Development and evaluation of mould for double curved concrete elements

The present paper describes a concept for a reconfigurable mould surface which is designed to fit the needs of contemporary architecture. The core of the concept presented is a dynamic surface manipulated into a given shape using a digital signal created directly from the CAD drawing of the design. This happen fast, automatic and without production of waste, and the manipulated surface is fair and robust, eliminating the need for additional, manual treatment. Limitations to the possibilities of the flexible form are limited curvature and limited level of detail, making it especially suited for larger, double curved surfaces like facades or walls, where the curvature of each element is relatively small in comparison to the overall shape

Replicability of nitrogen recommendations from ramped calibration strips in winter wheat

Ramped calibration strips have been suggested as a way for grain producers to determine nitrogen needs more accurately. The strips use incrementally increasing levels of nitrogen and enable producers to conduct an experiment in each field to determine nitrogen needs. This study determines whether predictions from the program Ramp Analyzer 1.2 are replicable in Oklahoma hard red winter wheat (Triticum aestivum). Predictions are derived from 36 individual strips from on-farm experiments—two pairs of adjacent strips at each of nine winter wheat fields in Canadian County, OK. The two pairs of strips within each field were between 120 and 155 m apart. Each strip was analyzed three times during the 2006–2007 growing season. Nitrogen recommendations from Ramp Analyzer 1.2 are not correlated even for strips that were placed side by side, and recommendations from strips in the same field show no more homogeneity than randomly selected strips throughout the county. The results indicate that ramped calibration strips are unlikely to produce accurate nitrogen requirement predictions at any spatial scale, whether at the county level or for subsections of a single field. In contrast, a procedure that uses only measures from the plot with no nitrogen and the plot with the highest level of nitrogen applied does show replicability. Thus, improvements in the ramped calibration strip technology are needed if it is to become viable.Fertilizer; Nitrogen; Precision agriculture; Ramped calibration strip; Winter wheat

Population Suppression of Western Corn Rootworm by Adult Control with ULV Malathion

ULV malathion (9.7 oz AI/acre) was applied by air to a 16 square-mile area during August of 1968, 1969, and 1970. Adult Diabrotica virgifera LeConte populations were reduced the following season by 39, 54, and 72%. No economic infestations occurred in the treated area the year following any application. Postspray migration of beetles was very limited, but adult migration during the peak emergence period the following season contributed to repopulation of the treated area. Migration and fecundity appear to be density-dependent factors which favor increases under low populations. Area suppression does not appear economically feasible, but adult control in individual fields may be an acceptable alternative to soil insecticides applied for larval control. A model was developed for timing treatments against adults; treatments between Aug. 1–15 should result in adequate population suppression to prevent damage the following season. Mid-August population levels of 1.0 beetle/ plant were an acceptable economic threshold for determining the need for control measures

Electrical Manipulation of Telecom Color Centers in Silicon

Silicon color centers have recently emerged as promising candidates for commercial quantum technology, yet their interaction with electric fields has yet to be investigated. In this paper, we demonstrate electrical manipulation of telecom silicon color centers by fabricating lateral electrical diodes with an integrated G center ensemble in a commercial silicon on insulator wafer. The ensemble optical response is characterized under application of a reverse-biased DC electric field, observing both 100% modulation of fluorescence signal, and wavelength redshift of approximately 1.4 GHz/V above a threshold voltage. Finally, we use G center fluorescence to directly image the electric field distribution within the devices, obtaining insight into the spatial and voltage-dependent variation of the junction depletion region and the associated mediating effects on the ensemble. Strong correlation between emitter-field coupling and generated photocurrent is observed. Our demonstration enables electrical control and stabilization of semiconductor quantum emitters

Operando XAS/XRD and Raman Spectroscopic Study of Structural Changes of the Iron Molybdate Catalyst during Selective Oxidation of Methanol

The structural changes of an iron molybdate/molybdenum oxide (Mo/Fe=2.0) catalyst for the selective oxidation of methanol to formaldehyde were studied using combined operando X‐ray absorption spectroscopy (XAS) and X‐ray diffraction (XRD) as well as operando Raman spectroscopy. Under operating conditions, the Mo K‐edge XANES spectra showed a transition from a mixture of α‐MoO$_{3}$ and Fe$_{2}$(MoO$_{4}$)$_{3}$ towards only Fe$_{2}$(MoO$_{4}$)$_{3}$. XRD and Raman spectroscopy also showed disappearance of the α‐MoO3 phase with time on stream. The results evidenced that the α‐MoO3 component evaporated completely, while the Fe$_{2}$(MoO$_{4}$)$_{3}$ component remained stable. This was linked to a decrease in catalytic activity. Further studies unraveled that the rate of α‐MoO$_{3}$ evaporation increased with increasing MeOH concentration, decreasing O$_{2}$ concentration and increasing temperature. The simultaneous measurements of catalytic activity and spectroscopy allowed to derive a structure‐activity relationship showing that α‐MoO$_{3}$ evaporation needs to be prevented to optimize MoO$_{3}$‐based catalysts for selective oxidation of methanol

Using Complex, Multi-Sectoral Data in a Needs Assessment to Inform Future Strategies in Childhood Asthma Management

The purpose of this needs assessment was to study the current state of asthma management in high-risk children in Houston, Texas to inform a theory-based approach to improving asthma management. The mixed-method assessment included multi-sectoral survey, quantitative, and geospatial data that address a range of social and community factors in family, community, home, and medical contexts. Houston Emergency Medical Services (EMS) provided ambulance-treated asthma data mapped by geographic area to identify where childhood asthma management was weakest. Texas Children’s Health Plan (TCHP) provided medication compliance rates and counts of children by zip code that TCHP considered high-risk according to claims data. Houston Independent School District (HISD) provided school nurse survey results from schools with high-rates of ambulance-treated asthma attacks regarding local barriers to asthma management. Elementary schools with children at highest risk were identified by overlaying the EMS data, TCHP data, and HISD school zone boundaries. Survey results from the high-rate schools indicate the priority challenges to childhood asthma management, including lack of resources, lack of communication, lack of knowledge of triggers, and inadequate time for quality care from providers. By weaving together EMS, TCHP, and HISD data, the needs assessment informed a socio-ecological view of gaps in high-risk childhood asthma management and control, specifically where and what to target. An assessment approach with multi-sectoral data, geospatial mapping, nurse input, current systems of care, education, and funding helped focus planning on a practical approach to asthma control solutions for high-risk children

SOILS Ammonium and Nitrate Nitrogen in Soil Profiles of Long-Term Winter Wheat Fertilization Experiments

ABSTRACT Accumulation of NH~ -N and NO3 -N in soils has not been thor. oughly evaluated in long-term continuous winter wheat (Triticum aes. tivum L.) production systems. The objectives of this study were to determine long-term response of winter wheat to N fertilization and to evaluate accumulation of NH~ -N and NO3 -N in the soil profile. Four long-term winter wheat soil fertility experiments on thermic Ustoll soils that received annual applications of N for > 18 yr at selected N rates were sampled. At each location, one soil core 4.4 cm in diameter was taken to a depth of 240 cm from plots receiving variable N rates. Cores were separated into 30-cm increments and analyzed for 2 M KCI-extractable NH~ -N and NO~-N. At all locations, NH~ -N levels were not significantly different from the check (no fertilizer N) when rates were applied at or below yield goal requirements (90 or45 kg N ha -~ vs. 0 N). At N rates >90 kg N ha -~, surface (0-15 cm) NH~ -N increased compared with the check, while subsurface NH~ -N did not. Similarly, when N rates were <90 kg N ha -~, no significant differences in either surface or subsurface NO 3 -N were found. At N rates >90 kg N ha -1, NO5 -N accumulated in the subsurface soil profile (>30 cm). Estimates of N rates determined from simultaneous solutions of NO5 -N accumulation minimums and yield maximums generated from quadratic regression were greater than N rates currently recommended to achieve yield goals at all locations. For these long-term continuous winter wheat experiments, no accumulation of NH~ -N and NO5 -N occurred at recommended N rates where near maximum yields were obtained. p AST AND PRESENT use of N fertilizers for winter wheat production has been related to the potential for NOA--N contamination of surface and subsurface water. Although N fertilizers are essential for economic grain production, long-term N accumulation as a result of excessive N rates has not been monitored closely. Work by Liang et al. (1991) found that residual soil NO~--N did not increase in the soil profile (0-60 cm) over a 4-yr period when comparing N rates of 170 and 400 kg ha -1 applied to corn. MacDonald et al. (1989) indicated that following harvest, unfertilized wheat plots had inorganic N contents equal to those where 234 kg N ha -1 had been applied. This work further suggested that almost all of the NO~--N at risk to leaching over the winter period comes from mineralization of organic N and not from unused fertilizer applied in the spring; therefore, even a drastic reduction in N fertilizer use would have little effect on NO~--N leaching. Lamb et al. (1985) reported that the addition of N fertilizer increased the amount of NO~-N accumulated but did not change the accumulation pattern. Tillage system (no-till, stubble mulch, and plow) did not affect the time at which the NOA--N started to accumulate during the fallow period nor the rate of accumulation (Lamb et al., 1985). Sharpley al. (1991) reported no evidence of N accumulation the soil profile (0--180 cm) after 5 yr for either no-till or reduced-till cultural practices with N fertilizer applied to sorghum at recommended rates (0--146 kg ha-1 yr-1), although annual total N in surface runoff . was 0.76 kg N ha -1 for no-till, 0.99 kg N ha -1 for reduced-till, and 7.28 kg N ha -1 for conventional till. Smika (1990) reported that time must be allowed for the equilibration of soil conditions before evaluating NO~--N accumulation, citing research that showed less NO~--N accumulation to 120 cm for reduced-till methods compared with conventional tillage for short-term studies, but more NO~--N accumulation for reducedtill methods in long-term studies. Tracy et al. (1990) noted that tillage method (conventional, no-till) did not affect NO~--N accumulation below 5 cm; differences in NO~--N in the topsoil were attributed to organic matter incorporation over 16 yr of winter wheat farming. Varvel and Peterson (1990) reported that high N application rates (180 kg N ha-1) resulted in greater residual soil NO~--N to 150 cm for continuous corn and grain sorghum systems than for other cropping systems. This same study found that all systems had similar NO~--N accumulation at lower N application rates. Work by Liang et al. (1991) found that under irrigation, 100 kg NOA--N ha -~ was lost from the rooting zone (0-60 cm) during four growing seasons, with the majority coming from the surface 40 cm. The effects of N fertilizer rate (90 and 180 kg ha -x) and nitrification inhibitors on urea lSN leaching and balance on a irrigated sandy loam were summarized by Waiters and Malzer (1990). The higher N application rate resulted in 3.4 times more N leached over a 3-yr period (206 vs. 88 kg ha -1 to 1.2 m depth). Nitrification inhibitors delayed N losses, but did not decrease the total N lost. Westerman and Tucker (1979) noted that the presence of organic residue can lower denitrification by increased immobilization of inorganic or mineralized N. Immobilization was thus considered to be an N conserving process competing with denitrification for nitrate. Nitrate studies in field microplots showed that 17% of applied 15N (120 kg N ha -~ equivalent) was still in the 45-cm soil profile after 1 yr (Kowalenko, 1989). Webster et al. (1986) evaluated the movement (92 and 102 kg NHnNO 3 ha -~) in clay and sandy loam field microplots and found that < 1% of the fertilizer was leached beyond 130 cm in the first winter following application. Response of wheat grain yields to N fertilization has been documented in numerous soil fertility experiments. However, very few of these experiments have included evaluation for more than 3 to 5 yr that also accounted for accumulation of NOA--N and NH~--N within the soil profile. The objectives of this study were to determine the long-term response of 9

The challenges of renewed independence: The Baltic states since 1991

This article offers a comparative assessment of how successfully Estonia, Latvia, and Lithuania have coped with the challenges of renewed independence since 1991, focusing on various aspects of political, economic, and social development. In the post-communist context the Baltic states have clearly outpaced other former Soviet republics and also performed reasonably well in comparison to the countries of Eastern Europe. The convergence of the Baltic experience, which began already in the early 20th century, has continued in the recent past as well, as the three states have adopted a number of similar approaches in domestic politics, the search for security, and economic policy. They also face a number of similar unsolved problems, including considerable political alienation, tensions in relations with Russia, socioeconomic disparity, and demographic challenges. The most important difference in the issues confronting the Baltic states today continues to be the large non-Baltic, mainly Russian presence in Estonia and Latvia, a result of Soviet-era policies. How to effect the meaningful integration of a multiethnic society remains a continuing challenge in these two countries. In contrast, population shifts under Soviet rule never became massive in Lithuania, and ethnic relations are a minor issue there today

Nanotitanium dioxide toxicity in mouse lung is reduced in sanding dust from paint

<p>Abstract</p> <p>Background</p> <p>Little is known of how the toxicity of nanoparticles is affected by the incorporation in complex matrices. We compared the toxic effects of the titanium dioxide nanoparticle UV-Titan L181 (NanoTiO₂), pure or embedded in a paint matrix. We also compared the effects of the same paint with and without NanoTiO₂.</p> <p>Methods</p> <p>Mice received a single intratracheal instillation of 18, 54 and 162 μg of NanoTiO₂or 54, 162 and 486 μg of the sanding dust from paint with and without NanoTiO₂. DNA damage in broncheoalveolar lavage cells and liver, lung inflammation and liver histology were evaluated 1, 3 and 28 days after intratracheal instillation. Printex 90 was included as positive control.</p> <p>Results</p> <p>There was no additive effect of adding NanoTiO₂to paints: Therefore the toxicity of NanoTiO₂was reduced by inclusion into a paint matrix. NanoTiO₂induced inflammation in mice with severity similar to Printex 90. The inflammatory response of NanoTiO₂and Printex 90 correlated with the instilled surface area. None of the materials, except of Printex 90, induced DNA damage in lung lining fluid cells. The highest dose of NanoTiO₂caused DNA damage in hepatic tissue 1 day after intratracheal instillation. Exposure of mice to the dust from paints with and without TiO₂was not associated with hepatic histopathological changes. Exposure to NanoTiO₂or to Printex 90 caused slight histopathological changes in the liver in some of the mice at different time points.</p> <p>Conclusions</p> <p>Pulmonary inflammation and DNA damage and hepatic histopathology were not changed in mice instilled with sanding dust from NanoTiO₂paint compared to paint without NanoTiO₂. However, pure NanoTiO₂caused greater inflammation than NanoTiO₂embedded in the paint matrix.</p