Molecular weight dependence and stereoselective chain cleavage during the early stages of the isotactic polypropylene pyrolysis

The comparative study on the pyrolysis of two Polypropylene samples, with a similar high isotactic character but quite distinct molecular weights, reveals a significant difference in their thermal performances. The detailed qualitative analysis of the parameters, which are expected to govern the thermal degradation, leads to reasonably assume a main role of the molecular weight in their relative early stabilities. Furthermore, the correlation found between the sharp initial build-up of the Eact and the selective cleavage of isotactic stereosequences in both samples, suggests the relevance of the stereoregular length into the energy required for chain scissionThe authors acknowledge the financial support of project MAT2016-79869-C2-1-P (AEI/FEDER, UE), as well as the kindly assistance of Repsol for the supply of samples.Peer reviewe

Can solar tower plants withstand the operational flexibility of combined cycle plants?

The aim of this work is to investigate the level of reliability of a 100 MWe solar tower plant operating as a load-following plant using actual operational data of combined cycle power plants. Despite the low cost, the steam generator has been identified as the main cause of unavailability of solar tower plants due to fatigue failures of tube-to-tubesheet joints, which can lead to steam/water leakage into the heat transfer fluid circuit, putting the plant performance at risk. A methodology based on the ASME code and EN standards is proposed to predict the fatigue failures of critical welded points of the steam generator, such as tube-to-tubesheet joints and other T-joints. The results show that the forced outages due to failures of the steam generator lead to an energy penalty that ranges over 230-453 GWh over the plant lifetime. The associated annual degradation rate ranges over 0.123-0.244%. Three tube leakage repair strategies are compared: tube-to-tubesheet weld crack repair, tube plugging and tube plugging with steam generator replacement. The latter strategy was shown to be the best practice because the lowest levelized cost of energy was obtained. In addition, the design of heat exchangers with a minimum of 20% extra area is highly recommended to not compromise the plant operation due to tube plugging. Last, the load-following operation of the solar tower plant increases the levelized cost of energy by approximately 1.6% in the case of tube repair and approximately 0.8% in the case of tube plugging with steam generator replacement.This research is partially funded by the Spanish government under the project RTI2018-096664-B-C21 (MICINN/FEDER, UE) and the fellowship "Programa de apoyo a la realización de proyectos interdisciplinares de I + D para jóvenes investigadores de la Universidad Carlos III de Madrid 2019-2020" under the project ZEROGASPAIN-CM-UC3M (2020/00033/001)

A Poglut1 mutation causes a muscular dystrophy with reduced Notch signaling and satellite cell loss

Skeletal muscle regeneration by muscle satellite cells is a physiological mechanism activated upon muscle damage and regulated by Notch signaling. In a family with autosomal recessive limbgirdle muscular dystrophy, we identified a missense mutation in POGLUT1 (protein O-glucosyltransferase 1), an enzyme involved in Notch posttranslational modification and function. In vitro and in vivo experiments demonstrated that the mutation reduces Oglucosyltransferase activity on Notch and impairs muscle development. Muscles from patients revealed decreased Notch signaling, dramatic reduction in satellite cell pool and a muscle-specific adystroglycan hypoglycosylation not present in patients’ fibroblasts. Primary myoblasts from patients showed slow proliferation, facilitated differentiation, and a decreased pool of quiescent PAX7+ cells. A robust rescue of the myogenesis was demonstrated by increasing Notch signaling. None of these alterations were found in muscles from secondary dystroglycanopathy patients. These data suggest that a key pathomechanism for this novel form of muscular dystrophy is Notch-dependent loss of satellite cells.Junta de Andalucía PI-0017-201

Changing prices after the reform of local public services: remunicipalization versus privatization

Privatization and remunicipalization have been used as alternative options to reform the delivery of local public services; in both cases, mainly because of disappointment with the service performance, although ideological preferences might also play a role. The drivers and effects of water privatization have been widely studied, whereas little empirical evidence is available for remunicipalization, particularly regarding its effects. Using a sample of Spanish municipalities, this paper assesses the change in the price of urban water following remunicipalization as compared to privatization. The main finding is that remunicipalization leads to smaller increases in price; this outcome is, however, due to a few atypical municipalities with abnormally low prices before the policy reform. Once these influential observations are controlled for, whether the reform consists of remunicipalization or privatization makes no difference regarding price changes. It is also found that remunicipalization is much more likely in cities governed by extreme left-wing parties.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work has been supported by the Spanish Agencia Estatal de Investigación, Ministerio de Ciencia e Innovación MCIN/AEI/https://doi.org/10.13039/501100011033 (projects PID2020-115135 GB-I00 to A.J.P.-T., PID2022-136235NB-I00 to F.G-G., and PID2022-138866OB-I00 to D.A. and G.B.); the Generalitat de Catalunya (project 2021 SGR 00261 to D.A. and G.B.); and the Generalitat Valenciana (project PROMETEO CIPROM/2022/50 to A.J.P.-T.)

Remunicipalization of Local Public Services: Policy Drivers and Changing Prices

Remunicipalization is triggered primarily by disappointment with the outcomes of private management of local public services, but an ideological preference for public management might also play a role. Even though urban water delivery is the service most affected by remunicipalization in developed countries, little empirical evidence is available on its effects. Using a sample of Spanish municipalities, this paper assesses the change in the price of urban water following remunicipalization as compared to privatization. The main finding is that remunicipalization leads to smaller increases in price; this outcome is, however, due to a few atypical municipalities with abnormally low prices for water before the policy reform. Once these influential observations are controlled for, the question of whether the reform consists of remunicipalization or privatization makes no difference regarding the change in prices. It is also found that remunicipalization is much more likely in local councils governed by extreme left-wing parties

Changing prices after the reform of local public services: Remunicipalization versus privatization

Privatization and remunicipalization have been used as alternative options to reform the delivery of local public services; in both cases mainly because of disappointment with the service performance, although ideological preferences might also play a role. The drivers and effects of water privatization have been widely studied, whereas little empirical evidence is available for remunicipalization, particularly regarding its effects. Using a sample of Spanish municipalities, this paper assesses the change in the price of urban water following remunicipalization as compared to privatization. The main finding is that remunicipalization leads to smaller increases in price; this outcome is, however, due to a few atypical municipalities with abnormally low prices before the policy reform. Once these influential observations are controlled for, whether the reform consists of remunicipalization or privatization makes no difference regarding price changes. It is also found that remunicipalization is much more likely in cities governed by extreme left-wing parties

Northern Shrimp (Pandalus borealis, Krøyer) from Spanish Bottom Trawl Survey 2009 in NAFO Div. 3LNO

The Spanish Institute of Oceanography carried out in 2009 two bottom trawl surveys in the NAFO Regulatory Area in Division 3NO and 3L during the months of June, July and August respectively. The results on Northern shrimp (Pandalus borealis) are presented and compared with those from previous surveys from the same series. In 2009 the catch (33 kg.) and estimated biomass (139 t.) confirm the decrease of shrimp importance from 2004 in 3NO. In 2009 the biomass estimated of northern shrimp in 3L Division was 74091 t. showing a drastic decline (50% with respect to 2008) after the upward trend a long the whole period studied. Catch results from the surveys and data analysis are discussed in this paper

Máster en Educación Matemática en Colombia

El grupo Didáctica de la Matemática: Pensamiento Numérico (FQM-193), del Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI) ha venido colaborando con la Universidad de los Andes de Bogotá, Colombia en la realización de un máster de profundización para profesores de matemáticas de secundaria en ejercicio. La primera versión de este máster se inició en enero de 2010. El programa busca contribuir al desarrollo del conocimiento didáctico de los profesores en formación, al guiarlos en la puesta en práctica de un ciclo del análisis didáctico e involucra esquemas metodológicos y de evaluación que se adaptan a su carácter semi virtual. En este trabajo se describirá el diseño curricular del programa y se presentarán unas primeras impresiones acerca de su desarrollo