114 research outputs found
On the durability of cores and rest roll dynamics
The printing industry is facing the same challenges as many other industries, in that demand is increasing for its processes to run faster and more reliably. Roll weight, width and web speed are steadily increasing which put increasing demands on unwinding stability and durability of cores.Durability and especially the unwinding stability of cores is one of the most important topics when designing new wider printing machine unwinders. The majority of paper and printing industry processes run with recyclable paperboard cores. A change in core geometry could lead to significant retrofitting costs for both the paper mill and printer.Winder and printing press reel stand design, especially with regards to chucks, can have a considerable effect on the maximum tolerated roll weight and unwinding web speed. It is important to use the right combinations of cores and chucks to maximize performance and cost savings.The risk of rest reel explosions increases rapidly in the vicinity of the resonance frequency of a rest reel. It is important to know the safe web speed ranges in different situations. The range of safe web speed can be estimated according to the presented theory. The maximum tolerated mid span vibration is typically +/-5 mm.Cores must also withstand the alternating, cyclic roll supporting stresses during winding and unwinding. The risk of core failure can be minimized by using cores which have sufficiently high dynamic delamination strength (roll weight capacity).The durability of cores can be estimated by dynamic chuck load capacity tests and by testing cores in simulated winding-unwinding conditions. The simulation test results are reduced to correspond to certain confidence levels by reducing the simulation curve by a certain number of standard deviations.With a sufficient number of chuck load capacity tests, statistically reduced winding-unwinding simulation results and test data concerning behavior of cores in the vicinity of resonance, core recommendations can be built for core users as shown here
Modelling soil moisture - soil strength relationship of fine-grained upland forest soils
The strength of soil is known to be dependent on water content but the relationship is strongly affected by the type of soil. Accurate moisture content - soil strength models will provide forest managers with the improved ability to reduce soil disturbances and increase annual forest machine utilization rates. The aim of this study was to examine soil strength and how it is connected to the physical properties of fine-grained forest soils; and develop models that could be applied in practical forestry to make predictions on rutting induced by forest machines. Field studies were conducted on two separate forests in Southern Finland. The data consisted of parallel measurements of dry soil bulk density (BD), volumetric water content (VWC) and penetration resistance (PR). The model performance was logical, and the results were in harmony with earlier findings. The accuracy of the models created was tested with independent data. The models may be regarded rather trustworthy, since no significant bias was found. Mean absolute error of roughly 20% was found which may be regarded as acceptable taken into account the character of the penetrometer tool. The models can be linked with mobility models predicting either risks of rutting, compaction or rolling resistance.Peer reviewe
Study of CD elongation of core in winding
In this paper the elongation of a core in a roll bottom is studied experimentally and theoretically. The CD elongation effects are of interest especially because they are known to contribute prominently to a two-drum winder vibration or roll instability phenomenon called bouncing in the paper industry.Analytical and numerical calculation models are used to study the effect of different geometrical, material, etc., parameters on the core and paper CD elongation. If the free lateral elongation and rotation is allowed and the friction between paper and the core is neglected, the radial and tangential stresses of the core are due to the radial pressure only. The lateral and shear stresses are equal to zero and the elongation depends on the pressure, Poisson's ratios in the thickness-machine and thickness-cross directions, elastic modulus in the thickness and tangential directions and the geometry. If the lateral frictional farces between the paper and core are also taken into account, another, equally effective elongation mechanism is introduced.The measurements of the paper and core elongation are in accordance with the calculated results. In practice, cores expand typically +/-1 mm/m depending on the tightness of the roll bottom and core properties. This study shows that the core elongation increases linearly with the radial pressure. Small diameter cores lengthen less than large cores. Cores with thicker wall thickness lengthen less than thinner cores, and cores with a bigger winding angle lengthen less than cores with a smaller winding angle (conventional cores).The radial moduli of paper and the core wall also play an important role in the elongation of the core. Preliminary studies suggest that the softer the paper the more it tends to widen. According to paper stack modulus measurements, the radial modulus of paper layers in the roll bottom can be less than 100 MPa, even with high winding pressures. The radial elastic modulus of the core wall is usually 100 - 200 MPa or even greater depending on the core type. It is possible that the frictional force between the core and paper could force the core to elongate more than it would without paper
Predicting rut depth induced by an 8-wheeled forwarder in fine-grained boreal forest soils
Key message Rut depth in fine-grained boreal soils induced by an 8-wheeled forwarder is best predicted with soil moisture content, cumulative mass of machine passes, bulk density and thickness of the humus layer. Context Forest machines are today very heavy and will cause serious damage to soil and prevent future growth if forest operations are carried out at the wrong time of the year. Forest operations performed during the wettest season should therefore be directed at coarse-grained soils that are not as prone to soil damage. Aims The study aimed at investigating the significance of the most important soil characteristics on rutting and developing models that can be utilized in predicting rutting prior to forest operations. Methods A set of wheeling tests on two fine-grained mineral soil stands in Southern Finland were performed. The wheeling experiments were conducted in three different periods of autumn in order to get the largest possible variation in moisture content. The test drives were carried out with an 8-wheeled forwarder. Results Soil moisture content is the most important factor affecting rut depth. Rut depth of an 8-wheeled forwarder in fine-grained boreal soil is best predicted with soil moisture content, cumulative mass of machine passes, bulk density and thickness of the humus layer. Conclusion The results emphasize the importance of moisture content on the risk of rutting in fine-grained mineral soils, especially with high moisture content values when soil saturation reaches 80%. The results indicate that it is of high importance that soil type and soil wetness can be predicted prior to forest operations.Peer reviewe
Gender differences in comorbidity of conduct disorder among adolescents in Northern Finland
Mauri Marttunen on työryhmän STUDY-70 Workgrp jäsen.Objectives: Conduct disorder (CD) refers to a pattern of severe antisocial and aggressive behaviour manifested in childhood or adolescence, with heavy costs to society. Though CD is a common psychiatric diagnosis among adolescents of both genders, gender differences in comorbidity of CD have been little studied. In this study we examined gender differences among adolescents with CD in causes for hospitalization, comorbid psychiatric diagnoses and somatic conditions. Study design: The original study sample consisted of 508 inpatient adolescents in Northern Finland (age 12-17); 155 of them (65 girls, 92 boys) fulfilled the DSM-IV criteria for CD. Methods: Diagnosis of CD and psychiatric comorbidities were obtained from the K-SADS-PL and somatic conditions from the EuropAsi. Results: As compared to boys with CD, suicidality (including suicidal ideation and behaviour) was significantly more commonly the cause of hospitalization among girls with CD (43% vs. 24%, p = 0.013). Among somatic conditions, there was a significant predominance in self-reported allergies among girls (60% vs. 25%, p Conclusions: Girls with CD seem to have an increased tendency to develop both comorbid psychiatric and somatic conditions as well as suicidality. New clinical aspects in treatment of CD and comorbid disorders among girls are discussed.Peer reviewe
Lifestyle Changes in Relation to Initiation of Antihypertensive and Lipid-Lowering Medication : A Cohort Study
Background--Lifestyle modification is a key component of cardiovascular disease prevention before and concurrently with pharmacologic interventions. We evaluated whether lifestyle factors change in relation to the initiation of antihypertensive or lipidlowering medication (statins). Methods and Results--The study population comprised 41 225 participants of the FPS (Finnish Public Sector) study aged =40 years who were free of cardiovascular disease at baseline and responded to =2 consecutive surveys administered in 4-year intervals in 2000-2013. Medication use was ascertained through pharmacy-claims data. Using a series of pre-post data sets, we compared changes in body mass index, physical activity, alcohol consumption, and smoking between 8837 initiators and 46 021 noninitiators of antihypertensive medications or statins. In participants who initiated medication use, body mass index increased more (difference in change 0.19; 95% CI, 0.16-0.22) and physical activity declined (-0.09 metabolic equivalent of task hour/day; 95% CI, -0.16 to -0.02) compared with noninitiators. The likelihood of becoming obese (odds ratio: 1.82; 95% CI, 1.63-2.03) and physically inactive (odds ratio: 1.08; 95% CI, 1.01-1.17) was higher in initiators. However, medication initiation was associated with greater decline in average alcohol consumption (-1.85 g/week; 95% CI, -3.67 to -0.14) and higher odds of quitting smoking (odds ratio for current smoking in the second survey: 0.74; 95% CI, 0.64-0.85). Conclusions--These findings suggest that initiation of antihypertensive and statin medication is associated with lifestyle changes, some favorable and others unfavorable. Weight management and physical activity should be encouraged in individuals prescribed these medications.Peer reviewe
Safety and Effectiveness of Direct Oral Anticoagulants Versus Warfarin in People with Atrial Fibrillation and Dementia
Objective:
To determine risks of embolic events, bleeding, and mortality with direct oral anticoagulants (DOACs) vs warfarin in people with atrial fibrillation (AF) and dementia. /
Design:
New-user retrospective cohort study using The Health Improvement Network database. /
Setting and Participants:
A population-based sample comprising people with AF and dementia prescribed DOACs or warfarin from August 2011 to September 2017. /
Methods:
Risk of ischemic stroke (IS), ischemic stroke/transient ischemic attack/systemic embolism (IS/TIA/SE), all-cause mortality, intracranial bleeding (ICB), gastrointestinal bleeding (GIB), and other bleeding were compared for DOACs vs warfarin using propensity score–adjusted Poisson regression. Incidence rate ratios (IRRs) and absolute risk differences (ARDs) were calculated. /
Results:
Overall, 2399 people with AF and dementia initiated DOACs (42%) or warfarin (58%). Before propensity score adjustment, patients who initiated DOACs were older and had more comorbidities. After adjustment, DOAC initiators demonstrated similar risks of IS, TIA, or SE; IS alone; and other bleeding but reduced ICB risk (IRR 0.27, 95% CI 0.08, 0.86; ARD −5.2, 95% CI –6.5, −1.0, per 1000 person-years) compared with warfarin. Increased risk of GIB (IRR 2.11, 95% CI 1.30, 3.42; ARD 14.8, 95% CI 4.0, 32.4, per 1000 person-years) and all-cause mortality (IRR 2.06, 95% CI 1.60, 2.65; ARD 53.0, 95% CI 30.2, 82.8, per 1000 person-years) were observed in DOAC initiators compared with warfarin. /
Conclusions and Implications:
Among people with AF and dementia, initiating treatment with DOACs compared with warfarin was associated with similar risks of IS, TIA, or SE and IS alone. DOAC-treated patients demonstrated reduced ICB risk but increased GIB and all-cause mortality risks. We cannot exclude the possible impact of residual confounding from channeling of DOACs toward older and sicker people, particularly for the outcome of all-cause mortality. Further safety data are urgently needed to confirm findings
Trajectory analyses of adherence patterns in a real-life moderate to severe asthma population
Background: Global Initiative for Asthma step 5 therapies (GINA-5), other than inhaled corticosteroids and long-acting β-agonists in fixed dose combinations (ICS/LABA FDC), often entail more expensive (eg, monoclonal biologics) or less safe (eg, maintenance oral corticosteroids [OCS]) treatments. It is therefore important to assess poor inhaler adherence as a possible cause of suboptimal response to ICS/LABA FDC before additional GINA-5. Objective: To determine rates of, and time to, additional GINA-5 after first-year ICS/LABA FDC use, and their association with inhaler adherence. Methods: Patients initiating ICS/LABA FDC between 2013 and 2017 were identified from Australian national dispensing data. Group-based trajectory modeling was used to estimate medication adherence patterns. Multivariable Cox proportional hazards models were used to examine the association between adherence trajectories and GINA-5 addition during 2-year follow-up. Results: In total, 3062 new ICS/LABA FDC users were identified, of whom 120 (3.9%) received additional GINA-5 (OCS: 89; long-acting muscarinic antagonists: 39; biologics: <3). Mean time to commencing additional GINA-5 was 705.2 (standard deviation, 1.7) days. Adherence trajectories were nonpersistent use (20%), seasonal use (8%), poor adherence (58%), and good adherence (13%). Although poor adherence was associated with longer time to additional GINA-5 (adjusted hazard ratio: 0.58; 95% confidence interval: 0.35-0.95), over 80% of additional GINA-5 was commenced in poorly adherent patients. Use of ≥2 OCS/antibiotic courses also predicted additional GINA-5. Conclusions: Almost 1 in 20 people with asthma commenced additional GINA-5 after ICS/LABA initiation, most of whom (>80%) were poorly adherent to inhaled preventers. There is a substantial unmet need for inhaler adherence to be addressed before prescribing additional GINA-5.</p
Trends in oral anticoagulant prescribing in individuals with type 2 diabetes mellitus: a population-based study in the UK
OBJECTIVE: To evaluate oral anticoagulant (OAC) prescribing trends in type 2 diabetes mellitus (T2DM) in the UK from 2001 to 2015. DESIGN: A cross-sectional drug utilisation study. SETTING: Electronic health records from The Health Improvement Network primary care database in the UK. PARTICIPANTS: Individuals with T2DM who received a record of OAC prescription. OUTCOME MEASURES: The prescribing trends of OAC medications in individuals with T2DM were examined from 2001 to 2015, stratified by age, gender and therapeutic classifications. RESULTS: A total of 361 635 individuals with T2DM were identified, of whom 36 570 were prescribed OAC from 2001 to 2015. The prevalence of OAC prescribing increased by 50.0%, from 1781 individuals receiving OAC prescriptions (IROACP) (4.4 (95% CI 4.2 to 4.6) per 100 persons) in 2001, to 17 070 IROACP (6.6 (95% CI 6.5 to 6.7) per 100 persons) in 2015. The prevalence of warfarin prescribing decreased by 14.0%, from 1761 individuals receiving warfarin prescriptions (IRWP) (98.9 (95% CI 98.4 to 99.4) per 100 persons) in 2001, to 14 533 IRWP (85.1 (95% CI 84.6 to 85.7) per 100 persons) in 2015. This corresponded with increased prescribing of direct oral anticoagulants (DOACs), from 18 individuals receiving DOAC prescriptions (IRDOACP) (0.1 (95% CI 0.08 to 0.23) per 100 persons) in 2010, to 3016 IRDOACP (17.6 (95% CI 17.1 to 18.2) per 100 persons) in 2015, during the same period. CONCLUSIONS: Prescribing of OACs in individuals with T2DM increased from 2001 to 2015. Since the introduction of DOACs, there has been a clear shift in prescribing towards these agents. Future studies are needed to assess the safety of coadministration of OAC medications and antidiabetic therapy with T2DM
Gastrointestinal bleeding risk with rivaroxaban vs aspirin in atrial fibrillation: a multinational study
Purpose:
Comparative gastrointestinal bleeding (GIB) risk between rivaroxaban and low‐dose aspirin is unknown in patients with atrial fibrillation (AF). This study investigated GIB risk with rivaroxaban vs aspirin among two separate AF cohorts in Hong Kong and the United Kingdom, using a common protocol approach.
Methods:
This was a population‐based cohort study using separate data from the Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong Hospital Authority (2010‐2018) and The Health Improvement Network (THIN) database in the United Kingdom (2011‐2017). Patients with AF newly prescribed aspirin or rivaroxaban were included. Cox proportional hazards regression was used to compare GIB risks for rivaroxaban vs aspirin, accounting for confounders using propensity score fine stratification approach.
Results:
In CDARS, 29 213 patients were included; n = 1052 (rivaroxaban), n = 28 161 (aspirin). Crude GIB event rates per 100 patient‐years in CDARS were 3.0 (aspirin) and 2.6 (rivaroxaban). No difference in GIB risk was observed between rivaroxaban and aspirin overall (HR = 1.04, 95%CI = 0.76‐1.42), and in dose‐stratified analyses (HR = 1.21, 95%CI = 0.84‐1.74 [20 mg/day]; HR = 0.80, 95%CI = 0.44‐1.45 [≤15 mg/day]). In THIN, 11 549 patients were included, n = 3496 (rivaroxaban) and n = 8053 (aspirin). Crude GIB event rates were 1.3 (aspirin) and 2.4 (rivaroxaban) per 100 patient‐years. No difference in GIB risk was observed between rivaroxaban and aspirin overall (HR = 1.40, 95%CI = 1.00‐1.98) and low‐dose rivaroxaban (≤15 mg/day) (HR = 1.00, 95%CI = 0.56‐1.30), but increased GIB risk was observed for rivaroxaban 20 mg/day vs aspirin (HR = 1.57, 95%CI = 1.08‐2.29).
Conclusion:
In patients with AF, GIB risk was comparable between aspirin and rivaroxaban ≤15 mg/day. GIB risk for rivaroxaban 20 mg/day vs aspirin remains uncertain and warrants further investigation
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