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Oaxaca, Mexico

Escamilla-Alvarado C.,Environmental Biotechnology and Renewable Energies R and D Group | Poggi-Varaldo H.M.,Environmental Biotechnology and Renewable Energies R and D Group | Ponce-Noyola T.,Microbial Genetics Group | Rios-Leal E.,CINVESTAV | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2015

A series of experiments were carried out aimed to evaluate the possibilities of integrating a stage for the saccharification of lignocellulosic substrates to a hydrogen, methane and enzymes producing biorefinery concept. Initially, three different substrates were saccharified using two sources of cellulases. The substrates were the organic fraction of municipal solid waste (OFMSW), fermented organic waste (FOW) produced after OFMSW fermentation in the hydrogen production stage, and filter paper bits. The enzymes evaluated were the enzyme extract obtained from Trichoderma reesei MCG 80 in our actual biorefinery process train and Celluclast® cellulases.All substrates were best hydrolyzed with the T. reesei extract. Saccharification efficiency on holocellulose basis of FOW was up to 73%, which represented 34% higher saccharification than OFMSW. Thereafter, the hydrolysis of FOW with the T. reesei extract was evaluated at different enzyme:substrate ratios in the range 40-120 filter paper units or FPUgVS-1. The lowest ratio of 40FPUgVS-1 presented the highest saccharification yield (11mgsugarsFPU-1). As an approach to further boost bioenergy production in the biorefinery, estimations of bioH2 production from FOW hydrolysates were performed, showing that the original hydrogen production from OFMSW (21LH2) could be doubled up to 43LH2 for each kilogram of dry OFMSW fed to the biorefinery.The H2 production in the H-M-Z-S inverse cascading biorefinery concept was found to be transcendental as it offers the possibilities of a renewable clean fuel and a pre-degraded substrate easily convertible into valuable bioproducts, or even into more biofuels. © 2015 Hydrogen Energy Publications, LLC.

Granados-Echegoyen C.,NovaUniversitas | Granados-Echegoyen C.,National Polytechnic Institute of Mexico | Perez-Pacheco R.,National Polytechnic Institute of Mexico | Alonso-Hernandez N.,National Polytechnic Institute of Mexico | And 3 more authors.
Asian Pacific Journal of Tropical Disease | Year: 2015

Objective: To determine chemical composition and mosquito larvicidal activity of essential oil from dried leaves of Persea americana against Culex quinquefasciatus. Methods: About 20 larvae in each group were used for larvicidal assays. The mortality, relative growth index, larval and pupal duration and viability were estimated. The essential oil was analyzed by solid phase microextraction using gas chromatography coupled to mass spectrometry. Results: The most abundant compounds were estragole (61.86%), sabinene (15.16%) and 1R-a-pinene (14.25%). The essential oil inhibited mosquito larvae growth up to 26.73% [relative growth index (RGI) = 0.74)] and 16.83% (RGI = 0.84) at 800 and 50 mg/L respectively, while the untreated control and group treated with polysorbate 20 showed the RGI of 1.01. The viability of larvae to pupae decreased 53.75% when used 800 mg/L essential oil causing prolongation of development of 14.14 days, while the control had durability in its development of 12 days. In the pupae-adult phase, when used 800 and 50 mg/L of essential oil, 22.36% and 21.81% adults were formed, and there was prolongation of 15.88 days and delay of 13.62 days respectively; however the control showed duration of 14.63 days. Mortality at the end of the experiment was recorded as 57.50% with treatment of 800 mg/L and gradually decreased to 40% with treatment of 50 mg/L essential oil. Conclusions: The study demonstrated that the larvicidal activity of essential oil of Mexican avocado inhibited the normal growth and development of mosquito larvae, prolonged larval and pupal duration. © 2015 by the Asian Pacific Journal of Tropical Disease.

Shcherbakov A.S.,National Institute of Astrophysics, Optics and Electronics | Campos Acosta J.,CSIC - Institute of Applied Physics | Moreno Zarate P.,National Institute of Astrophysics, Optics and Electronics | Moreno Zarate P.,NovaUniversitas | Pons Aglio A.,CSIC - Institute of Applied Physics
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

An advanced qualitative characterization of simultaneously existing various low-power trains of ultra-short optical pulses with an internal frequency modulation in a distributed laser system based on semiconductor heterostructure is presented. The scheme represents a hybrid cavity consisting of a single-mode heterolaser operating in the active mode-locking regime and an external long single-mode optical fiber exhibiting square-law dispersion, cubic Kerr nonlinearity, and linear optical losses. In fact, we consider the trains of optical dissipative solitons, which appear within double balance between the second-order dispersion and cubic-law nonlinearity as well as between the active-medium gain and linear optical losses in a hybrid cavity. Moreover, we operate on specially designed modulating signals providing non-conventional composite regimes of simultaneous multi-pulse active mode-locking. As a result, the mode-locking process allows shaping regular trains of picosecond optical pulses excited by multi-pulse independent on each other sequences of periodic modulations. In so doing, we consider the arranged hybrid cavity as a combination of a quasi-linear part responsible for the active mode-locking by itself and a nonlinear part determining the regime of dissipative soliton propagation. Initially, these parts are analyzed individually, and then the primarily obtained data are coordinated with each other. Within this approach, a contribution of the appeared cubically nonlinear Ginzburg-Landau operator is analyzed via exploiting an approximate variational procedure involving the technique of trial functions. © 2011 SPIE.

Zarate P.M.,National Institute of Astrophysics, Optics and Electronics | Zarate P.M.,NovaUniversitas | Shcherbakov A.S.,National Institute of Astrophysics, Optics and Electronics | Mansurova S.,NovaUniversitas
Journal of Applied Research and Technology | Year: 2012

Here we examine a new application of the adaptive detectors based on non-steady-state photo-electro-motive force effect for the detection of higher order correlation functions, aiming the estimation of the parameters of ultra short optical pulses arranged in high-repetition trains. For this purpose three beam interferometer scheme with two signal beams modulated at different frequencies is proposed. Theoretical analysis of non-steady-state photo-EMF current generated by light distribution formed by superposition of three waves is performed and the possibility to detect simultaneously second and higher order correlation function is demonstrated. Potential advantages and disadvantages of such detection scheme for measuring the higher order auto-correlations functions are discussed.

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