An inexpensive and continuous radon progeny detector for indoor air-quality monitoring

A silicon photodiode-based inexpensive detector working as a counter and spectrometer for alpha particles has been conceived, designed, constructed and analyzed in depth. Monte Carlo simulations by means of MCNPX ver. 2.7.0 code have been carried out to select the most suitable sensitive element for the intended applications. The detecting unit has been coupled to an Arduino board and tested for low-rate alpha-particle counting and spectroscopy. Results demonstrate a maximum count rate of 4000 s-1, an energy resolution corresponding to a full width at half maximum of 160 keV over the entire energy range of measured alpha (namely 4 ÷ 6.5 MeV), and the sensitive element’s intrinsic efficiency of about 100%. Being the detector capable of distinguishing alpha energy associated to decays of radon daughters, its applications include 222Rn progeny monitoring. The air sampling system has been realized by a volumetric micro-pump forcing the air-flow through a millipore filter. By knowing the air-flow rate processed and the corresponding alpha energy spectrum measured, the concentrations of 218Po, 214Po and 210Po are determined. The potential alpha energy concentration-in-air is inferred, and effective dose evaluated. Calibration and testing measurements have been carried out by comparing the obtained results to the outputs of professional and expensive radon progeny monitor. The detector capability of “following” radon progeny concentration-in-air vs. time has been demonstrated. The device studied here can be configured as a prototype for an inexpensive radon progeny sensor to be potentially suitable for indoor air-monitoring in residential buildings, evaluating people’s exposures to radon and initiating corrective actions (e.g., mechanical ventilation) if necessary

Energy and economic analysis of a residential Solar Organic Rankine plant

To answer the actual energy, water, economic, social and environmental challenges, renewable, distributed power plants need to be developed. Among renewables, solar tri-generative power plants can be a solution where there is big low temperature heating/cooling demand and small electricity demand, like many residential and industrial utilities. In this case, solar thermal plants can produce thermal energy with low cost and high efficiency. The higher temperature heat not needed by the user can be exploited via Organic Rankine Cycle to produce electrical energy and desalinized water via reverse osmosis. The present paper analyses, via TRNSYS simulation, a system composed of 50 m2 of CPC solar thermal collectors, 3 m3 of thermal storage, a synthetic heat transfer fluid, 3 kWe ORC, 8 kWth absorber, 200 l/h direct reverse osmosis desalination device. The system is able to produce power, heating/cooling and fresh water needs for a residential house. Although system’s components are well known technologies, the integration to a efficient and economic working system is still a challenge. Global energy and economic analyses have been performed. Low temperature heating/cooling terminals allow to increase not only the use of thermal energy but also the ORCand absorber efficiency. ORC-Absorber configuration and relative fluids and temperatures are central. Government support and/or cost reduction of 30% are necessary to have positive NPV and acceptable PBT and IR

Indoor radon survey in university buildings: a case study of Sapienza - University of Rome

The indoor radon concentration in underground workplaces pertaining to Sapienza – University of Rome have been monitored since the 90’s according to prescription of Italian Legislative Decree 230/95. In the last years, the recommendations contained in the Council Directive 2013/59/Euratom have shifted the focus to all indoor exposure situations by promoting actions to identify workplaces and dwellings with radon concentrations exceeding the reference level of 300 Bq/m3. In response to the upcoming transposition into national legislation, Sapienza has promoted the first Italian survey addressing workplaces in university buildings, regardless of the position with respect to the ground floor. The survey has interested more than three hundred workplaces, i.e. administration and professors’ offices, research and educational laboratories, conference rooms and classrooms, distributed in fifteen different buildings. Places monitored are strongly heterogeneous in terms of users’ habit, occupancy pattern and building characteristics. The influence of these parameters into seasonal variation have been addressed by organizing the survey in four quarters. The indoor radon concentration is measured by solid state nuclear track detectors, CR39. The aim of the paper is to present features, methods and intermediate results of the survey. The work, relying on the analysis of previous measurements interesting underground workplaces, focuses on methodology followed during all the preliminary and preparatory phases: active measurements by ionization chamber radon continuous monitor, radon progeny equilibrium factor estimations by radon daughters monitor, strategies for occupants’ awareness, positioning protocol and provisions to maximize representativity of results

The Constrained Politics of Local Public Investments under Cooperative Federalism

Public investment spending declined steadily in advanced economies during the last three decades. Germany is a case in point where the aggregate decline coincided with growing inequality in investments across districts. What explains variation in local investment spending? We assembled a novel dataset to investigate the effects of structural constraints and partisanship on German districts’ investment spending from 1995 to 2018. We find that the lack of fiscal and administrative capacity significantly influences local investment patterns. Yet, within these constraints, partisanship matters. Conservative politicians tend to prioritize public investment more than the left. This is especially the case when revenues from local taxes are low. As the fiscal conditions improve, left-wing politicians increase investment more strongly and hence the difference between the left and the right disappears. Our findings are indicative of how regional economic divergence can emerge even within cooperative federalist systems and show that, despite rigid fiscal rules, partisanship matters when parties face trade-offs over discretionary spending.Über die vergangenen Jahrzehnte sind öffentliche Investitionen in Industrieländern deutlich zurückgegangen. Dies ist auch in Deutschland zu beobachten, wo der Rückgang mit wachsenden Ungleichheiten zwischen Kreisen einherging. Dieser Beitrag untersucht diese interregionalen Diskrepanzen von öffentlichen Investitionen in Deutschland. Zu diesem Zweck nutzen wir einen neuen Datensatz, der strukturelle Bedingungen sowie parteipolitische Aspekte erfasst, die Investitionstätigkeit auf der Kreisebene zwischen 1995 und 2018 beeinflusst haben. Wir zeigen, dass Finanzprobleme sowie fehlendes technisches Personal die Investitionstätigkeit maßgeblich beschränkt haben. Gleichzeitig setzen unterschiedliche lokale Parteien in Anbetracht solcher strukturellen Beschränkungen unterschiedliche Prioritäten in ihren freiwilligen Ausgaben. Konservative Bürgermeister und Landräte tendieren dazu, öffentliche Investitionen mehr zu priorisieren als linke Politiker. Dies ist vor allem der Fall, wenn die Einnahmen aus Gewerbesteuern gering sind. Wenn die Einnahmen steigen, erhöhen linke Politiker ihre Ausgaben für öffentliche Investitionen allerdings stärker als rechte Politiker, sodass der Unterschied verschwindet. Diese Resultate indizieren, dass regionale Ungleichheiten in öffentlichen Investitionen sogar in kooperativen föderalen Systemen auftreten können und zeigen, wie Parteipolitik lokale Ausgabenentscheidungen selbst dann beeinflusst, wenn lokale Entscheidungsträger unter rigiden Regeln operieren.Contents 1 Introduction 2 Germany’s divergent local investments and the political economy of local public finances 3 Constrained partisanship: The politics of public investments in a multi-level polity Fiscal and administrative constraints for local public investments Local partisanship, voluntary spending priorities, and responsiveness to different constraints 4 Data and methodology Data Independent and dependent variables Methods 5 Empirical results The constraining effects of Germany’s semi-sovereign state on local public investments The constrained partisanship of investment spending 6 Concluding discussion Reference

The Constrained Politics of Local Public Investment Under Cooperative Federalism

Public investment spending declined steadily in advanced economies during the last three decades. Germany is a case in point where the aggregate decline coincided with growing inequality in investments across districts. What explains the variation in local investment spending? We assembled a novel data set to investigate the effects of structural constraints and partisanship on German districts’ investment spending from 1995 to 2018. We find that the lack of fiscal and administrative capacity significantly influences local investment patterns. Yet, within these constraints, partisanship matters. Conservative politicians tend to prioritize public investment more than the left. This is especially the case when revenues from local taxes are low. As the fiscal conditions improve, left-wing politicians increase investment more strongly and hence the difference between the left and the right disappears. Our findings are indicative of how regional economic divergence can emerge even within cooperative federal systems and show that, even when decision-makers operate under various institutional and structural constraints, partisanship matters for how these actors allocate discretionary spending.1. Introduction 2. Germany’s divergent patterns of local public investment and the political economy of subnational fiscal policymaking 3. Structural constraints and partisan choices: public investment in a multilevel polity 4. Data and methodology 5. Empirical results 6. Concluding discussion Footnotes Acknowledgments Supplementary material Reference

Efficient and stable perovskite large area cells by low-cost fluorene-xantene-based hole transporting layer

Among the new generation photovoltaics, perovskite solar cell (PSC) technology reached top efficiencies in a few years. Currently, the main objective to further develop PSCs is related to the fabrication of stable devices with cost-effective materials and reliable fabrication processes to achieve a possible industrialization pathway. In the n-i-p device configuration, the hole transporting material (HTM) used most is the highly doped organic spiro-fluorene-based material (Spiro-OMeTAD). In addition to the high cost related to its complex synthesis, this material has different issues such as poor photo, thermal and moisture stability. Here, we test on small and large area PSCs a commercially available HTM (X55, Dyenamo) with a new core made by low-cost fluorene-xantene units. The one-pot synthesis of this compound reduces 30 times its cost with respect to Spiro-OMeTAD. The optoelectronic performances and properties are characterized through JV measurement, IPCE (incident photon to current efficiency), steady-state photoluminescence and ISOS stability test. SEM (scanning electron microscope) images reveal a uniform and pinhole free coverage of the X55 HTM surface, which reduces the charge recombination losses and improves the device performance relative to Spiro-OMeTAD from 16% to 17%. The ISOS-D-1 stability test on large area cells without any encapsulation reports an efficiency drop of about 15% after 1000 h compared to 30% for the reference case

Direct-acting antivirals and visceral leishmaniasis: A case report

Background: Visceral leishmaniasis is a vector-borne parasitic disease caused by protozoa belonging to the genus Leishmania. The clinical presentation of visceral leishmaniasis strictly depends on the host immunocompetency, whereas depressive conditions of the immune system impair the capability to resolve the infection and allow reactivation from sites of latency of the parasite. Case presentation: We describe a case of visceral leishmaniasis (VL) that occurred in a patient with chronic hepatitis C treated with direct-acting antiviral drugs (DAA). The hypothesized mechanism is the alteration of protective inflammation mechanisms secondary to DAA therapy. Downregulation of type II and III IFNs, their receptors, which accompany HCV clearance achieved during treatment with sofosbuvir and ribavirin might have a negative impact on a risk for reactivation of a previous Leishmania infection. We know indeed that IFN-\u3b3 is important to enhance killing mechanisms in macrophages, which are the primary target cells of Leishmania. Conclusion: Since VL is endemic in Sicily as well as in other countries of the Mediterranean basin, physicians should be aware of the possible unmasking of cryptic Leishmania infection by DAAs

Prospects for Stochastic Background Searches Using Virgo and LSC Interferometers

We consider the question of cross-correlation measurements using Virgo and the LSC Interferometers (LIGO Livingston, LIGO Hanford, and GEO600) to search for a stochastic gravitational-wave background. We find that inclusion of Virgo into the network will substantially improve the sensitivity to correlations above 200 Hz if all detectors are operating at their design sensitivity. This is illustrated using a simulated isotropic stochastic background signal, generated with an astrophysically-motivated spectrum, injected into 24 hours of simulated noise for the LIGO and Virgo interferometers.Comment: 11 pages, uses IOP style files, submitted to CQG for GWDAW11 proceedings; revised in response to referee comment