49 research outputs found

    Standard costing and scientific management

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    Many have suggested that scientific management had a direct influence on the development of standard costing. This paper examines the relationship between these concepts in broad terms. While it is concluded that no direct relationship exists between scientific management and standard costing, the existence of an indirect relationship is acknowledged. Scientific management does not require any specific type of accounting system and standard costing does not require a certain type of management organization to operate. However, certain reports developed for the scientifically managed enterprise, when added to the germs of standard costing that existed, expedited the evolution of standard costing

    Reviews

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    Towards closing the gap between hygroscopic growth and activation for secondary organic aerosol: Part 1 – Evidence from measurements

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    Secondary Organic Aerosols (SOA) studied in previous laboratory experiments generally showed only slight hygroscopic growth, but a much better activity as a CCN (Cloud Condensation Nucleus) than indicated by the hygroscopic growth. This discrepancy was examined at LACIS (Leipzig Aerosol Cloud Interaction Simulator), using a portable generator that produced SOA particles from the ozonolysis of <i>α</i>-pinene, and adding butanol or butanol and water vapor during some of the experiments. The light scattering signal of dry SOA-particles was measured by the LACIS optical particle spectrometer and was used to derive a refractive index for SOA of 1.45. LACIS also measured the hygroscopic growth of SOA particles up to 99.6% relative humidity (RH), and a CCN counter was used to measure the particle activation. SOA-particles were CCN active with critical diameters of e.g. 100 nm and 55 nm at super-saturations of 0.4% and 1.1%, respectively. But only slight hygroscopic growth with hygroscopic growth factors ≤1.05 was observed at RH<98% RH. At RH>98%, the hygroscopic growth increased stronger than would be expected if a constant hygroscopicity parameter for the particle/droplet solution was assumed. An increase of the hygroscopicity parameter by a factor of 4–6 was observed in the RH-range from below 90% to 99.6%, and this increase continued for increasingly diluted particle solutions for activating particles. This explains an observation already made in the past: that the relation between critical super-saturation and dry diameter for activation is steeper than what would be expected for a constant value of the hygroscopicity. Combining measurements of hygroscopic growth and activation, it was found that the surface tension that has to be assumed to interpret the measurements consistently is greater than 55 mN/m, possibly close to that of pure water, depending on the different SOA-types produced, and therefore only in part accounts for the discrepancy between hygroscopic growth and CCN activity observed for SOA particles in the past

    VELOX - a new thermal infrared imager for airborne remote sensing of cloud and surface properties

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    The new airborne thermal infrared (TIR) imager VELOX (Video airbornE Longwave Observations within siX channels) is introduced. VELOX is a commercially available TIR camera system that has been adapted extensively for atmospheric applications, which are introduced in this paper. The system covers six spectral bands with centre wavelengths between 7.7 and 12 µm. Currently, VELOX is installed on board the German High Altitude and Long Range Research Aircraft (HALO) to observe cloud and surface properties. It provides observations of two-dimensional (2D) fields of upward terrestrial spectral radiance with a horizontal resolution of approximately 10 m×10 m at a target distance of 10 km. Atmospheric temperature values are rather low compared to the originally intended commercial applications of VELOX and range close to the detection limit of the sensor. This challenge requires additional calibration efforts to enable atmospheric applications of VELOX. Therefore, required sophisticated calibration and correction procedures, including radiometric calibrations, non-uniformity corrections, bad-pixel replacements, and window corrections, are presented. Furthermore, first observations of cloud properties acquired by VELOX during the EUREC4A (ElUcidating the RolE of Cloud-Circulation Coupling in ClimAte) campaign are discussed, including an analysis of the cloud top brightness temperature, cloud mask/fraction, and cloud top altitude data. The data reveal the potential of VELOX to resolve the cloud top temperature with a resolution of better than 0.1 K, which translates into a resolution of approximately 40 m in cloud top altitude

    Aerosol optical properties in the North China Plain during HaChi campaign: an in-situ optical closure study

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    The largest uncertainty in the estimation of climate forcing stems from atmospheric aerosols. In early spring and summer of 2009, two periods of in-situ measurements on aerosol physical and chemical properties were conducted within the HaChi (Haze in China) project at Wuqing, a town between Beijing and Tianjin in the North China Plain (NCP). Aerosol optical properties, including the scattering coefficient (σ<sub>sp</sub>), the hemispheric back scattering coefficient (σ<sub>bsp</sub>), the absorption coefficient (σ<sub>ap</sub>), as well as the single scattering albedo (ω), are presented. The diurnal and seasonal variations are analyzed together with meteorology and satellite data. The mean values of σ<sub>sp, 550 nm</sub> of the dry aerosol in spring and summer are 280±253 and 379±251 Mm<sup>−1</sup>, respectively. The average σ<sub>ap</sub> for the two periods is respectively 47±38 and 43±27 Mm<sup>−1</sup>. The mean values of ω at the wavelength of 637 nm are 0.82±0.05 and 0.86±0.05 for spring and summer, respectively. The relative high levels of σ<sub>sp</sub> and σ<sub>bsp</sub> are representative of the regional aerosol pollution in the NCP. Pronounced diurnal cycle of $σ<sub>sp</sub>, σ<sub>ap</sub> and ω are found, mainly influenced by the evolution of boundary layer and the accumulation of local emissions during nighttime. The pollutants transported from the southwest of the NCP are more significant than that from the two megacities, Beijing and Tianjin, in both spring and summer. An optical closure experiment is conducted to better understand the uncertainties of the measurements. Good correlations (<i>R</i>>0.98) are found between the values measured by the nephelometer and the values calculated with a modified Mie model. The Monte Carlo simulation shows an uncertainty of about 30 % for the calculations. Considering all possible uncertainties of measurements, calculated σ<sub>sp</sub> and σ<sub>bsp</sub> agree well with the measured values, indicating a stable performance of instruments and thus reliable aerosol optical data

    Delayed BCG immunization does not alter antibody responses to EPI vaccines in HIV-exposed and -unexposed South African infants.

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    BACKGROUND: Bacille Calmette-Guérin (BCG) is routinely given at birth in tuberculosis-endemic settings due to its protective effect against disseminated tuberculosis in infants. BCG is however contraindicated in HIV-infected infants. We investigated whether delaying BCG vaccination to 14 weeks of age affected vaccine-induced antibody responses to Haemophilus influenzae type b (Hib)-conjugate, pertussis, tetanus and Hepatitis B (HBV) vaccines, in HIV-exposed uninfected (HEU) and -unexposed uninfected (HUU) infants. METHODS: Infants were randomized to receive BCG at birth or at 14 weeks of age. Blood was taken at 14, 24, and 52 weeks of age and analyzed for Hib, pertussis, tetanus and HBV specific antibodies. RESULTS: BCG was given either at birth (106 infants, 51 HEU) or at 14 weeks of age (74 infants, 50 HEU). The timing of BCG vaccination did not influence the antibody response to any antigen studied. However, in a non-randomized comparison, HEU infants had higher Hib antibody concentrations at weeks 14 and 24 (p=0.001 and <0.001, respectively) and pertussis at week 24 (p=0.003). Conversely, HEU infants had lower antibody concentrations to HBV at 14 and 52 weeks (p=0.032 and p=0.031) with no differences in tetanus titres. CONCLUSIONS: HIV exposure, but not the timing of BCG vaccination, was associated with antibody concentrations to Hib, pertussis, HBV and tetanus primary immunization. CLINICAL TRIAL REGISTRATION: DOH-27-1106-1520

    A parameterization of low visibilities for hazy days in the North China Plain

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    Visibility degradation is a pervasive and urgent environmental problem in China. The occurrence of low visibility events is frequent in the North China Plain, where the aerosol loading is quite high and aerosols are strongly hygroscopic. A parameterization of light extinction (&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt;) for low visibilities on hazy days is proposed in this paper, based on visibility, relative humidity (RH), aerosol hygroscopic growth factors and particle number size distributions measured during the Haze in China (HaChi) Project. Observational results show that a high aerosol volume concentration is responsible for low visibility at RH &lt;90%; while for RH &gt;90%, decrease of visibility is mainly influenced by the increase of RH. The parameterization of &lt;i&gt;K&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt; is developed on the basis of aerosol volume concentrations and RH, taking into accounts the sensitivity of visibility to the two factors and the availability of corresponding data. The extinction coefficients calculated with the parameterization schemes agree well with the directly measured values

    Avspice Deo Rectore Magnificentissimo Serenissimo Principe Ac Domino Domino Wilhelmo Henrico Dvce Saxoniae ... Consentiente Amplissimo Philosophorvm Ordine De Recta Lingvarvm Discendarvm Ratione Dissertationem Philologicam d. [ ] IVI. MDCCXXXVIIII

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    Praeside M. Georgio Christiano Hallbavero Ordin. Philosoph. Adivncto Design. Scholae Senatoriae Ienensis Rectore Pvblice Defendet Io. Philipp. Havth Bipontinvs Sac. Lit. Cvltor. Societati Latinae Ienensis AdscriptvsVorlageform des Erscheinungsvermerks: Ienae Litteris Io. Frid. Schillii.Jena, Univ., Phil. Diss., 173
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