo de coqueamento retardado (denominado DC-SIM), foram geradas equações polinomiais simples para a previsão de rendimentos dos produtos da unidade em sua etapa reacional. Utilizando estas equações, curvas de nível foram obtidas, as quais auxiliam na análise do comportamento da unidade frente a modificações nas condições de operação. Duas aplicações consistiram na realização de testes em plantas industriais. Primeiramente, utilizando planejamentos em dois níveis, foram levantados novos modelos para o controle avançado de uma torre de fracionamento de naftas através da realização de testes de identificação utilizando perturbações em degrau. A metodologia de planejamento de experimentos possibilitou uma análise multivariável do sistema. Finalmente, foram realizados experimentos seguindo planejamentos com configuração estrela para a maximização da recuperação de moléculas na faixa de destilação do GLP nas áreas de fracionamento de gases das duas unidades de coqueamento retardado da Replan. Por se tratar da maior refinaria de petróleo do país, sendo responsável por cerca de 20% da capacidade de refino no Brasil, a utilização de planejamentos fatoriais foi de fundamental importância para a viabilização de alguns testes em planta, já que reduz significativamente o número de experimentos necessários quando comparada à metodologia de avaliação de um fator por vez. Desta forma, o impacto dos testes na produção de derivados foi minimizado. Além disso, os resultados obtidos propiciaram um ganho econômico expressivo para a refinaria. / Abstract: In this work, experimental design technique was applied to different optimization studies, which were carried out in the Paulínia Refinery (Replan). The work covers applications of the technique in laboratorial scale, in computational tool, and the use of the technique in different industrial plants. The laboratory studies consisted in the evaluation of the dependence of the metropolitan diesel oil lubricity in relation to its composition and in the development of a new methodology to determine the flash point of light fractions of petroleum. Through factorial designs applied to a delayed coke simulator (named DC-SIM), simple polynomial equations were generated to predict the products yields of the unit in the reaction step. Using these equations, contour plots were obtained, which helped the analysis of the process response due to changes in the operating conditions. Two applications were done in industrial plants. First, using two level factorial designs, new models were adjusted to be used in the advanced control of a naphtha fractionation tower. The identification tests were carried out giving step disturbance in the manipulated variables. The experimental design methodology allowed a multivariable analysis of the system. Finally, experiments were done according to star configuration factorial designs in order to maximize the recovery of LPG molecules in the gases fractionating units of two delayed coke plants of Replan. Since Replan is the biggest oil refinery in Brazil, responsible for 20% of the national refining capacity, the use of factorial designs had a fundamental importance to allow the running of some tests in the plant. It reduces significantly the number of experiments, when it is compared to univariate methodology. Therefore, the impact of the tests in the production was minimized. Furthermore, the results provided very expressive financial earns / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

O processo de obtenção diagnóstica da tuberculose (TB) é permeado por aspectos relacionados à acessibilidade aos serviços de saúde, que interferem diretamente na conduta do doente em buscar por atendimento após perceber o início dos sintomas da doença. Reconhecer esses aspectos pode contribuir na elaboração de medidas que levem à identificação precoce dos casos, diminuição do tempo diagnóstico e disseminação do agravo na comunidade. O presente estudo teve como objetivo, analisar o tempo do doente na busca por serviço de saúde para o diagnóstico da tuberculose no município de Ribeirão Preto - SP, 2009. Estudo descritivo do tipo transversal, realizado em Ribeirão Preto. De 113 doentes de TB, que estavam em tratamento no período de julho a novembro de 2009, foram entrevistados 94, que atenderam os critérios de seleção. Utilizou-se um questionário estruturado baseado no Primary Care Assessment Tool (PCAT) adaptado para o enfoque no diagnóstico da TB. Para a análise dos dados, medidas de tendência central (mediana e intervalos interquartis) foram utilizadas para analisar a variável: \"tempo decorrido entre sentir-se doente e a primeira procura pelo serviço de saúde\". Estabeleceu-se a mediana como valor mais adequado para a caracterização dos dois grupos de doentes (atraso e não atraso). Considerou-se atraso ao diagnóstico, doentes que demoraram mais de 15 dias para buscar pelo primeiro atendimento em um serviço de saúde. Em seguida, por meio do cálculo da Razão de Prevalência identificaram-se as variáveis sócio-demográficas, clínicas e da dimensão porta de entrada de maior atraso na busca por atendimento. O primeiro serviço de saúde procurado foram os Serviços de Pronto Atendimento (SPA) (57,4%), seguidos pelas Unidades de Atenção Básica (UAB) (24,5%) e Serviços Especializados (SE) (18,1%). Já o acesso ao diagnóstico ocorreu nos SE (60,6%), seguidos dos SPA (26,6%) e das UAB (12,8%). Quanto ao tempo de atraso ao diagnóstico, em relação às informações sócio-demográficos, o perfil dos doentes que mais demoraram para buscar pelos SPA foram: idade entre 50 a 59 anos (30 dias); SE: gênero masculino (30 dias), com escolaridade (21dias); renda acima de cinco salários mínimos (30 dias). Informações clínicas: SE: forma clínica pulmonar, caso novo e com co-infecção TB/HIV, (20 dias). Dimensão porta de entrada (primeiro serviço de saúde pocurado): UAB: sintomas moderados da doença (30 dias); SPA: não consumiam bebidas alcoólicas (25 dias) e com conhecimento satisfatório sobre a TB (26 dias); SE: não realizavam controle preventivo de saúde (30 dias), fumavam (20 dias), com conhecimento satisfatório sobre a TB (26 dias), não procuravam o serviço de saúde mais próximo do domicílio (30 dias). O serviço de saúde de maior acessibilidade foram os SPA, (funcionamento de 24h, demanda livre). É necessário capacitar as equipes de saúde, para identificarem os doentes de TB que tiveram maior atraso na busca por atendimento, favorecendo a acessibilidade ao diagnóstico precoce e contribuindo no controle da doença. / The process of obtaining diagnosis for tuberculosis (TB) is permeated by aspects relating to the accessibility of health services, which impact directly on the conduct of patients in search of medical attention after noticing the first symptoms of the disease. Recognising these aspects can contribute to the development of measures that lead to the early diagnosis of cases, reduction in the overall time taken in the diagnostic process and alleviation of the impacts of TB on the community. The aim of the present study was to analyse the patient time in the search in first health service for the diagnosis of tuberculosis in city of Ribeirao Preto, SP, 2009. Descriptive study, cross sectional conducted in Ribeirao Preto. Of 113 TB patients that were in treatment during the period between June and November of 2009, 94 were interviewed that fulfilled the selection criteria. A questionnaire was used based on the Primary Care Assessment tool (PCAT), which was adapted for focus on the diagnosis of TB. For the analysis of data, measures of central tendency (median and interquartile intervals) were utilised to analyse the variable: ,,time elapsed between the appearance of symptoms and the first search for health services\". The median was established as the most appropriate value for the characterisation of two groups of patients (timely and delay). Patients were considered ,,delay\" if the time between the first signs of illness and the search for health sercices was greater than 15 days. Next, through calculation of the prevalence ratios, socioeconomic, demographic, clinical and gateway dimension were identified for the greatest delay in the search in first health service. The emergency services (ES) room was the most common health service first sought by patients (57.4%), followed by primary health care (PHC) (24.5%), and finally specialists services (SS) (18.1%). The leading service with regard to obtaining a diagnosis was that of SS (60.1%), followed by ES (26.6%), and PHC (12.8%). Regarding the delay in obtaining a diagnosis, and with relation to socio-demographic information, patients that took the longest to seek health services through ES rooms were: between 50-59 years of age (30 days); SS: masculine (30 days), educated (21 days), receive a salary greater than five times the minimum wage (30 days). Clinical Information: SS: lung clinics, new cases and with co-infection TB/HIV (20 days). Gateway dimension (the search in first health service): PHC: moderate symptoms of the disease (30 days); ES: non-drinkers (30 days), and with a satisfactory knowledge of TB (26 days); SS: not practicing preventative health control (30 days), smokers (20 days), satisfactory knowledge of TB (26 days), didn\"t seek the health service closest to residence (30 days). The most accessible health service proved to be ES (functioning 24 hours, on demand). It is necessary to properly equip health care professionals so as to facilitate the identification of patients from TB that delayed in the search in first health service, facilitating the health service accessibility thus enabling the early diagnosis of the disease and contributing to its control.

A possibilidade do controle feminino sobre a reprodução, de escolha ou não pela maternidade, do número de filhos e de quando tê-los, se coloca como um fenômeno que vem se consolidando ao longo do tempo, acompanhando as diversas transformações na família, no casamento, na maternidade e na paternidade. Cresce, nesse contexto, o número de mulheres que postergam a maternidade para idades cada vez mais avançadas. Tal fenômeno vem muitas vezes carregado de idealizações e de desconhecimento, o que pode gerar a ilusão de um controle que não necessariamente equivale às vivências reais. O objetivo geral desta tese é o de investigar o fenômeno do adiamento da maternidade, na sociedade atual, com base nas vivências de mulheres de dois diferentes grupos que optaram por ter o primeiro filho depois dos trinta e cinco anos: aquelas que conseguiram e aquelas que não, seja porque ainda estivessem tentando, seja porque houvessem desistido. Como objetivo específico, pretende-se pensar a influência dos fatores conjugalidade, carreira profissional e história de vida, nas famílias de origem na determinação desse tipo de escolha. Para tanto, foram realizadas, a partir de uma metodologia clínico-qualitativa, a aplicação das pranchas 1, 2, 7MF, 10 e 16 do TAT, além de uma entrevista semidirigida, com oito mulheres quatro pertencentes a cada grupo com idades entre trinta e seis e quarenta e um anos, em um relacionamento estável, com mais de oito anos de escolaridade, habitantes da região metropolitana de São Paulo. Os dados foram analisados de acordo com o referencial psicanalítico, levando-se em conta, também, aspectos históricos e psicossociais que influenciam o fenômeno. Os resultados são apresentados de acordo com as seguintes categorias de análise: a experiência do adiamento da maternidade; a maternidade, como experiência para aquelas que se tornaram mães, e como experiência projetada, para aquelas que não se tornaram mães; conjugalidade; carreira profissional; relação com a própria mãe e conjugalidade dos pais; e a questão do poder. Conclui-se que o fenômeno do adiamento da maternidade, na sociedade contemporânea, mostra-se complexo e imerso em uma multiplicidade de significados. Em meio às especificidades de cada caso, algumas aproximações puderam ser feitas entre as experiências das mulheres dos dois grupos, especialmente no que diz respeito à valorização e idealização da conjugalidade, percebida inclusive como mais importante que o desenvolvimento de uma carreira profissional, bem como a possibilidade de integração dos aspectos que concernem ao poder em relação ao corpo e ao controle da reprodução por meio dos binômios: onipotência/impotência e elementos femininos/masculinos puros na mulher contemporânea, de um ponto de vista winnicottiano. As divergências mais marcantes entre os dois grupos se referem sobretudo à relação estabelecida com as próprias mães, além da conjugalidade dos pais. A postergação da maternidade, fenômeno tão atual e com potencial para mobilizar tantas angústias e sofrimentos, pode ser vivenciada pelas mulheres contemporâneas de maneira mais ou menos saudável ou criativa, com uma maior ou menor capacidade de integração da ambivalência, a depender dos recursos psíquicos individuais e do legado geracional / The womans option to control her fertility, to choose motherhood or not, to choose the number of children and the time to have them, is a phenomenon that has been establishing itself over time, following diverse transformations in the family and the marriage, as well as in motherhood and fatherhood. In this context, there has been an increase in the number of women who delay childbirth until later in life. Many times, such phenomenon comes loaded with idealization and lack of knowledge, which may generate an illusion of control that does not necessarily equate with the real experience. The general objective of this thesis is to investigate the phenomenon of delayed motherhood in current society from the perspective of two different groups of women who delayed childbirth to later than thirty-five years of age: those who had already succeeded and those who hadnt yet and either gave up or kept trying. The specific objective is to reflect on the influence of the following factors in determining the choice of delayed childbirth: marital situation, professional career and history of families of origin. For this purpose, it was used a clinical-qualitative methodology that included the application of pictures 1, 2, 7GF, 10 and 16 of the TAT (Thematic apperception test) and of semi-directed interviews with eight women (four from each group) with ages ranging from thirty-six to forty-one years, who were in a steady relationship, had more than eight years of schooling, and resided in the metropolitan region of São Paulo. The data are analyzed in accordance to the psychoanalytical referential, taking into account historical and psychosocial aspects that influence the phenomenon. The results are presented in accordance to the following categories of analysis: the experience of delayed childbirth; the experience of motherhood for those who became mothers and the projected experience for those who did not become mothers; marital life; professional career; relationship with their own mother; their parents marital life; and the power issue. The conclusion is that the phenomenon of delayed motherhood in contemporary society reveals itself as complex and immersed in a multiplicity of meanings. Among the specificities of each case, some proximity between the experiences of the women of the two different groups could be established particularly with regard to the attributed value and idealization of the marital relationship, perceived as more important than the development of a professional career; and with regard to the integration of the power aspects that refer to the body and the control of fertility, by means of the binomials: omnipotence/impotence and pure masculine/feminine elements in the contemporary woman, from a Winnicottian point of view. The remarkable divergences between the two groups referred especially to the relationship established with their own mothers and the marital life of their parents. The delayed motherhood, a current phenomenon with potential to stir much distress and suffering, can be experienced deeply by the contemporary women in a more or less healthy or creative way, to a greater or lesser degree of integration of their capacity for sustaining ambivalence, depending on the individual psychic resources and his/hers generational legacy