Asymmetries in the Responses of Regional Job Flows to Oil Price Shocks

This paper studies the effect of oil price innovations on manufacturing job flows across U.S states. First, I estimate a nonlinear structural equation model and compute impulse response functions by Monte Carlo integration. I find asymmetries in the responses of job flows to positive and negative oil price innovations. Yet, these asymmetries do not pass a test of symmetry on the impulse responses, especially after accounting for data mining. Third, I use a test for the absence of job reallocation to evaluate whether an unexpected increase in the real price of oil price triggers an important change in job reallocation. I find that oil price shocks have limited regional allocative effects

Asymmetries in the Responses of Regional Job Flows to Oil Price Shocks

This paper studies the effect of oil price innovations on manufacturing job flows across U.S states. First, I estimate a nonlinear structural equation model and compute impulse response functions by Monte Carlo integration. I find asymmetries in the responses of job flows to positive and negative oil price innovations. Yet, these asymmetries do not pass a test of symmetry on the impulse responses, especially after accounting for data mining. Third, I use a test for the absence of job reallocation to evaluate whether an unexpected increase in the real price of oil price triggers an important change in job reallocation. I find that oil price shocks have limited regional allocative effects

Essays On The Effects Of Oil Price Shocks And Monetary Shocks On Labor Reallocation

The debate regarding the asymmetric effects associated with oil and monetary shocks on the economy has revived interest in analyzing the channels of transmission that generate asymmetries in the response of economic activity to these shocks. This dissertation examines the role of the allocative channel in the transmission mechanism of oil shocks and monetary shocks on economic activity. Using methods by Kilian and Vigfusson (2011b), we analyze the impact of oil and monetary shocks on job creation and job destruction in manufacturing industries. We found that an unanticipated positive oil price shock triggers costly reallocation of labor across sectors and regions. Yet, no evidence of asymmetry was found in the response of job creation (job destruction) to positive and negative oil price shocks. Moreover, we found significant evidence of asymmetries in the response of job creation and job destruction to a positive monetary shock. This finding indicates that there is a significant costly labor reallocation process associated with an unanticipated increase in interest rates. Finally we inquire on whether the reduction in the effect of shocks since the Great moderation could be explained with the decline in the role of the allocative channel. We found that the effect of both oil price shocks and monetary shocks on Labor reallocation has reduced since the start of the Great Moderation

Industrial Investment in Ma'an Governorate, Obstacles, Opportunities and Successful Projects

Industrial investment is one of the most important factors that help achieving sustainable economic development. This study aims to explore the obstacles, which constrain industrial investments in Ma'an Governorate (located in south Jordan) and the incentives to promote these investments. It also aims to explore investment projects with successful future opportunities. A survey on government and private departments’ managers, individual entrepreneurs, and professionals in Ma’an Governorate was conducted for data collection. A total of 300 questionnaires were distributed. Out of this number, only 186 were returned. The response rate was about 58%. One-sample t-test and descriptive statistics showed that there are obstacles facing industrial investments, on the other side it showed that there are real incentives for industrial investments. The research findings show that the Governorate of Ma'an is eligible to attract various industrial projects, which have opportunities to be highly successful in the future such as glass factories, plastics, marble, clothing, and construction materials industries. This study recommends Jordanian government to improve basic infrastructure, promote private industrial investments and exploit the opportunities in the area through directing industrial investments towards the available resources. It also recommends promoting the governorate of Ma'an through media and highlights the prospects of success in various fields of industrial investment in a positive way. Keywords: Industrial Investment, investment obstacles, investment opportunities, future investment projects, Ma’an Governorate

Progress in experimental and theoretical evaluation methods for textile permeability

ABSTRACT: A great amount of attention has been given to the evaluation of the permeability tensor and several methods have been implemented for this purpose: experimental methods, as well as numerical and analytical methods. Numerical simulation tools are being seriously developed to cover the evaluation of permeability. However, the results are still far from matching reality. On the other hand, many problems still intervene in the experimental measurement of permeability, since it depends on several parameters including personal performance, preparation of specimens, equipment accuracy, and measurement techniques. Errors encountered in these parameters may explain why inconsistent measurements are obtained which result in unreliable experimental evaluation of permeability. However, good progress was done in the second international Benchmark, wherein a method to measure the in-plane permeability was agreed on by 12 institutes and universities. Critical researchers’ work was done in the field of analytical methods, and thus different empirical and analytical models have emerged, but most of those models need to be improved. Some of which are based on Cozeny-Karman equation. Others depend on numerical simulation or experiment to predict the macroscopic permeability. Also, the modeling of permeability of unidirectional fiber beds have taken the greater load of concern, whereas that of fiber bundle permeability prediction remain limited. This paper presents a review on available methods for evaluating unidirectional fiber bundles and engineering fabric permeability. The progress of each method is shown in order to clear things up

Etude expérimentale et modélisation de la perméabilité des renforts textiles tissés pour matériaux composites

La maitrise des procédés d’injection pour l’obtention de pièces en matériau composite à base de nappes tissées nécessite une bonne estimation de la perméabilité des tissus. Cette perméabilité est difficile à établir avec une bonne précision aussi bien de manière expérimentale qu’à l’aide de modèles numériques. L’objectif de cette thèse était de proposer un modèle analytique simple à mettre en œuvre et à la fois représentatif de cette perméabilité. Une étude approfondie de la littérature montre que les modèles analytiques existants ne sont pas assez précis et sont difficiles à appliquer en pratique. De même de nombreux résultats expérimentaux ont été publiés mais ne sont pas toujours transposables et fiables pour pouvoir être utilisés dans des outils de simulation d’un procédé d’injection. Dans ce travail nous avons proposé un modèle analytique de la perméabilité simple et performant s’appuyant sur une description de l’écoulement aux échelles mésoscopiques (interstices entre les torons de fibres) et microscopiques (pores entre les fibres élémentaires). Ce modèle est validé par une campagne expérimentale utilisant un protocole simple et efficace. Cette validation est complétée par un modèle éléments finis développés dans COMSOL. La perméabilité de 11 tissus différents (matériaux différents et tissages différents) a été évaluée expérimentalement. Les valeurs obtenues expérimentalement et par le modèle analytique montrent un très bon accord entre ces résultatsThe control of the injection processes for obtaining composite parts made using engineering textiles requires a good estimation of the permeability of these textiles. Permeability evaluation using both experimental and numerical methods faces difficulties. The objective of this thesis was to propose an analytical model that is simple to implement and representative of this permeability, taking into account the geometric diversity of different architectures. A thorough study of the literature shows that many analytical models exist and that many experimental results are available. Unfortunately, existing analytical models are not accurate enough, also they are difficult to be applied. Moreover, the experimental results are not always transposable and reliable to be used in simulation tools of the injection processes. In this work, we proposed an analytical model, simple and efficient, of the permeability based on a description of the flow at mesoscopic scales (interstices between fibers bundle) and microscopic scales (pores between elementary fibers). This model is validated by an experimental campaign using simple and efficient protocol. A numerical validation is also proposed, using a finite element model developed in COMSOL. The permeability of 11 different tissues (different materials and different weaves) was evaluated experimentally. The values obtained experimentally and by the analytical model show a very good agreement between these result

Progress in Experimental and Theoretical Evaluation Methods for Textile Permeability

A great amount of attention has been given to the evaluation of the permeability tensor and several methods have been implemented for this purpose: experimental methods, as well as numerical and analytical methods. Numerical simulation tools are being seriously developed to cover the evaluation of permeability. However, the results are still far from matching reality. On the other hand, many problems still intervene in the experimental measurement of permeability, since it depends on several parameters including personal performance, preparation of specimens, equipment accuracy, and measurement techniques. Errors encountered in these parameters may explain why inconsistent measurements are obtained which result in unreliable experimental evaluation of permeability. However, good progress was done in the second international Benchmark, wherein a method to measure the in-plane permeability was agreed on by 12 institutes and universities. Critical researchers’ work was done in the field of analytical methods, and thus different empirical and analytical models have emerged, but most of those models need to be improved. Some of which are based on Cozeny-Karman equation. Others depend on numerical simulation or experiment to predict the macroscopic permeability. Also, the modeling of permeability of unidirectional fiber beds have taken the greater load of concern, whereas that of fiber bundle permeability prediction remain limited. This paper presents a review on available methods for evaluating unidirectional fiber bundles and engineering fabric permeability. The progress of each method is shown in order to clear things up

In-plane permeability prediction model for non-crimp and 3D orthogonal fabrics

International audiencePermeability reflects the ease of flow inside a composite fabric. A predictive model has been developed to estimate the unidirectional permeability in both, the warp and weft directions, for a family of non-crimped and 3D orthogonal fabrics. The model is based on an analytical solution derived from previous studies, in which the microscopic permeability of unidirectional fiber bundles is estimated. The implementation of this model requires basic geometrical parameters of the fabric architecture. Those parameters include the dimension of the mesopores and architecture of the fiber bundles, which are determined from pictures taken for the fabric and from the textile data sheet. In addition, the average volume of mesopores and fiber bundles are calculated for different fiber volume fractions in the warp and weft directions. The model evaluates two contributions; the first one deals with the flow inside and in between the tows, while the second one figures out the flow deviations arising from the stitching yarns. The model uses effective radius and fiber volume fraction to evaluate permeability for the two flow contributions mentioned above. An experimental investigation validates the predictive model for five different fabrics and three different fiber volume fractions. Good agreement is found

Raumkrümmung zum Anfassen - Sektormodelle aus dem 3D-Drucker 6 Autor/innen

Sektormodelle sind Anschauungsmodelle für nicht-euklidische Geometrie. Sie wurden entwickelt, um die Grundkonzepte der allgemeinen Relativitätstheorie in zwei bzw. drei Dimensionen auf anschauliche Weise darzustellen (Zahn & Kraus, 2014; Zahn & Kraus, 2019). Für eine Einführung in die Allgemeine Relativitätstheorie kann man mit solchen Modellen beispielsweise den Raum in der Nähe eines Schwarzen Lochs oder das Innere eines Neutronensterns darstellen.Der Einsatz von Sektormodellen ist nicht nur im Physikunterricht möglich. Auch im Mathematikunterricht können sie genutzt werden, um sphärische und hyperbolische Geometrien darzustellen. Sektormodelle erlauben diverse Aktivitäten der Lernenden: beispielsweise können Lernende anhand der Modelle mit einfachen Mitteln Krümmungen bestimmen und den Verlauf von Geodäten untersuchen. Die einfacheren ebenen Sektormodelle können Lernende ausgehend von der Metrik auch selbst berechnen und konstruieren (Kraus & Zahn, 2016).In diesem Beitrag geben wir eine kurze Einführung in Sektormodelle und stellen Umsetzungen mit dem 3D-Drucker, sowie ihr Potential für den Einsatz im Physikunterricht vor

Raumkrümmung zum Anfassen - Sektormodelle aus dem 3D-Drucker 6 Autor/innen

Sektormodelle sind Anschauungsmodelle für nicht-euklidische Geometrie. Sie wurden entwickelt, um die Grundkonzepte der allgemeinen Relativitätstheorie in zwei bzw. drei Dimensionen auf anschauliche Weise darzustellen (Zahn & Kraus, 2014; Zahn & Kraus, 2019). Für eine Einführung in die Allgemeine Relativitätstheorie kann man mit solchen Modellen beispielsweise den Raum in der Nähe eines Schwarzen Lochs oder das Innere eines Neutronensterns darstellen.Der Einsatz von Sektormodellen ist nicht nur im Physikunterricht möglich. Auch im Mathematikunterricht können sie genutzt werden, um sphärische und hyperbolische Geometrien darzustellen. Sektormodelle erlauben diverse Aktivitäten der Lernenden: beispielsweise können Lernende anhand der Modelle mit einfachen Mitteln Krümmungen bestimmen und den Verlauf von Geodäten untersuchen. Die einfacheren ebenen Sektormodelle können Lernende ausgehend von der Metrik auch selbst berechnen und konstruieren (Kraus & Zahn, 2016).In diesem Beitrag geben wir eine kurze Einführung in Sektormodelle und stellen Umsetzungen mit dem 3D-Drucker, sowie ihr Potential für den Einsatz im Physikunterricht vor