The use of branched ketenedimers in solving the deposit problems related to the internal sizing of uncoated fine paper

Alkyl ketene dimers (AKD) are effective and highly hydrophobic sizing agents for the internal sizing of alkaline papers, but in some cases they may form deposits on paper machines and copiers. In addition, alkenyl succinic anhydrides (ASA)- based sizing agents are highly reactive, producing on-machine sizing, but under uncontrolled wet end conditions the hydrolysis of ASA may cause problems. This thesis aims at developing an improved ketene dimer based sizing agent that would have a lower deposit formation tendency on paper machines and copiers than a traditional type of AKD. The aim is also to improve the ink jet printability of a AKD sized paper. The sizing characteristics ofketene dimers have been compared to those of ASA. A lower tendency of ketene dimer deposit formation was shown in paper machine trials and in printability tests when branched fatty acids were used in the manufacture of a ketene dimer basedsizing agent. Fitting the melting and solidification temperature of a ketene dimer size to the process temperature of a paper machine or a copier contributes to machine cleanliness. A lower hydrophobicity of the paper sized with branched ketene dimer compared to the paper sized with traditional AKD was discovered. However, the ink jet print quality could be improved by the use of a branched ketene dimer. The branched ketene dimer helps in balancing the paper hydrophobicity for both black and color printing. The use of a high amount of protective colloidin the emulsification was considered to be useful for the sizing performance ofthe liquid type of sizing agents. Similar findings were indicated for both the branched ketene dimer and ASA.

A study of electromagnetic shielding properties of Ni79Fe16Mo5/copper films

The plane wave electromagnetic interference (EMI) shielding properties of DC sputtered Ni79Fe16Mo5 and copper layers were studied according to ASTM D 4935-89 on frequency range of 50 MHz – 2.5 GHz and RF magnetic shielding effectiveness by shielded magnetic loop probes. Results show that Ni79Fe16Mo5 provides better RF magnetic shielding above the layer thickness of approximately 120 nm. Copper provides better plane wave shielding effectiveness. The effect of shield internal interfaces was studied by depositing thin multilayer structures with and without a dielectric spacer layer.

Reagenssin pinta-aktiivisuuden hyödyntäminen sinkin uutossa

Työssä tutkittiin sinkin uutossa käytettävän di(2-etyyliheksyyli)fosforihappo (D2EHPA) -uuttoreagenssin faasikäyttäytymistä ja miten laimentimen koostumus, lämpötila ja orgaanisen faasin sinkkipitoisuus vaikuttavat faasitasapainoon. Laimentimen vaikutuksen havaittiin olevan pientä, kun taas lämpötilan nostaminen yli huoneenlämpötilan leventää faasidiagrammin yksifaasialuetta. Pienet orgaanisen faasin sinkkipitoisuudet eivät juuri vaikuta faasitasapainoon. Sinkin ja D2EHPA:n moolisuhteen ollessa välillä 0,1–0,2 kompleksin rakenne ilmeisesti muuttuu. Sinkkipitoisuuden kasvaessa yksifaasialue muodostuu pienemmillä ammoniakkimäärillä. Suurilla orgaanisen faasin sinkkipitoisuuksilla ja ammoniakkimäärillä muodostuu orgaanisen faasin ja vesifaasin välille kolmas nestefaasi. D2EHPA:n (40 p %) vesipitoisuuden ja viskositeetin pH riippuvuutta tutkittiin, kun laimentimena oli alifaattinen hiilivetyliuotin. Nostettaessa pH yli 3,5:n uuttoreagenssi alkoi muodostaa käänteismisellejä, jolloin orgaanisen faasin vesipitoisuus ja viskositeetti kasvoivat eksponentiaalisesti. Sinkin mukana uuttautuu epäpuhtauksia kuten Al3+, Co2+, Cu2+, Na+, Ni2+, Cl- ja F-. Takaisinuuton kautta epäpuhtaudet joutuvat talteenottoelektrolyysiin, jossa ne voivat vaikuttaa tuotteen laatuun ja laskea virtahyötysuhdetta. Tarkoituksena oli tutkia väheneekö epäpuhtauksien myötäuuttautuminen jollakin tietyllä sinkin latausasteella. Fluoridin ja kuparin uuttautumisen havaittiin vähenevän vasta, kun sinkin pitoisuus orgaanisessa faasissa oli yli 20 g/L lämpötilasta riippumatta. Fluoridi uuttautuu mahdollisesti alumiinikompleksina ja/tai fluorihappona. Koboltin ja nikkelin myötäuuttautumisen havaittiin vähenevän, kun sinkin latausaste oli yli 10 g/L. Natrium ja kloridi eivät myötäuuttautuneet.

The history of Lapland : containing a geographical description, and a natural history of that country; with an account of the inhabitants, their original, religion, customs, habits, marriages, conjurations, employments, &c. Written by John Scheffer, ... Translated from the last edition in Latin, and illustrated with many curious copper-cutts. To which are added, the travels of the King of Sweden's mathematicians into Lapland: the history of Livonia, and the wars there: also a journey into Lapland, Finland, &c. Written by Dr. Olof Rudbeck in the year 1701

Added engraved title page: The history of Lapland.

Modeling of fireside deposit formation in two industrial furnaces

Fireside deposits can be found in many types of utility and industrial furnaces. The deposits in furnaces are problematic because they can reduce heat transfer, block gas paths and cause corrosion. To tackle these problems, it is vital to estimate the influence of deposits on heat transfer, to minimize deposit formation and to optimize deposit removal. It is beneficial to have a good understanding of the mechanisms of fireside deposit formation. Numerical modeling is a powerful tool for investigating the heat transfer in furnaces, and it can provide valuable information for understanding the mechanisms of deposit formation. In addition, a sub-model of deposit formation is generally an essential part of a comprehensive furnace model. This work investigates two specific processes of fireside deposit formation in two industrial furnaces. The first process is the slagging wall found in furnaces with molten deposits running on the wall. A slagging wall model is developed to take into account the two-layer structure of the deposits. With the slagging wall model, the thickness and the surface temperature of the molten deposit layer can be calculated. The slagging wall model is used to predict the surface temperature and the heat transfer to a specific section of a super-heater tube panel with the boundary condition obtained from a Kraft recovery furnace model. The slagging wall model is also incorporated into the computational fluid dynamics (CFD)-based Kraft recovery furnace model and applied on the lower furnace walls. The implementation of the slagging wall model includes a grid simplification scheme. The wall surface temperature calculated with the slagging wall model is used as the heat transfer boundary condition. Simulation of a Kraft recovery furnace is performed, and it is compared with two other cases and measurements. In the two other cases, a uniform wall surface temperature and a wall surface temperature calculated with a char bed burning model are used as the heat transfer boundary conditions. In this particular furnace, the wall surface temperatures from the three cases are similar and are in the correct range of the measurements. Nevertheless, the wall surface temperature profiles with the slagging wall model and the char bed burning model are different because the deposits are represented differently in the two models. In addition, the slagging wall model is proven to be computationally efficient. The second process is deposit formation due to thermophoresis of fine particles to the heat transfer surface. This process is considered in the simulation of a heat recovery boiler of the flash smelting process. In order to determine if the small dust particles stay on the wall, a criterion based on the analysis of forces acting on the particle is applied. Time-dependent simulation of deposit formation in the heat recovery boiler is carried out and the influence of deposits on heat transfer is investigated. The locations prone to deposit formation are also identified in the heat recovery boiler. Modeling of the two processes in the two industrial furnaces enhances the overall understanding of the processes. The sub-models developed in this work can be applied in other similar deposit formation processes with carefully-defined boundary conditions.

Self-deposit, discovery, and delivery of scientific GIS datasets using GeoHydra

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Replacing Copper with New Carbon Nanomaterials in Electrical Machine Windings

Electrical machines have significant improvement potential. Nevertheless, the field is characterized by incremental innovations. Admittedly, steady improvement has been achieved, but no breakthrough development. Radical development in the field would require the introduction of new elements, such that may change the whole electrical machine industry system. Recent technological advancements in nanomaterials have opened up new horizons for the macroscopic application of carbon nanotube (CNT) fibres. With values of 100 MS/m measured on individual CNTs, CNT fibre materials hold promise for conductivities far beyond those of metals. Highly conductive, lightweight and strong CNT yarn is finally within reach; it could replace copper as a potentially better winding material. Although not yet providing low resistivity, the newest CNT yarn offers attractive perspectives for accelerated efficiency improvement of electrical machines. In this article, the potential for using new CNT materials to replace copper in machine windings is introduced. It does so, firstly, by describing the environment for a change that could revolutionize the industry and, secondly, by presenting the breakthrough results of a prototype construction. In the test motor, which is to our knowledge the first in its kind, the presently most electrically conductive carbon nanotube yarn replaces usual copper in the windings.

Finding Methods for Recognizing and Classifying Spare Part Criticality – Case Full Deposit Stripping Machines

The aim of this Master’s thesis is to find a method for classifying spare part criticality in the case company. Several approaches exist for criticality classification of spare parts. The practical problem in this thesis is the lack of a generic analysis method for classifying spare parts of proprietary equipment of the case company. In order to find a classification method, a literature review of various analysis methods is required. The requirements of the case company also have to be recognized. This is achieved by consulting professionals in the company. The literature review states that the analytic hierarchy process (AHP) combined with decision tree models is a common method for classifying spare parts in academic literature. Most of the literature discusses spare part criticality in stock holding perspective. This is relevant perspective also for a customer orientated original equipment manufacturer (OEM), as the case company. A decision tree model is developed for classifying spare parts. The decision tree classifies spare parts into five criticality classes according to five criteria. The criteria are: safety risk, availability risk, functional criticality, predictability of failure and probability of failure. The criticality classes describe the level of criticality from non-critical to highly critical. The method is verified for classifying spare parts of a full deposit stripping machine. The classification can be utilized as a generic model for recognizing critical spare parts of other similar equipment, according to which spare part recommendations can be created. Purchase price of an item and equipment criticality were found to have no effect on spare part criticality in this context. Decision tree is recognized as the most suitable method for classifying spare part criticality in the company.