Use of recycled broken bricks as Partial Replacement Coarse Aggregate for the Manufacturing of Sustainable Concrete

The bricks are one of the primary materials required for construction of homes that no used completely when executes all the walls due, the excess purchase, the cutting to be settle, the breaking for their transfer and its fixed dimensions; this situation requires monitoring on work site the order, cleanliness and accidents. A common practice is these bricks and/or waste are included in the clearing construction before being deposited or eliminated in dumps or sanitary landfills, with their early clogging and shortening them to ther design lifespan. An important alternative to reduce this waste, is to recycle them and reuse them as a concrete component material, due to their high absorption percentage that allows them to keep the water inside of them and then use it in the cement hydration process as internal curing of the concrete. In the present investigation, the effect of crushed clay brick as a replacement for coarse aggregate in concrete processing is studied. The results indicate that with 21 % replacement brick, the plastic contraction decreases, and the compressive strength and flexural strength increase

Mechanical Properties of an Eco-friendly Concrete with partial replacement of POC and Rubber

Concrete plants consume 10 billion tons of natural aggregates annually from quarries and gravel plants for produce concrete, this demand requires exploiting natural resources from mountains and rivers producing an ecological imbalance. One solution is to use Palm Oil Clinker (POC), which is eliminated in large quantities in the dumps and rivers without taking advantage of its puzolanic, binding and resistance properties as an aggregate in the concrete; another alternative is to apply rubber from abandoned and discarded tires as waste in landfills or burned, without taking advantage of its performance of improvement in concrete, increasing its resistance to impact and fatigue. Unable to find joint POC and rubber information, this research studies its influence replacing 2.5% rubber (grained and crushed) with 10%, 12.5% and 15% POC in the fine aggregate on traditional concrete; results indicate that with 12.5% of POC as the ideal percentage, the compressive strength, tensile strength and flexural strength rise between 2.16 - 9.54%, so the concrete obtained has a cost of less than 4.09% and has 3.65% less CO2 emission

Low Permeability Concrete for Buildings Located in Marine Atmosphere Zone using Clay Brick Powder

The concrete is not one hundred percent impermeable since the water that remains inside it causes its corrosion, in the case of reinforced concrete, exposed in an area of marine atmosphere, the sea salt mostly present in large particles of the marine spray, produce the reduction of the alkalinity of the concrete causing a rapid corrosion of the steel. There are buildings built in this marine area that have been designed without durability criteria, in which the use of pozzolanic materials is considered, for example, to fill the pores of the cement matrix and thus guarantee its impermeability. In the present study, the effect of clay brick powder (PLA) as a replacement for cement in concrete manufacturing is addressed, evaluating different characteristics of its components. The results indicate that pozzolanic activity and compressive strength increase, slump, voids content and the coefficient of permeability to water decreases

The xylanolytic enzyme system from the genus Penicillium

Indexación: ScopusIn nature, there are numerous microorganisms that efficiently degrade xylan, a major component of lignocellulose. In particular, filamentous fungi have demonstrated a great capability for secreting a wide range of xylanases, being the genus Aspergillus and Trichoderma the most extensively studied and reviewed among the xylan-producing fungi. However, an important amount of information about the production and genetics of xylanases from fungi of the genus Penicillium has accumulated in recent years. A great number of Penicillia are active producers of xylanolytic enzymes, and the use of xylanases from these species has acquired growing importance in biotechnological applications. This review summarizes our current knowledge about the properties, genetics, expression and biotechnological potential of xylanases from the genus Penicillium.https://www.sciencedirect.com/science/article/pii/S0168165606000824?via%3Dihu

"Fire burns matter: A case-control study of severe accidental burns in pediatric patients"

"Objective: We aimed to identify factors associated with severe accidental burns in patients ≤12 years old. Materials and methods: We conducted a matched case-control study, in which we retrospectively reviewed the medical records of children treated in a single institution from 2014-2016. We classified the cases (patients with severe burns) and controls (patients with non-severe burns) according to the criteria of the American Burn Association. We used multivariate conditional logistic regression analysis to identify the relationship between the etiology of burns and their severity. Results: We reviewed 180 cases and 90 controls. The most common etiology of burns was boiling water in both cases (65.6%) and controls (83.3%). Most burns occurred inside the home (84.1%) and in the afternoon (37.4%). Multivariate analysis identified that severe burns were mainly due to exposure to fire (odds ratio [OR]: 3.22, 95% confidence interval [CI]: 1.53-6.81). Similarly, these patients were more likely to live in a rural area (OR: 2.96, 95% CI: 1.17-6.19). Conclusions: In pediatric patients ≤12 years of age severe accidental burns are more likely to be caused by fire compared to boiling water. Public health interventions should focus on populations located in rural areas.

The use of indigenous knowledge in development: problems and challenges

The use of indigenous knowledge has been seen by many as an alternative way of promoting development in poor rural communities in many parts of the world. By reviewing much of the recent work on indigenous knowledge, the paper suggests that a number of problems and tensions has resulted in indigenous knowledge not being as useful as hoped for or supposed. These include problems emanating from a focus on the (arte)factual; binary tensions between western science and indigenous knowledge systems; the problem of differentiation and power relations; the romanticization of indigenous knowledge; and the all too frequent decontextualization of indigenous knowledge

Procedures for standard evaluation and data management of advanced potato clones. Summary guide to selecting potato clones for drought tolerance under field conditions international cooperators’ guide

Drought stress is a multidimensional stress and generally leads to changes in the physiological, morphological, ecological, biochemical, and molecular traits of plants (Farooq et al., 2009). In addition, it can negatively affect the quantity and quality of plant growth and yield (Zlatev and Lidon, 2012). Many plants have developed resistance mechanisms to tolerate drought stress, but these mechanisms are varied and depend on plant species (Hossain et al., 2016). There are several options for drought tolerance mechanisms in plants, including developmental, physiological, morphological, ecological, biochemical, and molecular mechanisms. Typically, the mechanisms involved in plant tolerance to drought follow a general plan: maintaining cell water homeostasis under drought conditions (Hossain et al., 2016). Impact of abiotic stresses on potato production will increase over the next decades, due to climate change and the extension of potato cultivation under drought/heat conditions (Hijmanns, 2003) since potato is extremely susceptible to drought (Monneveux et al., 2013). Plant adaptation to drought involves several different morphological and physiological characteristics; however, no specific traits have been reported since drought responses change according to plant genotype and growth stage. Stem height, number of green leaves and leaf length are considered to be the parameters most sensitive to moderate drought conditions (Deblonde and Ledent, 2001); however, these traits have shown inconsistency in many cases. In the present protocol, a selection of traits is shown as a result of previous experiments and exhaustive data analysis at the International Potato Center

The endoxylanases from family 11: Computer analysis of protein sequences reveals important structural and phylogenetic relationships

Indexación: Scopus.Eighty-two amino acid sequences of the catalytic domains of mature endoxylanases belonging to family 11 have been aligned using the programs MATCHBOX and CLUSTAL. The sequences range in length from 175 to 233 residues. The two glutamates acting as catalytic residues are conserved in all sequences. A very good correlation is found between the presence (at position 100) of an asparagine in the so-called 'alkaline' xylanases, or an aspartic acid in those with a more acidic pH optimum. Four boxes defining segments of highest similarity were detected; they correspond to regions of defined secondary structure: B5, B6, B8 and the carboxyl end of the alpha helix, respectively. Cysteine residues are not common in these sequences (0.7% of all residues), and disulfide bridges are not important in explaining the stability of several thermophilic xylanases. The alignment allows the classification of the enzymes in groups according to sequence similarity. Fungal and bacterial enzymes were found to form mostly separate clusters of higher similarity.https://www.sciencedirect.com/science/article/pii/S0168165602000020?via%3Dihu

Documentation of Subtype C HIV Type 1 Strains in Argentina, Paraguay and Uruguay.

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.Fil: Carrion, G.. U.S. Naval Medical Research Center Detachment; PerúFil: Eyzaguirre, L.. Henry M. Jackson Foundation; Estados UnidosFil: Montano, S. M.. U.S. Naval Medical Research Center Detachment; PerúFil: Laguna Torres, V.. U.S. Naval Medical Research Center Detachment; PerúFil: Serra, M.. National AIDS Control Program; UruguayFil: Aguayo, N.. National AIDS Control Program; ParaguayFil: Avila, Maria Mercedes. National Reference for AIDS; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruchansky, D.. National Laboratory of Reference for HIV-AIDS; UruguayFil: Pando, María de los Ángeles. National Reference for AIDS; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vinoles, Jose. National Laboratory of Reference for HIV-AIDS; UruguayFil: Perez, J.. U.S. Naval Medical Research Center Detachment; PerúFil: Barboza, A.. National AIDS Control Program; ParaguayFil: Chauca, G.. U.S. Naval Medical Research Center Detachment; PerúFil: Romero, A.. U.S. Naval Medical Research Center Detachment; PerúFil: Galeano, A.. Tropical Medicine Institute; ParaguayFil: Blair, P.J.. U.S. Naval Medical Research Center Detachment; PerúFil: Weissenbacher, Mercedes Crecencia. National Reference for AIDS; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Birx, D. L.. Walter Reed Army Institute of Research; Estados UnidosFil: Sanchez, J. L.. Walter Reed Army Institute of Research; Estados UnidosFil: Olson, J. G.. U.S. Naval Medical Research Center Detachment; PerúFil: Carr, J. K.. Henry M. Jackson Foundation; Estados Unido