Impact of wide bandgap p-type nc-Si on the performance of a-Si solar cells

This paper reports the impact of a wide bandgap p-type hydrogenated nanocrystalline silicon (nc-Si:H) on the performances of hydrogenated amorphous silicon (a-Si:H) based solar cells. The player consists of nanometer-sized Si crystallites and has a wide effective bandgap determined mainly by the quantum size-confinement effect (QSE). By incorporation of this p-layer into the devices we have obtained high performances of a-Si:H top solar cells with V-infinity=1.045 V and FF=70.3 %, and much improved mid and bottom a-SiGe:H cells, deposited on stainless steel (SS) substrate. The effects of the band-edge mismatch at the p/i-interface on the I-V characteristics of the solar cells arc discussed on the bases of the density-functional approach and the AMPS model.

Impact of wide bandgap p-type nc-Si on the performance of a-Si solar cells

This paper reports the impact of a wide bandgap p-type hydrogenated nanocrystalline silicon (nc-Si:H) on the performances of hydrogenated amorphous silicon (a-Si:H) based solar cells. The player consists of nanometer-sized Si crystallites and has a wide effective bandgap determined mainly by the quantum size-confinement effect (QSE). By incorporation of this p-layer into the devices we have obtained high performances of a-Si:H top solar cells with V-infinity=1.045 V and FF=70.3 %, and much improved mid and bottom a-SiGe:H cells, deposited on stainless steel (SS) substrate. The effects of the band-edge mismatch at the p/i-interface on the I-V characteristics of the solar cells arc discussed on the bases of the density-functional approach and the AMPS model.

Sinkkirikasteen liuotusprosessin kineettinen mallinnus

Työssä on tehty kineettinen simulointimalli sinkkirikasteen liuotusprosessista. Prosessi on pieni osa Kokkolan sinkinvalmistusprosessia, jonka muita osia ovat: pasutus, neutraaliliuotus, konversio, liuospuhdistus ja elektrolyysi. Rikasteen liuotukseen tulee konversioprosessin liuos ja liuotuksesta lähtevä neste menee takaisin neutraaliliuotukseen. Saostunut jarosiitti läjitetään. Kokkolan liuotusprosessi koostuu liettoreaktorista ja kahdesta neljän liuotusreaktorin sarjasta. Liuotukseen syötetään paluuhappoa liettoreaktoriin ja liuotuspiirien ensimmäisiin liuotusreaktoreihin. Happea syötetään kaikkiin liuotusreaktoreihin. Prosessin mallintamiseen käytettiin Aspen Plus-simulointiohjelmaa, johon pystyttiin syöttämään kineettisiä yhtälöitä. Reaktionopeusyhtälöitä käytettiin raudan hapetuksen, sulfidien liuotuksen ja jarosiitiin saostumisen mallintamiseen, eli kaikkiin liuotusreaktoreissa tapahtuviin reaktioihin. Kineettiset yhtälöt etsittiin kirjallisuudesta. Liettoreaktori puolestaan mallinnettiin syöttämällä ohjelmaan reaktioyhtälöt ja antamalla niille etenemisasteet. Jarosiitin liukenemisesta työssä on tehty laboratoriokokeita, koska aiheesta ei kirjallisuudesta löytynyt kineettistä tietoa. Liuotuskokeissa käytetyn kiintoaineen kuitenkin todettiin sisältävän liikaa götiittiä, että tuloksista olisi voitu laskea kinetiikkaa jarosiitin liukenemiselle. Simulointimallilla laskettiin yksi tapaus vertailukohdaksi, johon malliin tehtyjä muutoksia verrattiin. Mallilla tutkittiin konversiosta tulevan jarosiitin määrän vaikutusta, reaktorikoon merkitystä ja rikasteen liuotuksen sekä jarosiitin saostuksen reaktionopeuksien muutoksen vaikutuksia. Käytetyillä kineettisillä yhtälöillä reaktioiden todettiin tarvitsevan vain ¾ käytetystä reaktiotilavuudesta, rikasteen liuotusnopeuden kohtalaisen pienellä hidastamisen todettiin vähentävän sinkin saantoa ja jarosiitin saostuksen reaktionopeuden kasvulla todettiin myös olevan negatiivinen vaikutus sinkin saantoon. Simulointimallissa käytettyjen reaktionopeusyhtälöiden varmentaminen kokeilla todettiin tarpeelliseksi, sillä jo kohtalaisen pienillä muutoksilla havaittiin olevan merkitystä prosessin toimivuuteen. Lisäksi todettiin jarosiitin liukenemisen huomioimisen olevan tarpeen.

Apatite-Polymer Composite Particles for Controlled Delivery of BMP-2: In Vitro Release and Cellular Response

Bone morphogenetic protein-2 (BMP-2) has the ability to induce osteoblast differentiation of undifferentiated cells, resulting in the healing of skeletal defects when delivered with a suitable carrier. We have applied a versatile delivery platform comprising a novel composite of two biomaterials with proven track records – apatite and poly(lactic-co-glycolic acid) (PLGA) – to the delivery of BMP-2. Sustained release of this growth factor was tuned with variables that affect polymer degradation and/or apatite dissolution, such as polymer molecular weight, polymer composition, apatite loading, and apatite particle size. The effect of released BMP-2 on C3H10T1/2 murine pluripotent mesenchymal cells was assessed by tracking the expression of osteoblastic makers, alkaline phosphatase (ALP) and osteocalcin. Release media collected over 100 days induced elevated ALP activity in C3H10T1/2 cells. The expression of osteocalcin was also upregulated significantly. These results demonstrated the potential of apatite-PLGA composite particles for releasing protein in bioactive form over extended periods of time.

Genetic structure of populations of Rhizoctonia solani anastomosis group-1 IA from soybean in Brazil

The Basidiomycete fungus Rhizoctonia solani anastomosis group (AG)-1 IA is a major pathogen of soybean in Brazil, where the average yield losses have reached 30 to 60% in some states in Northern Brazil. No information is currently available concerning levels of genetic diversity and population structure for this pathogen in Brazil. A total of 232 isolates of R. solani AG1 IA were collected from five soybean fields in the most important soybean production areas in central-western, northern, and northeastern Brazil. These isolates were genotyped using 10 microsatellite loci. Most of the multilocus genotypes (MLGTs) were site-specific, with few MLGTs shared among populations. Significant population subdivision was evident. High levels of admixture were observed for populations from Mato Grosso and Tocantins. After removing admixed genotypes, three out of five field populations (Maranhao, Mato Grosso, and Tocantins), were in Hardy-Weinberg (HW) equilibrium, consistent with sexual recombination. HW and gametic disequilibrium were found for the remaining soybean-infecting populations. The findings of low genotypic diversity, departures from HW equilibrium, gametic disequilibrium, and high degree of population subdivision in these R. solani AG-1 IA populations from Brazil are consistent with predominantly asexual reproduction, short-distance dispersal of vegetative propagules (mycelium or sclerotia), and limited long-distance dispersal, possibly via contaminated seed. None of the soybean-infecting populations showed a reduction in population size (bottleneck effect). We detected asymmetric historical migration among the soybean-infecting populations, which could explain the observed levels of subdivision.

Validity of hand-to-foot measurement of bioimpedance: Standing compared with lying position

Objective: To assess the reliability of the standing measurement of hand-to-foot bioimpedance compared with measurements made in the lying position.Research Methods and Procedures: In 205 volunteers 6 to 89 years of age, 111 males and 94 females from six ethnic groups, effects of posture, time, and age on hand-to-foot resistance were studied over a range of body size. The effect of time in a position on resistance was also recorded in a small subset (n = 10), and repeat measurements over 3 days at the same time of the day were recorded in another subset (n = 12).Results: Lying impedance was consistently higher than standing, with the relationship (resistance lying/resistance standing) for the children (5 to 14 years) being 1.031, progressing to a ratio of 1.016 in those >60 years. The time spent static in either position did change resistance measurements - a decrease of up to 9 Omega (mean 5 Omega, 1.0%) over 10 minutes of standing and an increase of up to 7 Omega (mean 3 Omega, 0.7%) with lying.Discussion: In the field, measurements of hand-to-foot bioimpedance can be made in the standing position, and, with appropriate adjustment, previously validated recumbent equations can be used. Given that errors in the measurement of height and weight also affect the reliability of the derivation of body fat from bioelectrical conductance, the errors that may arise from a more practical standing measurement rather than lying are minimal.

Avaliação da variabilidade genética em uma população base de Eucalyptus camaldulensis Dehnh para fins de conservação e melhoramento genético

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variação geográfica no canto de anúncio de Dendropsophus Nanus (Anura, Hylidae)

Pós-graduação em Biologia Animal - IBILCE

Nanomechanics of cellulose crystals and cellulose-based polymer composites

Cellulose-polymer composites have potential applications in aerospace and transportation areas where lightweight materials with high mechanical properties are needed. In addition, these economical and biodegradable composites have been shown to be useful as polymer electrolytes, packaging structures, optoelectronic devices, and medical implants such as wound dressing and bone scaffolds. In spite of the above mentioned advantages and potential applications, due to the difficulties associated with synthesis and processing techniques, application of cellulose crystals (micro and nano sized) for preparation of new composite systems is limited. Cellulose is hydrophilic and polar as opposed to most of common thermoplastics, which are non-polar. This results in complications in addition of cellulose crystals to polymer matrices, and as a result in achieving sufficient dispersion levels, which directly affects the mechanical properties of the composites. As in other composite materials, the properties of cellulose-polymer composites depend on the volume fraction and the properties of individual phases (the reinforcement and the polymer matrix), the dispersion quality of the reinforcement through the matrix and the interaction between CNCs themselves and CNC and the matrix (interphase). In order to develop economical cellulose-polymer composites with superior qualities, the properties of individual cellulose crystals, as well as the effect of dispersion of reinforcements and the interphase on the properties of the final composites should be understood. In this research, the mechanical properties of CNC polymer composites were characterized at the macro and nano scales. A direct correlation was made between: Dispersion quality and macro-mechanical properties Nanomechanical properties at the surface and tensile properties CNC diameter and interphase thickness Lastly, individual CNCs from different sources were characterized and for the first time size-scale effect on their nanomechanical properties were reported. Then the effect of CNC surface modification on the mechanical properties was studied and correlated to the crystalline structure of these materials.

Polarity correspondence in comparative number magnitude judgments

When asked which of two digits is greater, participants respond more quickly if physical size corresponds to number magnitude, such as in 3 7, than when the two attributes contradict each other, such as in 3 7. This size congruence effect in comparative number judgments is a well-documented phenomenon. We extended existing findings by showing that this effect does not depend on physical size of the number alone but can be observed with number symmetry. In addition, we observed that symmetric numbers are judged as being smaller than asymmetric numbers, which renders an interpretation of the number symmetry congruence effect in terms of physical size implausible. We refer to the polarity correspondence principle (Proctor & Cho, 2006) to explain the present findings.

Comparative efficacy of seven psychotherapeutic interventions for patients with depression: a network meta-analysis

BACKGROUND Previous meta-analyses comparing the efficacy of psychotherapeutic interventions for depression were clouded by a limited number of within-study treatment comparisons. This study used network meta-analysis, a novel methodological approach that integrates direct and indirect evidence from randomised controlled studies, to re-examine the comparative efficacy of seven psychotherapeutic interventions for adult depression. METHODS AND FINDINGS We conducted systematic literature searches in PubMed, PsycINFO, and Embase up to November 2012, and identified additional studies through earlier meta-analyses and the references of included studies. We identified 198 studies, including 15,118 adult patients with depression, and coded moderator variables. Each of the seven psychotherapeutic interventions was superior to a waitlist control condition with moderate to large effects (range d = -0.62 to d = -0.92). Relative effects of different psychotherapeutic interventions on depressive symptoms were absent to small (range d = 0.01 to d = -0.30). Interpersonal therapy was significantly more effective than supportive therapy (d = -0.30, 95% credibility interval [CrI] [-0.54 to -0.05]). Moderator analysis showed that patient characteristics had no influence on treatment effects, but identified aspects of study quality and sample size as effect modifiers. Smaller effects were found in studies of at least moderate (Δd = 0.29 [-0.01 to 0.58]; p = 0.063) and large size (Δd = 0.33 [0.08 to 0.61]; p = 0.012) and those that had adequate outcome assessment (Δd = 0.38 [-0.06 to 0.87]; p = 0.100). Stepwise restriction of analyses by sample size showed robust effects for cognitive-behavioural therapy, interpersonal therapy, and problem-solving therapy (all d>0.46) compared to waitlist. Empirical evidence from large studies was unavailable or limited for other psychotherapeutic interventions. CONCLUSIONS Overall our results are consistent with the notion that different psychotherapeutic interventions for depression have comparable benefits. However, the robustness of the evidence varies considerably between different psychotherapeutic treatments.

Fragments in philosophy and science,

Philosophy: its relation to life and education.--The idealism of Spinoza.--Recent discussion in materialism.--Professor Watson on reality and time.--The cosmic and the moral.--Psychology past and present.--The postulates of physiological psychology.--The origin of volition in childhood.--Imitation: a chapter in the natural history of consciousness.--The origin of emotional expression.--The perception of external reality.--Feeling, belief, and judgment.--Memory for square size.--The effect of size-contrast upon judgments of position in the retinal field.--An optical illusion.--New questions in mental chronometry.--Types of reaction.--The "type-theory" of reaction.--The psychology of religion.--Shorter philosophical papers.--Shorter literary papers.

Mechanisms influencing levitation and the scaling laws in nanopores: Oscillator model theory

We provide here a detailed theoretical explanation of the floating molecule or levitation effect, for molecules diffusing through nanopores, using the oscillator model theory (Phys. Rev. Lett. 2003, 91, 126102) recently developed in this laboratory. It is shown that on reduction of pore size the effect occurs due to decrease in frequency of wall collision of diffusing particles at a critical pore size. This effect is, however, absent at high temperatures where the ratio of kinetic energy to the solid-fluid interaction strength is sufficiently large. It is shown that the transport diffusivities scale with this ratio. Scaling of transport diffusivities with respect to mass is also observed, even in the presence of interactions.

Three essays on trade and investment

From H. G. Johnson's work (Review of Economic Studies, 1953–54) on tariff retaliation, the questions of whether a country can win a “tariff war” and how or even the broader question of what will affect a country's strategic position in setting bilateral tariff have been tackled in various situations. Although it is widely accepted that a country will have strategic advantages in winning the tariff war if its relative monopoly power is sufficiently large, it is unclear what are the forces behind such power formation. The goal of this research is to provide a unified framework and discuss various forces such as relative country size, absolute advantages and relative advantages simultaneously. In a two-country continuum-of-commodity neoclassical trade model, it is shown that sufficiently large relative country size is a sufficient condition for a country to choose a non-cooperative tariff Nash equilibrium over free trade. It is also shown that technology disparities such as absolute advantage, rate of technology disparity and the distribution of the technology disparity all contribute to a country's strategic position and interact with country size. ^ Leverage effect is usually used to explain the phenomenon of asymmetric volatility in equity returns. However, leverage itself can only account for parts of the asymmetry. In this research, it is shown that stock return volatility is related to firms’ financial status. Financially constrained firms tend to be more sensitive to the return changes. Financial constraint factor explains why some firms tend to be more volatile than others. I found that the financial constraint factor explains the stock return volatility independent of other factors such as firm size, industry affiliation and leverage. Firms’ industry affiliations are shown to be very weak in differentiating volatility. Firm size is proven to be a good factor in distinguishing the different levels of volatility and volatility-return sensitivity. Leverage hypothesis is also partly corroborated and the situation where leverage effect is not applicable is discussed. Finally, I examined the macroeconomic policy's effects on overall market volatility. ^

Land, Power and Technology : Essays on Political Economy and Historical Development

Land Ownership and Development: Evidence from Postwar Japan This paper analyzes the effect of land ownership on technology adoption and structural transformation. A large-scale land reform in postwar Japan enforced a large number of tenant farmers who were cultivating land to become owners of this land. I find that the municipalities which had many owner farmers after the land reform tended to experience a quick entry of new agricultural machines which became available after the reform. The adoption of the machines reduced the dependence on family labor, and led to a reallocation of labor from agriculture to industries and service sectors in urban centers when these sectors were growing. I also analyze the aggregate impact of labor reallocation on economic growth by using a simple growth model and micro data. I find that it increased GDP by about 12 percent of the GDP in 1974 during 1955-74. I also find a large and positive effect on agricultural productivity. Loyalty and Treason: Theory and Evidence from Japan's Land Reform A historically large-scale land reform in Japan after World War II enforced by the occupation forces redistributed a large area of farmlands to tenant farmers. The reform demolished hierarchical structures by weakening landlords' power in villages and towns. This paper investigates how the change in the social and economic structure of small communities affects electoral outcomes in the presence of clientelism. I find that there was a considerable decrease in the vote share of conservative parties in highly affected areas after the reform. I find the supporting evidence that the effect was driven by the fact that the tenant farmers who had obtained land exited from the long-term tenancy contract and became independent landowners. The effect was relatively persistent. Finally, I also find the surprising result that there was a decrease, rather than an increase, in turnout in these areas after the reform.  Geography and State Fragmentation We examine how geography affects the location of borders between sovereign states in Europe and surrounding areas from 1500 until today at the grid-cell level. This is motivated by an observation that the richest places in this region also have the highest historical border presence, suggesting a hitherto unexplored link between geography and modern development, working through state fragmentation. The raw correlations show that borders tend to be located on mountains, by rivers, closer to coasts, and in areas suitable for rainfed, but not irrigated, agriculture. Many of these patterns also hold with rigorous spatial controls. For example, cells with more rivers and more rugged terrain than their neighboring cells have higher border densities. However, the fragmenting effects of suitability for rainfed agriculture are reversed with such neighbor controls. Moreover, we find that borders are less likely to survive over time when they separate large states from small, but this size-difference effect is mitigated by, e.g., rugged terrain.