The detection of nitro pesticides in mainstream and sidestream cigarette smoke using electron monochromator-mass spectrometry

Over the past decade, electron monochromator-mass spectrometry (EM-MS) has been shown to be a selective and sensitive technique for the analysis of a wide variety of electrophilic compounds in complex matrixes. Here, for the first time, three different dinitroaniline pesticides, flumetralin, pendimethalin, and trifluralin, have been shown to be present in both mainstream and sidestream tobacco smoke using an EM-MS system. A number of cigarettes were tested that included three pure-tobacco-type cigarettes, an experimental reference cigarette, and 11 commercial cigarettes. Due to the complexity of the smoke particulate matter, the pesticides were identified only after each sample was subjected to a multistep cleanup process that included phenyl solid-phase extraction; an acid wash; aminopropyl solid-phase extraction; and finally, normal phase LC fractionation. All cigarette types tested showed the presence of the three pesticides in the tobacco smoke, with flumetralin ranging from trace levels up to 37 (+/- 9) ng/cig, pendimethalin ranging from trace levels up to 10.4 (+/- 0.6) ng/cig, and trifluralin ranging from trace levels up to 47 (+/- 17) ng/cig. Acute toxicity information is presented for the three pesticides.     

Ti-Al-Fe低成本钛合金TIG焊焊接组织和性能研究

研究了Ti-Al-Fe低成本钛合金钨极氩弧焊焊接接头的内部质量、组织和力学性能,并与TC4钛合金进行了比较。结果表明,Ti-Al-Fe低成本钛合金焊缝表面质量良好,焊缝内部融合良好,无焊接缺陷,可焊性好; 2种合金的焊缝区宏观组织均由粗大的柱状晶和少量等轴晶组成,Ti-Al-Fe合金柱状晶组织较细,晶内由针状次生α相和少量的长条状初生α相组成; 2种合金热影响区均为粗大的等轴晶,晶内由大量初生α相和少量针状次生α相及残余β相组成; Ti-Al-Fe低成本钛合金焊缝抗拉强度达到1 204 MPa,比TC4钛合金高111 MPa。     

Relationships between vegetation indices,fractional cover retrievals and the structure and composition of Brazilian Cerrado natural vegetation

This study explores the use of the relationship between the normalized difference vegetation index (NDVI) and the shortwave infrared ratio (SWIR32) vegetation indices (VI) to retrieve fractional cover over the structurally complex natural vegetation of the Cerrado of Brazil using a time series of imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS). Data from the EO-1 Hyperion sensor with 30 m pixel resolution is used to sample geographic and seasonal variation in NDVI, SWIR32, and the hyperspectral cellulose absorption index (CAI), and to derive end-member values for photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV), and bare soil (BS) from a suite of protected and/or natural vegetation sites across the Cerrado. The end-members derived from relatively pure 30 m pixels are then applied to a 500 m pixel resolution MODIS time series using linear spectral unmixing to retrieve PV, NPV, and BS fractional cover (F_PV, F_NPV, and F_BS). The two-way interaction response of MODIS-equivalent NDVI and SWIR32 was examined for regions of interest (ROI) collected within protected areas and nearby converted lands. The MODIS NDVI, SWIR32 and retrieved F_PV, F_NPV, and F_BS are then compared to detailed cover and structural composition data from field sites, and the influence of the structural and compositional variation on the VIs and cover fractions is explored. The hyperion ROI analysis indicated that the two-way NDVI–SWIR32 response behaved as an effective surrogate for the two-way NDVI–CAI response for the campo limpo/grazed pasture to cerrado sensu stricto woody gradient. The SWIR32 sensitivity to the NPV and BS variation increased as the dry season progressed, but Cerrado savannah exhibited limited dynamic range in the NDVI–CAI and NDVI–SWIR32 two-way responses compared to the entire landscape, which also comprises fallow croplands and forests. Validation analysis of MODIS retrievals with Quickbird-2 images produced an RMSE value of 0.13 for F_PV. However, the RMSE values of 0.16 and 0.18 for F_BS and F_NPV, respectively, were large relative to the seasonal and inter-annual variation. Analysis of site composition and structural data in relation to the MODIS-derived NDVI, SWIR32 and F_PV, F_NPV, and F_BS, indicated that the VI signal and derived cover fractions were influenced by a complex mix of structure and cover but included a strong year-to-year seasonal effect. Therefore, although the MODIS NDVI–SWIR32 response could be used to retrieve cover fractions across all Cerrado land covers including bare cropland, pastures and forests, sensitivity may be limited within the natural Cerrado due to sub-pixel heterogeneity and limited BS and NPV sensitivity.     

Planning transport infrastructure: examining the politics of transport planning in Melbourne,Sydney and Perth

Abstract

Australian cities have observed a “consensus turn” expressed as broad public support of greater accessibility and public transport provision as revealed in metropolitan strategic plans. In contrast large-scale road projects proposed to traverse the inner-city of three major Australian cities reveals an ongoing and deep-seated attachment by some to car-based travel in Australian urban transport planning. Comparative case studies of these three road projects in Melbourne, Sydney and Perth explores the impact that an antagonistic relationship between the state and community has on the culture of transport planning. Through observational insights, policy and media analysis and interviews with community groups, we show that this antagonistic planning culture arises when there is a fracture between metropolitan strategic plan-making and project planning, and when clear channels of communication and deliberation are undermined.     

Ultrasonography in dentistry

This paper reviews diagnostic applications of ultrasound to dentistry, or dental ultrasonography, beginning with pioneering work of the 1960s up through present lines of research. Clinical, in vivo applications that are of direct interest to dental practice are reviewed here, including measurements of enamel thickness and periodontal pocket depth. In vitro research that involves destructive tooth preparation or procedures, such as sound speed measurements or scanning acoustic microscopy, also are included. Although dental ultrasonography has been studied for over 40 years, most methods are not quite ready for routine clinical use, and there remains much opportunity for diagnostic ultrasonography to significantly impact the practice of dentistry.     

Assessing creativity with divergent thinking tasks: Exploring the reliability and validity of new subjective scoring methods.

Divergent thinking is central to the study of individual differences in creativity, but the traditional scoring systems (assigning points for infrequent responses and summing the points) face well-known problems. After critically reviewing past scoring methods, this article describes a new approach to assessing divergent thinking and appraises its reliability and validity. In our new Top 2 scoring method, participants complete a divergent thinking task and then circle the 2 responses that they think are their most creative responses. Raters then evaluate the responses on a 5-point scale. Regarding reliability, a generalizability analysis showed that subjective ratings of unusual-uses tasks and instances tasks yield dependable scores with only 2 or 3 raters. Regarding validity, a latent-variable study (n=226) predicted divergent thinking from the Big Five factors and their higher-order traits (Plasticity and Stability). Over half of the variance in divergent thinking could be explained by dimensions of personality. The article presents instructions for measuring divergent thinking with the new method. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of nitro-polycyclic aromatic hydrocarbons in conventional diesel and Fischer-Tropsch diesel fuel emissions using electron monochromator-mass spectrometry

The presence of nitro-polycyclic aromatic hydrocarbons (NPAHs) in diesel fuel emissions has been studied for a number of years predominantly because of their contribution to the overall health and environmental risks associated with these emissions. Electron monochromator-mass spectrometry (EM-MS) is a highly selective and sensitive method for detection of NPAHs in complex matrixes, such as diesel emissions. Here, EM-MS was used to compare the levels of NPAHs in fuel emissions from conventional (petroleum) diesel, ultra-low sulfur/low-aromatic content diesel, Fischer-Tropsch synthetic diesel, and conventional diesel/synthetic diesel blend. The largest quantities of NPAHs were detected in the conventional diesel fuel emissions, while the ultra-low sulfur diesel and synthetic diesel fuel demonstrated a more than 50% reduction of NPAH quantities when compared to the conventional diesel fuel emissions. The emissions from the blend of conventional diesel with 30% synthetic diesel fuel also demonstrated a more than 30% reduction of the NPAH content when compared to the conventional diesel fuel emissions. In addition, a correlation was made between the aromatic content of the different fuel types and NPAH quantities and between the nitrogen oxides emissions from the different fuel types and NPAH quantities. The EM-MS system demonstrated high selectivity and sensitivity for detection of the NPAHs in the emissions with minimal sample cleanup required.     

Task conflict and team creativity: A question of how much and when.

Bridging the task conflict, team creativity, and project team development literatures, we present a contingency model in which the relationship between task conflict and team creativity depends on the level of conflict and when it occurs in the life cycle of a project team. In a study of 71 information technology project teams in the greater China region, we found that task conflict had a curvilinear effect on team creativity, such that creativity was highest at moderate levels of task conflict. Additionally, we found this relationship to be moderated by team phase, such that the curvilinear effect was strongest at an early phase. In contrast, at later phases of the team life cycle, task conflict was found to be unrelated to team creativity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis and evaluation of tetra(2,7-octadienyl) titanate as a reactive diluent for air-drying alkyd paints

Environmental regulations are forcing the reformulation of many decorative and protective coatings systems. In particular, air-drying solventborne alkyd paints need to meet increasingly stringent emission limits and often must be reformulated with suitable exempt solvents or reactive diluents to achieve volatile organic compound (VOC) reduction. In the research summarized in this article, a new reactive diluent, tetra(2,7-octadienyl) titanate, was synthesized and evaluated in alkyd formulations for VOC reduction and property enhancement. A soy-based long-oil alkyd resin; a soy-based high-solids, long-oil alkyd resin; and a linseed-based, high-solids long-oil alkyd resin were evaluated in combination with the new reactive diluent at weight percentages ranging from 10% to 50%. Characterization included measuring viscosity, film dry times, and film performance of the reactive diluent formulations in comparison to neat alkyd resins used as control. The tetra(2,7-octadienyl) titanate formulations consistently exhibited reduced viscosities and dry times as a function of concentration. The resulting films were harder and more thoroughly cured than the control systems.