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Articles containing the keyword 'loading'

Category : Article

article id 7401, category Article
Veijo Heiskanen. (1950). Tutkimuksia pinopuutavaran proomuun lastauksesta. Acta Forestalia Fennica vol. 58 no. 1 article id 7401. https://doi.org/10.14214/aff.7401
English title: Investigations on loading piled wood into barges.
Original keywords: polttopuu; puunkuljetus; vesikuljetus; kuljetuskustannukset; proomukuljetus; proomu; lastaus; työtutkimus; työaika
English keywords: firewood; barges; time studies; transportation costs; water transport; transportation of timber; loading
Abstract | View details | Full text in PDF | Author Info

In Finland, transportation of wood by vessels has decreased, but is still an important mode of transport especially for firewood. In 1941-1947, nearly 25% of the firewood procured by the State Fuel Board was transported by vessels. This investigation concentrates on loading of wood into barges, since the share of wages of total expenses is greatest in this phase. The loading work amounts to nearly 40% of the total wages.

Two methods of loading barges are used in Finland: loading from the shore and truck loading. This study concentrates on the more common method, loading from the shore. A time study was conducted on the different stages of loading and piling wood into barges, most of which is done by hand. Most time-consuming part of the work is transporting the logs to the barge with a wheelbarrow, comprising over 40% of the working time. Time required for loading firewood is almost twice as much as loading pulp wood. Recommendations for loading places and organization of work are given in the article to improve the efficiency of the work.

The PDF includes a summary in English.

  • Heiskanen, E-mail: vh@mm.unknown (email)

Category : Research article

article id 23062, category Research article
Tobias Semberg, Anders Nilsson, Rolf Björheden, Linnea Hansson. (2024). Real-time target point identification and automated log grasping by a forwarder, using a single stereo camera for both object detection and boom-tip control. Silva Fennica vol. 58 no. 1 article id 23062. https://doi.org/10.14214/sf.23062
Keywords: vector analysis; forwarder; forest operations; loading; boom automation; object detection; stereo camera
Highlights: Simple target-point detection in real time using only a stereo camera; Sturdiness ensured through the simple feedback system based on the same camera; Automated boom-tip control and log grasping successfully tested on full-sized forwarder; A step toward semi-automation (operator support) or autonomous forwarding.
Abstract | Full text in HTML | Full text in PDF | Author Info
The forest industry is constantly striving to increase productivity and cut costs, and many research and innovation projects are currently focusing on semi-automated or autonomous systems. A key element, with several possible solutions, is automated log grasping, where researchers and manufacturers are looking for efficient and sturdy ways to solve the task in real-time forwarding operations. This study presents a simple method for automated log grasping using only a single stereo camera for object detection (log and grapple) and a simple controller moving the boom, with feedback from the camera as boom-tip control. The accuracy, precision, and repeatability of the method was tested on a full-scale forwarder. Boom movements were examined from two different start positions in relation to the target position, with the log placed at three different angles. The overall log-grasping success was also evaluated. The tests were performed in a full-scale, real-time operation, without hand-eye calibration or other sensor data from the machine. The method was precise, with high repeatability, but the grasping point showed a minor systematic offset, depending on log angle. However, the deviation in accuracy was too small to affect the success rate. In practice, the most difficult log angles can be avoided by moving the machine slightly. The log grasping method may become part of an autonomous forwarding system or could provide operator support in semi-automated systems.
  • Semberg, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: tobias.semberg@skogforsk.se
  • Nilsson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: anders.nilsson@skogforsk.se
  • Björheden, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden ORCID https://orcid.org/0000-0002-4158-102X E-mail: rolf.bjorheden@skogforsk.se
  • Hansson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden ORCID https://orcid.org/0000-0002-9788-1734 E-mail: linnea.hansson@skogforsk.se (email)
article id 1607, category Research article
Yanlin Fu, Juan A. Oliet, Guolei Li, Jiaxi Wang. (2017). Effect of controlled release fertilizer type and rate on mineral nutrients, non-structural carbohydrates, and field performance of Chinese pine container-grown seedlings. Silva Fennica vol. 51 no. 2 article id 1607. https://doi.org/10.14214/sf.1607
Keywords: growth; nursery fertilization; Pinus tabulaeformis; nutrient loading; outplanting performance
Highlights: We demonstrated that Chinese pine container-grown seedling nutrient status and non-structural carbohydrate content were sufficient over a wide range of fertilization rates; Fertilization at 80 mg N seedling–1 was optimal for seedling responses in the nursery and field; Nursery fertilization using controlled release fertilizer (CRF) with a single coating layer yielded better seedling nursery performance than CRF with multiple coatings.
Abstract | Full text in HTML | Full text in PDF | Author Info

Although controlled release fertilizer (CRF) with single and multiple-layer coatings are extensively used in tree seedlings, studies that compare the impact of CRF type and application rate on seedling growth, nutrient storage, and, most importantly, outplanting performance, are lacking. In the current study, container-grown Pinus tabulaeformis Carr. (Chinese pine) seedlings were fertilized with commercial CRF with either one or multiple coating layers with equivalent formulation and longevity, at six rates ranging from 40 to 240 mg N seedling–1. Seedlings were sampled for dry mass, non-structural carbohydrate (NSC) content, and mineral nutrient status at the end of the growing season in the nursery, and subsequently outplanted for one season. Compared to Chinese pine seedlings fertilized with single-layer CRF treatments, seedlings treated with multiple-layer CRF had higher starch concentrations but reduced dry mass and N, P, K concentrations in the nursery, and reduced diameter growth in the field. Fertilization rates of 80 and 120 mg N seedling–1 generally yielded maximal plant dry mass and mineral nutrient content. Field survival peaked at 80 mg N seedling–1. Seedling growth, soluble sugar content, and starch concentration in the nursery and survival in the field consistently decreased at rates of 200 and 240 mg N seedling–1. In our study, optimal nursery and field performance of P. tabulaeformis were observed using single layer CRF at 80 mg N seedling–1 (3.3 g CRF l–1 media).

  • Fu, Key Laboratory for Silviculture and Conservation, Ministry of Education, Beijing Forestry University; Beijing Laboratory of Urban and Rural Ecological Environment; 35 East Qinghua Road, Haidian District, Beijing 100083, China E-mail: bjfu_fu@163.com
  • Oliet, Department of Natural Systems and Resources, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain E-mail: juan.oliet@upm.es
  • Li, Key Laboratory for Silviculture and Conservation, Ministry of Education, Beijing Forestry University; Beijing Laboratory of Urban and Rural Ecological Environment; 35 East Qinghua Road, Haidian District, Beijing 100083, China E-mail: glli226@163.com (email)
  • Wang, Key Laboratory for Silviculture and Conservation, Ministry of Education, Beijing Forestry University; Beijing Laboratory of Urban and Rural Ecological Environment; 35 East Qinghua Road, Haidian District, Beijing 100083, China E-mail: wjx198979@163.com
article id 1475, category Research article
Jiaxi Wang, Haiqun Yu, Guolei Li, Feng Zhang. (2016). Growth and nutrient dynamics of transplanted Quercus variabilis seedlings as influenced by pre-hardening and fall fertilization. Silva Fennica vol. 50 no. 2 article id 1475. https://doi.org/10.14214/sf.1475
Keywords: nutrient loading; nutrient storage; nursery transplanting; seedling quality
Highlights: High pre-hardening fertilization favored seedling growth and nutrient storage at the rapid growth and hardening phases following transplantation. Overall, high fall fertilization was beneficial only at the hardening phase; The combination of 100 mg N seedling–1 during pre-hardening with 36 mg N seedling–1 during hardening was recommended for satisfactory transplanting performance for Quercus variabilis.
Abstract | Full text in HTML | Full text in PDF | Author Info

Stored nutrient reserves are closely correlated with survival and growth of transplanted seedlings. Previous studies have proven that combining pre-hardening fertilization (PF) with fall fertilization (FF) built seedling nutrient reserves more effectively; however, their effect on transplanting performance is poorly documented. We investigated the independent and interacting effects of 2 levels of PF and 4 levels of FF on seedling growth, nutrient acquisition and accumulation during different growth phases 1 year after transplanting of Quercus variabilis Blume in a nursery. High PF benefited nutrient reserves and subsequent transplanted seedling growth and tissue nutrient storage at the end of the rapid growth and hardening phases. Fall fertilization with 36 mg N increased stem dry mass and tissue nutrient content at the end of the hardening phase. At the conclusion of establishment, PF and FF showed a significant interaction for N and K uptake from soil. At the end of the rapid growth and hardening phases, high PF consistently increased nutrient uptake. Enhanced N and K uptake occurred following application of 36 mg N of FF at the end of the hardening phase. Distinct roles for PF and FF on 3 phases of transplanted seedlings demonstrated the necessity to evaluate fertilization in terms of nutrient reserves and subsequent transplanting performance in consecutive phases. Combining 100 mg N seedling–1 during pre-hardening with 36 mg N seedling–1 during fall yielded ideal transplanting performance for Quercus variabilis seedlings.

  • Wang, Key Laboratory for Silviculture and Conservation, Ministry of Education; Beijing Laboratory of Urban and Rural Ecological Environment, Beijing Forestry University, 35 East Qinghua Road, Haidian District, Beijing 100083, China E-mail: wjx198979@163.com
  • Yu, Beijing Forestry Carbon Administration, room 201, No.1 Xiao Huang Zhuang Bei Jie, Dongcheng District, Beijing 100013, China E-mail: yuhq@bfdic.com
  • Li, Key Laboratory for Silviculture and Conservation, Ministry of Education; Beijing Laboratory of Urban and Rural Ecological Environment, Beijing Forestry University, 35 East Qinghua Road, Haidian District, Beijing 100083, China E-mail: glli226@163.com (email)
  • Zhang, Beijing Forestry Carbon Administration, room 201, No.1 Xiao Huang Zhuang Bei Jie, Dongcheng District, Beijing 100013, China E-mail: zhangf@bfdic.com
article id 441, category Research article
Ane Zubizarreta-Gerendiain, Petri Pellikka, Jordi Garcia-Gonzalo, Veli-Pekka Ikonen, Heli Peltola. (2012). Factors affecting wind and snow damage of individual trees in a small management unit in Finland: assessment based on inventoried damage and mechanistic modelling. Silva Fennica vol. 46 no. 2 article id 441. https://doi.org/10.14214/sf.441
Keywords: Pinus sylvestris; Picea abies; Betula spp.; critical wind speed; snow loading; damage risk
Abstract | View details | Full text in PDF | Author Info
In this work, we assessed the factors affecting wind and snow damage of individual trees in a small management unit in western Finland. This was done based on inventoried damage and observed wind speeds and snow loading in storms Pyry and Janika in 2001 and Mielikki in 2002 together with mechanistic model. First, we studied which factors explain the observed damage in individual trees. Secondly, we studied how well the mechanistic model (HWIND) could predict the wind speed needed to uproot individual trees at the margins of permanent upwind edges. We found that Pyry storm caused 70% and Janika and Mielikki 18 and 12% of observed damage. In Janika storm, all trees uprooted. In other storms, both uprooting and stem breakage occurred. Scots pine suffered the most damage. Recently thinned stands on the upwind edges of open areas suffered the most damage. But, damage occurred also on soils with relatively shallow anchorage. HWIND predicted correctly damage for 69% of all uprooted trees. No-uprooting was correctly predicted for 45 and 19% of standing trees (all Scots pines), which were measured within and at the immediate upwind edge of same stands. HWIND model needs further validation at the permanent edges and/or on soils with shallow rooting to improve its prediction accuracy in such conditions.
  • Zubizarreta-Gerendiain, Technical University of Lisbon, School of Agriculture, Forest Research Centre, Lisbon, Portugal E-mail: azg@nn.po
  • Pellikka, University of Helsinki, Dept. of Geosciences and Geography, Helsinki, Finland E-mail: pp@nn.fi
  • Garcia-Gonzalo, Technical University of Lisbon, School of Agriculture, Forest Research Centre, Lisbon, Portugal E-mail: jgg@nn.po
  • Ikonen, University of Eastern Finland, School of Forest Sciences, Joensuu, Finland E-mail: vpi@nn.fi
  • Peltola, University of Eastern Finland, School of Forest Sciences, Joensuu, Finland E-mail: heli.peltola@uef.fi (email)

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