Reactor for fluidized bed silane decomposition

An improved heated fluidized bed reactor and method for the production of high purity polycrystalline silicon by silane pyrolysis wherein silicon seed particles are heated in an upper heating zone of the reactor and admixed with particles in a lower zone, in which zone a silane-containing gas stream, having passed through a lower cooled gas distribution zone not conducive to silane pyrolysis, contacts the heated seed particles whereon the silane is heterogeneously reduced to silicon

Social Norms and Choice: A Weak Folk Theorem for Repeated Matching Games

A folk theorem for repeated matching games is established that holds if the stage game is not a pure coordination game. It holds independent of population size and for all matching rules-including rules that depend on players choices or the history of play. This paper also establishes an equilibrium condition and using this discovers two differences between the equilibria of repeated matching games and standard repeated games. Trigger strategies are not equilibria and there is no simple optimal penal code.

HUMANITIES IN THE AGE OF ALGORITHMS : A mixed-methods study on the futures of Akava Special Branches in 2036

This master’s thesis in Futures Studies is connected to an assignment from trade union Aka-va Special Branches (AE) to create futures images and to ideate new services for the union in 2036. The research question is the following: How did the mixed-methods foresight process conducted online serve the creation of futures images and new services for Akava Special Branches in 2036? The images and service ideas were cocreated in a mixed-methods foresight process combining elements from Futures Studies and Service Design. The process followed the framework of a participatory futures workshop and was divided into pre-workshop, work-shop, and post-workshop phases. Other methodological tools used were futures window, PESTEL-chart, Dator’s futures archetypes, survey, and futures image. In addition, mood-boards and storyboards, typical Service Design tools, were used to refine the futures images. The end-products of the process were four futures images (consisting of a narrative, a moodboard, and a storyboard) and seven new service ideas. The images were evaluated by the participants in terms of probability and preferability, and the new service ideas in terms of facility to execute and preferability. The workshops were organised with AE’s stakeholders and took place completely online. The online environment promoted accessibility and resulted with heterogenous groups and a representative sample of the intended focus groups. The MIRO platform enabled cocreation but required a tutorial and basic IT-skills to run smoothly. However, facilitating more than one group with MIRO and Microsoft Teams was challenging. Not being physically present at the same place also hindered the communication between the participants. PESTEL-chart worked as a cradle for the pre-assignment and then as a tool for shared understanding in the workshop phase. It also fed driving forces to Dator’s chart of archetypes. Focusing on the Finnish labour market, AE’s organisation and member profile throughout the workshops ensured the micro and macro perspectives in the futures images. The moodboards and storyboards emphasised the communicative value of the images. Evaluation of the images and service ideas after the actual workshops brought an additional layer of validation to the process. The mixed-methods foresight process could be applied to creating futures for any labour union and, as a modified version, for any generic organisationPro-gradu on liitoksissa ammattiliitto Akavan Erityisalojen (AE) toimeksiantoon luoda liitolle tulevaisuuskuvia ja ideoita uusista palveluista vuonna 2036. Tutkielman tutkimuskysymys on: miten verkkopohjainen monimenetelmällinen ennakointiprosessi palveli tulevaisuuksien luomista ja uusien palveluiden ideointia Akavan Erityisaloille vuodelle 2036? Ennakointiprosessissa yhdistyivät tulevaisuudentutkimuksen ja palvelumuotoilun menetelmät. Prosessi noudatteli tulevaisuustyöpajan rakennetta ja oli jaettu esiosioon, varsinaiseen ja jälkiosioon. Muita tulevaisuudentutkimukselle tyypillisiä menetelmällisiä työkaluja olivat tulevaisuusikkuna, PESTEL-taulukko, Jim Datorin tulevaisuusarkkityypit, kyselytutkimus ja tulevaisuuskuvat. Palvelumuotoilun työkaluista tulevaisuuskuvia täydentämään käytettiin tunnelmataulua ja palvelusarjakuvaa. Prosessin lopputuotteet olivat neljä tulevaisuuskuvaa koostuen narratiivista, tunnelma-taulusta ja palvelusarjakuvasta sekä seitsemän uutta palveluideaa. Lisäksi osallistujat arvioivat kuvat todennäköisyyden ja toivottavuuden ja palveluideat toimeenpanon helppouden ja toivottavuuden perusteella. Työpajoihin kutsuttiin Akavan Erityisalojen sidosryhmiä ja ne järjestettiin kokonaan verkossa. Verkkoympäristö helpotti osallistumista työpajoihin ja edesauttoi edustavan osallistujaotoksen saamista ja heterogeenisten ryhmien muodostamista. MIRO-alustalla oli helppo luoda näyttäviä tehtävänantoja. Alusta mahdollisti yhteiskehittämisen, mutta vaati osallistujilta harjoittelua ja tietoteknisten perustaitojen hallintaa. Fasilitointi MIRO:n ja Microsoft Teamsin välityksellä oli hankalaa, ja ne mahdollistivat keskittymisen vain yhteen ryhmään kerrallaan. Kehollisen läsnäolon puute myös rajoitti osallistujien välistä viestintää. PESTEL-taulukko toimi hyvin ennakkotehtävässä ja yhteisen ymmärryksen luomiseksi varsinaisen työpajan alussa. Se myös syötti hyvin muutosilmiöitä Datorin tulevaisuuden arkkityyppien taulukkoon. Saman kolmitasoisen katsantotavan säilyttäminen (Suomen työmarkkinajärjestelmä, AE:n organisaatio ja jäsentaso) prosessin eri vaiheissa toi johdonmukaisuutta tulevaisuuskuviin. Tunnelmataulut ja palvelusarjakuvat voimistivat kuvien viestejä. Tulevaisuuskuvien ja palveluideoiden arvottaminen varsinaisten työpajojen jälkeen toi prosessiin lisää uskottavuutta. Monimenetelmällinen metodi olisi sovellettavissa muidenkin ammattiliittojen ja muutoksin toistenkin organisaatioiden tulevaisuuksien rakentamiseen

IN-SYNC. V. Stellar kinematics and dynamics in the Orion A Molecular Cloud

The kinematics and dynamics of young stellar populations enable us to test theories of star formation. With this aim, we continue our analysis of the SDSS-III/APOGEE IN-SYNC survey, a high resolution near infrared spectroscopic survey of young clusters. We focus on the Orion A star-forming region, for which IN-SYNC obtained spectra of $\sim2700$ stars. In Paper IV we used these data to study the young stellar population. Here we study the kinematic properties through radial velocities ($v_r$). The young stellar population remains kinematically associated with the molecular gas, following a $\sim10\:{\rm{km\:s}}^{-1}$ gradient along filament. However, near the center of the region, the $v_r$ distribution is slightly blueshifted and asymmetric; we suggest that this population, which is older, is slightly in foreground. We find evidence for kinematic subclustering, detecting statistically significant groupings of co-located stars with coherent motions. These are mostly in the lower-density regions of the cloud, while the ONC radial velocities are smoothly distributed, consistent with it being an older, more dynamically evolved cluster. The velocity dispersion $\sigma_v$ varies along the filament. The ONC appears virialized, or just slightly supervirial, consistent with an old dynamical age. Here there is also some evidence for on-going expansion, from a $v_r$--extinction correlation. In the southern filament, $\sigma_v$ is $\sim2$--$3$ times larger than virial in the L1641N region, where we infer a superposition along the line of sight of stellar sub-populations, detached from the gas. On the contrary, $\sigma_v$ decreases towards L1641S, where the population is again in agreement with a virial state.Comment: 14 pages, 13 figures, ApJ accepte

Coevolutionary games - a mini review

Prevalence of cooperation within groups of selfish individuals is puzzling in that it contradicts with the basic premise of natural selection. Favoring players with higher fitness, the latter is key for understanding the challenges faced by cooperators when competing with defectors. Evolutionary game theory provides a competent theoretical framework for addressing the subtleties of cooperation in such situations, which are known as social dilemmas. Recent advances point towards the fact that the evolution of strategies alone may be insufficient to fully exploit the benefits offered by cooperative behavior. Indeed, while spatial structure and heterogeneity, for example, have been recognized as potent promoters of cooperation, coevolutionary rules can extend the potentials of such entities further, and even more importantly, lead to the understanding of their emergence. The introduction of coevolutionary rules to evolutionary games implies, that besides the evolution of strategies, another property may simultaneously be subject to evolution as well. Coevolutionary rules may affect the interaction network, the reproduction capability of players, their reputation, mobility or age. Here we review recent works on evolutionary games incorporating coevolutionary rules, as well as give a didactic description of potential pitfalls and misconceptions associated with the subject. In addition, we briefly outline directions for future research that we feel are promising, thereby particularly focusing on dynamical effects of coevolutionary rules on the evolution of cooperation, which are still widely open to research and thus hold promise of exciting new discoveries.Comment: 24 two-column pages, 10 figures; accepted for publication in BioSystem

Semiparametric EM-estimation of censored linear regression models for durations

This paper investigates the sensitivity of maximum quasi likelihood estimators of the covariate effects in duration models in the presence of misspecification due to neglected heterogeneity or misspecification of the hazard function. We consider linear models for r(T) where T is duration and r is a known, strictly increasing function. This class of models is also referred to as location-scale models. In the absence of censoring, Gould and Lawless (1988) have shown that maximum likelihood estimators of the regression parameters are consistent and asymptotically normally distributed under the assumption that the location-scale structure of the model is of the correct form. In the presence of censoring, however, model misspecification leads to inconsistent estimates of the regression coefficients for most of the censoring mechanisms that are widely used in practice. We propose a semiparametric EM-estimator, following ideas of Ritov (1990), and Buckley and James (1979). This estimator is robust against misspecification and is highly recommended if there is heavy censoring and if there may be specification errors. We present the results of simulation experiments illustrating the performance of the proposed estimator

Complementarities and Collusion in an FCC Spectrum Auction

We empirically study bidding in the C Block of the US mobile phone spectrum auctions. Spectrum auctions are conducted using a simultaneous ascending auction design that allows bidders to assemble packages of licenses with geographic complementarities. While this auction design allows the market to find complementarities, the auction might also result in an inefficient equilibrium. In addition, these auctions have equilibria where implicit collusion is sustained through threats of bidding wars. We estimate a structural model in order to test for the presence of complementarities and implicit collusion. The estimation strategy is valid under a wide variety of alternative assumptions about equilibrium in these auctions and is robust to potentially important forms of unobserved heterogeneity. We make suggestions about the design of future spectrum auctions.Technology and Industry

Effects Of Experimental Scale On The Adsorption Of Two Pharmaceutical Drugs Detected In Municipal Wastewater Effluent

Pharmaceutical drugs are being produced and consumed in increasing quantities every year and are poorly treated by conventional wastewater treatment processes, leading to increasing detection of such compounds in surface water, groundwater, and municipal drinking water. Soil aquifer treatment (SAT) is a promising method for treating these emerging compounds through combined adsorption and degradation of target compounds in soil. This thesis examines the consistency of results from typical studies like adsorption isotherms and soil columns utilized in analysis of SAT performance, across varying experimental scales. The adsorption behavior of two pharmaceuticals was investigated as a function of experimental scale and soil organic content in adsorbent media. This thesis shows that broad trends in pharmaceutical adsorption are not dependent upon experimental scale. Across adsorption isotherm, bench-scale soil column, and large-scale soil column experiments, adsorption and of both drugs was greater in organic soil than inorganic soil, although dispersive transport may have increased in some experiments. Across all experiments, carbamazepine was adsorbed by soils more than diclofenac. Some inconsistencies were observed across scales between the two organic soils, a mediumorganic and high-organic soil, where adsorption was generally greater in high organic soil, but sometimes observed to be greater in medium organic soil. This may suggest that the decrease of experimental control resulting from increased experimental scale obfuscates more nuanced relationships in SAT experimental conditions. Broad trends in data showing whether or not a soil displayed significant adsorptive behavior and which pharmaceutical was adsorbed more were consistent. However, the degree of partitioning via adsorption varied across scales as experimental control decreased with increasing physical scale

A review of wildland fire spread modelling, 1990-present 3: Mathematical analogues and simulation models

In recent years, advances in computational power and spatial data analysis (GIS, remote sensing, etc) have led to an increase in attempts to model the spread and behvaiour of wildland fires across the landscape. This series of review papers endeavours to critically and comprehensively review all types of surface fire spread models developed since 1990. This paper reviews models of a simulation or mathematical analogue nature. Most simulation models are implementations of existing empirical or quasi-empirical models and their primary function is to convert these generally one dimensional models to two dimensions and then propagate a fire perimeter across a modelled landscape. Mathematical analogue models are those that are based on some mathematical conceit (rather than a physical representation of fire spread) that coincidentally simulates the spread of fire. Other papers in the series review models of an physical or quasi-physical nature and empirical or quasi-empirical nature. Many models are extensions or refinements of models developed before 1990. Where this is the case, these models are also discussed but much less comprehensively.Comment: 20 pages + 9 pages references + 1 page figures. Submitted to the International Journal of Wildland Fir