The Impact of Uncertainty Shocks under Measurement Error: A Proxy SVAR approach

A growing literature considers the impact of uncertainty using SVAR models that include proxies for uncertainty shocks as endogenous variables. In this paper we consider the impact of measurement error in these proxies on the estimated impulse responses. We show via a Monte-Carlo experiment that measurement error can result in attenuation bias in impulse responses. In contrast, the proxy SVAR that uses the uncertainty shock proxy as an instrument does not su¤er from this bias. Applying this latter method to the Bloom (2009) data-set results in impulse responses to uncertainty shocks that are larger in magnitude and more persistent than those obtained from a recursive SVAR

THE FEDERAL RESERVE'S IMPLICIT INFLATION TARGET AND MACROECONOMIC DYNAMICS: AN SVAR ANALYSIS

This article identifies shocks to the Federal Reserve's inflation target as vector autoregression innovations that make the largest contribution to future movements in long-horizon inflation expectations. The effectiveness of this scheme is documented via Monte-Carlo experiments. The estimated impulse responses indicate that a positive shock to the target is associated with a large increase in inflation and long-term interest rates in the United States. Target shocks are estimated to be a vital factor behind the increase in inflation during the pre-1980 period and are an important driver of the decline in long-term interest rates over the last two decades

Thermal expansion coefficients in Invar processed by selective laser melting

This work investigates whether the unique low thermal expansion property of Invar (64Fe–36Ni) is retained after processing using the additive manufacturing process selective laser melting (SLM). Using this process, near-full-density components (99.96%) were formed by melting thin (20 μm) layers of powdered Invar (15–45 μm particle size). The mechanical properties of SLM Invar were comparable to that of cold-drawn Invar36®; however, the thermal coefficient of expansion was observed to be a lower value and negative up until 100 °C. This negative value was attributed to residual stress in the as-deposited parts. The low thermal expansion property of Invar was still maintained when processed using a non-conventional layer-based additive manufacturing technique

Granulomatous gastritis: a diagnostic dilemma?

Granulomatous inflammation of the gastrointestinal tract is an uncommon entity, an aetiopathogenic diagnosis can be reached only by combining the morphological examination with clinical and laboratory investigations. We report two cases of granulomatous gastritis: a 27-year-old woman presenting with weight loss and a 55-year-old woman presenting with epigastric pain and vomiting. Upper oesophagastroduodenoscopy in these cases showed antral hyperaemia and histopathology showed non-caseating gastric granulomatous inflammation. Both the cases were extensively worked-up for possible tuberculosis (TB) as the Patients lived in an endemic area, before starting steroids for the possibility of Crohn\u27s disease (CD). The first Patient improved but the second Patient had a flare of underlying undiagnosed TB. Granulomatous gastritis present a diagnostic challenge for treating physicians because of similar clinical, laboratory and endoscopical features between CD and intestinal TB

Multi-objective optimisation for minimum quantity lubrication assisted milling process based on hybrid response surface methodology and multi-objective genetic algorithm

© 2019 by SAGE Publications Ltd.Parametric modelling and optimisation play an important role in choosing the best or optimal cutting conditions and parameters during machining to achieve the desirable results. However, analysis of optimisation of minimum quantity lubrication–assisted milling process has not been addressed in detail. Minimum quantity lubrication method is very effective for cost reduction and promotes green machining. Hence, this article focuses on minimum quantity lubrication–assisted milling machining parameters on AISI 1045 material surface roughness and power consumption. A novel low-cost power measurement system is developed to measure the power consumption. A predictive mathematical model is developed for surface roughness and power consumption. The effects of minimum quantity lubrication and machining parameters are examined to determine the optimum conditions with minimum surface roughness and minimum power consumption. Empirical models are developed to predict surface roughness and power of machine tool effectively and accurately using response surface methodology and multi-objective optimisation genetic algorithm. Comparison of results obtained from response surface methodology and multi-objective optimisation genetic algorithm depict that both measured and predicted values have a close agreement. This model could be helpful to select the best combination of end-milling machining parameters to save power consumption and time, consequently, increasing both productivity and profitability.Peer reviewedFinal Published versio

Synthesis and Magnetic Properties of Cobalt Ferrite (CoFe2O4) Nanoparticles Prepared by Wet Chemical Route

Magnetic nanoparticles of cobalt ferrite have been synthesized by wet chemical method using stable ferric and cobalt salts with oleic acid as the surfactant. X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) confirmed the formation of single phase cobalt ferrite nanoparticles in the range 15-48nm depending on the annealing temperature and time. The size of the particles increases with annealing temperature and time while the coercivity goes through a maximum, peaking at around 28nm. A very large coercivity (10.5kOe) is observed on cooling down to 77K while typical blocking effects are observed below about 260K. The high field moment is observed to be small for smaller particles and approaches the bulk value for large particles.Comment: 18 pages, accepted in JMMM, (May, 2006

Magnetic response of core-shell cobalt ferrite nanoparticles at low temperature

Cobaltferritenanoparticles (size: 26±4nm) have been synthesized by coprecipitation route. The coercivity of nanoparticles follows a simple model of thermal activation of particle moments over the anisotropy barrier in the temperature range of 30–300K in accordance with Kneller’s law; however, at low temperatures

Forced vital capacity, forced expiratory volume in 1st second and forced expiratory ratio in automobile spray paint workers

Background: Automobile industry is a place where workers are exposed to harmful chemicals and toxic substances. Workers engaged in automobile spray painting are at a risk of developing respiratory problems. This is due to exposure to low molecular weight compounds (isocyanates) in spray paints.Methods: The present study was conducted on 100 male subjects comprising of the study group (n=50) and the control group (n=50), 18-35 years of age, non-smoker and with no pre occupational respiratory illness. The study group included workers working for 6-8 hours a day and exposed to spray paints for ≤5 years and the controls were age and BSA matched healthy office workers of the same locality. A preformed questionnaire was given to subjects and pulmonary functions parameters (forced vital capacity (FVC), forced expiratory volume in 1st second (FEV1), forced expiratory ratio (FEV1/FVC)) were recorded by computerised spirometer (Medspiror).Results: The two groups did not differ significantly on physical parameters. The pulmonary function parameters of the study group (FVC p=0.036, FEV1/FVC p=0.000) were found to be significantly different when compared to that of controls. As the age, weight, height and BSA increases there was a significant decrease in FEV1 in study group. Duration of exposure (<3 and more than equal to 3) had no statistically significant impact on pulmonary function tests (FVC p=0.139, FEV1 p=0.339, FEV1/FVC p=0.158) in the study  group.Conclusions: Exposure to automobile spray paint impairs lung functions