REST2: High-performance solar radiation model for cloudless-sky irradiance, illuminance, and photosynthetically active radiation – Validation with a benchmark dataset

REST2, a high-performance model to predict cloudless-sky broadband irradiance, illuminance and photosynthetically active radiation (PAR) from atmospheric data, is presented. Its derivation uses the same two-band scheme as in the previous CPCR2 model, but with numerous improvements. Great attention is devoted to precisely account for the effect of aerosols, in particular.Detailed research-class measurements from Billings, OK are used to assess the performance of the model for the prediction of direct, diffuse and global broadband irradiance. These measurements were made in May 2003 during a sophisticated radiative closure experiment, which involved the best radiometric instrumentation currently available and many ancillary instruments. As a whole, these exceptional measurements constitute the only known modern benchmark dataset made specifically to test the intrinsic performance of radiation models. Using this dataset as reference, it is shown that REST2 performs better than CPCR2 for irradiance, illuminance or PAR predictions. The availability of the turbidity data required by REST2 or other similar models is also discussed, as well as the effect that turbidity has on each component of broadband irradiance, PAR irradiance and illuminance, and on the diffuse/global PAR ratio.     

State governance evolution in resource-rich transition economies: An application to Russia and Kazakhstan

Following a decade of transition in the Former Soviet Union (FSU), governance of the oil and gas sectors has evolved to economic nationalism. In the newly independent states this has manifested itself through greater (direct) state ownership or participation in oil and gas production, at the expense of both domestic (in the case of Russia) and international oil companies, as well as legislative developments that increase the flow of oil and gas value to the state. Here we analyse some of the dynamics giving rise to economic nationalism within a model of a state capacity and the ability to implement policy and extract value. Our analysis is based on the institutional and economic functioning of the oil and gas sector. We analyse a vector of institutions and examine Production Sharing Agreements and National Oil Companies.     

Applicability of X-ray reflectometry to studies of polymer solar cell degradation

Although degradation of polymer solar cells is widely acknowledged, the cause, physical or chemical, has not been identified. The purpose of this work is to determine the applicability of X-ray reflectometry for in situ observation of physical degradation mechanisms. We find that the rough interfaces of the polymer solar cell constituent layers seriously obstruct the sensitivity of the technique, rendering it impossible to elucidate changes in the layer/interface structure at the sub-nanometer level.     

Does precontemplation represent a homogeneous stage category? A latent class analysis on German smokers.

The authors examined the subtype structure of smokers classified in the precontemplation stage of change within the transtheoretical model. From a general practice-based sample of 1,499 daily smoking patients from Germany (participation rate 80%), they used a subgroup of 929 smokers who were classified in the precontemplation stage and applied latent class analysis, using the pros and cons of nonsmoking and smoking cessation self-efficacy as the defining variables. Cross-sectional validation of the emerging classes was based on smoking behavior and processes of change variables. For longitudinal validation, generalized estimation equation analyses were used on motivational and abstinence criteria from 6-, 12-, 18-, and 24-month follow-ups. A 4-class model best represented the data. Three subtypes (labeled progressive, immotive, and disengaged pessimistic) were similar to clusters identified in U.S. studies. The 4th (disengaged optimistic), by contrast, was reminiscent of a type that had previously only emerged in a Dutch study. Cross-sectional and longitudinal validation results confirmed the distinctiveness and predictive power of the classes. The findings highlight the importance of tailoring interventions for smoking behavior change to the needs of different subgroups of precontemplating smokers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Not yet human: Implicit knowledge, historical dehumanization, and contemporary consequences.

Historical representations explicitly depicting Blacks as apelike have largely disappeared in the United States, yet a mental association between Blacks and apes remains. Here, the authors demonstrate that U.S. citizens implicitly associate Blacks and apes. In a series of laboratory studies, the authors reveal how this association influences study participants' basic cognitive processes and significantly alters their judgments in criminal justice contexts. Specifically, this Black-ape association alters visual perception and attention, and it increases endorsement of violence against Black suspects. In an archival study of actual criminal cases, the authors show that news articles written about Blacks who are convicted of capital crimes are more likely to contain ape-relevant language than news articles written about White convicts. Moreover, those who are implicitly portrayed as more apelike in these articles are more likely to be executed by the state than those who are not. The authors argue that examining the subtle persistence of specific historical representations such as these may not only enhance contemporary research on dehumanization, stereotyping, and implicit processes but also highlight common forms of discrimination that previously have gone unrecognized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Robust design considering highly nonlinear structural behavior

The optimization of structures subject to highly nonlinear behavior, particularly crash structures, requires observance of all design-significant scatterings. This paper presents a time-saving method to generate structures satisfying robust design demands. A vital aspect of robust design from the aircraft industries’ point of view is the consideration of fail-safe approaches accounting for possible structural failure from previous loading or manufacturing inaccuracies. Additional structural elements are utilized to prevent (after failure occurred) the structure from deforming out of bounds. This paper presents an approach on how to include this in the robust design process.     

Surface enrichment of biomimetic apatites with biologically-active ions Mg2+ and Sr2+: A preamble to the activation of bone repair materials

The surface activation of calcium phosphate-based biomaterials for bone repair is an emerging route for improving bone regeneration processes. One way for such activation is through the exchange of surface calcium ions with biologically-active cations such as Mg²⁺ or Sr²⁺. In this work, the interactions of non-carbonated and carbonated nanocrystalline apatites with Mg²⁺ and Sr²⁺ were investigated by means of ion exchange experiments in solution. Langmuir-type isotherms were determined. For both Sr and Mg, a greater uptake was observed on the carbonated sample, and on both types of apatites the maximum strontium uptake was greater than that of magnesium. Inverse exchanges showed that the proportion of reversibly fixed ions after surface exchange was close to 85% for Mg and 75–80% for Sr. The results are related to the presence of a surface hydrated layer on the nanocrystals and possible exchange mechanisms are discussed. Our results favor the hypothesis of hetero-ionic surface exchanges (Mg²⁺↔Ca²⁺, Sr²⁺↔Ca²⁺) within the hydrated layer, and some analogy with octacalcium phosphate (OCP) is considered. This work should prove helpful for the control and understanding of the activation of synthetic apatite-based powders or scaffolds with bioactive elements, as well as for the global understanding of biomineralization processes.