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91.
In many cases, treatment of wastewaters requires a combination of processes that very often includes biological treatment. Wet oxidation (WO) in combination with biotreatment has been successfully used for the treatment of refractory wastes. Therefore, information about the biodegradability of wastewater solutes and particulates after wet oxidation is very important. The present work proposes a model that can describe the oxidation process via organic concentration characteristics such as chemical oxygen demand (COD), biochemical oxygen demand (BOD), and immediately available BOD (IA BOD) and so can allow the prediction of biodegradability (i.e., BOD/COD ratio). The reaction mechanism includes the destruction of nonbiodegradable substances bytwo pathways: oxidation to carbon dioxide and water and oxidation to larger biodegradable compounds with their further degradation to smaller ones measured via IA BOD. The destruction of small biodegradable compounds to end products is also included in the model. The experiments were performed at different temperatures (170-200 degrees C) and partial oxygen pressures (0.5-1.5 MPa) in a batch stainless steel high-pressure autoclave. The model of concentrated thermomechanical pulp circulation water was selected for the experiments. The proposed model correlates with the experimental data well and it is compared with other WO models in the literature. 相似文献
92.
Mechanical, impact, and relaxation properties of in situ synthesized carbon nanotubes‐polyaniline (CNT‐PANi) hybrid nanoparticle‐filled poly(propylene) (PP) composites with or without an amphiphilic dispersing agent were investigated using tensile testing, notched Charpy impact testing, and dynamical mechanical testing methods. The reference material was MWCNT filled PP composite. Ethyl gallate (EG) was the dispersing agent which realizes high conductivity in PP composites with hybrid filler. Measured properties showed quite similar behavior of CNT‐PANi hybrid and neat CNT filled composites. Addition of 20% EG in PP did not cause essential differences compared to the neat PP. When the dispersing agent was added in filler containing PP composites, remarkable effects were observed, especially in PP‐hybrid composites. Mechanically, these materials had improved tensile properties, but they were brittle compared to the materials without dispersing agent. Dynamic mechanical analysis showed improvement in storage modulus, and in loss modulus the α transition was well observable. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
93.
Matti Aula Ahti Leppänen Juha Roininen Eetu-Pekka Heikkinen Kimmo Vallo Timo Fabritius Marko Huttula 《Metallurgical and Materials Transactions B》2014,45(3):839-849
Emission spectroscopy is a potential method for gaining information on electric arc furnace (EAF) process conditions. Previous studies published in literature on industrial EAF emission spectra have focused on a smaller scales and DC arc furnaces. In this study emission spectrum measurements were conducted for 140t AC stainless steelmaking EAF at Outokumpu Stainless Oy, Tornio Works, Finland. Four basic types of emission spectra were obtained during the EAF process cycle. The first one is obscured by scrap steel, the second is dominated by thermal radiation of the slag, the third is dominated by alkali peaks and sodium D-lines and the fourth is characterized by multiple atomic emission peaks. The atomic emission peaks were identified by comparing them to the NIST database for atomic emission lines and previous laboratory measurements on EAF slag emission spectra. The comparison shows that the optic emission of an arc is dominated by slag components. Plasma conditions were analyzed by deriving plasma temperature from optical emissions of Ca I lines. The analysis suggests that accurate information on plasma conditions can be gained from outer plasma having a plasma temperature below 7000 K (6727 °C). 相似文献
94.
Juha Tommila Arto Aho Antti Tukiainen Ville Polojrvi Joel Salmi Tapio Niemi Mircea Guina 《Progress in Photovoltaics: Research and Applications》2013,21(5):1158-1162
We report on the performance of biomimicked antireflection coating applied to dilute nitride solar cell. The coating consists of nanostructures replicating the moth‐eye geometry and has been fabricated by nanoimprint lithography directly within the window layer covering the dilute nitride absorbing junction. The mean reflectivity within the spectral range of 320–1800 nm remains under 5% for incident angles up to 45°. The effect of the coating on the cell performance was assessed by measuring the current–voltage characteristics under simulated solar illumination. A clear performance increase was identified when comparing a solar cell with the moth‐eye coating with a solar cell having a standard SiNx/SiO2 coating. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
95.
Mika Horttanainen Juha Kaikko Riikka Bergman Minna Pasila-Lehtinen Janne Nerg 《Applied Thermal Engineering》2010,30(2-3):110-118
Expectations on wastewater sludge treatment and recovery of its energy and material contents are increasing because of the tightening legislation and the obligation to reduce environmental impacts of sludge disposal. The objective of this study was to analyze the performance of a heat and power generating sludge combustion plant from technical and economical viewpoints and to compare the studied concept to optional sludge treatment technologies. The plant performance was modeled for sewage sludge produced by approximately 200,000 inhabitants. Two plant sizes below 1000 kWe range were investigated, the smaller plant using sludge as the only fuel and the larger plant with wood chips as the additional fuel. The plants were compared with heat-only plants of similar size. The payback periods for heat-only plants are typically shorter than with the cogenerating plants because the changes in plant investment affect stronger the economy than do the revenues from selling electricity. The gate fee of sludge treatment has the strongest effect on the payback period. The selection of the plant concept (cogeneration, heat only or pure electricity generation) is, however, affected more by the local demand of heat and electricity than pure economy. The selection of the optimal technology for sludge treatment is a complicated task. The studied concept can be the optimal choice, for example, if there is no cement kiln or co-combustion possibility near the source of sludge, if there is no land enhancement demand for the digested sludge, or if the energy surplus from combustion compared to anaerobic digestion is considered more valuable than nutrient recovery possibility from digestion. If the new technology concept is found competitive, it still has to meet the challenge of acceptability from the business, social and cultural points of view. 相似文献
96.
Jari Rosti Juha Koivisto Paola Traversa Xavier Illa Jean-Robert Grasso Mikko J. Alava 《International Journal of Fracture》2008,151(2):281-297
The dynamics of a “peeling front” or an elastic line is studied under creep (constant load) conditions. Our experiments show
in most cases an exponential dependence of the creep velocity on the inverse force (mass) applied. In particular, the dynamical
correlations of the avalanche activity are discussed here. We compare various avalanche statistics to those of a line with
non-local elasticity, and study various measures of the experimental avalanche-avalanche and temporal correlations such as
the autocorrelation function of the released energy and aftershock activity. From all these we conclude, that internal avalanche
dynamics seems to follow “line depinning”-like behavior, in rough agreement with the depinning model. Meanwhile, the correlations
reveal subtle complications not implied by depinning theory. Moreover, we also show how these results can be understood from
a geophysical point of view. 相似文献
97.
Kaisa Grönman Risto Soukka Terhen Järvi‐Kääriäinen Juha‐Matti Katajajuuri Mika Kuisma Heta‐Kaisa Koivupuro Margareetta Ollila Marja Pitkänen Olli Miettinen Frans Silvenius Rabbe Thun Helena Wessman Lassi Linnanen 《Packaging Technology and Science》2013,26(4):187-200
The environmental impacts of packages have been found to be relatively small compared with the food items they contain. Furthermore, from the environmental and operational point of view, the most significant task of the package is to protect the product, which is important to acknowledge in the packaging design process. This study introduces a guiding framework for designing sustainable food packaging. In this approach, the entire life cycle of the product–package combination is taken into consideration. The emphasis is on the prevention of food losses in packaging design as a major environmental criterion. Consideration of the properties of both the package and the product itself when designing the final package will lead to a better end result with smaller product losses and environmental impacts. By using different assessment methods in the different stages of the packaging design, the sustainability of the package can be enhanced. The decision making of the packaging designer is facilitated with methods that are introduced step by step and in a certain order that will also allow for corrective measures through back‐loops in the design process. The purpose is to integrate sustainability aspects at all stages firmly into the design process. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
98.
Matias Ståhle Tuomas Ahola Miia Martinsuo 《International Journal of Project Management》2019,37(1):145-160
The delivery of integrated solutions calls for effective integration across the functional interfaces of the project-based firm (PBF) throughout the solution's life cycle. We scrutinize cross-functional integration in a triadic setting involving the PBF's sales, project operations, and services functions by focusing on the flow of customer information (information from and about customers) across three functional interfaces. Drawing on a qualitative case study, we develop a categorization consisting of four distinct types of integration mechanisms: meetings, IT systems, personal involvement, and processes and rules. Our results show that in the focal PBF, customer information flows are strongest in the sales–project operations interface and weakest in the sales–services interface. Furthermore, sales and services functions were found to rely predominantly on personal involvement mechanisms in transferring customer information. Our results highlight the need to integrate and manage customer information flows, especially between the sales–services interface, when delivering integrated solutions. 相似文献
99.
Core sampling method (extracting a portion of a flow from the core of the flow) will reduce diffusional losses of highly diffusive species (e.g., aerosol nanoparticles, ions, and gases) when transporting them through a sampling tube. Revealing parameters governing the sampling efficiency of a core sampling system, ηsam, helps to design the apparatus and to optimize its performance. In this study, we report an analytical solution for quantifying the ηsam by solving the convection diffusion equation of laminar flow field. The analytical results were experimentally evaluated using 1–5?nm tungsten oxide nanoparticles. ηsam is governed by a dimensionless loss parameter and the transport-to-sample flow ratio. Theoretically predicted values for ηsam agree with experimental results, e.g., the relative deviation is within 5% when the value for the loss parameter is less than 0.1. The core sampling method is recommended to work at the loss parameter less than 0.1 such that ηsam is equal or close to the maximum value of unity and is also insensitive to variations in sampling conditions. In this study, how to apply the findings in designing and optimizing a core sampling system was discussed. A core sampling apparatus was then designed and experimentally evaluated. Its sampling efficiency was shown to be significantly higher than those of a tee, a cross fitting, and a Y fitting when the same sampling conditions were used.
Copyright © 2019 American Association for Aerosol Research 相似文献
100.
Rachel I. Adams Hanna Leppänen Anne M. Karvonen José Jacobs Alicia Borràs-Santos Maria Valkonen Esmeralda Krop Ulla Haverinen-Shaughnessy Kati Huttunen Jan-Paul Zock Anne Hyvärinen Dick Heederik Juha Pekkanen Martin Täubel 《Indoor air》2021,31(6):1952-1966
Moisture-damaged buildings are associated with respiratory symptoms and underlying diseases among building occupants, but the causative agent(s) remain a mystery. We first identified specific fungal and bacterial taxa in classrooms with moisture damage in Finnish and Dutch primary schools. We then investigated associations of the identified moisture damage indicators with respiratory symptoms in more than 2700 students. Finally, we explored whether exposure to specific taxa within the indoor microbiota may explain the association between moisture damage and respiratory health. Schools were assessed for moisture damage through detailed inspections, and the microbial composition of settled dust in electrostatic dustfall collectors was determined using marker-gene analysis. In Finland, there were several positive associations between particular microbial indicators (diversity, richness, individual taxa) and a respiratory symptom score, while in the Netherlands, the associations tended to be mostly inverse and statistically non-significant. In Finland, abundance of the Sphingomonas bacterial genus and endotoxin levels partially explained the associations between moisture damage and symptom score. A few microbial taxa explained part of the associations with health, but overall, the observed associations between damage-associated individual taxa and respiratory health were limited. 相似文献