Functionalized carbon nanotubes as a filler for dielectric elastomer composites with improved actuation performance

Among the broad class of electro-active polymers, dielectric elastomer actuators represent a rapidly growing technology for electromechanical transduction. In order to further develop this applied science, the high driving voltages currently needed must be reduced. For this purpose, one of the most widely considered approaches is based on making elastomeric composites with highly polarizable fillers in order to increase the dielectric constant while maintaining both low dielectric losses and high-mechanical compliance. In this work, multi-wall carbon nanotubes were first functionalized by grafting either acrylonitrile or diurethane monoacrylate oligomers, and then dispersed into a polyurethane matrix to make dielectric elastomer composites. The procedures for the chemical functionalization of carbon nanotubes and proper characterizations of the obtained products are provided in detail. The consequences of the use of chemically modified carbon nanotubes as a filler, in comparison to using unmodified ones, were studied in terms of dielectric, mechanical and electromechanical response. In particular, an increment of the dielectric constant was observed for all composites throughout the investigated frequency spectrum, but only in the cases of modified carbon nanotubes did the loss factor remain almost unchanged with respect to the simple matrix, indicating that conductive percolation paths did not arise in such systems. An effective improvement in the actuation strain was observed for samples loaded with functionalized carbon nanotubes

Analysis of municipal mergers in the state of Rio Grande do Sul : evaluation of the economic efficiency of the municipalities through Data Envelopment Analysis (DEA)

O estudo objetiva analisar como fusões municipais no Estado do Rio Grande do Sul (RS) podem impactar positivamente no grau de eficiência econômica dos municípios. A pesquisa dispõe de abordagem quantitativa, descritiva e documental. Para tanto utilizou-se a Análise por Envoltória de Dados (DEA) para mensurar a eficiência econômica dos municípios por meio de variáveis de entrada e de saída extraídas do sítio eletrônico do Tribunal de Contas do Estado do RS, do InstitutoBrasileiro de Geografia e Estatística e da Secretaria do Tesouro Nacional. Os dados coletados evidenciaram que os micros e pequenos municípios tendem a depender financeiramente da União e do Estado, possuindo receita própria irrisória. Após a primeira aplicação do modelo, foram selecionados os municípios com eficiência econômica abaixo da média do estado, os quais em sua maioria possuíam até 15 mil habitantes. Posteriormente foi realizada uma proposta de fusão municipal reduzindo os municípios selecionadosde 208 para 45, novamente analisados através do modelo selecionado. Após nova aplicação do modelo, foi constatado o aumento do grau de eficiência dos municípios. Ademais, as fusões analisadas suprimiriam o número de micro e pequenos municípios em cerca de52%, além de reduzir 1.377 vereadores, gerando uma economia de aproximadamente 58 milhões de reais aos cofres públicos. A partir da crise financeira dos municípios brasileiros que tem sido amplamente noticiada, o estudo contribui gerando discussões acercade medidas como fusões municipais que visam aumentar a eficiência econômica dos municípios.The study aims to analyze how municipal mergers in the State of Rio Grande do Sul (RS) can positively impact the degree of economic efficiency of municipalities. The research has a quantitative, descriptive and documentary approach. For this purpose, Data Envelopment Analysis (DEA) was used to measure the economic efficiency of municipalities through input and output variables extracted from the website of the Court of Auditors of the State of RS, the Brazilian Institute of Geography and Statistics and the National Treasury Secretariat. The collected data showed that the micro and small municipalities tend to depend financially on the Union and the State, having their own negligible income. After the first application of the model, municipalities with economic efficiency below the state average were selected, most of which had up to 15,000 inhabitants. Subsequently, a proposal for a municipal merger was carried out, reducing the selected municipalities from 208 to 45, again analyzed using the selected model. After a new application of the model, an increase in the degree of efficiency of the municipalities was verified. Furthermore, the mergers analyzed would suppress the number of micro and small municipalities by around 52%, in addition to reducing 1,377 councillors, generating savings of approximately 58 million reais to public coffers. From the financial crisis of Brazilian municipalities that has been widely reported, the study contributes by generating discussions about measures such as municipal mergers that aim to increase the economic efficiency of municipalities

ANÁLISE DE FUSÕES MUNICIPAIS NO ESTADO DO RIO GRANDE DO SUL: AVALIAÇÃO DA EFICIÊNCIA ECONÔMICA DOS MUNICÍPIOS POR MEIO DA ANÁLISE POR ENVOLTÓRIA DE DADOS (DEA)

O estudo objetiva analisar como fusões municipais no Estado do Rio Grande do Sul (RS) podem impactar positivamente no grau de eficiência econômica dos municípios. A pesquisa dispõe de abordagem quantitativa, descritiva e documental. Para tanto utilizou-se a Análise por Envoltória de Dados (DEA) para mensurar a eficiência econômica dos municípios por meio de variáveis de entrada e de saída extraídas do sítio eletrônico do Tribunal de Contas do Estado do RS, do Instituto Brasileiro de Geografia e Estatística e da Secretaria do Tesouro Nacional. Os dados coletados evidenciaram que os micros e pequenos municípios tendem a depender financeiramente da União e do Estado, possuindo receita própria irrisória. Após a primeira aplicação do modelo, foram selecionados os municípios com eficiência econômica abaixo da média do estado, os quais em sua maioria possuíam até 15 mil habitantes. Posteriormente foi realizada uma proposta de fusão municipal reduzindo os municípios selecionados de 208 para 45, novamente analisados através do modelo selecionado. Após nova aplicação do modelo, f O estudo objetiva analisar como fusões municipais no Estado do Rio Grande do Sul (RS) podem impactar positivamente no grau de eficiência econômica dos municípios. A pesquisa dispõe de abordagem quantitativa, descritiva e documental. Para tanto utilizou-se a Análise por Envoltória de Dados (DEA) para mensurar a eficiência econômica dos municípios por meio de variáveis de entrada e de saída extraídas do sítio eletrônico do Tribunal de Contas do Estado do RS, do Instituto Brasileiro de Geografia e Estatística e da Secretaria do Tesouro Nacional. Os dados coletados evidenciaram que os micros e pequenos municípios tendem a depender financeiramente da União e do Estado, possuindo receita própria irrisória. Após a primeira aplicação do modelo, foram selecionados os municípios com eficiência econômica abaixo da média do estado, os quais em sua maioria possuíam até 15 mil habitantes. Posteriormente foi realizada uma proposta de fusão municipal reduzindo os municípios selecionados de 208 para 45, novamente analisados através do modelo selecionado. Após nova aplicação do modelo, foi constatado o aumento do grau de eficiência dos municípios. Ademais, as fusões analisadas suprimiriam o número de micro e pequenos municípios em cerca de 52%, além de reduzir 1.377 vereadores, gerando uma economia de aproximadamente 58 milhões de reais aos cofres públicos. A partir da crise financeira dos municípios brasileiros que tem sido amplamente noticiada, o estudo contribui gerando discussões acerca de medidas como fusões municipais que visam aumentar a eficiência econômica dos municípios

Prevalence and prenatal ultrasound detection of clubfoot in a non-selected population: an analysis of 549 931 births in Tuscany

Objective: To evaluate the prevalence and prenatal ultrasound detection of clubfoot in Tuscany during a period of 20 years. Methods: This is a descriptive analysis on data from the Tuscan register of congenital defects, covering a 20-year period from 1992 to 2011. The Tuscan registry of congenital defects is a population-based register for the epidemiologic surveillance of congenital anomalies. The study included all cases of pre- or postnatally diagnosed clubfoot (isolated clubfoot and cases associated with other congenital defects). Overall prevalence and pre-natal detection rates were calculated. Results: Among the 549 931 deliveries recorded in Tuscany between 1992 and 2011, 858 cases of clubfoot were registered, with a prevalence of 1.56/1000. Seventy-eight percent of cases were isolated. The detection rate was higher when the defect was associated with other anomalies compared to isolated forms. Over the study period, there was a substantial improvement in the prenatal detection of clubfoot (from 11 to 31% overall). For isolated forms, detection rate improved from 4 to 16%, and for cases associated with other congenital defects, it increased from 43 to 73%. Conclusion: Prevalence of clubfoot in Tuscany is 1.56 per 1000 births, in agreement with the incidence reported in epidemiological studies in Europe. Prenatal detection of clubfoot improved over time. The detection rate was higher in cases associated with other anomalies

Evolution of calcite surfaces upon thermal decomposition, characterized by electrokinetics, in-situ XRD, and SEM

The present study analyses transformation pathways of pristine and thermally treated porous limestone and dense marble surfaces by means of time-resolved streaming current and potential measurements coupled with scanning electron microscopy and in-situ X-ray diffraction. The results reveal that under nonequilibrium conditions the zeta potential (ζ) of natural carbonates may exhibit positive and negative signs and ζ drifts in opposite directions. Sample surface roughness influences ζ because it contributes to dissolution, as observed particularly in the initial period of time-resolved measurements. Thermal treatment causes a temporary charge reversal from negative to positive. The reactivity of calcium hydroxide on calcite surfaces governs the net electrokinetic potential and isoelectric point (IEPpH), even at low surface coverage, as cross-validated by in-situ XRD. It was also found that pore conductivity may lead to ~90% underestimation of ζ when assessed by streaming potential. SEM studies revealed micro cracks inducement on marble after thermal treatment, which can result in underestimation of ζ up to the same extent as for the porous limestone. When an asymmetric cell configuration involving calcite and polypropylene surfaces is used, the fractional contribution of polypropylene to the IEPpH is 0.3 and to the overall determined ζ up to 0.5. Our findings contribute to the understanding of nonequilibrium and time-dependent electrokinetic potential modifications associated with the reactivity of porous surfaces. This study highlights the effectiveness of the streaming potential technique for monitoring such changes further supported by the use of ancillary techniques to analyze the extend of chemo-mineralogical and physical alterations

Laboratory-based surveillance of invasive listeriosis in Northern Italy over a fourteen-year period: epidemiological and clinical results

Introduction Invasive listeriosis is a rare foodborne disease with a large public health impact, because of the severity of its clinical manifestations and high fatality rate. In this study, we provide a snapshot of epidemiology of listeriosis in Lombardy Region, Northern Italy, reviewing enhanced surveillance data collected over fourteen years, after the implementation of a voluntary laboratory-based surveillance system for the referral of clinical isolates of Listeria monocytogenes to a regional reference laboratory, since 2005. Methods Invasive listeriosis cases data from 2005 to 2018 were extracted from the regional laboratory-based surveillance system database and compared with the regional mandatory notification disease system data. Results Over the fourteen period under study, 533 Listeria monocytogenes isolates were detected by the laboratory surveillance system, 55 of which from pregnancy-related cases. The median age of non-pregnancy-associated patients was 71 years, with 64.6% of cases observed in the elderly. Cases with underlying medical risk conditions accounted for 92.1%, and the fatality rate was 26.2%. By integrating data from the two sources, a total of 935 cases were recorded. The collection of data through the laboratory surveillance system allowed to increase the surveillance sensitivity by 18%. Conclusions Our results documented the growing epidemiological relevance of listeriosis through the analysis of two information sources. The data we obtained were consistent with the literature, except for pregnancy-related cases, which are often underdiagnosed. This study highlighted the importance of laboratory-based surveillance system, which led to a significant increase in the sensitivity of the mandatory notification system

Ventricular Dyssynchrony: 12-month Evaluation In Ischemic Versus Nonischemic CRT Patients

Objective: Few data exist about the potential differences in the dyssynchrony status of cardiac resynchronization therapy (CRT) candidates stratified by etiology of heart failure, and about the evolution of dyssynchrony at long-term follow-up. We provided a description of intra-ventricular dyssynchrony at baseline, 6 months and 12 months in ischemic and nonischemic CRT patients.Methods: Tissue Doppler Imaging was performed in 35 CRT candidates (18 ischemic, 17 nonischemic) at baseline, and at 6-month and 12-month follow-up. A group of 11 healthy subjects was considered for comparison.Results: At baseline, the standard deviation and the maximum activation delay between any 2 segments were significantly greater in ischemic (38±33ms, 94±76ms) and nonischemic (38±24ms, 96±62ms) patients versus controls (9±7ms, 22±15ms) (all p<0.05). The average time to activation for posterior and lateral wall was significantly higher in nonischemic patients, while the anterior septum activated later in ischemic patients. At 6-month follow-up, standard deviation and maximum delay did not vary in nonischemic while decreased in ischemic group. All changes persisted at 12 months.Conclusions No baseline differences were observed between ischemic and nonischemic patients using studied indices. At 6- and 12-month follow-up, only ischemic patients presented a significant reduction in dyssynchrony values, although in both groups CRT did not lead to a complete normalization of LV synchronism

Preparation of water suspensions of nanocalcite for cultural heritage applications

The consolidation of degraded carbonate stone used in ancient monuments is an important topic for European cultural heritage conservation. The products most frequently used as consolidants are based on tetraalkoxy- or alkylalkoxy-silanes (in particular tetraethyl-orthosilicate, TEOS), resulting in the formation of relatively stable amorphous silica or alkylated (hydrophobic) silica inside the stone pores. However, silica is not chemically compatible with carbonate stones; in this respect, nanocalcite may be a suitable alternative. The present work concerns the preparation of water suspensions of calcite nanoparticles (CCNPs) by controlled carbonation of slaked lime using a pilot-scale reactor. A simplified design of experiment was adopted for product optimization. Calcite nanoparticles of narrow size distribution averaging about 30 nm were successfully obtained, the concentration of the interfacial agent and the size of CaO being the most critical parameters. Primary nanoparticle aggregation causing flocculation could be substantially prevented by the addition of polymeric dispersants. Copolymer-based dispersants were produced in situ by controlled heterophase polymerisation mediated by an amphiphilic macro-RAFT (reversible addition-fragmentation transfer) agent. The stabilized CCNP aqueous dispersions were then applied on carbonate and silicate substrates; Scanning Electron Microscopy (SEM)analysis of cross-sections allowed the evaluation of pore penetration, interfacial binding, and bridging (gap-filling) properties of these novel consolidants