Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties

We study the details of electronic transport related to the atomistic structure of silicon quantum dots embedded in a silicon dioxide matrix using ab initio calculations of the density of states. Several structural and composition features of quantum dots (QDs), such as diameter and amorphization level, are studied and correlated with transport under transfer Hamiltonian formalism. The current is strongly dependent on the QD density of states and on the conduction gap, both dependent on the dot diameter. In particular, as size increases, the available states inside the QD increase, while the QD band gap decreases due to relaxation of quantum confinement. Both effects contribute to increasing the current with the dot size. Besides, valence band offset between the band edges of the QD and the silica, and conduction band offset in a minor grade, increases with the QD diameter up to the theoretical value corresponding to planar heterostructures, thus decreasing the tunneling transmission probability and hence the total current. We discuss the influence of these parameters on electron and hole transport, evidencing a correlation between the electron (hole) barrier value and the electron (hole) current, and obtaining a general enhancement of the electron (hole) transport for larger (smaller) QD. Finally, we show that crystalline and amorphous structures exhibit enhanced probability of hole and electron current, respectively.

Making a Modern Highway: Transformation of Iowa Roadways in the Mid-Twentieth Century, 2014

The booklet tells the history of the construction of the Iowa Highway 376 Bridge within the context of significant modernization and expansion of the highway system in Iowa in the 1950s. Curvy, narrow highways were widened and straightened and narrow iron truss bridges were replaced with more modern concrete and steel structures, changing the landscape of rural Iowa. Bridge engineer Herbert A Arthur, who designed the Iowa Highway 376 Bridge, was a prolific bridge engineer in the 1950s. This booklet serves to inform the public of this significant aspect of Iowa transportation history.

Genetic characterization of ninety elite soybean cultivars using coefficient of parentage

The objective of this work was to estimate the coefficient of parentage and to understand the genetic structure of 90 elite soybean cultivars, which are adapted to different Brazilian environments. A total of 4,005 coefficients of parentage (f) were obtained and used to group the cultivars by UPGMA method. The constructed dendrogram showed several related cultivar groups which shared similar ancestors and clearly showed the genetic structure of the main Brazilian cultivars. Effective population sizes (Ne) were also estimated for cultivars in different generations. The average f = 0.2124 value, obtained from cultivars classified into four decades according to the release year, suggested effective soybean population sizes of 11 and 13 calculated using arithmetic and weighted means, respectively. The relatively small Ne and the high parentage coefficient support the conclusion that there is a high similarity degree among the main soybean cultivars in Brazil.

Development of Stage-Discharge Relations for Ungaged Bridge Waterways in Western Iowa, TR-567, 2010

Stage-discharge relations constitute a viable, alternative technique for estimating accurately flow for ungaged sites. In this research, we have utilized pressure transducers and Large Scale Particle Image Velocimetry techniques to develop stage-discharge relations at eleven sites in the Hungry Canyon Area (HCA) of southwestern Iowa under different hydrologic conditions. We have employed these data to calibrate and verify an established hydrologic model and then we have used this model to provide a stage discharge relation for different hydrologic conditions (i.e. rating curves). The benefits of the project are numerous including that the discharge data will be used for a number of purposes, including operational decision making in the HCA about the design of water-control and conveyance structures, input for hydraulic and hydrologic models, and calculation of sediment and other water quality constituents transport and “loads”, and for decision making. This project has also pointed out the difficulties in measuring flows in ungaged streams with ice jams, steep banks, erodible beds, and floating debris.

L'empresa xarxa a Catalunya : TIC, productivitat, competitivitat, salaris i rendiment a les empreses de Catalunya. Informe final de recerca (volum II)

El projecte de recerca L'empresa xarxa a Catalunya. TIC, productivitat, competitivitat, salaris i beneficis a l'empresa catalana té com a objectiu principal constatar que la consolidació d'un nou model estratègic, organitzatiu i d'activitat empresarial, vinculat amb la inversió i l'ús de les TIC (o empresa xarxa), modifica substancialment els patrons de comportament dels resultats empresarials, en especial la productivitat, la competitivitat, les retribucions dels treballadors i el benefici. La contrastació empírica de les hipòtesis de treball l'hem feta per mitjà de les dades d'una enquesta a una mostra representativa de 2.038 empreses catalanes. Amb la perspectiva de l'impacte de la inversió i l'ús de les TIC no s'aprecia una relació directa entre els processos d'innovació digital i els resultats de l'activitat de l'empresa catalana. En aquest sentit, hem hagut de segmentar el teixit productiu català per a buscar les organitzacions en què el procés de coinnovació tecnològica digital i organitzativa és més present i en què la intensitat de l'ús del coneixement és un recurs molt freqüent per a poder copsar impactes rellevants en els principals resultats empresarials. Això és així perquè l'economia catalana, avui, presenta una estructura productiva dual.

L'empresa xarxa a Catalunya : TIC, productivitat, competitivitat, salaris i rendiment a les empreses de Catalunya. Informe final de recerca (volum I)

El projecte de recerca L'empresa xarxa a Catalunya. TIC, productivitat, competitivitat, salaris i beneficis a l'empresa catalana té com a objectiu principal constatar que la consolidació d'un nou model estratègic, organitzatiu i d'activitat empresarial, vinculat amb la inversió i l'ús de les TIC (o empresa xarxa), modifica substancialment els patrons de comportament dels resultats empresarials, en especial la productivitat, la competitivitat, les retribucions dels treballadors i el benefici. La contrastació empírica de les hipòtesis de treball l'hem feta per mitjà de les dades d'una enquesta a una mostra representativa de 2.038 empreses catalanes. Amb la perspectiva de l'impacte de la inversió i l'ús de les TIC no s'aprecia una relació directa entre els processos d'innovació digital i els resultats de l'activitat de l'empresa catalana. En aquest sentit, hem hagut de segmentar el teixit productiu català per a buscar les organitzacions en què el procés de coinnovació tecnològica digital i organitzativa és més present i en què la intensitat de l'ús del coneixement és un recurs molt freqüent per a poder copsar impactes rellevants en els principals resultats empresarials. Això és així perquè l'economia catalana, avui, presenta una estructura productiva dual.

Can the impact of bed closure in intensive care units be reliably monitored?

OBJECTIVE: To assess the properties of various indicators aimed at monitoring the impact on the activity and patient outcome of a bed closure in a surgical intensive care unit (ICU). DESIGN: Comparison before and after the intervention. SETTING: A surgical ICU at a university hospital. PATIENTS: All patients admitted to the unit over two periods of 10 months. INTERVENTION: Closure of one bed out of 17. MEASUREMENTS AND RESULTS: Activity and outcome indicators in the ICU and the structures upstream from it (emergency department, operative theater, recovery room) and downstream from it (intermediate care units). After the bed closure, the monthly medians of admitted patients and ICU hospital days increased from 107 (interquartile range 94-112) to 113 (106-121, P=0.07) and from 360 (325-443) to 395 (345-436, P=0.48), respectively, along with the linear trend observed in our institution. All indicators of workload, patient severity, and outcome remained stable except for SAPS II score, emergency admissions, and ICU readmissions, which increased not only transiently but also on a mid-term basis (10 months), indicating that the process of patient care delivery was no longer predictable. CONCLUSIONS: Health care systems, including ICUs, are extraordinary flexible, and can adapt to multiple external constraints without altering commonly used activity and outcome indicators. It is therefore necessary to set up multiple indicators to be able to reliably monitor the impact of external interventions and intervene rapidly when the system is no longer under control.

GRW as an ontology of dispositions

The paper argues that the formulation of quantum mechanics proposed by Ghirardi, Rimini and Weber (GRW) is a serious candidate for being a fundamental physical theory and explores its ontological commitments from this perspective. In particular, we propose to conceive of spatial superpositions of non-massless microsystems as dispositions or powers, more precisely propensities, to generate spontaneous localizations. We set out five reasons for this view, namely that (1) it provides for a clear sense in which quantum systems in entangled states possess properties even in the absence of definite values; (2) it vindicates objective, single-case probabilities; (3) it yields a clear transition from quantum to classical properties; (4) it enables to draw a clear distinction between purely mathematical and physical structures, and (5) it grounds the arrow of time in the time-irreversible manifestation of the propensities to localize.

Hitsauksen mekanisointi laivan runkorakenteiden valmistuksessa

Hitsauksen mekanisoinnilla ja erityisesti kevytmekanisoinnilla saavutetaan melko pienin kustannuksin suuria etuja tuottavuudessa, laadussa ja työergonomiassa. Mekanisoinnin avulla voidaan saavuttaa soveltuvissa kohteissa hitsauksen kaariaikasuhteen kaksinkertaistuminen esim. 10 %:sta 20 %:iin. Tämä voi tarkoittaa kohteen kokonaishitsaustyöajan puolittumista. Mekanisoinnin tehokas hyödyntäminen edellyttää kuitenkin, että laitteet ovat helppokäyttöisiä ja haluttuja hitsauksen apuvälineitä. Genesis-projekti, jonka on määrä valmistua syksyllä 2009, tuo uuden haasteen Aker Yardsin Turun telakalle. Aluksen aikaisempia laivoja suurempi koko aiheuttaa haasteita tilankäytölle ja kapasiteetin riittävyydelle. Lisäksi käytettävät rakenteet aiheuttavat tuotantoon erityisiä ongelmia, joihin tämän diplomityön puitteissa on etsitty soveltuvia mekanisointiratkaisuja. Diplomityössä mekanisointilaitehankinnoilla lisättiin telakan laitekantaa ja korvattiin vanhentuneita laitteita. Laitteiden käyttöönotossa tarkasteltiin laitteiden puutteita ja pyrittiin löytämään käytettävyyttä parantavia ratkaisuja. Tässä työssä esitellyillä parannuksilla käytössä oleviin laitteisiin ja työmenetelmiin hitsauksen mekanisoinnin käyttöä voitaisiin lisätä vielä merkittävästi.