The capability of capacitive sensors in the monitoring relative humidity in hypogeum environments

Hypogeum environments are characterized by high levels of relative humidity (RH). Most humidity sensors currently in use are based on the capacitive effect of the dielectric material to change according to water vapour uptake. In hypogeum environments the dielectric material can be saturated by water vapor, implying a significant error in the RH measurement. To improve the capacity of this type of humidity sensors, a modified hygrometer capacitive sensor, which uses a heating cycle to avoid the condensation, has been recently developed by Rotronic®. During four field campaigns in two different hypogea environments (the Monkey Tomb in Siena and the Mithreum of Caracalla Baths in Rome), RH was measured using the conventional capacitive sensor (CCS) and the heated capacitive sensor (HCS). The purpose of this study was to investigate the capability of HCS to detect RH variations when the environmental conditions were close to vapor saturation. Significant differences were found between the measurements of the two sensors: when RH was close to 100%, the CCS was not able to detect the RH decrease, giving only a measure of RH=100%, while HCS detected such a RH decrease. Therefore, these results encourage the use of HCS in the monitoring of RH levels in extreme humidity sites such as hypogea sites

Z Extremization in Chiral-Like Chern Simons Theories

We study the localized free energy on S^3 of three-dimensional N=2 Chern-Simons matter theories at weak coupling. We compute the two loop R charge in three different ways, namely by the standard perturbative approach, by extremizing the localized partition function at finite N and by applying the standard saddle point approximation for large N. We show that the latter approach does not reproduce the expected result when chiral theories are considered. We circumvent these problems by restoring a reflection symmetry on the eigenvalues in the free energy. Thanks to this symmetrization we find that the three methods employed agree. In particular we match the computation for a model whose four dimensional parent is the quiver gauge theory describing D3 branes probing the Hirzebruch surface. We conclude by commenting on the application of our results and to the strong coupling regime.Comment: 20 pages, 1 figure, using jheppub.st

BPS states and their reductions

We develop a method to identify the BPS states in the Hilbert space of a supersymmetric field theory on a generic curved space which preserves at least two real supercharges. We also propose a one-to-one map between BPS states in d-dimensional field theories and states that contribute to the supersymmetric partition function of a corresponding (d-1)-dimensional field theory. As an application we obtain the superconformal index on rounded and squashed three spheres, and we show a natural reduction of the respective indices to the three-dimensional exact partition functions. We discuss the validity of the correspondence both at the perturbative and at the non-perturbative level and exploit the idea to uplift the computation of the exact supersymmetric partition function on a general manifold to a higher dimensional index.Comment: 25 pages, 1 figure, typos fixe

Review on Nonoccupational Personal Solar UV Exposure Measurements

Solar ultraviolet (UV) radiation follows people during their whole life. Exposure to UV radiation is vital but holds serious risks, too. The quantification of human UV exposure is a complex issue. UV exposure is directly related to incoming UV radiation as well as to a variety of factors such as the orientation of the exposed anatomical site with respect to the sun and the duration of exposure. The use of badge-sensors allows assessing the UV exposure of differently oriented body sites. Such UV devices have been available for over 40 years, and a variety of measuring campaigns have been undertaken since then. This study provides an overview of those studies which reported measurements of the personal UV exposure (PE) during outdoor activities of people not related to their occupation. This overview is given chronologically to show the progress of knowledge in this research and is given with respect to different activities. Special focus is put on the ratio of personal exposure to ambient UV radiation. This ratio, when given as a function of solar elevation, allows estimating PE at any other location or date if ambient UV radiation is known

Bootstrapping Neural tests for conditional heteroskedasticity

We deal with bootstrapping tests for detecting conditional heteroskedasticity in the context of standard and nonstandard ARCH models. We develope parametric and nonparametric bootstrap tests based both on the LM statistic and a neural statistic. The neural tests are designed to approximate an arbitrary nonlinear form of the conditional variance by a neural function. While published tests are valid asymptotically, they are not exact in finite samples and suffer from a substantial size distortion: the finite-sample error remains non-negligible, even for several hundred observations. Here, we treat this problem using bootstrap methods, making possible a better finite-sample estimate of the distribution of the test statistic. A graphical presentation employing a size-correction principle is used to show the true power of the tests rather than the spurious nominal power typically givenBootstrap, Artificial Neural Networks, ARCH models, inference tests

CleAir monitoring system for particulate matter. A case in the Napoleonic Museum in Rome

Monitoring the air particulate concentration both outdoors and indoors is becoming a more relevant issue in the past few decades. An innovative, fully automatic, monitoring system called CleAir is presented. Such a system wants to go beyond the traditional technique (gravimetric analysis), allowing for a double monitoring approach: the traditional gravimetric analysis as well as the optical spectroscopic analysis of the scattering on the same filters in steady-state conditions. The experimental data are interpreted in terms of light percolation through highly scattering matter by means of the stretched exponential evolution. CleAir has been applied to investigate the daily distribution of particulate matter within the Napoleonic Museum in Rome as a test case

A Bootstrap Neural Network Based Heterogeneous Panel Unit Root Test: Application to Exchange Rates

This paper proposes a bootstrap artificial neural network based panel unit root test in a dynamic heterogeneous panel context. An application to a panel of bilateral real exchange rate series with the US Dollar from the 20 major OECD countries is provided to investigate the Purchase Power Parity (PPP). The combination of neural network and bootstrapping significantly changes the findings of the economic study in favour of PPP.Artificial neural network, panel unit root test, bootstrap, Monte Carlo experiments, exchange rates.

Examination on total ozone column retrievals by Brewer spectrophotometry using different processing software

The availability of long-term records of the total ozone content (TOC) represents a valuable source of information for studies on the assessment of short-and long-term atmospheric changes and their impact on the terrestrial ecosystem. In particular, ground-based observations represent a valuable tool for validating satellite-derived products. To our knowledge, details about software packages for processing Brewer spectrophotometer measurements and for retrieving the TOC are seldom specified in studies using such datasets. The sources of the differences among retrieved TOCs from the Brewer instruments located at the Italian stations of Rome and Aosta, using three freely available codes (Brewer Processing Software, BPS; O3Brewer software; and European Brewer Network (EUBREWNET) level 1.5 products) are investigated here. Ground-based TOCs are also compared with Ozone Monitoring Instrument (OMI) TOC retrievals used as an independent dataset since no other instruments near the Brewer sites are available. The overall agreement of the BPS and O3Brewer TOC data with EUBREWNET data is within the estimated total uncertainty in the retrieval of total ozone from a Brewer spectrophotometer (1%). However, differences can be found depending on the software in use. Such differences become larger when the instrumental sensitivity exhibits a fast and dramatic drift which can affect the ozone retrievals significantly. Moreover, if daily mean values are directly generated by the software, differences can be observed due to the configuration set by the users to process single ozone measurement and the rejection rules applied to data to calculate the daily value. This work aims to provide useful information both for scientists engaged in ozone measurements with Brewer spectrophotometers and for stakeholders of the Brewer data products available on Web-based platforms

North Atlantic marine ¹⁴C reservoir effects: implications for late-Holocene chronological studies

We investigated surface ocean–atmosphere 14C offsets for the later Holocene at eight locations in the eastern North Atlantic. This resulted in 11 new ΔR assessments for the west coast of Ireland, the Outer Hebrides, the north coast of the Scottish mainland, the Orkney Isles and the Shetland Isles over the period 1300–500 BP. Assessments were made using a robust Multiple Paired Sample (MPS) approach, which is designed to maximize the accuracy of ΔR determinations. Assessments are placed in context with other available data to enable reconstruction of a realistic picture of surface ocean 14C activity over the Holocene period within the North Atlantic region