WURC - Wood Ultrastructure Research Centre 1996-2007 Final report

The Wood Ultrastructure Research Centre (WURC) (http://www-wurc.slu.se) at the Swedish University of Agricultural Sciences (SLU) was established July 1st 1996. The partners in the initial framework of WURC were STFI-Packforsk (STFI-Packforsk), the Royal Institute of Technology (KTH) and Chalmers University of Technology (CTH) together with seven forest industry-related companies including: AssiDomän, Korsnäs, Mo och Domsjö, SCA, StoraEnso Södra Cell and Eka Chemicals. Through various divisions and mergers two further companies (Holmen, KappaKraftliner) joined WURC in phase 3 making a total of 9 supporting industries that remained with the Centre throughout its duration. The number of Universities involved in WURC´s activities expanded during later phases and members from the Departments of Biochemistry and Quantum Chemistry, Uppsala University as well from the Division of Chemistry, Karlstad University and Department of Natural Sciences, Örebro University also participated in the Centre’s activities. WURC´s mission has been to significantly increase the basic knowledge on wood and pulp fibres regarding their morphological ultrastructure, chemical structure and physical properties and to determine how these properties change after different chemical, mechanical and enzymatic treatments. The research conducted has been primarily fundamental in character and long-term and based on cooperation between Universities, industrial research Institutes and the R & D units of forest industry-related industries. During phases 3 and 4, WURC added more applied projects in-line with the industries request and began applying the knowledge gathered and the experimental toolbox developed from the more fundamental projects to specific industrial problems associated with Strength Delivery and Mechanical pulps). The establishment of WURC in Sweden has provided the opportunity for specialists from a number of widely different disciplines to cooperate and build a united body to carry out research on wood fibre structure mainly at the micro- and nano-levels; a research area which at the start of WURC was insignificantly developed in the country, but also elsewhere in comparison to the economic importance of the industry. During later phases, the nucleus of WURC´s activities between the University partners was concentrated to the UppsalaStockholm area. During phase 3, the number of projects in WURC´s portfolio was twenty reflecting a quadrupling from phases 1 - 2 and the interest in this type of research from both academia and industry alike. During phase 4, the number of projects was progressively reduced in-line with the running down and completing of the Centre´s activities. WURC has attained a high level of competence in the area of wood fibre ultrastructure during its ca 11 years existence. It has become internationally recognized (e.g. by annual international conferences, involvement in European COST actions, peer reviewed publications and symposium presentations, exchange of guest researchers etc) as a major Centre of Excellence interacting with the Swedish pulp and paper industry. By nature of its research, competence and critical mass (e.g. 50-60 people were involved wholly or part-time in WURC´s activities during years 2003/4) (phase 3), WURC was quite unique in the world. During the last 11 years, WURC scientists have been involved in over 300 scientific papers and symposia presentations and at closing, 17 PhD and 7 Licentiate graduates (wholly or partly financed) had successfully defended their theses within the Centre. The Centre has further organized 10 international, 11 major internal industry/academia interactive seminars and numerous other industry-academia project-group meetings through its era. The Centre has had an international advisory group of leading scientists that have further been active in advising WURC´s management, vetting project developments and directions during annual seminars. WURC has used a working model based on interactions between industry and academia at all levels throughout its phases. Initially WURC´s board was comprised of representatives from member companies, VINNOVA, SLU and later on STFI-Packforsk. The chairman has been from STFI-Packforsk and the directors from StoraEnso (1996-1998), SLU (1998-2007) and vice-director from Sveaskog (2001-2007). WURC has had an Industrial Advisory (Reference) Group (IRG) comprised of representatives from all the supporting companies and together with WURC´s management team used to vet all project proposals for both academic and industrial possibilities. During phases 3/4, the group was very active in the establishment and running of industry orientated projects involving industry project leaders. The group has monitored the progress of the WURC projects and provided specialized fibre materials (e.g. chemical/mechanical pulps, wood samples) for the different projects. WURC has had a primary focus on fundamental research on fibre ultrastructure, thus the major major added benefits of the Centre has been the creation and development of interdisciplinary interactions between the Swedish pulp and paper industry and WURC scientists in a research area of common interest. During its later phases, WURC revised its major research focus to include industrial orientated projects concerning Pulp 2000, Strength Delivery and Mechanical pulps. Research of the more applied nature comprised ca 35 % of WURC´s total budget in phases 3/4 and within this group; the majority of the in-kind contributions from WURC´s industrial partners (ca 36 %) were located. During later phases, the in kind contributions from industry/University also exceeded that contracted. The challenge for WURC´s future has been to retain its academic standard at international level and at the same time further develop the industrial applications and significance of its knowledge. Great efforts were made to secure financing for continuation of the Centre after the VINNOVA Competence Centre era in 2007. This process was initiated already Autumn 05 and progressed through board activities, numerous management meetings, a writing of gaps in our knowledge document by WURC´s scientists and areas of research priority given by WURC´s member companies. This culminated in a successful application to VINNOVAs “Branschforsknings fund” February 08 for program entitled Process and product developments through unique knowledge of wood fibre ultrastructure (2008- 2011) (WURC INNOVATION). The program will include strong collaboration between University/Institute partners SLU, STFI-Packforsk, KTH and Mid-Sweden University with member companies EkaChemicals, Holmen, SCA, SmurfitKraftliner, StoraEnso and Södra Cell. Securement of the new grant with continued industry support is a testimony to the success WURC has achieved

Försök med olika material i bryggor vid Öresund : lägesrapport nr 4

Denna rapport innehåller resultat från den fjärde besiktningen av olika trä-, plast- och kompositmaterial exponerade sedan 2013 (några material sedan 2014 och 2016) i två bryggor vid Sibbarps badplats i Malmö strax norr om Øresundsbron. Tanken med att exponera materialen i denna miljö är att relativt snabbt får besked om vilka material som ser ut att klara sig bäst och uppfylla Malmö Stads gatukontors krav på utseende, hållbarhet och funktion i en utsatt miljö. Försöket har, trots att det pågått under en förhållandevis kort tid, givit värdefull information om olika materials egenskaper och lämplighet för användning utomhus i utsatta miljöer med hänsyn till fuktpåverkan och angrepp av biologiska skadegörare, men även med hänsyn till mekaniska och utseendemässiga aspekter. Samtliga trämaterial har snabbt blivit gråa, medan plast- och kompositmaterialen ännu efter ca 77 månaders exponering i stort sett har kvar sin ursprungsfärg. Samtliga trämaterial och trä-plastkompositer har i varierande grad fått påväxt av missfärgande svamp, alger och i några fall även av lavar. Materialen av återvunnen plast har i stort sett klarat sig utan påväxt. Rötskador har efter ca 77 månader observerats på samtliga plankor impregnerade med Organowood. Huruvida rötskadorna beror på dålig impregnering med undermålig inträngning och/eller upptagning av kiselprodukt eller på dålig rötskyddseffekt eller på en kombination av de båda har inte med säkerhet kunnat fastställas. Rötskador har även observerats på plankor av Sioo-behandlad gotländsk furukärnved, där angrepp uppkommit i kvarsittande splintved, ek och robinia. Små begynnande angrepp runt skruvskallar observerades efter ca 40 månader i jättetuja (Western red cedar) och roble, möjligen orsakad av kemisk nedbrytning, s k ”nail sickness”. De mekaniska egenskaperna skiljer sig en hel del mellan materialen. Sprickbildning och uppfläkning av virkesytan, särskilt på kantsidor, kan i värsta fall orsaka skador på framför allt bara fötter. Ek och robinia har visat sig särskilt utsatta för ogynnsam sprickbildning. Samtliga trämaterial med rillad yta har också utsatts för viss sprickbildning i rillorna. För bryggor, gångdäck och altaner, där folk ofta vistas barfota avrådes därför för användning av material, inklusive rillat, som ger upphov till stor sprickbildning

Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris

The Swedish Cellulosa Companiy, SCA, has today 280 000 ha planted with lodgepole pine (Pinus contorta var. latifolia) ("C") which is equivalent to 14 % of its total forest area. Exotic lodgepole pine has in previous experimental stands shown a superior growth than the native Scots pine (Pinus sylvestris L.) ("S").But also the comparison could be questioned because stand histories were was unknown and also differences in age between C and S existed. To establish a better comparison between the coniferous species initiated SCA in 1970 new experimental stands where C and S were planted under the same conditions. These experimental stands were measured 1979, 1984 and 1991 and the data were used for development of growth models. The purpose of this study was to follow up growth- and saw timber quality development in SCA´s experimental stands with C and S. On the basis of previous comparisons of the species the following hypothesis were formulated: • The total growth is up till now 50 % superior in C than in S • The dominant height in studied stands is developing according to height curves both for C and S • The "future stems" have almost the same saw timber quality in C and S Nine experimental stands from Åsarna in Jämtlad to Vilhelmina in Lapland (middle north Sweden) were visited in autumn 2007. In every experimental stand ten permanent plots were examined, five in C stands and five in S. On those plots all trees with dbh > 5 cm were callipered and height was measured on sample trees. About 20 "potential final cut trees" were appointed within a radius of 10 m and the criterion for those trees was that they visually showed on good saw timber quality. The total growth, including thinned trees for C was as a mean value 53 % higher than for S. The average growing stock was 179 m3sk/ha in C and 134 m3sk/ha in S. The development of C follows the yield models as predicted. Until 1991 C had a higher survival rate than S. Three C stands were tinned (9064, 9066 and 9072) in the beginning of 2000. Those stands had a higher natural mortality. The top height development the last 16 years followed the height development curves. For C the top height in average followed the curve for site index T27 and S top height is increased with the curve for T24. Of the "potential final cut trees" 21 % of C were straight and with no spike knots and for S the corresponding figure was 30 %. In the C stands a larger amount of the future stems had a bend while the S stands had more future stems with spike knots.SCA har idag 280 000 ha skogsmark planterad med contorta (Pinus contorta var. Latifolia) (”C”) vilket motsvarar ca 14 % av det totala skogsmarksinnehavet. Contortan har i tidigare försöksplanteringar visat på en högre tillväxt än tall (Pinus sylvestris L.) (”S”) men jämförelserna kunde kritiseras eftersom tallbeståndens historik var okänd och åldersskillnader mellan tall och contorta förekom. För att få en bättre jämförelse mellan contorta och tall lade SCA ut ett antal försöksodlingar i början av 1970 talet där contorta och tall odlas under lika villkor. Dessa bestånd är inmätta tre gånger tidigare och ligger till grund för produktionsmodeller. Syftet med detta arbete var att följa upp och jämföra produktion och kvalitetsutveckling i SCA:s odlingsförsök med contorta och tall. På grundval av tidigare contortastudier formulerades följande hypoteser: • Totalproduktionen har hittills varit ca 50 % högre i C än i S • Övre höjden har utvecklats enligt SI-kurvorna för både C och S • Framtidsträden har nästan lika god timmerkvalitet hos C som hos S Nio lokaler besöktes från Åsarna i Jämtland till Vilhelmina i Lappland under hösten 2007. I varje lokal fanns tio permanenta försöksytor, fem i contortabeståndet och fem i tallbeståndet. På varje provyta klavades alla träd med dbh > 5 cm och höjd mättes på provträden. Cirka 20 potentiella slutavverkningsträd utsågs inom en radie på 10 meter. Kriteriet för dessa träd var att de bedömdes vara mest lämpade för god tillväxt och timmerproduktion (vitala, raka, sprötoch klykfria). På framtidsträden bedömdes kvalitet uppdelat på tre bedömningsgrunder, krök, spröt och dubbeltopp. Resultaten visar att contortan har under ca 40 år i snitt inklusive gallring och naturlig avgång producerat 53 % mer än tallen. Den stående volymen i contortabestånden var i snitt 179 m3 sk/ha och i tallbestånden 134 m3 sk/ha. Fram till 1991 hade contortabestånden högre överlevnadstakt än tallbestånden. Tre contortabestånd var gallrade (9064 9066 and 9072) och dessa bestånd hade en hög andel avgångar i form av vindfällen och toppbrott. Överhöjdsutvecklingen de senaste 16 åren för contorta följer höjdutvecklingskurvan för T27 medan tallen följer kurvan för T24. Av de utvalda potentiella slutavverkningsträd var 21 % av contortaträden helt raka och utan spröt. För tallen så var 30 % av stammarna fina timmerträd. Contortan hade större andel av framtidsstammarna med krök medan tallen hade fler stammar med spröt

Image segmentation using snakes and stochastic watershed

The purpose of computerized image analysis is to extract meaningful information from digital images. To be able to find interesting regions or objects in the image, first, the image needs to be segmented. This thesis concentrates on two concepts that are used for image segmentation: the snake and the stochastic watershed. First, we focus on snakes, which are described by contours moving around on the image to find boundaries of objects. Snakes usually fail when concentric contours with similar appearance are supposed to be found successively, because it is impossible for the snake to push off one boundary and settle at the next. This thesis proposes the two-stage snake to overcome this problem. The two-stage snake introduces an intermediate snake that moves away from the influence region of the first boundary, to be able to be attracted by the second boundary. The two-stage snake approach is illustrated on fluorescence microscopy images of compression wood cross-sections for which previously no automated method existed. Further, we discuss and evolve the idea of stochastic watershed, originally a Monte Carlo approach to determine the most salient contours in the image. This approach has room for improvement concerning runtime and suppression of falsely enhanced boundaries. In this thesis, we propose the exact evaluation of the stochastic watershed (ESW) and the robust stochastic watershed (RSW), which address these two issues separately. With the ESW, we can determine the result without any Monte Carlo simulations, but instead using graph theory. Our algorithm is two orders of magnitude faster than the original approach. The RSW uses noise to disrupt weak boundaries that are consistently found in larger areas. It therefore improves the results for problems where objects differ in size. To benefit from the advantages of both new methods, we merged them in the fast robust stochastic watershed (FRSW). This FRSW uses a few realizations of the ESW, adding noise as in the RSW. Finally, we illustrate the RSW and the FRSW to segment in vivo confocal microscopy images of corneal endothelium. Our methods outperform the automatic segmentation algorithm in the commercial software NAVIS