Recommendation of RILEM Technical Committee 250-CSM: Test method for Textile Reinforced Mortar to substrate bond characterization

Textile Reinforced Mortar (TRM), also known as Fabric Reinforced Mortar or Fabric Reinforced Cementitious Matrix, composites are an emerging technology for the external repair and strengthening of existing structures. For most applications, the effectiveness of the TRM reinforcement relies on its bond performance. This recommendation identifies the best practice to characterize the bond behaviour of TRM. A shear bond test method is proposed to determine the peak axial stress (associated with the maximum load that can be transferred from the structural member to the externally bonded TRM reinforcement), the stress–slip relationship and the failure mode that controls the TRM-to-substrate load transfer capacity. Guidelines on specimen manufacturing, experimental setup, test execution, and determination of test results are provided.     

Experimental and numerical analysis of heat transfer and airflow on an interactive building facade

The envelope of a building is mainly responsible for its energy demand. Different kinds of double skin facades (DSFs) are nowadays used as a building envelope to reduce the energy demand and improve aesthetical view of buildings. Although DSF are already extensively used, their thermal performance is not well understood. This study presents a decoupling method capable to evaluate thermal performances and analyze fluid phenomena in a DSF. The solar radiation effects were evaluated with an analytical model and computational fluid dynamics (CFD) simulations were used to evaluate complex flow and thermal effect on a commercial DSF. With the decoupling approach to account for the effects of solar radiation and flow, the numerical results obtained by the CFD approach agree well with the experimental data collected on a full scale test room with a ventilated DSF. The method can be used to establish a database to develop a tool for DSF design.     

Effect of Water on the Ethanolysis of Waste Cooking Soybean Oil Using a Tin(II) Chloride Catalyst

Biodiesel production from cheap lipid raw materials is economically welcome, but a high free fatty acids (FFA) content makes it incompatible with traditional alkaline catalysts. Although liquid mineral acids are alternatively used, serious drawbacks such as high corrosiveness and large effluent generation, as well as the impossibility of catalyst reuse compromises its application. Contrarily, solid acid catalysts appear to be an attractive option; however, the water present or generated during FFA esterification provokes the leaching and deactivation of these catalysts. Thus, in this work we have evaluated the use of tin chloride SnCl₂, which is less corrosive, water tolerant, and a recyclable Lewis acid catalyst, on FFA ethanolysis using waste cooking oil samples (WCO). Additionally, the main kinetic parameters of the reactions were assessed. Compared to pTSA (p-toluenesulfonic-acid), a catalyst also evaluated, SnCl₂ efficiently promoted FFA ethanolysis even in the presence of high amounts of water (ca. 0.1–5.0% w/w). Moreover, the homogeneous SnCl₂ catalyst was easily recovered and reused successively, without loss of activity.     

Influence of molecular weight on the crystallization of poly(vinylidene fluoride)

Five samples of Poly (vinylidene fluoride) with a molecular weight from 45,000 to 260,000 were analyzed by means of FT-IR spectroscopy in order to study the influence of molecular weight on the crystallization process. The spectra of films obtained from methylethylketone solutions revealed the prevalence of form II () in the case of lower and of form III () in the higher molecular weight samples. The amount of form III was found to increase as the Mv decreased and as annealing temperatures increased. The deconvolution technique of vibrational spectra allowed detection of small amounts of other forms accompanying the prevailing one.     

Wild Brazilian Mustard (Brassica juncea L.) Seed Oil Methyl Esters as Biodiesel Fuel

Wild mustard (Brassica juncea L.) oil is evaluated as a feedstock for biodiesel production. Biodiesel was obtained in 94 wt.% yield by a standard transesterification procedure with methanol and sodium methoxide catalyst. Wild mustard oil had a high content of erucic (13(Z)-docosenoic; 45.7 wt.%) acid, with linoleic (9(Z),12(Z)-octadecadienoic; 14.2 wt.%) and linolenic (9(Z),12(Z),15(Z)-octadecatrienoic; 13.0 wt.%) acids comprising most of the remaining fatty acid profile. The cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of the methyl esters was 61.1, 5.33 mm² s⁻¹ (40 °C) and 4.8 h (110 °C), respectively. The cloud, pour and cold filter plugging points were 4, −21 and −3 °C, respectively. Other properties such as acid value, lubricity, free and total glycerol content, iodine value, Gardner color, specific gravity, as well as sulfur and phosphorous contents were also determined and are discussed in light of biodiesel standards ASTM D6751 and EN 14214. Also reported are the properties and composition of wild mustard oil, along with identification of wild mustard collected in Brazil as Brassica juncea L. (2n = 36) as opposed to the currently accepted Sinapis arvensis L. (2n = 18) classification. In summary, wild mustard oil appears to be an acceptable feedstock for biodiesel production. Disclaimer: Product names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

C-HEAP: A Heterogeneous Multi-Processor Architecture Template and Scalable and Flexible Protocol for the Design of Embedded Signal Processing Systems

The key issue in the design of Systems-on-a-Chip (SoC) is to trade-off efficiency against flexibility, and time to market versus cost. Current deep submicron processing technologiesenable integration of multiple software programmable processors (e.g., CPUs,DSPs) and dedicated hardware components into a single cost-efficient IC. Ourtop-down design methodology with various abstraction levels helps designingthese ICs in a reasonable amount of time. This methodology starts with a high-levelexecutable specification, and converges towards a silicon implementation.A major task in the design process is to ensure that all components (hardwareand software) communicate with each other correctly. In this article, we tacklethis problem in the context of the signal processing domain in two ways: wepropose a modular, flexible, and scalable heterogeneous multi-processor architecturetemplate based on distributed shared memory, and we present an efficient andtransparent protocol for communication and (re)configuration. The protocolimplementations have been incorporated in libraries, which allows quick traversalof the various abstraction levels, so enabling incremental design. The designdecisions to be taken at each abstraction level are evaluated by means of(co-)simulation. Prototyping is used too, to verify the system's functionalcorrectness. The effectiveness of our approach is illustrated by a designcase of a multi-standard video and image codec.He currently works with Magma Design Automation. E-mail:     

A penetration test to study the mechanical response of mortar in ancient masonry buildings

A simple method for studying the mechanical response of the mortar in existing masonry buildings is presented herein. The method is based on the measurement of the penetration depth increment of a steel probe (4 mm diameter) at each hammer blow (impact energy=2.2 J). Numerous tests were carried out on different laboratory specimens in order to formulate a relationship between the compressive strength and the probe penetration rate, and a series of tests on actual masonry elements confirmed that the proposed relationship is sound.

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Résumé On présente une méthode d’essai simple pour évaluer la resistance à la compression des mortiers des murs existants. La méthode proposée ici est basée sur la mesure de la profondeur de pénétration d’une sonde d’acier (4 mm de diamètre), à chaque coup de scléromètre (énergie d’impact=2,2 Joule). Les résultats de nombreux essais effectués sur des éprouvettes construites en laboratoire ont permis d’obtenir une relation entre la résistance à la compression du mortier et la vitesse de pénétration de la sonde. En outre, la validité de cette méthode a été confirmée par une série d’essais effectués sur des murs existants.

     

Occult hepatitis B among patients with chronic renal failure on hemodialysis from a capital city in northeast Brazil

Occult hepatitis B (OHB) is characterized by the presence of HBV‐DNA in the absence of HBsAg in the serum of patients. Hemodialysis patients are at high risk for hepatitis B virus and there are few data on the prevalence of OHB in this population, mainly in Brazil. Thus, the aim of this study was to determine the prevalence of OHB in patients undergoing hemodialysis. A cross‐sectional study was performed, including 301 patients on chronic hemodialysis at two dialysis centers in São Luís (Maranhão), northeast Brazil. Serological tests were performed for HBsAg, anti‐HBc, anti‐HBs, and anti‐HCV using enzyme immunoassays (ELISA); HBV‐DNA and HCV‐RNA were studied by real‐time PCR. The mean age was 49 ± 15 years, and 128 (42%) were female. Serological tests confirmed that all samples were HBsAg negative. Anti‐HBc was positive in 114 (38%) patients, anti‐HBc and anti‐HBs were simultaneously positive in 104 (35%), and anti‐HBc alone was positive in 10 (3%). Tests were negative for anti‐HBc and anti‐HBs in 55 patients (18%). Anti‐HBs was the only positive marker in 132 (44%) patients. Anti‐HCV was positive in 15 (5%) patients with HCV‐RNA present in 14 of them (93%). HBV‐DNA was positive in seven cases (2.3%). There was no association of HBV‐DNA with age, gender, time on dialysis, previous kidney transplant, or HBV serological pattern, but there was a positive correlation with the presence of anti‐HCV (P < 0.001). OHB in chronic renal failure patients on hemodialysis appears to be a relevant finding, suggesting that studying HBV‐DNA in this population using sensitive molecular tests should be a recommended course of action, especially in candidates for renal transplant.