Temperate UV-Accelerated Weathering Cycle Combined with HT-GPC Analysis and Drop Point Testing for Determining the Environmental Instability of Polyethylene Films.

Polyethylene films are one of the most frequently used packaging materials in our society, due to their combination of strength and flexibility. An unintended consequence of this high use has been the ever-increasing accumulation of polyethylene films in the natural environment. Previous attempts to understand their deterioration have either focused on their durability using polymer analysis; or they have focused on changes occurring during outdoor exposure. Herein, this study combines those strategies into one, by studying the chemical and physical changes in the polyethylene structure in a laboratory using molecular weight and IR spectroscopic mapping analysis, combined with temperate UV-accelerated weathering cycles. This approach has been correlated to real-world outdoor exposure timeframes by parallel testing of the sample polyethylene films in Florida and France. The formation of polyethylene microparticles or polyethylene waxes is elucidated through comparison of drop point testing and molecular weight analysis.

Correlation of a Temperate UV-Weathering Cycle to Outdoor Exposure for the Determination of the Environmental Instability of Polyethylene Films Using HT-GPC Analysis.

Accelerated UV-weathering cycles are predominately used for evaluating the durability of plastic materials, particularly polyethylene (PE) films. The point of failure for this testing is usually the loss of a physical property, such as the loss of tensile strength over time. For plastics designed to be instable under environmental conditions, the accelerated weathering cycles are yet to be defined and their correlation to outdoor exposure has yet to be made. This study demonstrates the utility of a newly defined temperate accelerated UV-weathering cycle, recently codified in the British Standard PAS 9017:2020. In addition, the effectiveness of the laboratory weathering cycle has been correlated to real-world outdoor exposure through simultaneous testing of the same samples at a specialist outdoor exposure site in Florida. The utility of the testing methodology and the performance of the polyethylene samples was demonstrated through the use of High Temperature Gel Permeation Chromatography (HT-GPC) analysis. The data led to a detailed insight into the physico-chemical changes occurring in the PE films upon exposure to environmental stimuli. By comparison, and surprisingly, the techniques employed appear to provide an insight into the processes in which secondary micro-particles of PE are formed from macro-polyethylene samples. The temperate accelerated UV-weathering cycle over 14 days demonstrated an approximate correlation to 90 days of outdoor exposure in Florida for the PE film studied.

A Situação de paragem cardiorrespiratória: experiências dos enfermeiros / The Cardiorespiratory Arrest Situation: Nurses' Experiences

A Paragem Cardiorrespiratória (PCR) é um evento que pode ocorrer em meio intra-hospitalar, normalmente de modo inesperado. Exige uma resposta imediata e eficiente o que gera nos profissionais de saúde, nomeadamente nos enfermeiros que na maior parte das vezes se encontram na primeira linha, stress e até dilemas éticos. Neste sentido, surge este estudo que visa compreender as experiências dos enfermeiros de uma unidade de internamento perante uma situação de PCR. Este assenta numa abordagem qualitativa, com caráter descritivo simples e exploratório, em que a estratégia de recolha de dados incidiu na entrevista semiestruturada, dirigida a oito enfermeiros. Os dados foram analisados com o recurso à técnica de análise de conteúdo. Dos dados sobressaem fatores que dificultam a atuação do enfermeiro perante a situação de PCR nomeadamente, a inexperiência do enfermeiro, o défice de conhecimentos relativos aos equipamentos e aos procedimentos, fatores relacionados com os recursos (humanos, materiais e condições físicas) e a tomada de decisão em reanimar ou não reanimar. O trabalho em equipa, a formação contínua e a partilha de experiências para reflectir sobre a situação e ajudar no alívio do stress, foram também os fatores facilitadores que emergiram no estudo. Foi visível também que a situação desencadeia diversos sentimentos nos enfermeiros, sentimentos positivos como a felicidade e a satisfação e sentimentos negativos como a angústia, a ansiedade, a frustração, a impotência, o medo e o stress. Esta dualidade de sentimentos surge da possibilidade de se conseguir salvar a vida da pessoa. Estes resultados sugerem que é importante implementar estratégias/dinâmicas favorecedoras de uma formação contínua e de partilha de experiências nas equipas que proporcionam uma melhor intervenção nestas situações.

The Cardiopulmonary Arrest (CPA) is an event that can occur in a hospital environment, typically in an unexpected way. Requires an immediate response and efficient that generates in health professionals, especially nurses, most of whom are in the first line, stress and even ethical dilemmas. In this regard, this study aims to understand the experiences of nurses in a Nursing unit in a situation of CPA. This is based on a qualitative approach, with character simple descriptive and exploratory, in that the strategy of data collection focused on semi-structured interviews, addressed to eight nurses. The data were analyzed with the use of content analysis technique. The data stand out factors that hinder the action of the nurse in this situation of CPA in particular were the inexperience of the nurse, the lack of knowledge concerning the equipment and procedures, factors related to the resources (human, material and physical conditions) and the decision-making in resuscitate or do not resuscitate order. The teamwork, continuous training and the sharing of experiences to reflect on the situation and help to relieve stress, were also the facilitating factors that emerged in the study. It was visible that the CPA situation triggers various feelings in nurses, positive feelings, such as happiness and satisfaction and negative feelings such as fear, anxiety, frustration, helplessness, fear and stress. This duality of feelings comes from the possibility of being able to save person's life. These results suggest that it is important to implement strategies/dynamic favoring a continuous training and sharing of experiences in the teams that provide a better intervention in these situations.