Mixing of high-consistency fiber-foam suspensions

Foam-forming has been gaining attention recently to manufacture sustainable packaging and cushioning products in various sectors, including food, automobile and construction [1]. Conventionally, foam suspension is made in a mixing tank at a lower fibre consistency, ≤ 2% resulting in large volumes of water consumption. Besides, the excess moisture from the final foam-formed product needs to be removed by drying. Replacing the current foaming methods with High-consistency foam (HCF) can reduce water consumption, drying energy and equipment footprint. However, increasing the fibre consistency makes the rheology of fibre-foam suspension complex [2], posing challenges in mixing. The present work focuses on mixing this complex suspension to generate a homogeneous HCF by selecting proper impeller geometry, mixing time and surfactant dosage. The lab-scale testing facility consisted of a 0.43 m tall and 0.16 m wide transparent acrylic tank equipped with a top-mount impeller assembly. Three impeller geometries, namely bend-disc, Bakker turbine and high solidity pitched blade turbine, and four impeller combinations were used. Chemi-thermomechanical pulp (CTMP) with a mean fibre length of 2.0 mm, a width of 39 μm and Canadian standard freeness (CSF) of 600 ml was used as the fibre material. The consistency varied from 5% to 15%. An 80/20 mol% mixture of sodium dodecyl sulphate (SDS) and Tween 20 (T 20) was used as the surfactant. The surfactant dosage was varied from 0.5 g/l to 2.0 g/l based on fibre consistency. The quality of the HCF was assessed in terms of air content, foaming time and X-ray microtomography. Preliminary results indicated that the used impeller combination should be selected on the base of fibre consistency. No improvement in the air content was noticed beyond 1.2 g/l surfactant dosage. However, increasing the surfactant dosage reduced foaming time at higher consistencies. Currently, experiments are carried out to understand the role of fibre length and the addition of binders such as guar gum in the mixing. In summary, this work provides an understanding of the mixing geometry and foam chemistry that enables the manufacturing of sustainable packaging products at a much lower water consumption

中山間地域で暮らす要介護高齢者の医療福祉ニーズの構造とその関連要因

高知県立大学平成27年

Cost-effectiveness analysis of guidelines for antihypertensive care in Finland

<p>Abstract</p> <p>Background</p> <p>Hypertension is one of the major causes of disease burden affecting the Finnish population. Over the last decade, evidence-based care has emerged to complement other approaches to antihypertensive care, often without health economic assessment of its costs and effects. This study looks at the extent to which changes proposed by the 2002 Finnish evidence-based Current Care Guidelines concerning the prevention, diagnosis, and treatment of hypertension (the ACCG scenario) can be considered cost-effective when compared to modelled prior clinical practice (the PCP scenario).</p> <p>Methods</p> <p>A decision analytic model compares the ACCG and PCP scenarios using information synthesised from a set of national registers covering prescription drug reimbursements, morbidity, and mortality with data from two national surveys concerning health and functional capacity. Statistical methods are used to estimate model parameters from Finnish data. We model the potential impact of the different treatment strategies under the ACCG and PCP scenarios, such as lifestyle counselling and drug therapy, for subgroups stratified by age, gender, and blood pressure. The model provides estimates of the differences in major health-related outcomes in the form of life-years and costs as calculated from a 'public health care system' perspective. Cost-effectiveness analysis results are presented for subgroups and for the target population as a whole.</p> <p>Results</p> <p>The impact of the use of the ACCG scenario in subgroups (aged 40–80) without concomitant cardiovascular and related diseases is mainly positive. Generally, costs and life-years decrease in unison in the lowest blood pressure group, while in the highest blood pressure group costs and life-years increase together and in the other groups the ACCG scenario is less expensive and produces more life-years. When the costs and effects for subgroups are combined using standard decision analytic aggregation methods, the ACCG scenario is cost-saving and more effective.</p> <p>Conclusion</p> <p>The ACCG scenario is likely to reduce costs and increase life-years compared to the PCP scenario in many subgroups. If the estimated trade-offs between the subgroups in terms of outcomes and costs are acceptable to decision-makers, then widespread implementation of the ACCG scenario is expected to reduce overall costs and be accompanied by positive outcomes overall.</p