Titanium hexafluoride pretreatments are known to improve paint adhesion and function as a barrier between the coating and the hot dip galvanized (HDG) steel surface. Interactions at the zinc/pretreatment interface are...Titanium hexafluoride pretreatments are known to improve paint adhesion and function as a barrier between the coating and the hot dip galvanized (HDG) steel surface. Interactions at the zinc/pretreatment interface are of utmost importance for the formation of pretreatment layers and the corrosion resistance of color coated hot dip galvanized steels. Removal rate of inert aluminum oxide from HDG steel samples by chemical dissolution was studied. XPS measurements showed that the surface Al2O3 layer thickness decreased rapidly already at mild alkaline cleaning, while complete removal of Al required severe etching. Low reactivity of an Al2O3-rich surface was confirmed by impaired formation of a titanium hexafluoride pretreatment layer. Grain boundaries and deformation twinnings were shown to be of importance for the reactivity of the HDG surface and for the precipitation of the pretreatment chemical. Helium ion microscopy images and electron probe microanalysis (EPMA) of a pretreated sample showed accumulation of the pretreatment chemical at the grain boundaries. Al removal rate was fast at the deformation twinnings at the grain plateaus. Slow Al removal was observed at dendritic valleys and grain boundaries. The results increase understanding of the reactivity of hot dip galvanized steel surface.展开更多
Social media platforms provide new value for markets and research companies.This article explores the use of social media data to enhance customer value propositions.The case study involves a company that develops wea...Social media platforms provide new value for markets and research companies.This article explores the use of social media data to enhance customer value propositions.The case study involves a company that develops wearable Internet of Things(IoT)devices and services for stress management.Netnography and semantic annotation for recognizing and categorizing the context of tweets are conducted to gain a better understanding of users’stress management practices.The aim is to analyze the tweets about stress management practices and to identify the context from the tweets.Thereafter,we map the tweets on pleasure and arousal to elicit customer insights.We analyzed a case study of a marketing strategy on the Twitter platform.Participants in the marketing campaign shared photos and texts about their stress management practices.Machine learning techniques were used to evaluate and estimate the emotions and contexts of the tweets posted by the campaign participants.The computational semantic analysis of the tweets was compared to the text analysis of the tweets.The content analysis of only tweet images resulted in 96%accuracy in detecting tweet context,while that of the textual content of tweets yielded an accuracy of 91%.Semantic tagging by Ontotext was able to detect correct tweet context with an accuracy of 50%.展开更多
Pyrogenic organic matter(PyOM)is formed during wildfires and prescribed burnings or produced intentionally in the form of biochar for soil amendment purposes.It is attracting a growing scientific and practical interes...Pyrogenic organic matter(PyOM)is formed during wildfires and prescribed burnings or produced intentionally in the form of biochar for soil amendment purposes.It is attracting a growing scientific and practical interest due to its important role in the global carbon cycle and agronomic applications as a soil enhancer.Most of the studies on the physicochemical properties of PyOM have been conducted using fresh biochars even though the characteristics of PyOM are expected to alter due to aging processes in soil environment.In this paper,we report the results of a study that utilized X-ray microtomography and elemental analysis to investigate the chemical and structural changes in the PyOM formed during prescribed burning events and aged thereafter for 1–71 years in a boreal forest soil.Our results indicate that changes in elemental composition occurred at decadal timescales,and an apparent steady state was reached ca.30 years after PyOM formation and exposure to the environment.At such timescales,PyOM was able to retain its porous structure originating from the cellular structure of the initial wood tissues.However,structural analysis revealed several effects of aging on the pore structure,such as the formation of surface coating layers,pore fillings,and fractures.These changes may alter pore size distribution and accessibility of the pores and further alter the influence of PyOM on soil functions,such as the transfer and retention of water and nutrients in PyOM pores.展开更多
Historically,wildfires have played an important role in forest dynamics in Fennoscandia.In Finland,the annually burned area has diminished in recent decades.This has led to a decline of fire-adapted habitat types and ...Historically,wildfires have played an important role in forest dynamics in Fennoscandia.In Finland,the annually burned area has diminished in recent decades.This has led to a decline of fire-adapted habitat types and species,many of which have become red-listed.In Fennoscandia,there is a long tradition of silvicultural burnings to enhance tree regeneration.Recently,prescribed burnings have been modified for biodiversity goals following the recommendations that have emerged from ecological research.Prominent biodiversity gains can be obtained by combining sufficient retention levels with burnings.Consequently,burning and retention have been recommended by recent national red-list assessments,strategies,and forest-management guidelines,and they have been adopted in forest-certification standards in Finland.Contrary to these recommendations,the opposite development has taken place:(1)the ecological efficiency of the criterion concerning prescribed burning in the PEFC forestcertification standard has been impaired,(2)state funding to encourage private forest owners to apply prescribed burning was reduced significantly,and(3)prescribed burnings have been abandoned altogether in commercial state-owned forests.Traditional burnings with variable retention have also been partially replaced with burning of small retention-tree groups.This new method is less risky and cheaper,but its ecological benefits are questionable because small-sized fires produce much smaller areas of burned forest soil with less fire-affected wood than traditional silvicultural burnings.Generally,the widely accepted goal to increase burnings with retention appears difficult to achieve and would require stronger political will and economic support from the government.We identified several actions that could improve the weakened situation of fire-dependent biodiversity and recommend the following:(1)setting a clear goal and ensuring sufficient funding for the burnings—including restoration burnings in conservation areas—and targeting these to specific fire-continuum areas with sufficient retention to ensure the continuity of fire-affected habitats at landscape level;(2)renewing the current subsidizing policies to encourage private landowners to perform prescribed burnings in regeneration areas after final fellings,and to safeguard accidental forest-fire areas as set-asides;(3)renewing the current prescribed-burning criterion of the Finnish PEFC forest-certification standard with more ambitious ecological goals;and(4)re-introducing prescribed burnings in commercial state forests where management targets are under political steering.展开更多
In managed forests,leaving retention trees during final harvesting has globally become a common approach to reconciling the often conflicting goals of timber production and safeguarding biodiversity and delivery of se...In managed forests,leaving retention trees during final harvesting has globally become a common approach to reconciling the often conflicting goals of timber production and safeguarding biodiversity and delivery of several ecosystem services.In Finland,the dominant certification scheme requires leaving low levels of retention that can benefit some specific species.However,species responses are dependent on the level of retention and the current low amounts of retention clearly do not provide the habitat quality and continuity needed for declining and redlisted forest species which are dependent on old living trees and coarse woody debris.Several factors contribute to this situation.First,the ecological benefits of the current low retention levels are further diminished by monotonous standwise use of retention,resulting in low variability of retention habitat at the landscape scale.Second,the prevailing timber-oriented management thinking may regard retention trees as an external cost to be minimized,rather than as part of an integrated approach to managing the ecosystem for specific goals.Third,the main obstacles of development may still be institutional and policy-related.The development of retention practices in Finland indicates that the aim has not been to use ecological understanding to attain specific ecological sustainability goals,but rather to define the lowest level of retention that still allows access to the market.We conclude that prevailing retention practices in Finland currently lack ecological credibility in safeguarding biodiversity and they should urgently be developed based on current scientific knowledge to meet ecological sustainability goals.展开更多
文摘Titanium hexafluoride pretreatments are known to improve paint adhesion and function as a barrier between the coating and the hot dip galvanized (HDG) steel surface. Interactions at the zinc/pretreatment interface are of utmost importance for the formation of pretreatment layers and the corrosion resistance of color coated hot dip galvanized steels. Removal rate of inert aluminum oxide from HDG steel samples by chemical dissolution was studied. XPS measurements showed that the surface Al2O3 layer thickness decreased rapidly already at mild alkaline cleaning, while complete removal of Al required severe etching. Low reactivity of an Al2O3-rich surface was confirmed by impaired formation of a titanium hexafluoride pretreatment layer. Grain boundaries and deformation twinnings were shown to be of importance for the reactivity of the HDG surface and for the precipitation of the pretreatment chemical. Helium ion microscopy images and electron probe microanalysis (EPMA) of a pretreated sample showed accumulation of the pretreatment chemical at the grain boundaries. Al removal rate was fast at the deformation twinnings at the grain plateaus. Slow Al removal was observed at dendritic valleys and grain boundaries. The results increase understanding of the reactivity of hot dip galvanized steel surface.
基金This work was supported by Taif University Researchers Supporting Project number(TURSP-2020/292),Taif University,Taif,Saudi Arabia.This research was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the fast-track Research Funding Program.
文摘Social media platforms provide new value for markets and research companies.This article explores the use of social media data to enhance customer value propositions.The case study involves a company that develops wearable Internet of Things(IoT)devices and services for stress management.Netnography and semantic annotation for recognizing and categorizing the context of tweets are conducted to gain a better understanding of users’stress management practices.The aim is to analyze the tweets about stress management practices and to identify the context from the tweets.Thereafter,we map the tweets on pleasure and arousal to elicit customer insights.We analyzed a case study of a marketing strategy on the Twitter platform.Participants in the marketing campaign shared photos and texts about their stress management practices.Machine learning techniques were used to evaluate and estimate the emotions and contexts of the tweets posted by the campaign participants.The computational semantic analysis of the tweets was compared to the text analysis of the tweets.The content analysis of only tweet images resulted in 96%accuracy in detecting tweet context,while that of the textual content of tweets yielded an accuracy of 91%.Semantic tagging by Ontotext was able to detect correct tweet context with an accuracy of 50%.
基金financially supported by the Ministry of Education and Culture,Finland,under project Carbon 4.0:AnalysisUtilization of Biological Data in Complex Carbon Ecosystems for JH and HL and project Bioproduct and Clean Bioeconomy—RDI FlagShip in Xamk for RK and KR。
文摘Pyrogenic organic matter(PyOM)is formed during wildfires and prescribed burnings or produced intentionally in the form of biochar for soil amendment purposes.It is attracting a growing scientific and practical interest due to its important role in the global carbon cycle and agronomic applications as a soil enhancer.Most of the studies on the physicochemical properties of PyOM have been conducted using fresh biochars even though the characteristics of PyOM are expected to alter due to aging processes in soil environment.In this paper,we report the results of a study that utilized X-ray microtomography and elemental analysis to investigate the chemical and structural changes in the PyOM formed during prescribed burning events and aged thereafter for 1–71 years in a boreal forest soil.Our results indicate that changes in elemental composition occurred at decadal timescales,and an apparent steady state was reached ca.30 years after PyOM formation and exposure to the environment.At such timescales,PyOM was able to retain its porous structure originating from the cellular structure of the initial wood tissues.However,structural analysis revealed several effects of aging on the pore structure,such as the formation of surface coating layers,pore fillings,and fractures.These changes may alter pore size distribution and accessibility of the pores and further alter the influence of PyOM on soil functions,such as the transfer and retention of water and nutrients in PyOM pores.
文摘Historically,wildfires have played an important role in forest dynamics in Fennoscandia.In Finland,the annually burned area has diminished in recent decades.This has led to a decline of fire-adapted habitat types and species,many of which have become red-listed.In Fennoscandia,there is a long tradition of silvicultural burnings to enhance tree regeneration.Recently,prescribed burnings have been modified for biodiversity goals following the recommendations that have emerged from ecological research.Prominent biodiversity gains can be obtained by combining sufficient retention levels with burnings.Consequently,burning and retention have been recommended by recent national red-list assessments,strategies,and forest-management guidelines,and they have been adopted in forest-certification standards in Finland.Contrary to these recommendations,the opposite development has taken place:(1)the ecological efficiency of the criterion concerning prescribed burning in the PEFC forestcertification standard has been impaired,(2)state funding to encourage private forest owners to apply prescribed burning was reduced significantly,and(3)prescribed burnings have been abandoned altogether in commercial state-owned forests.Traditional burnings with variable retention have also been partially replaced with burning of small retention-tree groups.This new method is less risky and cheaper,but its ecological benefits are questionable because small-sized fires produce much smaller areas of burned forest soil with less fire-affected wood than traditional silvicultural burnings.Generally,the widely accepted goal to increase burnings with retention appears difficult to achieve and would require stronger political will and economic support from the government.We identified several actions that could improve the weakened situation of fire-dependent biodiversity and recommend the following:(1)setting a clear goal and ensuring sufficient funding for the burnings—including restoration burnings in conservation areas—and targeting these to specific fire-continuum areas with sufficient retention to ensure the continuity of fire-affected habitats at landscape level;(2)renewing the current subsidizing policies to encourage private landowners to perform prescribed burnings in regeneration areas after final fellings,and to safeguard accidental forest-fire areas as set-asides;(3)renewing the current prescribed-burning criterion of the Finnish PEFC forest-certification standard with more ambitious ecological goals;and(4)re-introducing prescribed burnings in commercial state forests where management targets are under political steering.
文摘In managed forests,leaving retention trees during final harvesting has globally become a common approach to reconciling the often conflicting goals of timber production and safeguarding biodiversity and delivery of several ecosystem services.In Finland,the dominant certification scheme requires leaving low levels of retention that can benefit some specific species.However,species responses are dependent on the level of retention and the current low amounts of retention clearly do not provide the habitat quality and continuity needed for declining and redlisted forest species which are dependent on old living trees and coarse woody debris.Several factors contribute to this situation.First,the ecological benefits of the current low retention levels are further diminished by monotonous standwise use of retention,resulting in low variability of retention habitat at the landscape scale.Second,the prevailing timber-oriented management thinking may regard retention trees as an external cost to be minimized,rather than as part of an integrated approach to managing the ecosystem for specific goals.Third,the main obstacles of development may still be institutional and policy-related.The development of retention practices in Finland indicates that the aim has not been to use ecological understanding to attain specific ecological sustainability goals,but rather to define the lowest level of retention that still allows access to the market.We conclude that prevailing retention practices in Finland currently lack ecological credibility in safeguarding biodiversity and they should urgently be developed based on current scientific knowledge to meet ecological sustainability goals.
