Natural Resources Research Institute Technical Report

The University of Minnesota Duluth Natural Resources Research Institute (NRRI) completed a preliminary, screening cradle-to-gate life-cycle assessment (LCA) of Hennepin County, MN bridge 27C53, which was constructed on County Road 202 in the Elm Creek Park Reserve. The LCA utilized data from the bill of materials (BOM) and construction drawings, which were provided by Dr. Brian Brashaw of the USDA Forest Service, Forest Products Laboratory (FPL). The system boundary included material and fuel consumption for timber and structural steel materials fabrication; material and fuel consumption for fabrication of steel hardware, bituminous overlay, and related components; and transport of materials to the construction site. Because this preliminary screening LCA study was cradle-to-gate, use phase activities and disposal/recycling of the timber bridge were excluded. The majority of the life-cycle inventory data was secondary data from the DATASMART life-cycle inventory (LCI) database. This study also used the cut-off approach method for recycling and utilized the LTS 2019 method to translate the LCI data into environmental impacts; this method combines the ReCiPe Endpoint (H) v1.03 method with three endpoint categories (Human Health, Ecosystems, Resources) and the Cumulative Energy Demand, Climate Change, and Water Use impact categories. It was found that the bituminous (asphalt) overlay generally accounted for the largest impact in most impact categories, ranging from 9% to 46%, while the nail-laminated deck panels contributed 18% to 24% of the impacts in five of the six impact categories. The steel hardware, structural steel, and copper naphthenate (CuNap)-treated solid timber components contributed an average of 25%, 8%, and 5% of the impacts in each impact category, respectively

Natural Resources Research Institute Technical Report

The University of Minnesota Duluth Natural Resources Research Institute (NRRI) completed a preliminary, screening cradle-to-gate life-cycle assessment (LCA) of St. Louis County, MN bridge 516, which was constructed approximately 7.4 miles W/SW of Babbitt, MN over the Embarrass River. The LCA utilized data from the bill of materials (BOM) and construction drawings, which were provided by Dr. Brian Brashaw of the USDA Forest Service, Forest Products Laboratory (FPL). The system boundary included material and fuel consumption for timber and structural steel materials fabrication; material and fuel consumption for fabrication of steel hardware, bituminous overlay, and related components; and transport of materials to the construction site. Because this preliminary screening LCA study was cradle-to-gate, use phase activities and disposal/recycling of the timber bridge were excluded. The majority of the life-cycle inventory data was secondary data from the DATASMART life-cycle inventory (LCI) database. This study also used the cut-off approach method for recycling and utilized the LTS 2019 method to translate the LCI data into environmental impacts; this method combines the ReCiPe Endpoint (H) v1.03 method with three endpoint categories (Human Health, Ecosystems, Resources) and the Cumulative Energy Demand, Climate Change, and Water Use impact categories. It was found that the steel beam supports account for the largest portion of total impacts in each impact category, ranging from 32% to 77%, while the glulam deck panels contribute 24% to 36% of the impacts in four of the six impact categories. The galvanized steel components and asphalt contribute an average of 12% and 7% of the impacts in each impact category, respectively

Using Thermal Modification Technology to Add Value to Small‐Diameter Logs from Underutilized Species

USDA Wood Education and Resource Cente

Choreography of the transcriptome, photophysiology, and cell cycle of a minimal photoautotroph, prochlorococcus

The marine cyanobacterium Prochlorococcus MED4 has the smallest genome and cell size of all known photosynthetic organisms. Like all phototrophs at temperate latitudes, it experiences predictable daily variation in available light energy which leads to temporal regulation and partitioning of key cellular processes. To better understand the tempo and choreography of this minimal phototroph, we studied the entire transcriptome of the cell over a simulated daily light-dark cycle, and placed it in the context of diagnostic physiological and cell cycle parameters. All cells in the culture progressed through their cell cycles in synchrony, thus ensuring that our measurements reflected the behavior of individual cells. Ninety percent of the annotated genes were expressed, and 80% had cyclic expression over the diel cycle. For most genes, expression peaked near sunrise or sunset, although more subtle phasing of gene expression was also evident. Periodicities of the transcripts of genes involved in physiological processes such as in cell cycle progression, photosynthesis, and phosphorus metabolism tracked the timing of these activities relative to the light-dark cycle. Furthermore, the transitions between photosynthesis during the day and catabolic consumption of energy reserves at night— metabolic processes that share some of the same enzymes — appear to be tightly choreographed at the level of RNA expression. In-depth investigation of these patterns identified potential regulatory proteins involved in balancing these opposing pathways. Finally, while this analysis has not helped resolve how a cell with so little regulatory capacity, and a ‘deficient’ circadian mechanism, aligns its cell cycle and metabolism so tightly to a light-dark cycle, it does provide us with a valuable framework upon which to build when the Prochlorococcus proteome and metabolome become available