Effects of Steel Flexible Tracks on Forwarder Peak Load Distribution: Results from a Prototype Load Test Platform

Steel flexible tracks (SFT) are regularly installed on bogie axles of forwarders to improve traction and extend trafficability by increasing the contact area between machines and operating surface. The study quantified dynamic peak loads exerted by a forwarder driving either on wheels or using additional SFT on its rear bogie axle. To examine load distribution of a full-scale forwarder, a load test platform was designed and constructed. Three scenarios were tested with the forwarder unloaded and loaded to quantify load distribution between wheels driven directly over the steel load test platform (Scenario 1) and SFT when either driven directly over the steel load test platform (Scenario 2) or when driven over a 20 cm layer of sand placed over the platform (Scenario 3). The platform proved to be an appropriate measuring device for full-scale tests. Results indicate that, when operated on the sand layer, SFT (installed on the forwarder’s rear unloaded axle) decreased dynamic peak loads by about 30% compared to wheels. The use of SFT on bogie axles of forest machines is recommended to lower soil disturbances, especially through a reduction of peak loads often responsible for negatively altering soil physical properties

Effects of Steel Flexible Tracks on Forwarder Peak Load Distribution: Results from a Prototype Load Test Platform

Steel flexible tracks (SFT) are regularly installed on bogie axles of forwarders to improve traction and extend trafficability by increasing the contact area between machines and operating surface. The study quantified dynamic peak loads exerted by a forwarder driving either on wheels or using additional SFT on its rear bogie axle. To examine load distribution of a full-scale forwarder, a load test platform was designed and constructed. Three scenarios were tested with the forwarder unloaded and loaded to quantify load distribution between wheels driven directly over the steel load test platform (Scenario 1) and SFT when either driven directly over the steel load test platform (Scenario 2) or when driven over a 20 cm layer of sand placed over the platform (Scenario 3). The platform proved to be an appropriate measuring device for full-scale tests. Results indicate that, when operated on the sand layer, SFT (installed on the forwarder’s rear unloaded axle) decreased dynamic peak loads by about 30% compared to wheels. The use of SFT on bogie axles of forest machines is recommended to lower soil disturbances, especially through a reduction of peak loads often responsible for negatively altering soil physical properties

Influence of Saturated Organic Matter on the Accuracy of In-Situ Measurements Recorded with a Nuclear Moisture and Density Gauge

The impact of machines on forest soils is regularly assessed and quantified using absolute bulk density, which is most frequently obtained by soil cores. However, to allow for repeated measurements at the exact same locations, non-destructive devices are increasingly being used to determine soil bulk density and moisture content in field studies. An example of such a device is a nuclear moisture and density gauge (NMDG), originally designed as a control measurement for soil bulk density and moisture content in geotechnical applications. Unlike road construction or foundation projects that use mineral soil or gravel, forest soils have complex structures and the presence of organic matter, which can skew moisture and density readings from a NMDG. To gain further knowledge in this respect, we performed controlled tests in a sandbox to quantify the influence of varying amounts of saturated organic matter (3, 5, 10, and 15%) mixed with mineral soil in different layers (0–5, 0–10, 0–20 and 0–40 cm) on the accuracy of soil moisture content obtained by a NMDG and soil theta probe at varying depths. Main results illustrated that the presence of saturated organic matter per se was not problematic but moisture content overestimations and related underestimation of dry bulk density occurred when the tested measurement depth was below the created organic layer. Since forest soils often exhibit higher organic matter contents in the upper horizon, correction factors are suggested to minimize the moisture content variations between NMDG and reference method. With the use of correction factors, NMDG can present a non-destructive, fast, and accurate method of measuring soil moisture and bulk density in forestry applications

Advanced Malignant Melanoma: Immunologic and Multimodal Therapeutic Strategies

Immunologic treatment strategies are established in malignant melanoma treatment, mainly focusing on Interleukin-2 in advanced disease and interferon alpha in the adjuvant situation. In advanced disease, therapies with IL-2, interferon and different chemotherapeutic agents were not associated with better patient survival in the vast majority of patients. Therefore, an overview of novel immunological agents and combined therapeutic approaches is presented in this review, covering allogenic and autologous vaccine strategies, dendritic cell vaccination, strategies for adoptive immunotherapy and T cell receptor gene transfer, treatment with cytokines and monoclonal antibodies against the CTLA-4 antigen. As emerging treatment strategies are based on individual molecular and immunological characterization of individual tumors/patients, tailored targeted drug therapies move into the focus of treatment strategies. Multimodal combination therapies with considerable potential in altering the immune response in malignant melanoma patients are currently emerging. As oncology moves forward into the field of personalized therapies, a careful molecular and immunological characterization of patients is crucial to select patients for individual targeted treatment

Übertragung von hochratigen Datensignalen in Breitbandkommunikationsnetzen

Untersuchungen von Übertragungsstörungen bei einer DVB-C-Übertragung in Breitbandkommunikationsnetzen (BK-Netzen, HFC-Netzen).Investigations in Interference on DVB-C signals during their transmission in cable networks (HFC networks)

Assessing the Ability of Hardwood and Softwood Brush Mats to Distribute Applied Loads

In cut-to-length mechanized forest harvest operations, trees are cut, delimbed, and bucked to standard lengths directly in the harvest block. This in-stand processing, generates harvesting residue composed of tree limbs, tops, and foliage, which is frequently placed on machine operating trails to prolong trail trafficability and protect forest soils against heavy loadings. These so-called brush mats vary both in quantity and quality based on harvested wood and stand characteristics. The objectives of this study were to determine, quantify, and compare the load distributing capabilities of hardwood and softwood brush mats of different amounts (10, 20, 30, and 40 kg m-2) compared to no brush (0 kg m-2). This was done by laboratory tests analyzing the difference in strain recorded below brush mats at small scale when exposed to single and repetitive loadings. Brush mats (approx. 37 cm x 37 cm in area) were placed inside a test structure including a top open box with the bottom filled with a 15 cm thick layer of sand, below which strain gauges were installed. The entire test structure was positioned on a load frame programmed to lower a loading disk directly over the brush mat, thereby applying increasing loads up to 10 kN on the mat. Results suggest that for specific brush amounts and loadings, softwood brush showed a slightly better capacity to laterally distribute exerted loads than hardwood brush, especially at brush amounts of 10 and 20 kg m-2. At higher brush amounts, the differences of recorded loadings (strains) between the tested softwood and hardwood brush were reduced and at 40 kg m-2 hardwood brush contributed to a lower response of the strain gauges than softwood brush when subjected to 5 and 10 kN loadings