Testing Theories of Job Creation: Does Supply Create Its Own Demand?

Although search-matching theory has come to dominate labor economics in recent years, few attempts have been made to compare the empirical relevance of search-matching theory to efficiency wage and bargaining theories, where employment is determined by labor demand. In this paper we formulate an empirical equation for net job creation, which encompasses search-matching theory and a standard labor demand model. Estimation on firm-level data yields support for the labor demand model, wages and product demand affect job creation, but we find no evidence that unemployed workers contribute to job creation, as predicted by search-matching theory.job creation, involuntary unemployment, search-matching, labor demand, competitiveness

Combustion and fuel characterisation of wheat distillers dried grain with solubles (DDGS) and possible combustion applications

The present transition to a sustainable global energy system requires that biomass is increasingly combusted for heat and power production. Agricultural fuels considered include alkali-rich fuels with high phosphorus content. One such fuel is wheat distiller’s dried grain with solubles (wheat DDGS) from wheat-based ethanol production. Further increases in ethanol production may saturate the current market for wheat DDGS as livestock feed, and fuel uses are therefore considered. Fuel properties of wheat DDGS have been determined. The ash content (5.4 ± 1.6 %wt d.s.) is similar to many agricultural fuels. In comparison to most other biomass fuels the sulphur content is high (0.538 ± 0.232 %wt d.s.), and so are the contents of nitrogen (5.1 ± 0.6 %wt d.s.), phosphorus (0.960. ± 0.073 %wt d.s.) and potassium (1.30 ± 0.35 %wt d.s.). To determine fuel-specific combustion properties, wheat DDGS and mixes between wheat DDGS and logging residues (LR 60 %wt d.s. and DDGS 40 %wt d.s.), and wheat straw (wheat straw 50 %wt d.s., DDGS 50 %wt d.s.) were pelletized and combusted in a bubbling fluidised bed combustor (5 kW) and in a pellets burner combustor (20 kW). Pure wheat DDGS powder was also combusted in a powder burner (150 kW). Wheat DDGS had a high bed agglomeration and slagging tendency compared to other biomass fuels, although these tendencies were significantly lower for the mixture with the Ca-rich LR, probably reflecting the higher first melting temperatures of K–Ca/Mg-phosphates compared to K-phosphates. Combustion and co-combustion of wheat DDGS resulted in relatively large emissions of fine particles (<1 μm) for all combustion appliances. For powder combustion PMtot was sixteen times higher than from softwood stem wood. While the Cl concentrations of the fine particles from the the mixture of LR and wheat DDGS in fluidised bed combustion were lower than from combustion of pure LR, the Cl- and P-concentrations were considerably higher from the wheat DDGS mixtures combusted in the other appliances at higher fuel particle temperature. The particles from powder combustion of wheat DDGS contained mainly K, P, Cl, Na and S, and as KPO3 (i.e. the main phase identified with XRD) is known to have a low melting temperature, this suggests that powder combustion of wheat DDGS should be used with caution. The high slagging and bed agglomeration tendency of wheat DDGS, and the high emissions of fine particles rich in K, P and Cl from combustion at high temperature, mean that it is best used mixed with other fuels, preferably with high Ca and Mg contents, and in equipment where fuel particle temperatures during combustion are moderate, i.e. fluidised beds and possibly grate combustors rather than powder combustors

Impact of ice aggregate parameters on microwave and sub-millimetre scattering properties

Microwave scattering properties for 1101 aggregates were calculated using DDA (Discrete Dipole Approximation), at three typical radar bands (13.4, 35.6, 94.1 GHz) and three passive microwave frequencies (183.31, 325.15 and 664 GHz). The aggregates were generated in a semi-physical stochastic fashion and are composed of hexagonal crystals of varying axis ratio, ranging from 1/15 (plates) to 15 (columns). Horizontally aligned particles were assumed and scattering properties were assessed for zenith/nadir observations. Crystal axis ratio, number of crystals, effective density and aerodynamic area, were found to correlate with extinction and back-scattering efficiencies. However, the dependency between these variables and scattering properties vary between the frequencies. Interestingly, bulk extinction was found to have a relatively low sensitivity to particle shape at 664 GHz. Furthermore, extinction was found to be less shape sensitive than back-scattering. These results are promising for the sake of the upcoming Ice Cloud Imager (ICI) mission. In addition, for the considered set of aggregates, it is shown that both bulk extinction and back-scattering are more directly related to snow fall than ice water content. Triple frequency signatures were also calculated, which demonstrated clear dependence on constituent crystal axis ratio and conversely on aggregate effective density, in agreement with the literature

Proof-of-concept of a novel scalable magnetic bead-based cell separation technology

Advanced Therapy Medicinal Products (ATMPs) are gaining great interest for the treatment of severe, currently consider incurable, diseases. Therapies based on stem cells have an enormous potential in applications such as cardiac cells and neurons to name a few. However, the production of these cell systems is expensive, complex and lack, nowadays, scalability both for their cultivation and the purification. The lack of scalability is a major bottleneck to bring these therapies to patient at commercial scale. Magnetic beads are well-established for sorting of cells, e.g. magnetic activated cell sorting. However, today´s systems size is still limited in terms of scale-up potential. We have developed a new scalable separation process based on the magnetic bead MAG for the isolation of receptor positive cell subpopulations. We have previously published that our new magnetic bead system MAG is extremely gentle towards cells1 and can easily be scaled up at pilot-scale for the separation of monoclonal antibody from a cell suspension2. In the present study, this magnetic bead system has been further developed for cell separation. In a model system with a mixture of hMSC and HER2+ SK BR3 cells (20:80), a proof-of-concept was demonstrated showing exceptional elimination of the HER2+ cells. Different ligand densities were evaluated, showing that the largest cell removals were achieved with the lowest ligand densities. Furthermore, in a study of mechanical and chemical stress conditions, the MAG separation system showed robustness of sorting performances. From our previous knowledge about the scalability of the MAG magnetic beads separation, this provides promising potential for the production of therapeutic stem cells at larger scale. 1. Brechmann, N. A.; Schwarz, H.; Eriksson, P.-O.; Eriksson, K.; Shokri, A.; Chotteau, V., Antibody capture process based on magnetic beads from very high cell density suspension. Biotechnology and Bioengineering 2021, n/a, (n/a). 2. Brechmann, N. A.; Eriksson, P.-O.; Eriksson, K.; Oscarsson, S.; Buijs, J.; Shokri, A.; Hjälm, G.; Chotteau, V., Pilot-scale process for magnetic bead purification of antibodies directly from non-clarified CHO cell culture. Biotechnology Progress 2019, 35, (3), e2775

Using passive and active observations at microwave and sub-millimetre wavelengths to constrain ice particle models

Satellite microwave remote sensing is an important tool for determining the distribution of atmospheric ice globally. The upcoming Ice Cloud Imager (ICI) will provide unprecedented measurements at sub-millimetre frequencies, employing channels up to 664 GHz. However, the utilization of such measurements requires detailed data on how individual ice particles scatter and absorb radiation, i.e. single scattering data. Several single scattering databases are currently available, with the one by Eriksson et al. (2018) specifically tailored to ICI. This study attempts to validate and constrain the large set of particle models available in this database to a smaller and more manageable set. A combined active and passive model framework is developed and employed, which converts CloudSat observations to simulated brightness temperatures (TBs) measured by the Global Precipitation Measurement (GPM) Microwave Imager (GMI) and ICI. Simulations covering about 1 month in the tropical Pacific Ocean are performed, assuming different microphysical settings realized as combinations of the particle model and particle size distribution (PSD). Firstly, it is found that when the CloudSat inversions and the passive forward model are considered separately, the assumed particle model and PSD have a considerable impact on both radar-retrieved ice water content (IWC) and simulated TBs. Conversely, when the combined active and passive framework is employed instead, the uncertainty due to the assumed particle model is significantly reduced. Furthermore, simulated TBs for almost all the tested microphysical combinations, from a statistical point of view, agree well with GMI measurements (166, 186.31, and 190.31 GHz), indicating the robustness of the simulations. However, it is difficult to identify a particle model that outperforms any other. One aggregate particle model, composed of columns, yields marginally better agreement with GMI compared to the other particles, mainly for the most severe cases of deep convection. Of the tested PSDs, the one by McFarquhar and Heymsfield (1997) is found to give the best overall agreement with GMI and also yields radar dBZ–IWC relationships closely matching measurements by Protat et al. (2016). Only one particle, modelled as an air–ice mixture spheroid, performs poorly overall. On the other hand, simulations at the higher ICI frequencies (328.65, 334.65, and 668.2 GHz) show significantly higher sensitivity to the assumed particle model. This study thus points to the potential use of combined ICI and 94 GHz radar measurements to constrain ice hydrometeor properties in radiative transfer (RT) using the method demonstrated in this paper

Review of multi-hazard indices : Focus on methods applicable for a Swedish context

A literature review of methods where different hazards are combined into a multi-hazard index or method are presented in this report. The purpose of the review is to get an insight into approaches to combine different hazards into a multi-hazard index or method. To directly combine hazards, it is necessary to present them with the same unit of measure. This can be done with different measures for normalizing or using weights. Maps are often used to get an understanding of the spatial distribution of the hazard as well as the hazard level. No specific method or tool that can be applied directly for relevant hazards in Sweden have been found in this review. However, several general principles and methods that are considered valuable for the Extreme-Index project are identifie

Proof-of-concept of a novel scalable magnetic bead-based cell separation technology

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Volcanism of the Palaeoproterozoic Bushveld Large Igneous Province : the Rooiberg Group, Kaapvaal Craton, South Africa

The volcanic rocks of the Rooiberg Group represent the uppermost unit in the Palaeoproterozoic Transvaal Supergroup and form one of the largest provinces of silicic volcanic rocks in the world. Although stratigraphically associated with the Transvaal basin-fill, the Rooiberg Group is petrogenetically linked with the larger Bushveld magmatic event for which emplacement was preceded by the extrusion of the vast Rooiberg lava flows in the northern part of the Kaapvaal Craton. Like many silicic-dominated Large Igneous Provinces (LIPs), which are increasingly recognised in the rock record, the Rooiberg Group volcanics are intracontinental, subaerial, and are dominated by voluminous lava flows. Originally, the Rooiberg Group is inferred to have covered an area of more than 200,000 km2 of which, after erosion, an area of 50,000–67,000 km2 remains. The lava flows form a stratigraphic succession up to 6 km thick, and are divided into four formations in ascending order: Dullstroom, Damwal, Kwaggasnek and Schrikkloof. Due to a scarcity of reliable geochronological data, the temporal span of the Rooiberg Group is poorly understood. The Rooiberg Group consists of basaltic to rhyolitic lava erupted from fissural volcanism with estimated eruption temperatures of the rhyolitic lavas exceeding 1000 ◦C. Minor explosive eruptions are represented by pyroclastic rocks, and subordinate sedimentary interbeds originated from sandy fluvial and lacustrine processes. The rocks are essentially undeformed and have not been buried so that their original textures are well preserved. The Bushveld Complex and the associated Rooiberg Group lava flows are proposed to have formed as a result of partial melting of subcontinental lithosphere and lower crust by a mantle plume. This thorough review of the geochronology, physical volcanology, and geochemistry of the Rooiberg Group enables construction of a geodynamic model.The University of Pretoria and the National Research Foundation of South Africa.http://www.elsevier.com/locate/precamre