128 research outputs found

    Halloysite nanotubes as nano-carriers of corrosion inhibitors in cement formulations

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    The ingress of water, as a vehicle for many harmful substances, is the main cause of all the major physical and chemical degradation processes affecting concrete buildings. To prevent damage and protect concrete surfaces, coatings are generally used. Cement-based coatings in particular can act as a physical barrier and reduce the permeability of surfaces. In case of chloride-induced corrosion, corrosion inhibitors are also generally used, and nano-carriers have been proven to provide a long-term protective effect. In this work, we designed a surface protection cementitious coating enhanced with nano-silica and halloysite nanotubes (HNTs). HNTs were loaded with a corrosion inhibitor, benzotriazole (BTA), and used as nano-reservoir, while nano-silica was used to improve the structure of the protective coating and to strengthen its adhesion to the surface of application. The cementitious coatings were characterized with a multi-technique approach including thermal and spectroscopic analysis, scanning electron microscopy, specific surface area and pore size distribution, and Vickers hardness test. The release of BTA was monitored through UV-vis analysis, and the transportation of BTA through coated mortars was studied in simulated rain conditions. We evidenced that the presence of silica densifies the porous structure and increases the interfacial bond strength between the protective coating and the surface of application. We report here, for the first time, that HNTs can be used as nano-carriers for the slow delivery of anti-corrosion molecules in cement mortars

    Pengembangan Aplikasi Interactive TV Pada Platform Set-Top Box Tertanam Berbasis Windows Embedded 7

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    . Interactive TV Application Development on Embedded Set-Top Box Platform Based on Windows Embedded 7. With the novelty of television technology that marked by the boom of DTV, Internet enabled Set-Top Box, and DVR, television users become more aware to interactive and rich experience of multimedia contents viewing on their television that later become the concept of interactive TV.Interactive TV allows viewers to take control of what they want to see something conventional TV can’t afford. In this research, there will be an application developed so that the user could enjoy extended services through their TV set. CETV is a proof of concept of interactive TV concept that enables users to access extended services. CETV is a group of 7 different application module that has their own feature and functionality. CETV delivers extended services and contents that bring interactivity and control to television users

    Dimensi Context Aware untuk Manajemen Penerangan dalam Gedung

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    Inefisiensi energi pada sistem penerangan dalam gedung diantaranya karena tidak terkendalinya pemakaian penerangan secara konsisten. Salah satu alternatif penyelesaian permasalahan tersebut adalah perlu adanya manajemen sistem penerangan. Paper ini mencoba mengusulkan diagram dimensi context aware sistem manajemen penerangan yang merupakan pondasi untuk pengembangan sistem yang cerdas. Sebuah contoh arsitektur dan pengembangan kelas utama yang mengacu pada diagram tersebut dicoba untuk dikembangkan. Teknologi pervasive computing digunakan sebagai pendekatan awal desain sehingga pengelolaan dan pemantauan penerangan dapat dioptimalkan guna efisiensi energi listrik

    Dimensi Context Aware untuk Manajemen Penerangan dalam Gedung

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    Inefisiensi energi pada sistem penerangan dalam gedung diantaranya karena tidak terkendalinya pemakaian penerangan secara konsisten. Salah satu alternatif penyelesaian permasalahan tersebut adalah perlu adanya manajemen sistem penerangan. Paper ini mencoba mengusulkan diagram dimensi context aware sistem manajemen penerangan yang merupakan pondasi untuk pengembangan sistem yang cerdas. Sebuah contoh arsitektur dan pengembangan kelas utama yang mengacu pada diagram tersebut dicoba untuk dikembangkan. Teknologi pervasive computing digunakan sebagai pendekatan awal desain sehingga pengelolaan dan pemantauan penerangan dapat dioptimalkan guna efisiensi energi listrik

    Effect of phosphate additives on the hydration process of magnesium silicate cements: Thermal and spectroscopic characterization

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    The role of phosphate additives on the hydration process of magnesium silicate cement pastes was investigated through a multi-technique approach. A MgO/SiO2 mixture was hydrated for 28 days either in the absence or in the presence of sodium hexametaphosphate, trimetaphosphate or orthophosphate. Information on the kinetics of the hydration reaction was acquired by monitoring the free water index by means of differential scanning calorimetry, while the hydration products were thoroughly investigated by X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy and 29Si solid-state nuclear magnetic resonance spectroscopy. The overall results provide new insight into the effect of phosphates on the hydration reaction and on the structure of magnesium silicate hydrate cements. All additives showed a plasticizing effect and promoted the formation of the binding phase magnesium silicate hydrate (M–S–H), without significantly altering its structure. Sodium orthophosphate was found to be by far the best-performing additive, even better than sodium hexametaphosphate, which is commonly used in these cementitious formulations. For the first time, 31P solid-state NMR investigation allowed orthophosphate ion to be identified as the effective species

    A mild alkali treated jute fibre controlling the hydration behaviour of greener cement paste

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    To reduce the antagonistic effect of jute fibre on the setting and hydration of jute reinforced cement, modified jute fibre reinforcement would be a unique approach. The present investigation deals with the effectiveness of mild alkali treated (0.5%) jute fibre on the setting and hydration behaviour of cement. Setting time measurement, hydration test and analytical characterizations of the hardened samples (viz., FTIR, XRD, DSC, TGA and free lime estimation) were used to evaluate the effect of alkali treated jute fibre. From the hydration test, the time (t) required to reach maximum temperature for the hydration of control cement sample is estimated to be 860 min, whilst the time (t) is measured to be 1040 min for the hydration of a raw jute reinforced cement sample. However, the time (t) is estimated to be 1020 min for the hydration of an alkali treated jute reinforced cement sample. Additionally, from the analytical characterizations, it is determined that fibre-cement compatibility is increased and hydration delaying effect is minimized by using alkali treated jute fibre as fibre reinforcement. Based on the analyses, a model has been proposed to explain the setting and hydration behaviour of alkali treated jute fibre reinforced cement composite

    Identifying Schistosoma japonicum Excretory/Secretory Proteins and Their Interactions with Host Immune System

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    Schistosoma japonicum is a major infectious agent of schistosomiasis. It has been reported that large number of proteins excreted and secreted by S. japonicum during its life cycle are important for its infection and survival in definitive hosts. These proteins can be used as ideal candidates for vaccines or drug targets. In this work, we analyzed the protein sequences of S. japonicum and found that compared with other proteins in S. japonicum, excretory/secretory (ES) proteins are generally longer, more likely to be stable and enzyme, more likely to contain immune-related binding peptides and more likely to be involved in regulation and metabolism processes. Based on the sequence difference between ES and non-ES proteins, we trained a support vector machine (SVM) with much higher accuracy than existing approaches. Using this SVM, we identified 191 new ES proteins in S. japonicum, and further predicted 7 potential interactions between these ES proteins and human immune proteins. Our results are useful to understand the pathogenesis of schistosomiasis and can serve as a new resource for vaccine or drug targets discovery for anti-schistosome

    Human IgG1 Responses to Surface Localised Schistosoma mansoni Ly6 Family Members Drop following Praziquantel Treatment

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    The heptalaminate-covered, syncytial tegument is an important anatomical adaptation that enables schistosome parasites to maintain long-term, intravascular residence in definitive hosts. Investigation of the proteins present in this surface layer and the immune responses elicited by them during infection is crucial to our understanding of host/parasite interactions. Recent studies have revealed a number of novel tegumental surface proteins including three (SmCD59a, SmCD59b and Sm29) containing uPAR/Ly6 domains (renamed SmLy6A SmLy6B and SmLy6D in this study). While vaccination with SmLy6A (SmCD59a) and SmLy6D (Sm29) induces protective immunity in experimental models, human immunoglobulin responses to representative SmLy6 family members have yet to be thoroughly explored.Using a PSI-BLAST-based search, we present a comprehensive reanalysis of the Schistosoma mansoni Ly6 family (SmLy6A-K). Our examination extends the number of members to eleven (including three novel proteins) and provides strong evidence that the previously identified vaccine candidate Sm29 (renamed SmLy6D) is a unique double uPAR/Ly6 domain-containing representative. Presence of canonical cysteine residues, signal peptides and GPI-anchor sites strongly suggest that all SmLy6 proteins are cell surface-bound. To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE) responses against two surface-bound representatives (SmLy6A and SmLy6B) within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment. While pre-treatment IgG1 prevalence for SmLy6A and SmLy6B differs amongst the studied population (7.4% and 25.3% of the cohort, respectively), these values are both higher than IgG1 prevalence (2.7%) for a sub-surface tegumental antigen, SmTAL1. Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively) when compared to rising IgG1 levels against sub-surface SmTAL1.Collectively, these results expand the number of SmLy6 proteins found within S. mansoni and specifically demonstrate that surface-associated SmLy6A and SmLy6B elicit immunological responses during infection in endemic communities
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