Solvent‐Induced Morphology in Polymer‐Based Systems for Organic Photovoltaics

Studies on the influence of four different solvents on the morphology and photovoltaic performance of bulk‐heterojunction films made of poly(3‐hexylthiophene) (P3HT) and [6,6]‐phenyl‐C₆₁ butyric acid methyl ester (PCBM) via spin‐coating for photovoltaic applications are reported. Solvent‐dependent PCBM cluster formation and P3HT crystallization during thermal annealing are investigated with optical microscopy and grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) and are found to be insufficient to explain the differences in device performance. A combination of atomic force microscopy (AFM), X‐ray reflectivity (XRR), and grazing‐incidence small‐angle X‐ray scattering (GISAXS) investigations results in detailed knowledge of the inner film morphology of P3HT:PCBM films. Vertical and lateral phase separation occurs during spin‐coating and annealing, depending on the solvent used. The findings are summarized in schematics and compared with the IV characteristics. The main influence on the photovoltaic performance arises from the vertical material composition and the existence of lateral phase separation fitting to the exciton diffusion length. Absorption and photoluminescence measurements complement the structural analysis.     

The media use of American youngsters in the age of narcissism : Surviving in a 24/7 media shock and awe – distracted by everything

Digital life in the age of nonstop connection is not easy, especially not for the so-called Millennials, youngsters born after 1980. Research findings, such as the recently released comprehensive reports by the Kaiser Family Foundation and Pew Foundation, highlight that media are among the most powerful forces in young people’s lives today. Eight- to twenty-somethings in the US spend more than 50 h in front of a screen each week. That is more than a regular working week. The TV shows they watch, video games they play, songs they listen to, books they read, text messages they send and websites they visit are an enormous part of their lives, offering a constant stream of messages about families, peers, relationships, gender roles, sex, violence, food, values, clothes, and so on.     

Structural elucidation of direct analysis in real time ionized nerve agent simulants with infrared multiple photon dissociation spectroscopy

Infrared multiple photon dissociation (IRMPD) was used to generate vibrational spectra of ions produced with a direct analysis in real time (DART) ionization source coupled to a 4.7 T Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The location of protonation on the nerve agent simulants diisopropyl methylphosphonate (DIMP) and dimethyl methylphosphonate (DMMP) was studied while solutions of the compounds were introduced for extended periods of time with a syringe pump. Theoretical vibrational spectra were generated with density functional theory calculations. Visual comparison of experimental mid-IR IRMPD spectra and theoretical spectra could not establish definitively if a single structure or a mixture of conformations was present for the protonated parent of each compound. However, theoretical calculations, near-ir IRMPD spectra, and frequency-to-frequency and statistical comparisons indicated that the protonation site for both DIMP and DMMP was predominantly, if not exclusively, the phosphonyl oxygen instead of one of the oxygen atoms with only single bonds.     

Method of applying internal standard to dried matrix spot samples for use in quantitative bioanalysis

A novel technique is presented that addresses the issue of how to apply internal standard (IS) to dried matrix spot (DMS) samples that allows the IS to integrate with the sample prior to extraction. The TouchSpray, a piezo electric spray system, from The Technology Partnership (TTP), was used to apply methanol containing IS to dried blood spot (DBS) samples. It is demonstrated that this method of IS application has the potential to work in practice, for use in quantitative determination of circulating exposures of pharmaceuticals in toxicokinetic and pharmacokinetic studies. Three different methods of IS application were compared: addition of IS to control blood prior to DBS sample preparation (control 1), incorporation into extraction solvent (control 2), and the novel use of TouchSpray technology (test). It is demonstrated that there was no significant difference in accuracy and precision data using these three techniques obtained using both manual extraction and direct elution.     

Temperature effects on the optical path length of infrared liquid transmission cells

Infrared (IR) spectroscopy is widely used for studies of temperature-dependent properties of liquids and solutions, such as thermal denaturation of proteins and other molecules of biological interest. The variation of the spectroscopic signals with temperature can be affected by the changes in the optical path length due to the thermal expansion of the components of the sample cell. In this report we investigate the temperature dependence of the optical path length for a liquid IR sample cell of a design typical for aqueous solution experiments. The path lengths were measured from the interference fringes, both in dry cells and with cells partially filled with water. We found that the optical path length variations are significant, on the order of several percent within the temperature range used (0-87 °C). Several commercially available spacers (Teflon, mylar, and lead) and gaskets (Teflon, lead, silicone rubber, Viton, and neoprene) were tested to find materials with either the smallest or most reproducible effect. Teflon, due to its phase transition (known as the "knee point") near room temperature, leads to abrupt changes in path length when used as either spacer or gasket component. On the other hand, Teflon is preferred for its inertness, while several of the other tested materials, most notably lead, are not practically usable due to adhesion to the cell windows upon heating and contact with the aqueous sample. The combination that yielded the most reproducible results, with minimal complications due to adhesion, was Teflon spacer with neoprene gaskets. The implications of the optical path length changes for the temperature-dependent IR experiments and their possible corrections are discussed.     

Synthesis of submicron-sized spherical Y2O3 powder for transparent YAG ceramics

Spherical monodispersed, submicron-sized Y₂O₃ powder was prepared via a homogeneous precipitation method using nitrate and urea as raw materials. The structure, phase evolution and morphology of Y₂O₃ precursor and the calcined powder were studied by FTIR, TG/DTA, XRD and SEM methods. The sphere size of the precursor was about 250 nm and that of Y₂O₃ powder calcined at 800 °C for 2 h was about 200-210 nm. With the spherical Y₂O₃ powder and a commercial Al₂O₃ ultrafine powder, high transparent YAG ceramics was fabricated by vacuum sintering at 1780 °C for 6 h through a solid-state reaction method. The in-line transmittances of the as-fabricated YAG ceramics at the wavelength of 1064 nm and 400 nm were 82.8% and 79.5%, respectively, which were much higher than that of the YAG ceramics with a commercial Y₂O₃ powder and a commercial Al₂O₃ ultrafine powder directly. The superior properties are attributed to the good morphology, dispersibility and uniform grain size of the as-prepared spherical Y₂O₃ powder, which matches that of the commercial Al₂O₃ powder.     

Modeling the decay of ammonium oxidizing bacteria

A bench-scale sequencing batch reactor was used to study factors affecting the endogenous decay of the ammonium oxidizing biomass (AOB) in different operating conditions. AOB decay was very sensitive to oxygen concentration, and increased up to 0.4 d⁻¹ for oxygen concentration of 7 mg O₂ L⁻¹. The decay in anaerobic conditions was shown to be very low (0.03 d⁻¹) when compared to literature data.The effect of nitrite and nitrate on AOB decay was also studied. The correlation was quite weak suggesting that both nitrate and nitrite absence had little impact on decay which is contrary to what is typically assumed in some of the existing process models. A simple expression for the decay of AOB was proposed, calibrated and validated using the results of batch kinetic tests and of the continuous sequencing batch reactor monitoring.     

Identification and chemical characterization of specific organic indicators in the effluents from chemical production sites

The structural diversity of the wastewater composition was described by the use of detailed non-target screening analyses of industrial effluents from chemical production sites. Determination of the indicative organic compounds acting as potential molecular indicators for industrial emissions from chemical production industries has been possible due to (i) detailed characterisation of industrial contaminants and identification of compounds with high source specificity, (ii) quantitative determination of the organic constituents in the industrial effluents and (iii) the review of their industrial applications. The determination of potential site-specific markers and industrial molecular indicators corresponding to certain production processes (production of starting materials for manufacturing paper and printing inks, powder coatings as well as epichlorohydrin production) was performed in this work.The results of this study allowed significant contributions to the chemical characterisation of industrial contaminants and isolation of indicators that can act as representatives of industrial effluents in the aquatic environment.     

Life style and home environment are associated with racial disparities of asthma and allergy in Northeast Texas children

A high prevalence and racial disparities in asthma and allergy have been observed in American children. This study aimed to identify risk factors for asthma and allergy among children, and their contribution to racial disparities in allergy prevalence. A population-based cross-sectional study was carried out among children aged 1-8 years in Northeast Texas 2008-2009. The health conditions, life style and home environment of 3766 children were surveyed by parental questionnaires through e.g. daycares, elementary school, and medical clinics. Among participants who indicated their ethnicity, 255 were Mexican-Americans, 178 Afro-Americans and 969 Caucasians. Afro-American children had a significantly higher prevalence of asthma and eczema. Caucasian had the highest prevalence of rhinitis. Compared to Mexican-American children, Afro-American and Caucasian children were breast fed shorter time, more often went to day care center, had pets and environmental tobacco smoke exposure at home more often. For all children, being at a day care center, being exposed to dampness and environmental tobacco smoke at home were strong risk factors for asthma and allergy. Central air conditioning system was associated with an increased prevalence of wheeze among Mexican-American children, while pets were associated with an increased risk of rhinitis among Afro-American and Caucasian children. Caucasian children were generally not healthier than relatively poor Mexican-American children. Differences in the prevalence of asthma and allergy between races cannot be explained by socioeconomic status only. Life style and home environmental exposures are important risk factors for asthma and allergy in Northeast Texas children.     

上海玻璃博物馆

G+玻璃主题园概念的诞生上海轻工玻璃有限公司计划在上海玻璃工厂的原址上打造一个全新的玻璃博物馆。老园区内分布着30栋不同年代、规模各异的建筑。logon(罗昂)为园区制定了20年的发展策略,并重新命名为G+玻璃主题园区(玻璃、艺术、研究和技术园区)。