Nexus between U.S Energy Sources and Economic Activity: Time-Frequency and Bootstrap Rolling Window Causality Analysis

This paper explores the relationship between U.S economic activity and renewable energy sources namely hydroelectric power, geothermal energy, wood energy, waste energy, biofuel, biomass energy, and total renewable energy. Monthly data for the period January 1981 to March 2015 is used to depict the comovements between the variables through Wavelet Squared Coherence (WTC) and Multiple Wavelet Coherence (MWCC) approaches. Maximal overlap wavelet correlation and cross-correlation measures, analogous to WTC and MWCC, show strong positive comovement in long-run. The causal linkage between economic activity and renewable energy sources is examined through bootstrap rolling window causality. The analysis reveals the significant reciprocal effects between the economic activity and energy use during the periods of extreme events. Overall, findings indicate that renewable energy sources play an important role in stimulating economic activity. This shows that present study has important implications for US energy policy authorities

Nexus between U.S Energy Sources and Economic Activity: Time-Frequency and Bootstrap Rolling Window Causality Analysis

This paper explores the relationship between U.S economic activity and renewable energy sources namely hydroelectric power, geothermal energy, wood energy, waste energy, biofuel, biomass energy, and total renewable energy. Monthly data for the period January 1981 to March 2015 is used to depict the comovements between the variables through Wavelet Squared Coherence (WTC) and Multiple Wavelet Coherence (MWCC) approaches. Maximal overlap wavelet correlation and cross-correlation measures, analogous to WTC and MWCC, show strong positive comovement in long-run. The causal linkage between economic activity and renewable energy sources is examined through bootstrap rolling window causality. The analysis reveals the significant reciprocal effects between the economic activity and energy use during the periods of extreme events. Overall, findings indicate that renewable energy sources play an important role in stimulating economic activity. This shows that present study has important implications for US energy policy authorities

Identification of Carotid Plaques Composition through a Compact Microwave Sensor

International audienceMicrowave biosensor brings the prominent promise ofdielectric parameters detection to characterize biological tissues. Thispromise has already been materialized in multiple fields of healthcareand body parts. Yet when it comes to carotid plaque sticking to basicsimulations, and correlating that with real-time measurements isarguably much harder. Measuring and simulating carotid plaquescomprise a wide range of sub-problems, such as the heterogeneity anduniquity of each plaque, the different thicknesses, and various areasof interest. In this study, a miniaturized microwave biosensor wasproposed to perform dielectric characterizations of atheromatousplaques present in arterial tissues. The designed microwave biosensoremploys a Complementary Split Ring Resonator (CSRR) topology at2.3 GHz. Electromagnetic modeling and experimentalcharacterization have been carried out to validate the developedequivalent electrical model with very good precision and to calibrateit using other material. Atheroma measurements were achieved andcompared to data obtained by simulation and then correlated with thehistology result

Profondeur de pénétration des ondes micro-ondes dans les tissus biologiques multicouches à l'aide d'un biocapteur micro-ondes compact

The goal of this research is to investigatemicrowaves penetration depth through polymorphic biologicaltissues. This study aims to improve an existing sensor basedon a Complementary Split Ring Resonator (CSRR) structure,designed to differentiate carotid artery atherosclerotic plaques.Multilayered animal tissues (skin, fat, muscle) are studied tocharacterize and simulate the neck composition, where the carotidplaque is localized.Keywords —micro

In vitro analysis of carotid lesions using a preliminary microwave sensor to detect vulnerable plaques: Correlation with histology, Duplex ultrasound examination, and computed tomography scanner: The Imaging and Microwave Phenotyping Assessment of Carotid stenosis Threat (IMPACT) study

Objective: Progress in best medical treatment have made identification of best candidates for carotid surgery more difficult. New diagnostic modalities could be helpful in this perspective. Microwaves (MWs) can quantify dielectric properties (complex relative permittivity) of biological tissues and MW technology has emerged as a promising field of research for distinguishing abnormal tissues from healthy ones. We here evaluated the ability of a dedicated MW sensor developed in our laboratory to identify vulnerable carotid lesions. Methods: We included 50 carotid lesions in this study. The plaques were analyzed and classified preoperatively by ultrasound (US) examination, computed tomography angiography and tested postoperatively using a MW sensor. Histopathological analysis was used as a gold standard to separate vulnerable plaques (VPs) from nonvulnerable plaques (NVPs). Results: VPs were more frequently types 2 or 3 plaques (on US examination), had a greater proportion of low (<60 Hounsfield unit) and moderate (60-130 Hounsfield unit) attenuation components (computed tomography angiography) and displayed higher dielectric constant values (MW) than NVPs, which had an opposite profile. NVPs were more frequently asymptomatic plaques compared with VPs (P = .035). Multivariate analysis showed that US examination and MW identified VPs with a sensitivity of 77% and a specificity of 76% (cutoff value, –0.045; area under the curve, 0.848; P < .0001). Conclusions: We found that the presence of types 2 to 3 (on US examination) and high dielectric constant plaques in vitro was highly indicative of a VP based on histological analysis. Further studies are needed to determine the potential of MW to identify the most dangerous asymptomatic carotid lesions