Effect of Long-Term Forest Fertilization on Scots Pine Xylem Quality and Wood Borer Performance

We tested whether changes in long-term nutrient availability would affect the xylem quality and characteristics of Scots pine trees as a food source for the larvae of the xylophagous wood borer Hylotrupes bajulus L. (Cerambycidae). We looked for an effect of host plant growth and xylem structural traits on H. bajulus larval performance, and looked for delayed effects of long-term forest fertilization on xylem chemical quality. In general, larval performance was dependent on larval developmental stage. However, the growth of larvae also varied with host plant quality (increases in the concentration of nitrogen and carbon-based secondary compounds of xylem were correlated with a decrease in the larval growth rate). The greater annual growth of trees reduced tracheid length and correlated positively with second-instar H. bajulus growth rate. This is consistent with the hypothesis that intrinsic growth patterns of host plants influence the development of the xylophagous wood borer H. bajulus.     

Enteropathogenic Yersinia in the Pork Production Chain: Challenges for Control

Enteropathogenic Yersinia comprising pathogenic Yersinia enterocolitica and Yersinia pseudotuberculosis, are zoonotic pathogens causing foodborne intestinal illness in humans. Y. enterocolitica is common in pork production and pork is associated with infections in humans. Therefore, there is a need to reduce the occurrence and spread of these pathogens within the pork production chain. It would be most effective to control enteropathogenic Yersinia at the farm level. However, at present, feasible intervention methods are lacking and more research is needed. The most effective way to prevent the spread of Y. enterocolitica is to buy piglets from Y. enterocolitica‐negative farms. At slaughterhouses, the occurrence of enteropathogenic Yersinia can be reduced but not completely removed by slaughter hygiene and changing slaughter methods. After slaughter, it is difficult to control enteropathogenic Yersinia, since they can survive and even multiply during cold storage and under modified atmosphere. In addition, current knowledge and actions in both domestic and professional kitchens are insufficient for the prevention of yersiniosis. The significance of Y. pseudotuberculosis carried by pigs is uncertain. Although data are still lacking for pathogenic Y. enterocolitica in many aspects, there is even a greater lack of information regarding Y. pseudotuberculosis in pork production. There is a definite need for further research on these pathogens.     

当前造纸设备研究与发展方向

论述了造纸设备的研究与开发主体已从原来的以造纸厂为主转向目前的以造纸机械厂为主,且集中在少数实力雄厚的造纸机械厂中.同时介绍了纸机、纸板机及整饰设备的最新技术动向.     

Total and extractable element concentrations in bed sand material from a medium-sized (32 MW) municipal district heating plant incinerating peat, stumps, sawdust and recycled wood

In Finland, the new limit values of total heavy metal, polychlorinated biphenyl (PCB) and polycyclic aromatic hydrocarbon (PAH), as well as the extractable heavy metal, dissolved organic carbon (DOC), fluoride, sulphate, and chloride concentrations for bed sand material used as an earth construction agent came into force in June 2009. The total heavy metal (i.e. Cd, Cu, Pb, Cr, Zn, As, V, Ba and Mo) concentrations in the studied bed sand material were clearly lower than the current Finnish limit values for the maximum allowable heavy metal concentrations for materials used as an earth construction agent. However, the extractable concentration of Ba (24.6 mg kg⁻¹; d.w.) in the bed sand material exceeded the limit value for covered structures (20 mg kg⁻¹; d.w.). However, in Finland, the competent environmental authority may relax the maximum limit values up to 30% in certain circumstances. Therefore, if, the environmental authority relaxes the maximum limit value for the extractable concentration of Ba by up to 30% to the value of 26 mg kg⁻¹ (d.w.) for covered structures, the extractable concentration of Ba (24.6 mg kg⁻¹; d.w.) in the bed sand material is below this relaxation.     

Effect of Residual Stress and Strain-Induced α′-Martensite on Delayed Cracking of Metastable Austenitic Stainless Steels

The role of residual stresses and strain-induced α′-martensite in delayed cracking of metastable austenitic stainless steels was studied by means of Swift cup tests, measurement of residual stresses by X-ray diffraction and ring slitting, and α′-martensite content determination. Low-Ni, high-Mn austenitic stainless steels, e.g., AISI 201, were compared with Fe-Cr-Ni austenitic stainless steels. The presence of α′-martensite seemed to be a necessary prerequisite for delayed cracking to occur in austenitic stainless steels with typical internal hydrogen concentrations (<5 ppm). Stable low-Ni austenitic stainless steel was not prone to delayed cracking. The low-Ni metastable grades showed more severe cracking at lower degree of deformation and lower volume fraction of α′-martensite than that of the metastable 300-series grades. The limiting α′-martensite content, below which delayed cracking did not occur, decreased along with the nickel content of the material. The strain-induced martensitic transformation substantially increased the magnitude of residual stresses in deep-drawn cups. One explanation for high sensitivity of the low-Ni grades to delayed cracking after deep drawing is their higher residual stresses compared to that of the Fe-Cr-Ni grades. Alloying elements of the stainless steels, nickel, and carbon in particular, influence the sensitivity to delayed cracking through their effect on the properties of the α′-martensite.     

Partial Virtual Channel Sharing: A Generic Methodology to Enhance Resource Management and Fault Tolerance in Networks-on-Chip

We present a novel Partial Virtual channel Sharing (PVS) NoC architecture which reduces the impact of faults on performance and also tolerates faults within the routing logic. Without PVS, failure of a component impairs the fault-free connected components, which leads to considerable performance degradation. Improving resource utilization is key in enhancing or sustaining performance with minimal overhead when faults or overload occurs. In the proposed architecture, autonomic virtual-channel buffer sharing is implemented with a novel algorithm that determines the sharing of buffers among a set of ports. The runtime allocation of the buffers depends on incoming load and fault occurrence. In addition, we propose an efficient technique for maintaining the accessibility of a processing element (PE) to the network even if its router is faulty. Our techniques can be used in any NoC topology and for both, 2D and 3D NoCs. The synthesis results for an integrated video conference application demonstrate 22 % reduction in average packet latency compared to state-of-the-art virtual channel (VC) based NoC architecture. Extensive quantitative simulation has been carried out with synthetic benchmarks. Simulation results reveal that the PVS architecture improves the performance significantly in presence of faults, compared to other VC-based NoC architectures.     

Sorption of Pb(II), Cr(III), Cu(II), As(III) to peat,and utilization of the sorption properties in industrial waste landfill hydraulic barrier layers

The low conductivity landfill barrier layers protect the groundwater and soil by limiting the water flow through the bottom layers of the landfill material. Many materials used in hydraulic barrier layers also have sorption properties which could be used to reduce environmental risks. The adsorption of lead, chromium, copper, and arsenic to peat was studied with a batch-type test and a column test for compacted peat, both without pH adjustment in acidic conditions. Peat adsorbed all the metals well, 40 000 mg/kg of lead, 13 000 mg/kg of chromium, and 8400 mg/kg of copper in the column test. Arsenic was only tested in a batch-type test, and in that peat adsorbed 60 mg/kg of arsenic. The column test showed heavy metals to be adsorbed on the surface layers of the compacted peat sample, on the first centimeter of the sample. The adsorption was much greater in the column test than in the batch-type test, partly due to the different pH conditions and the buffer capacity of the peat in the column test. The liquid/solid ratio of the column experiment represented a time period of approximately 40 years in a landfill, under Finnish climate conditions. The hydraulic conductivity of the peat decreased as it was compressed, but it already met the hydraulic conductivity limits set by European Union legislation for the hydraulic barrier layer (1 × 10⁻⁹ m/s at a pressure of 150 kPa for a 5-m layer), with a pressure of 50 kPa. The results show that peat would be an excellent material to construct compacted, low hydraulic conductivity layers with adsorption properties in, e.g. industrial waste landfills.     

Atmospheric circulation patterns influencing variations in organic carbon fluxes in the River Oulujoki,Finland

Atmospheric circulation generally influences regional climate variability and thereby controls catchment hydrology and consequently transport of elements in natural riverine systems. This study examined dependencies between total organic carbon (TOC) variability in the River Oulujoki (Finland) during 1963–2011 and prominent atmospheric circulation patterns (ACPs), which manifest natural climatic conditions over Finland and control hydrological processes in the river catchment. North Atlantic Oscillation, Scandinavia, East Atlantic and East Atlantic/West Russia patterns were statistically significant ACPs affecting variations in TOC export at River Oulujoki lower basin area. In the River Oulujoki, TOC export was largely controlled by changes in TOC fluxes generated from tributaries of river and near areas to its main channel. Besides, runoff from Lake Oulujärvi slightly influenced TOC export variability in the River Oulujoki. Understanding such responses of TOC fluxes to ACPs is a useful tool for sustainable water resources planning and management on regional and local scales.     

Application of a multiline material characterization method to inkjet printed electronics

Material characterization has become increasingly important with the adoption of simulation‐based workflow for microwave electronics design. This article focuses on the characterization of printable electronics materials using transmission‐line measurements and demonstrates the capability of the multiline characterization method to separate dielectric and conductor losses when line geometry and material properties vary between the lines. The effects of multiline algorithm, number of line standards, and methods for selecting optimal line lengths are demonstrated. Consistent characterization results are obtained from inkjet‐printed transmission lines on two different substrate materials. In addition, local conductor thickness variations are demonstrated as an effective way to decrease losses. Finally, the simulation‐based procedure for determining the material properties is outlined and applied to printable electronics characterization. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:177–183, 2014.