Ventilation system design for a church pipe organ using numerical simulation and on-site measurement

Since old churches have had heating installed, more complaints have arisen of organs sounding out of tune. Sound frequency of organ pipes is dependent on air temperature. Old churches tend to have very large volumes, so are typically heated just before and during services in wintertime, in order to reduce energy usage. Warm air plumes rise at radiators and spread out into the room, finally reaching the cold organ casing where they cause a non-uniform temperature distribution within. If pipes standing in different temperature zones are played at the same time the organ sounds out of tune due to clearly audible beats (interference between two slightly different frequencies). The purpose of this study was to design a ventilation system inside the organ casing, able to create a uniform temperature distribution around the pipes. A computational fluid dynamic (CFD) model was developed for the St. Martin church in Oberesslingen, Germany. It was validated by on-site measurements that had been carried out in the organ casing of the church. Four organ divisions containing 300–500 pipes were represented by equivalent porous material zones. Their properties were determined using an auxiliary two-dimensional model of a staggered array consisting of 392 pipes. The effect of different ventilation system settings on the temperature field in the organ casing was examined. Best results were achieved by a system consisting of two ventilation lines together with a thin, synthetic net placed at the open interface between church and organ casing in order to reduce warm air inflow.     

Two time-dependent responses of chicks to imprinting stimuli.

Analyzed in detail the conditions eliciting approach behavior to the imprinting stimulus in White Leghorn, New Hampshire, and hybrid White Leghorn-New Hampshire chicks. It was found that the approach response to a relatively weak imprinting stimulus could arise by 2 different mechanisms. Some Ss approached the stimulus object within a few min.; others needed a considerably longer stimulation, essentially a conditioning, to elicit the approach response. The 2 mechanisms, which were termed "prompt approach" and "conditioned approach," were distinguished on the basis of the different conditions required for eliciting them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of Facebook,Tuenti, Twitter and Myspace among young Spanish people

This research describes and analyses the use made by young Spanish people of Tuenti, Facebook, Twitter and Myspace, exploring several variables: level of functional knowledge; frequency of use; place of use; reason for use; purpose and main activity; recipients of communication; degree of difficulty, satisfaction and preference; and intentions regarding future use. We designed and administered an online questionnaire to 757 students enrolled in secondary education (7th–11th levels and Vocational Education and Training) at seven educational centres. The results show that young Spanish people know about and use social networks on a daily basis. Tuenti was the one used with most frequency, followed by Facebook and Twitter. Myspace was the least known and used. Female subjects had a greater functional knowledge of these networks and reported a higher regular use of them. Participants used the social networks in their homes and preferred Tuenti because it is easy to use, allows them to communicate with friends and classmates and provides them with acceptable satisfaction as regards their need for prestige, acceptance and approval through the creation and maintenance of groups of friends and the publication of their achievements and self-realisations. The implications of the results obtained for psychological and social development are discussed.     

Which h-index? — A comparison of WoS,Scopus and Google Scholar

This paper compares the h-indices of a list of highly-cited Israeli researchers based on citations counts retrieved from the Web of Science, Scopus and Google Scholar respectively. In several case the results obtained through Google Scholar are considerably different from the results based on the Web of Science and Scopus. Data cleansing is discussed extensively.     

A numerical performance study of a fixed-bed reactor for methanol synthesis by CO2 hydrogenation

Synthetic fuels are needed to replace their fossil counterparts for clean transport. Presently, their production is still inefficient and costly. To enhance the process of methanol production from CO₂ and H₂ and reduce its cost, a particle-resolved numerical simulation tool is presented. A global surface reaction model based on the Langmuir-Hinshelwood-Hougen-Watson kinetics is utilized. The approach is first validated against standard benchmark problems for non-reacting and reacting cases. Next, the method is applied to study the performance of methanol production in a 2D fixed-bed reactor under a range of parameters. It is found that methanol yield enhances with pressure, catalyst loading, reactant ratio, and packing density. The yield diminishes with temperature at adiabatic conditions, while it shows non-monotonic change for the studied isothermal cases. Overall, the staggered and the random catalyst configurations are found to outperform the in-line system.     

Effect of TiO2 and 11 minor elements on the reactivity of ground-granulated blast-furnace slag in blended cements

Ground-granulated blast-furnace slags (GGBS) are glasses (>99%) of the CaO-Al₂O₃-SiO₂ compositional system and are widely used as supplementary cementitious materials. Differences in reactivity of GGBS were screened by modifying the content of 12 minor elements (namely Ba, Ce, Cs, Cr, K, Mn, P, Sn, Sr, Ti, V, and Zr). Scanning electron microscopy observations showed that most elements entered the silicate glass matrix, only Sn was reduced to its metallic form and P accumulated in minor minerals. Mortar strength tests showed that 2 day compressive strength was reduced by >50% for a TiO₂ content of 2.5 wt% in the slag. At 28 days the loss in compressive strength was still >40%. Calorimetric tests on other element additions showed that the content of network modifiers (Ba, Cs, K and Sr) and GGBS reactivity are positively correlated, whereas Ce, Cr, V, and Zr significantly decreased reactivity. Finally, it is shown that these effects can be estimated by the concentration and the weighted field strength of the added element.     

Highly cited retracted papers

Scientometrics - We examine the number of citations in 10 highly cited retracted papers, and compare their current pre- and post-citation values. We offer some possible explanations for the...     

Chemically Diverse Multifunctional Peptide Platforms with Antimicrobial and Cell Adhesive Properties

Bacterial infections and incomplete biomaterial integration are major problems that can lead to the failure of medical implants. However, simultaneously addressing these two issues remains a challenge. Here, we present a chemical peptide library based on a multifunctional platform containing the antimicrobial peptide LF1-11 and the cell-adhesive motif RGD. The scaffolds were customized with catechol groups to ensure straightforward functionalization of the implant surface, and linkers of different length to assess the effect of peptide accessibility on the biological response. The peptidic platforms significantly improved the adhesion of mesenchymal stem cells and showed antimicrobial effects against Staphylococcus aureus. Of note is that peptides bearing spacers that were too long displayed the lowest efficiency. Subsequently, we designed a platform replacing linear RGD by cyclic RGD; this further enhanced eukaryotic cell adhesion while retaining excellent antimicrobial properties, thus being a suitable candidate for tissue engineering applications.     

Archival Practices and the Making of “Memories”

Following Derrida (1995), our article explores the relationship between archival practices and archival documents on the assumption that “archivization produces as much as it records the event” (Derrida 1995, 17). On this approach, archival practices are understood as non-innocent practices that, in the act of “preservation,” help make specific “memories” at the expense of others (Barad 2007; Derrida 1995; Foucault 1972). We take up this issue in relation to the curation of social science quantitative research data and argue that the ontological identity of data is constituted through historically- and culturally-specific data curation practices including data cleaning, data anonymization, and metadata preparation.