Numerical Calculation of the Heat Transfer Coefficient in a Turbulent Particle Pipe Flow

R. Avila,J. Cervantes 대한기계학회 1993 International Symposium on Transport Phenomena in Vol.2 No.1

Performance of carbon fiber added to anodes of conductive cement-graphite pastes used in electrochemical chloride extraction in concretes

M. J. Pellegrini-Cervantes,C. P. Barrios-Durstewitz,R. E. Nú,ñ,ez-Jaquez,F. J. Baldenebro-Lopez,R. Corral-Higuera,S. P. Arredondo-Rea,M. Rodriguez-Rodriguez,O. Llanes-Cardenas,R. Beltran-Chaco 한국탄소학회 2018 Carbon Letters Vol.26 No.-

Pollution of chloride ion-reinforced concrete can trigger active corrosion processes that reduce the useful life of structures. Multifunctional materials used as a counter-electrode by electrochemical techniques have been used to rehabilitate contaminated concrete. Cement-based pastes added to carbonaceous material, fibers or dust, have been used as an anode in the non-destructive Electrochemical Chloride Extraction (ECE) technique. We studied the performance of the addition of Carbon Fiber (CF) in a cement-graphite powder base paste used as an anode in ECE of concretes contaminated with chlorides from the preparation of the mixture. The experimental parameters were: 2.3% of free chlorides, 21 days of ECE application, a Carbon Fiber Volume Fraction (CFVF) of 0.1, 0.3, 0.6, 0.9%, a lithium borate alkaline electrolyte, a current density of 4.0 A / m2 and a cement/graphite ratio of 1.0 for the paste. The efficiency of the ECE in the traditional technique using metal mesh as an anode was 77.6% and for CFVF of 0.9% it was 90.4%, with a tendency to increase to higher percentages of the CFVF in the conductive cement-graphite paste, keeping the pH stable and achieving a homogeneous ECE in the mass of the concrete contaminated with chlorides.

Synthesis of branched geminal zwitterionic liquids as wettability modifiers in enhanced oil recovery processes

J.F. Ramı´rez-Pe´ rez,R. Herna´ndez-Altamirano,J.M. Martı´nez-Magada´n,R. Cartas-Rosado,E. Soto-Castruita,R. Cisneros-Devora,L.A. Alca´ zar-Vara,R. Oviedo-Roa,V.Y. Mena-Cervantes,L.S. Zamudio-Rivera 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.45 No.-

A new class of branched geminal zwitterionic liquids (BGZLs) betaine base with a long alkyl chains witheither 8 (BGZL-ZW8) or 12 (BGZL-ZW12) carbons was synthesized and characterized by nuclearmagnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopic techniques. The BGZLsmolecules presents functionality as viscosity reducer and wettability modifier with application inenhanced oil recovery (EOR) processes with good oil recovery factors (ORF). The above is demonstratedby performing spontaneous imbibition tests on embedded limestone cores with light and heavy crudeoils in Amott cells at high temperature (90 8C) and different concentrations of BGZLs in presence ofconnate water with high salinity and hardness (36,275 ppm as NaCl and 6700 ppm hardness as CaCO3). The rheological behavior of BGZLs was also determined as viscosity reducers in heavy crude oil atconcentrations of 2000, 1000 and 500 ppm at temperatures of 25 and 40 8C, in the range of 36.11% to25 8C and 43.31% to 40 8C. To explain the mechanism through BGZLs act as viscosity reducers, werealized theoretical studies using the density functional theory (DFT), also as wettability modifierstaking BGZL-ZW8 and BGZL-ZW12 behavior, observed in the experimental part. The interaction energiesshow that BGZLs can disaggregate asphaltene (Asph) dimmer (Asph:Asph) by the formation ofsupramolecular sandwich complex (Asph:BGZL:Asph) among BGZLs and Asph:Asph, modifying theproperties of crude oil such as viscosity, is possible to support the fact of the BGZLs can desorbs Asphmolecules of the rock surface, modifying the calcite surface (Cs) wettability of oil-wet to water-wet. Theresults of this research show that it is feasible the use of zwitterionic liquids as viscosity and wettabilitymodifier in EOR process.

Electrical percolation and fluidity of conductive recycled mortar cement: graphite powder: recycled sand with addition of industrial waste carbon fiber

Espinoza-Moreno C. A.,Rodriguez-Rodriguez M.,Pellegrini-Cervantes M. J.,Barrios-Durstewitz C. P.,Núñez-Jaquez R. E.,Peinado-Guevara H. J.,Chinchillas-Chinchillas M.,Fajardo-San-Miguel G. 한국탄소학회 2021 Carbon Letters Vol.31 No.4

The use of recycled materials, such as the fne recycled aggregate made from concrete waste and carbon fber (CF) product of industrial waste, for the manufacture of conductive recycled mortars (CRM), transforms the mortar base cement normally made with cement:sand in a sustainable multifunctional material, conferring satisfactory mechanical and electrical properties for non-structural uses. This action provides ecological benefts, reducing the use of natural fne aggregates from rivers and the amount of concrete waste deposited in landflls resulting from construction waste. In this investigation the efect of the addition of CF on electrical properties in hardened, wet and dry state, electric percolation in dry state and fuidity of the wet mixture of a cement based CRM was evaluated: fne recycled aggregate: graphite powder, CRM specimens with dimensions of 4×4×16 cm. were manufactured for 3, 7 and 28 days of age and sand/cement ratios=1.00, graphite/cement=1.00, water/cement=0.60 and CF=0.1, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0% compared to the weight of cement. The results demonstrated the efect of the addition of CF in CRM, reducing fuidity of the mixtures due to the opposition generated by its physical interaction of CF with recycled sand or recycled fne aggregate and graphite powder (GP), in its case, placing the electric percolation percolation at 0.30% and 0.45% of CF for CRM with and without GP, respectively. Increases in electrical conductivity (EC) without the presence of GP are defned by the contact between the CF and the conductive paths formed. In contrast, with the presence of GP, the EC is defned by the contact between the CF and the GP simultaneously, forming conductive routes with greater performance in its EC.

Spectroscopic needs for imaging dark energy experiments

Newman, J.A.,Abate, A.,Abdalla, F.B.,Allam, S.,Allen, S.W.,Ansari, R.,Bailey, S.,Barkhouse, W.A.,Beers, T.C.,Blanton, M.R.,Brodwin, M.,Brownstein, J.R.,Brunner, R.J.,Carrasco Kind, M.,Cervantes-Cota, North-Holland 2015 Astroparticle physics Vol.63 No.-

Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z's): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, lower-scatter photo-z's will result in smaller random errors on cosmological parameters; while systematic errors in photometric redshift estimates, if not constrained, may dominate all other uncertainties from these experiments. The desired optimization and calibration is dependent upon spectroscopic measurements for secure redshift information; this is the key application of galaxy spectroscopy for imaging-based dark energy experiments. Hence, to achieve their full potential, imaging-based experiments will require large sets of objects with spectroscopically-determined redshifts, for two purposes:*Training: Objects with known redshift are needed to map out the relationship between object color and z (or, equivalently, to determine empirically-calibrated templates describing the rest-frame spectra of the full range of galaxies, which may be used to predict the color-z relation). The ultimate goal of training is to minimize each moment of the distribution of differences between photometric redshift estimates and the true redshifts of objects, making the relationship between them as tight as possible. The larger and more complete our ''training set'' of spectroscopic redshifts is, the smaller the RMS photo-z errors should be, increasing the constraining power of imaging experiments. Requirements: Spectroscopic redshift measurements for ~30,000 objects over >~15 widely-separated regions, each at least ~20arcmin in diameter, and reaching the faintest objects used in a given experiment, will likely be necessary if photometric redshifts are to be trained and calibrated with conventional techniques. Larger, more complete samples (i.e., with longer exposure times) can improve photo-z algorithms and reduce scatter further, enhancing the science return from planned experiments greatly (increasing the Dark Energy Task Force figure of merit by up to ~50%). Options: This spectroscopy will most efficiently be done by covering as much of the optical and near-infrared spectrum as possible at modestly high spectral resolution (λ/Δλ>~3000), while maximizing the telescope collecting area, field of view on the sky, and multiplexing of simultaneous spectra. The most efficient instrument for this would likely be either the proposed GMACS/MANIFEST spectrograph for the Giant Magellan Telescope or the OPTIMOS spectrograph for the European Extremely Large Telescope, depending on actual properties when built. The PFS spectrograph at Subaru would be next best and available considerably earlier, c. 2018; the proposed ngCFHT and SSST telescopes would have similar capabilities but start later. Other key options, in order of increasing total time required, are the WFOS spectrograph at TMT, MOONS at the VLT, and DESI at the Mayall 4m telescope (or the similar 4MOST and WEAVE projects); of these, only DESI, MOONS, and PFS are expected to be available before 2020. Table 2-3 of this white paper summarizes the observation time required at each facility for strawman training samples. To attain secure redshift measurements for a high fraction of targeted objects and cover the full redshift span of future experiments, additional near-infrared spectroscopy will also be required; this is best done from space, particularly with WFIRST-2.4 and JWST. Calibration: The first several moments of redshift distributions (the mean, RMS redshift dispersion, etc.), must be known to high accuracy for cosmological constraints not to be systematics-dominated (equivalently, the moments of the distribution of differences between photometric and true redshifts could be determined instead). The ultimate goal of calibration is to characterize these moments for every subsample used in analyses - i.e., to minimi

Medicinal Plant Extracts and Their Use As Wound Closure Inducing Agents

Mitzzy F. Medellin-Luna,Julio E. Castan˜eda-Delgado,V. Yordani Martı´nez-Balderas,Alberto R. Cervantes-Villagrana 한국식품영양과학회 2019 Journal of medicinal food Vol.22 No.5

Skin insult and damage start a complex healing process that involves a myriad of coordinated reactions at both the cellular and molecular level occurring simultaneously. These processes can be divided into that of cell migration and tissue remodeling of the wound. In addition, it is well known that deep wounds that derive from surgical procedures need a multidisciplinary approach to have a successful wound healing process. Recently, there has been a renowned interest in the identification of active compounds derived from ornamental, edible, and wild plants being used in the cosmetic and skin product industry. Recent reports suggest that active components of several plants such as Propolis and Aloe vera could be used to induce the process of wound healing and tissue regeneration and reducing therefore the time to complete wound closure. Other plant species such as Achillea millefolium or Salvia officinalis have anti-inflammatory properties and promote cellular proliferation contributing to faster tissue regeneration. It has been described that Malva sylvestris influences the formation of fibrosis-free granulation tissue in the skin. Recent observations suggest that Casearia sylvestris induces the angiogenic process. These effects have been evaluated in cell lines, different animal models, and some in randomized clinical trials. In this review we summarize the evidence of plant extracts and their active components (when known) in the acceleration of the wound closure process and tissue repair.

First constraint on coherent elastic neutrino-nucleus scattering in argon

Akimov, D.,Albert, J. B.,An, P.,Awe, C.,Barbeau, P. S.,Becker, B.,Belov, V.,Blackston, M. A.,Bolozdynya, A.,Cabrera-Palmer, B.,Cervantes, M.,Collar, J. I.,Cooper, R. L.,Daughhetee, J.,del Valle Coello American Physical Society 2019 Physical review. D Vol.100 No.11

Observation of coherent elastic neutrino-nucleus scattering

Akimov, D.,Albert, J. B.,An, P.,Awe, C.,Barbeau, P. S.,Becker, B.,Belov, V.,Brown, A.,Bolozdynya, A.,Cabrera-Palmer, B.,Cervantes, M.,Collar, J. I.,Cooper, R. J.,Cooper, R. L.,Cuesta, C.,Dean, D. J.,D American Association for the Advancement of Scienc 2017 Science Vol.357 No.6356

<P>The coherent elastic scattering of neutrinos off nuclei has eluded detection for four decades, even though its predicted cross section is by far the largest of all low-energy neutrino couplings. This mode of interaction offers new opportunities to study neutrino properties and leads to a miniaturization of detector size, with potential technological applications. We observed this process at a 6.7s confidence level, using a low-background, 14.6-kilogram CsI[Na] scintillator exposed to the neutrino emissions from the Spallation Neutron Source at Oak Ridge National Laboratory. Characteristic signatures in energy and time, predicted by the standard model for this process, were observed in high signal-to-background conditions. Improved constraints on nonstandard neutrino interactions with quarks are derived from this initial data set.</P>