Evaluating Patient Preferences of Maintenance Therapy for the Treatment of Chronic Obstructive Pulmonary Disease: A Discrete Choice Experiment in the UK, USA and Germany.

Introduction: With increasing availability of different treatments for chronic obstructive pulmonary disease (COPD), we sought to understand patient preferences for COPD treatment in the UK, USA, and Germany using a discrete choice experiment (DCE). Methods: Qualitative research identified six attributes associated with COPD maintenance treatments: ease of inhaler use, exacerbation frequency, frequency of inhaler use, number of different inhalers used, side effect frequency, and out-of-pocket costs. A DCE using these attributes, with three levels each, was designed and tested through cognitive interviews and piloting. It comprised 18 choice sets, selected using a D-efficient experimental design. Demographics and disease history were collected and the final DCE survey was completed online by participants recruited from panels in the UK, USA and Germany. Responses were analyzed using mixed logit models, with results expressed as odds ratios (ORs). Results: Overall, 450 participants (150 per country) completed the DCE; most (UK and Germany, 97.3%; USA, 98.0%) were included in the final analysis. Based on relative attribute importance, avoidance of side effects was found to be most important (UK: OR 11.65; USA: OR 7.17; Germany: OR 11.45; all p<0.0001), followed by the likelihood of fewer exacerbations (UK: OR 2.22; USA: OR 1.63; Germany: OR 2.54; all p<0.0001) and increased ease of use (UK: OR 1.84; USA: OR 1.84; Germany: OR 1.60; all p<0.0001). Number of inhalers, out-of-pocket costs, and frequency of inhaler use were found to be less important. Preferences were relatively consistent across the three countries. All participants required a reduction in exacerbations to accept more frequent inhaler use or use of more inhalers. Conclusion: When selecting COPD treatment, individuals assigned the highest value to the avoidance of side effects, experiencing fewer exacerbations, and ease of inhaler use. Ensuring that patients' preferences are considered may encourage treatment compliance

PRS45 Cost Effectiveness of Umeclidinium/Vilanterol (UMEC/VI) Combination Therapy Among Symptomatic COPD Patients

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Studies on physico-mechanical behaviour of kenaf/glass fiber reinforced epoxy hybrid composites

In this study, various treated, untreated, and treated kenaf/glass fiber composites were fabricated using epoxy resin. A portion of kenaf fibers were subjected to treatment with alkali, sub-portion was taken for benzoyl peroxide and potassium permanganate prior to composite fabrication. This treatment on the composite material was undertaken to achieve improved modification of the interface between the matrix and fiber bond. A portion of the glass fiber was used for enhancing the mechanical properties of the hybrid composite. The tensile strength, flexural, density, water absorption and chemical resistance of the composites were analyzed using standard methods. FTIR was conducted on the fiber to ascertain the chemical treatment on the fibers, FESEM was used for the morphological study. The results obtained showed that the tensile and flexural strength improved from 46.45-298.3 kgf, and 10.5-54.7 kgf, respectively, in the composite samples. Chemical resistance of the kenaf fiber treated potassium permanganate composite improved compared to the untreated fiber composite in both cases. The density and water absorption properties of the composites were found to decrease in the treated fibers compared to untreated fiber composites, this treated composites showed less water absorption and density. The FTIR result revealed that reaction has taken place between the fiber and the treatment reagent. Hence, fiber modification has improved the properties of the composites due to increase in fiber-matrix interaction. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; KEY WORDS: Chemical properties, Epoxy resin, Hybrid, Kenaf, Mechanical strength, Natural fiber &nbsp; Bull. Chem. Soc. Ethiop. 2021, 35(1), 171-184. DOI: https://dx.doi.org/10.4314/bcse.v35i1.1

Effects of Precipitation Hardening on Mechanical Properties of Multistage Stirred Cast AA6063 Composites

This research work is to study the effects of precipitation hardening on multistage stirred cast alumina reinforced AA6063 composites which were achieved through production of alumina (Al2O3) reinforced AA6063 alloy, using four stage stir casting method; determination of the effect of precipitation hardening heat treatment on the samples produced; and characterization of the microstructures and some mechanical properties of the cast and precipitation hardened aluminium matrix composite.This work studied the effects of precipitation hardening on multistage stirred cast alumina reinforced AA 6063 composite through production of alumina reinforced AA6063 alloy by four stage stir casting method, determination of effect of precipitation hardening heat treatment and characterization of microstructures and some mechanical properties of as-cast and heat treated samples of aluminium matrix composites. The amounts of AA 6063 and alumina particles required for the production of aluminium composites with 0, 3, 6, 9, 12 and 15 volume percent of alumina were determined by charge calculations. The particles of alumina were initially pre- heated at 300 oC to enhance wetability with aluminium alloy. The AA 6063 alloy was charged into a gas fired crucible furnace and the liquid was allowed to cool to a viscous mass at temperature of about 600 oC so as to introduce alumina particles. Stirring operations were performed manually and mechanically at 750 oC and 300 rpm, to ensure uniform distribution of reinforcement within the matrix, before pouring into permanent metal mould. The samples produced were solutionized at 550 oC for one hour, quenched in water and later aged at 180 oC for 2, 3 and 4 hours. Some samples were reserved for control experimentation. Mechanical responses of the composite were investigated by tensile, hardness and impact test carried out on the samples. The structures of the samples were examined by optical and scanning electron microscopes. The results trend showed that as the volume fraction of alumina and aging time increase, the strength and hardness values also increase with corresponding decrease in impact value. Composite with 15% alumina aged at 4 hours showed highest strength and hardness values of 262.77 MPa and 64.12 BHN, respectively with impact value of 9.86 J. The study showed that multistage stir casting method and precipitation hardening heat treatment are capable of improving the mechanical properties of AA 6063-Al2O3 composites.Self-sponsore

COMPARISON OF ROAD TRAFFIC ACCIDENT PREDICTION MODELS FOR TWO-LANE HIGHWAY INTEGRATING TRAFFIC AND PAVEMENT CONDITION PARAMETERS

In Nigeria, literature on the integration of traffic of pavement condition and traffic characteristics in predicting road traffic accident frequency on 2-lane highways are scanty, hence this article to fill the gap. A comparison of road traffic accident frequency prediction models on IIesha-Akure-Owo road based on the data observed between 2012 and 2014 is presented. Negative Binomial (NB), Ordered Logistic (OL) and Zero Inflated Negative Binomial (ZINB) models were used to model the frequency of road traffic accident occurrence using road traffic accident data from the Federal Road Safety Commission (FRSC) and pavement conditions parameters from pavement evaluation unit of the Federal Ministry of Works, Kaduna. The explanatory variables were: annual average daily traffic (aadt), shoulder factor (sf), rut depth (rd), pavement condition index (pci), and international roughness index (iri). The explanatory variables that were statistically significant for the three models are aadt, sf and iri with the estimated coefficients having the expected signs. The number of road traffic accident on the road increases with the traffic volume and the international roughness index while it decreases with shoulder factor. The systematic variation explained by the models amounts to 87.7, 78.1 and 74.4% for NB, ZINB and OL respectively. The research findings suggest the accident prediction models that should be integrated into pavement rehabilitation. &nbsp; Keywords: &nbsp

Artificial intelligent based friction modelling and compensation in motion control system

The interest in the study of friction in control engineering has been driven by the need for 10 precise motion control in most of industrial applications such as machine tools, robot 11 systems, semiconductor manufacturing systems and Mechatronics systems. Friction has 12 been experimentally shown to be a major factor in performance degradation in various 13 control tasks. Among the prominent effects of friction in motion control are: steady state 14 error to a reference command, slow response, periodic process of sticking and sliding (stick-15 slip) motion, as well as periodic oscillations about a reference point known as hunting when 16 an integral control is employed in the control scheme. Table 1 shows the effects and type of 17 friction as highlighted by Armstrong et. al.(1994). It is observed that, each of task is 18 dominated by at least one friction effect ranging from stiction, or/and kinetic to negative 19 friction (Stribeck). Hence, the need for accurate compensation of friction has become 20 important in high precision motion control. Several techniques to alleviate the effects of 21 friction have been reported in the literature (Dupont and Armstrong, 1993; Wahyudi, 2003; 22 Tjahjowidodo, 2004; Canudas, et. al., 1986). 23 One of the successful methods is the well-known model-based friction compensation 24 (Armstrong et al., 1994; Canudas de Wit et al., 1995 and Wen-Fang, 2007). In this method, 25 the effect of the friction is cancelled by applying additional control signal which generates a 26 torque/force. The generated torque/force has the same value (or approximately the same) 27 with the friction torque/force but in opposite direction