Nonequilibrium modeling of an ammonia-water rectifyng column via fundamental thermodynamic and transport relations

A nonequilibrium heat and mass transfer model is presented for the steady-state operation of a rectifying column, employed in ammonia-water absorption refrigeration systems to dehumidify the ammonia vapor leaving the generator. The thermodynamic state relations of the mixture are derived from two equations representing the Gibbs free energy in terms of temperature, pressure and concentration for the liquid and the vapor phases. Two of the transport properties, surface tension and liquid diffusivity required original relations, as presented here in. The resulting nonlinear system of equations is solved by efficient use of the Newton-Raphson code that minimizes the order of the Jacobian matrix without losing any model information or the quadratic order of convergence of the numerical method. Accuracy tests are performed by grid refinement and by comparison with results in the literature. A sensitivity study is presented showing the influence of some alternative methods for estimation of the transport properties on the temperature and concentration profiles.54055

Project 20: Midwives' insight into continuity of care models for women with social risk factors: what works, for whom, in what circumstances, and how.

INTRODUCTION:Continuity of care models are known to improve clinical outcomes for women and their babies, but it is not understood how. A realist synthesis of how women with social risk factors experience UK maternity care reported mechanisms thought to improve clinical outcomes and experiences. As part of a broader programme of work to test those theories and fill gaps in the literature base we conducted focus groups with midwives working within continuity of care models of care for women with social factors that put them at a higher chance of having poor birth outcomes. These risk factors can include poverty and social isolation, asylum or refugee status, domestic abuse, mental illness, learning difficulties, and substance abuse problems. OBJECTIVE:To explore the insights of midwives working in continuity models of care for women with social risk factors in order to understand the resources they provide, and how the model of care can improve women's outcomes. DESIGN:Realist methodology was used to gain a deeper understanding of how women react to specific resources that the models of care offer and how these resources are thought to lead to particular outcomes for women. Twelve midwives participated, six from a continuity of care model implemented in a community setting serving an area of deprivation in London, and six from a continuity of care model for women with social risk factors, based within a large teaching hospital in London. FINDINGS:Three main themes were identified: 'Perceptions of the model of care, 'Tailoring the service to meet women's needs', 'Going above and beyond'. Each theme is broken down into three subthemes to reveal specific resources or mechanisms which midwives felt might have an impact on women's outcomes, and how women with different social risk factors respond to these mechanisms. CONCLUSIONS/IMPLICATIONS FOR PRACTICE:Overall the midwives in both models of care felt the service was beneficial to women and had a positive impact on their outcomes. It was thought the trusting relationships they had built with women enabled midwives to guide women through a fragmented, unfamiliar system and respond to their individual physical, emotional, and social needs, whilst ensuring follow-up of appointments and test results. Midwives felt that for these women the impact of a trusting relationship affected how much information women disclosed, allowing for enhanced, needs led, holistic care. Interesting mechanisms were identified when discussing women who had social care involvement with midwives revealing techniques they used to advocate for women and help them to regain trust in the system and demonstrate their parenting abilities. Differences in how each team provided care and its impact on women's outcomes were considered with the midwives in the community-based model reporting how their location enabled them to help women integrate into their local community and make use of specialist services. The study demonstrates the complexity of these models of care, with midwives using innovative and compassionate ways of working to meet the multifaceted needs of this population

Los deberes sin conciencia y sin razón en la doctrina moral de Hostos

How to cite: Suárez-Silverio, E. J. (2004). Los deberes sin conciencia y sin razón en la doctrina moral de Hostos. Pedagogía, 37(1), 64-75.Cómo citar: Suárez-Silverio, E. J. (2004). Los deberes sin conciencia y sin razón en la doctrina moral de Hostos. Pedagogía, 37(1), 64-75

La metáfora ocular y representativa del pensamiento y la educación

Since Plato a metaphor has dominated western thought. This metaphor depicts reason as possessing a ‘mental eye’ that apprehends truths in the same way in which our perceptual vision reflects and reproduces things. The visual metaphor is accompanied by an objectivist doctrine in which humans beings grasp knowledge, instead of constructing it. The problem emerges when we forget that it is only a metaphor and begins to believe that it is an accurate description of how we learn. This ocular metaphor has reinforced a passive view of learning which is responsible for the way in which we have designed education as a process of reproduction. Why was vision, and not some other perceptual sense, employed? It is argued that vision contains some elements which are not found in the other senses. To conclude, the possibility of portraying learning by non representative means is examined. How to cite: Suárez-Silverio, E. J. (2011). La metáfora ocular y representativa del pensamiento y la educación. Pedagogía, 42(1), 79-102. Retrieved from https://revistas.upr.edu/index.php/educacion/article/view/16618Desde Platón, ha dominado en el pensamiento occidental una metáfora que presenta la razón como poseedora de un ‘ojo mental’. De la misma forma en que la vista refleja y reproduce las cosas, el intelecto capta las verdades. Esta metáfora va acompañada de una doctrina objetivista en la que los seres humanos descubrimos, y no construimos, el saber. El problema surge cuando olvidamos que es una metáfora y comenzamos a creer que es una fiel descripción de cómo aprendemos. La metáfora ocular ha reforzado una concepción pasiva del aprendizaje que es responsable por la manera en que se ha diseñado la educación como un proceso de reproducción. ¿Por qué se emplea la visión y no otro sentido? Se arguye que la visión contiene unos elementos que no se encuentran en los otros sentidos. Por último, se examina la posibilidad no representativa de caracterizar el aprendizaje. Cómo citar: Suárez-Silverio, E. J. (2011). La metáfora ocular y representativa del pensamiento y la educación. Pedagogía, 42(1), 79-102. Recuperado a partir de https://revistas.upr.edu/index.php/educacion/article/view/1661

El constructivismo radical de Glasersfeld versus el constructivismo pragmático de Dewey

The constructivist critique usually centers on the comparison between the radical constructivism (RC) of Glasersfeld and the more moderate conception (MC) associated with Piaget. This comparison, while interesting, is limited by both a resemblance and a difference between both models. While RC confronts the issue of how reality is formed from a more conceptual perspective, MC focuses on how these cognitive abilities develop in children. Both RC and MC assume a dualist conception of construction: There exists an ego that ontologically precedes and is distinguished from the surrounding world. On the other hand, the pragmatist constructivism (PC) associated to Dewey surmounts the resemblance and difference establishing a new comparative framework. In reference to the resemblance, both RC and PC are grounded on a philosophical base and not on a matrix that focuses in the evolution of the cognitive abilities (as is the case with MC). In reference to the common element found in RC and MC, PC assumes a monist conception of experience: The distinction between the subject that constructs and the formed reality are two secondary, derived aspects of experience. In this sense PC presents an advantage over RC and MC. How to cite: Suárez-Silverio, E. J. (2014). El constructivismo radical de Glasersfeld versus el constructivismo pragmático de Dewey. Pedagogía, 47(1), 115-158. Retrieved from https://revistas.upr.edu/index.php/educacion/article/view/16360La crítica constructivista usualmente contrasta el constructivismo radical (CR) de Glasersfeld y la versión más moderada del constructivismo (CM), asociada a Piaget. Esta comparación, aunque interesante, está limitada por una diferencia y una similitud inherente a ambos modelos. Mientras que el CR confronta el asunto de cómo se construye la realidad desde una perspectiva más conceptual, el CM estudia este tema desde el desarrollo de las capacidades cognitivas en los niños. Tanto el CR como el CM asumen una concepción dualista de la construcción: existe un sujeto que ontológicamente precede y se diferencia del mundo que le rodea. En cambio, el constructivismo pragmático (CP) de Dewey supera esta diferencia y similitud, con una nueva perspectiva comparativa. Con relación a la primera, tanto el CR como el CP se establecen en un marco filosófico y no desde una matriz que se enfoca en la evolución de las capacidades cognitivas (como en el CM). En lo que se refiere al punto común que hallamos en el CR y el CM, el CP asume una visión monista de la experiencia: la distinción entre el sujeto que construye y la realidad configurada son dos aspectos que secundariamente distinguimos en el flujo de la experiencia. Es en este sentido que el CP presenta una ventaja conceptual sobre el CR y el CM. Cómo citar: Suárez-Silverio, E. J. (2014). El constructivismo radical de Glasersfeld versus el constructivismo pragmático de Dewey. Pedagogía, 47(1), 115-158. Recuperado a partir de https://revistas.upr.edu/index.php/educacion/article/view/1636

Preliminary findings on the experiences of care for parents who suffered perinatal bereavement during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic poses an unprecedented risk to the global population. Maternity care in the UK was subject to many iterations of guidance on how best to reconfigure services to keep women, their families and babies, and healthcare professionals safe. Parents who experience a pregnancy loss or perinatal death require particular care and support. PUDDLES is an international collaboration investigating the experiences of recently bereaved parents who suffered a late miscarriage, stillbirth, or neonatal death during the global COVID-19 pandemic, in seven countries. In this study, we aim to present early findings from qualitative work undertaken with recently bereaved parents in the United Kingdom about how access to healthcare and support services was negotiated during the pandemic. METHODS: In-depth semi-structured interviews were undertaken with parents (N = 24) who had suffered a late miscarriage (n = 5; all mothers), stillbirth (n = 16; 13 mothers, 1 father, 1 joint interview involving both parents), or neonatal death (n = 3; all mothers). Data were analysed using a template analysis with the aim of investigating bereaved parents' access to services, care, and networks of support, during the pandemic after their bereavement. RESULTS: All parents had experience of utilising reconfigured maternity and/or neonatal, and bereavement care services during the pandemic. The themes utilised in the template analysis were: 1) The Shock & Confusion Associated with Necessary Restrictions to Daily Life; 2) Fragmented Care and Far Away Families; 3) Keeping Safe by Staying Away; and 4) Impersonal Care and Support Through a Screen. Results suggest access to maternity, neonatal, and bereavement care services were all significantly reduced, and parents' experiences were notably affected by service reconfigurations. CONCLUSIONS: Our findings, whilst preliminary, are important to document now, to help inform care and service provision as the pandemic continues and to provide learning for ongoing and future health system shocks. We draw conclusions on how to enable development of safe and appropriate services during this pandemic and any future health crises, to best support parents who experience a pregnancy loss or whose babies die

Disclosure of non-recent (historic) childhood sexual abuse: What should researchers do?

Non-recent (historic) childhood sexual abuse is an important issue to research, though often regarded as taboo and frequently met with caution, avoidance or even opposition from research ethics committees. Sensitive research, such as that which asks victim-survivors to recount experiences of abuse or harm, has the propensity to be emotionally challenging for both the participant and the researcher. However, most research suggests that any distress experienced is usually momentary and not of any clinical significance. Moreover, this type of research offers a platform for voices which have often been silenced, and many participants report the cathartic effect of recounting their experiences in a safe, non-judgemental space. With regard to the course of such research, lines of inquiry which ask adult participants to discuss their experiences of childhood sexual abuse may result in a first-time disclosure of that abuse by the victim-survivor to the researcher. Guidance about how researchers should respond to first-time disclosure is lacking. In this article, we discuss our response to one research ethics committee which had suggested that for a qualitative study for which we were seeking ethical approval (investigating experiences of pregnancy and childbirth having previously survived childhood sexual abuse), any disclosure of non-recent (historic) childhood sexual abuse which had not been previously reported would result in the researcher being obliged to report it to relevant authorities. We assess this to be inconsistent with both law and professional guidance in the United Kingdom; and provide information and recommendations for researchers and research ethics committees to consider

Disclosure of non-recent (historic) childhood sexual abuse: What should researchers do?

Non-recent (historic) childhood sexual abuse is an important issue to research, though often regarded as taboo and frequently met with caution, avoidance or even opposition from research ethics committees. Sensitive research, such as that which asks victim-survivors to recount experiences of abuse or harm, has the propensity to be emotionally challenging for both the participant and the researcher. However, most research suggests that any distress experienced is usually momentary and not of any clinical significance. Moreover, this type of research offers a platform for voices which have often been silenced, and many participants report the cathartic effect of recounting their experiences in a safe, non-judgemental space. With regard to the course of such research, lines of inquiry which ask adult participants to discuss their experiences of childhood sexual abuse may result in a first-time disclosure of that abuse by the victim-survivor to the researcher. Guidance about how researchers should respond to first-time disclosure is lacking. In this article, we discuss our response to one research ethics committee which had suggested that for a qualitative study for which we were seeking ethical approval (investigating experiences of pregnancy and childbirth having previously survived childhood sexual abuse), any disclosure of non-recent (historic) childhood sexual abuse which had not been previously reported would result in the researcher being obliged to report it to relevant authorities. We assess this to be inconsistent with both law and professional guidance in the United Kingdom; and provide information and recommendations for researchers and research ethics committees to consider

Pills and prayers: a comparative qualitative study of community conceptualisations of pre-eclampsia and pluralistic care in Ethiopia, Haiti and Zimbabwe.

BACKGROUND: Pre-eclampsia is a leading cause of preventable maternal and perinatal deaths globally. While health inequities remain stark, removing financial or structural barriers to care does not necessarily improve uptake of life-saving treatment. Building on existing literature elaborating the sociocultural contexts that shape behaviours around pregnancy and childbirth can identify nuanced influences relating to pre-eclampsia care. METHODS: We conducted a cross-cultural comparative study exploring lived experiences and understanding of pre-eclampsia in Ethiopia, Haiti and Zimbabwe. Our primary objective was to examine what local understandings of pre-eclampsia might be shared between these three under-resourced settings despite their considerable sociocultural differences. Between August 2018 and January 2020, we conducted 89 in-depth interviews with individuals and 17 focus group discussions (n = 106). We purposively sampled perinatal women, survivors of pre-eclampsia, families of deceased women, partners, older male and female decision-makers, traditional birth attendants, religious and traditional healers, community health workers and facility-based health professionals. Template analysis was conducted to facilitate cross-country comparison drawing on Social Learning Theory and the Health Belief Model. RESULTS: Survivors of pre-eclampsia spoke of their uncertainty regarding symptoms and diagnosis. A lack of shared language challenged coherence in interpretations of illness related to pre-eclampsia. Across settings, raised blood pressure in pregnancy was often attributed to psychosocial distress and dietary factors, and eclampsia linked to spiritual manifestations. Pluralistic care was driven by attribution of causes, social norms and expectations relating to alternative care and trust in biomedicine across all three settings. Divergence across the contexts centred around nuances in religious or traditional practices relating to maternal health and pregnancy. CONCLUSIONS: Engaging faith and traditional caregivers and the wider community offers opportunities to move towards coherent conceptualisations of pre-eclampsia, and hence greater access to potentially life-saving care

Trips de los Agrios. Su biología y medios de lucha

Pertenecen estos insectos al orden de los Tisanópteros, y los que vamos a describir, causantes de daños en los agrios, están encuadrados dentro del suborden Terebrantia. Sus caracteres generales son los siguientes: Insectos pequeñísimos -su longitud total varía de 1 a 3 mm., siendo lo normal 1'2-1'5 mm.-, estrechos, aplanados, con una coloración que varía de amarillo a negro en los adultos, mientras las larvas son generalmente amarilloanaranjadas. Poseen una cabeza rectangular, en la que llevan insertos tres ocelos, dos grandes ojos compuestos, dos antenas bastante largas, con 6 a 9 artejos, según especies, formando los dos o tres últimos -que son de menor tamaño- una pieza afilada denominada «estilo». El aparato bucal pertenece al tipo chupador, Poseen tres pares de patas bastante largas, aunque la locomoción la efectúan generalmente reptando, y dos pares de alas que están reducidas a una estrecha lámina quitinosa con largos pelos (cilios) y que no están adaptadas para el vuelo, pues apenas pueden volar unos pocos centímetros, siendo el agente difusor, por excelencia, el viento, que los traslada a distancias enormes