Box–Behnken factorial design study of the variables affecting metal electrodeposition in membraneless fluidized bed electrodes

BACKGROUND: Heavy metal removal from industrial wastewaters has been studied intensively since it is well known that they can cause severe problems to human health and aquatic life, even at very low concentrations. Traditional precipitation or adsorption technologies only transfer the problem to the solid phase, therefore new technologies, such as electrodeposition using fluidized bed electrodes (FBE), have been considered to avoid contamination. RESULTS: Copper electrodeposition from diluted solutions was carried out using a membraneless FBE. The supporting electrolyte concentration (C_s) was the main variable affecting the current efficiency (CE), energy consumption (EC), and space‐time yield (Y). Although it does not change the response surface morphology, increasing C_s there was an important improvement of CE, Y, and EC. The effects of current and bed expansion are much more complex, since an interaction effect between these two variables was verified. Considering only the region of active kinetic control, copper can be optimally recovered with CE > 90%, Y ～93 kg h^?1 m^?3, and EC ～3.2 kWh kg^?1 by applying the highest levels of the independent variables. CONCLUSIONS: The results suggest that electrodeposition using a membraneless FBE is an excellent method for the treatment of effluents contaminated with copper or other metals. © 2012 Society of Chemical Industry     

Mapping the literature on credit unions: a bibliometric investigation grounded in Scopus and Web of Science

Scientometrics - Credit unions play a relevant role in providing microcredit and other financial services. Because such financial cooperative organizations have drawn the attention of a significant...     

Inhibition of angiotensin I converting enzyme by anacardic acids isolated from Cashew nut (Anacardium occidentale Linn.) shell liquid

Hypertension represents one of the most common maladies of western civilizations caused by bad dietary practices and lack of exercise. Angiotensin-I-converting enzyme inhibitors (ACEi) have been shown to be very efficient in the prevention of hypertension. ACEi are also implicated (by their ability to reduce the product of ACE activity namely angiotensin-II levels, which has oncogenic and increased cell proliferation effects) to be efficient anticancer agents. Therefore, we evaluated the potential antihypertension capacities of anacardic acids purified from Cashew (Anacardium occidentale Linn.) nut shell liquid by inhibition of ACE using analytical reverse-phase high performance liquid chromatography. The ability to inhibit ACE showed the following relation: anacardic-3 (IC₅₀ = 12 µM) > anacardic acid-4 (IC₅₀ = 20 µM) > anacardic acid-2 (IC₅₀ = 33 µM) > anacardic acid-1 (IC₅₀ = 39 µM) as compared to the positive control captopril (IC₅₀ = 6.85 nM). Salicylic acid lacking a phytyl side chain was negative. The capacity of purified anacardic acids to inhibit ACE thereby represents the most potent naturally available plant chemicals described so far, as a potential means of reducing hypertension. The inhibition of angiotensin II production indicated that anacardic acids could also have utility in cancer prevention and recurrence, and reduction of cardiotoxicity during chemotherapy.     

Proteogenomic Characterization of the Cement and Adhesive Gland of the Pelagic Gooseneck Barnacle Lepas anatifera

We focus on the stalked goose barnacle L. anatifera adhesive system, an opportunistic less selective species for the substrate, found attached to a variety of floating objects at seas. Adhesion is an adaptative character in barnacles, ensuring adequate positioning in the habitat for feeding and reproduction. The protein composition of the cement multicomplex and adhesive gland was quantitatively studied using shotgun proteomic analysis. Overall, 11,795 peptide sequences were identified in the gland and 2206 in the cement, clustered in 1689 and 217 proteinGroups, respectively. Cement specific adhesive proteins (CPs), proteases, protease inhibitors, cuticular and structural proteins, chemical cues, and many unannotated proteins were found, among others. In the cement, CPs were the most abundant (80.5%), being the bulk proteins CP100k and -52k the most expressed of all, and CP43k-like the most expressed interfacial protein. Unannotated proteins comprised 4.7% of the cement proteome, ranking several of them among the most highly expressed. Eight of these proteins showed similar physicochemical properties and amino acid composition to known CPs and classified through Principal Components Analysis (PCA) as new CPs. The importance of PCA on the identification of unannotated non-conserved adhesive proteins, whose selective pressure is on their relative amino acid abundance, was demonstrated.     

Temperature coefficient of optical path of tellurite glasses doped with gold nanoparticles

This work reports on the thermo optical parameters of TeO₂–PbO–GeO₂ glasses as a function of the concentration of gold nanoparticles. Techniques such as thermal lens and heat capacity measurements allowed the determination of the thermal diffusivity D, thermal conductivity K and the temperature coefficient of optical path (ds/dT). It is shown an expressive decrease in ds/dT as a function of gold nanoparticles concentration, while the opposite effect was observed for the thermal diffusivity D.     

Cmc of PMMA-<Emphasis Type="Italic">block</Emphasis>-PDMAEMA measured by NPN fluorescence

Relationships able to predict the behavior of polymers based on their chemical structure are necessary for the rational synthesis of materials with desired properties. The state-of-art of polymer chemistry allows one to synthesize, using techniques such as RAFT, polymers with tailored chemical structures to study that kind of relationships. In this study, RAFT was used to synthesize copolymers—poly(methyl methacrylate)-block-poly[(2-dimethylamino)ethyl methacrylate]—that form aggregates in water at neutral and acidic pH’s. Cmc of each copolymer was determined by fluorescence using the probe N-phenyl-1-naphthylamine (NPN), and the values are consistent with the particular chemical structure of each one. These findings can be useful in future studies of dependence of cmc on the chemical structure and solution conditions and to tailor polymers with specific properties and applications, making the cmc determination faster and more accurate. To the best of our knowledge, this it the first time that NPN is used to determine the cmc of this kind of positively charged copolymers.     

An Insight into the Role of Non-Porphyrinoid Photosensitizers for Skin Wound Healing

The concept behind photodynamic therapy (PDT) is being successfully applied in different biomedical contexts such as cancer diseases, inactivation of microorganisms and, more recently, to improve wound healing and tissue regeneration. The effectiveness of PDT in skin treatments is associated with the role of reactive oxygen species (ROS) produced by a photosensitizer (PS), which acts as a “double agent”. The release of ROS must be high enough to prevent microbial growth and, simultaneously, to accelerate the immune system response by recruiting important regenerative agents to the wound site. The growing interest in this subject is reflected by the increasing number of studies concerning the optimization of relevant experimental parameters for wound healing via PDT, namely, light features, the structure and concentration of the PS, and the wound type and location. Considering the importance of developing PSs with suitable features for this emergent topic concerning skin wound healing, in this review, a special focus on the achievements attained for each PS class, namely, of the non-porphyrinoid type, is given.     

Error estimation for proper generalized decomposition solutions: A dual approach

The proper generalized decomposition is a well-established reduced order method, used to efficiently obtain approximate solutions of multi-dimensional problems in a procedure that controls the effects of the “curse of dimensionality.” The question of assessing the quality of the solutions obtained and adapting the approximations assumed, for example, the finite element meshes used, so that the best result is obtained at minimal cost, remains a relevant challenge. This article deals with finite element solutions for solid mechanics problems, using the error obtained from a dual analysis, the difference between complementary solutions, to bound the error in the solutions and to drive an optimal adaptivity process, which obtains meshes with errors significantly lower than those obtained using a uniform refinement.