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- Gard Timmerfors, Jessica, et al.
(author)
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New drum-chipping technology for a more uniform size distribution of wood chips
- 2019
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In: Holzforschung. - : De Gruyter. - 0018-3830 .- 1437-434X.
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Journal article (peer-reviewed)abstract
- Wood chips from a novel type of drum chipper were compared to wood chips from a conventional disc chipper in an evaluation based on demonstration-scale and industrial-scale machinery. The evaluation was performed as the wood chippers were used as production machines in a kraft pulp mill using softwood. The average bulk density of the wood chips from the disc chipper and the drum chipper was similar and within the range of 138-140 kg/m 3 . The size distribution of the wood chips was investigated using a conventional screening method, and by using an automatized image-analysis system based on laser scanning. The average length was set to be the same, but the wood chips from the drum chipper had a more uniform length. The average thickness was similar, but the drum chipper generated slightly more thinner wood chips. Compared to the disc chipper and using the screening method, the drum chipper generated a similar fraction of oversized and overthick wood chips, 51% more large accept chips, 11% more total accept chips, and 74% less pin chips and fines. Image analysis resulted in similar data. The results indicate that drum chippers warrant further attention as an alternative to conventional industrial-scale disc chippers. ©2019 Jessica Gard Timmerfors et al.
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2. |
- Miloff, Alexander, et al.
(author)
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Automated virtual reality exposure therapy for spider phobia vs. in-vivo one-session treatment : A randomized non-inferiority trial
- 2019
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In: Behaviour Research and Therapy. - : Elsevier BV. - 0005-7967 .- 1873-622X. ; 118, s. 130-140
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Journal article (peer-reviewed)abstract
- This study compared the efficacy of a technician-assisted single-session virtual reality exposure therapy (VRET) for the treatment of spider phobia featuring low-cost consumer-available hardware and novel automated software to gold-standard in-vivo one-session treatment (OST), using a parallel group randomized non-inferiority design. Method Participants (N = 100) were randomized to VRET and OST arms. Assessors blinded to treatment allocation evaluated participants at pre- and post-treatment as well follow-up (3 and 12 months) using a behavioral approach test (BAT) and self-rated fear of spider, anxiety, depression and quality-of-life scales. A maximum post-treatment difference of 2-points on the BAT qualified as non-inferiority margin. Results Linear mixed models noted large, significant reductions in behavioral avoidance and self-reported fear in both groups at post-treatment, with VRET approaching the strong treatment benefits of OST over time. Non-inferiority was identified at 3- and 12- months follow-up but was significantly worse until 12-months. There was no significant difference on a questionnaire measuring negative effects. Conclusions Automated VRET efficaciously reduced spider phobia symptoms in the short-term and was non-inferior to in-vivo exposure therapy in the long-term. VRET effectiveness trials are warranted to evaluate real-world benefits and non-specific therapeutic factors accruing from the presence of a technician during treatment. ClinicalTrials.gov (NCT02533310).
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