Carbon capture from biomass flue gases for CO2 enrichment in greenhouses.

Heating and CO2 enrichment systems can improve yields in intensive greenhouse agriculture Combining both techniques, which are currently applied commercially, can potentially enhance their effect. The CO2 must be separated from the other noxious gases present (such as CO, NOX, and SO2) to avoid them becoming part of the supply. The CO2 is then provided to the greenhouse on demand in the same way as the heating. In this work, we show that an improved food productivity of a pilot-scale greenhouse system combined with CO2 capture by adsorption using activated carbon and heating with alternative fuel. The proposed system's overall performance was evaluated and optimized. The best values were 46.7 g/kg of CO2 storage capacity on the adsorbent bed, 99.99 % removal rate harmful gases from the gas supplied to the greenhouse, CO2 levels of 1851.0 ± 262.8 mg/Nm3 of the CO2 levels in the greenhouse, and an enrichment time of 2.18 ± 0.92 h/day. The system's effective performance over extended periods (November-February) was confirmed and the productivity of a crop species (tomato) was compared to a control, showing an increment of 18 %. The results indicate that this is a valuable option for increasing the crop yield. By integrating this combined system with advanced climate control strategies, it is possible to maximize the CO2 provided per day, leading to higher yields. The system proved to be stable under real pilot-scale conditions over winter periods (four months).

The effect of aromatherapy with lavender (Lavandula angustifolia) on serum melatonin levels.

OBJECTIVE: Physiologically, blood melatonin levels decrease as a person ages and the older adult commonly presents with insomnia and other types of sleep disorders. Alternative therapies can be used to attenuate sleep disturbances. The aim of the present study was to analyze the effect of aromatherapy with lavender on serum melatonin levels in the noninstitutionalized older adult (OA). DESIGN AND SETTING: A pre-experimental, quantitative study with a pre-test - post-test design was conducted on 67 OAs that included both sexes. MAIN OUTCOME MEASURES: Serum melatonin levels were measured before and after eight sessions of aromatherapy with lavender that lasted 4 weeks. The results were expressed as mean ±â€¯standard deviation of melatonin levels (pg/ml). The differences were compared using the Student's t-test and statistical significance was set at a p ≤ 0.05. RESULTS: Blood melatonin levels significantly increased in the total population after the intervention with aromatherapy (pg/ml): 102.3 ±â€¯33.4 VS 132.5 ±â€¯42.3, p = 0.000004. There were significant differences in the pre-test and post-test phases in the women and men measured as separate groups (p = 0.00005 and p = 0.026), respectively. However, those differences were not observed when the measurements were compared between the two sexes, before (p = 0.64) or after (p = 0.31) the intervention. CONCLUSION: Aromatherapy with lavender essential oil similarly favors an increase in blood melatonin levels in both older adult men and women.

Effect of ultrasound pre-treatment on the physicochemical composition of Agave durangensis leaves and potential enzyme production.

Approximately 1 million tons of agave plants are processed annually by the Mexican tequila and mezcal industry, generating vast amounts of agroindustrial solid waste. This type of lignocellulosic biomass is considered to be agroindustrial residue, which can be used to produce enzymes, giving it added value. However, the structure of lignocellulosic biomass makes it highly recalcitrant, and results in relatively low yield when used in its native form. The aim of this study was to investigate an effective pre-treatment method for the production of commercially important hydrolytic enzymes. In this work, the physical and chemical modification of Agave durangensis leaves was analysed using ultrasound and high temperature as pre-treatments, and production of enzymes was evaluated. The pre-treatments resulted in modification of the lignocellulosic structure and composition; the ultrasound pre-treatment improved the production of inulinase by 4 U/mg and cellulase by 0.297 U/mg, and thermal pre-treatment improved ß-fructofuranosidase by 30 U/mg.

The effect of C content on the mechanical properties of Ti-Zr coatings.

In this study, Ti-Zr and Ti-Zr-C coatings were deposited at room temperature via pulsed-DC magnetron sputtering. A 70Ti-30Zr at% target and a 99.99% graphite plate were used to deposit samples. In order to modify C content, coatings were deposited at different target powers such as 50, 75 and 100 W. Changes on the structure, microstructure and mechanical properties due to C addition were studied. Results indicate that the as-deposited coatings were partly crystalline and that an increment on C content stabilized α' phase and inhibited the appearance of ω precipitates. Therefore, Ti-Zr-C alloys with C>1.9 at% showed only α' phase whereas the others alloys exhibited α'+ω structures. Hardness values from 12.94 to 34.31 GPa were obtained, whereas the elastic modulus was found between 181.84 and 298 GPa. Finally, a high elastic recovery ratio (0.69-0.87) was observed as a function of composition. The overall properties of these coatings were improved due to C content increment, martensitic α' phase and nanocrystalline grain size (10-16 nm).

Metallographic preparation of Zn-21Al-2Cu alloy for analysis by electron backscatter diffraction (EBSD).

Samples of Zn-21Al-2Cu alloy (Zinalco) that will be heavily deformed were prepared using five different manual mechanical metallographic methods. Samples were analyzed before tensile testing using the orientation imaging microscopy-electron backscatter diffraction (OIM-EBSD) technique. The effect of type and particle size during the final polishing stages for this material were studied in order to identify a method that produces a flat, damage free surface with a roughness of about 50 nm and clean from oxide layers, thereby producing diffraction patterns with high image quality (IQ) and adequate confidence indexes (CI). Our results show that final polishing with alumina and silica, as was previously suggested by other research groups for alloys that are difficult to prepare or alloys with low melting point, are not suitable for manual metallographic preparation of this alloy. Indexes of IQ and CI can be used to evaluate methods of metallographic preparation of samples studied using the OIM-EBSD technique.

Unsupervised cardiac image segmentation via multiswarm active contours with a shape prior.

This paper presents a new unsupervised image segmentation method based on particle swarm optimization and scaled active contours with shape prior. The proposed method uses particle swarm optimization over a polar coordinate system to perform the segmentation task, increasing the searching capability on medical images with respect to different interactive segmentation techniques. This method is used to segment the human heart and ventricular areas from datasets of computed tomography and magnetic resonance images, where the shape prior is acquired by cardiologists, and it is utilized as the initial active contour. Moreover, to assess the performance of the cardiac medical image segmentations obtained by the proposed method and by the interactive techniques regarding the regions delineated by experts, a set of validation metrics has been adopted. The experimental results are promising and suggest that the proposed method is capable of segmenting human heart and ventricular areas accurately, which can significantly help cardiologists in clinical decision support.

Serum ferritin and nutritional status in older adults at eldercare facilities.

OBJECTIVES: To identify serum ferritin levels and their association with nutritional status determined by Body Mass Index in older adults at four eldercare facilities. METHODS: An exploratory, cross-sectional study was carried out on 100 older adults residing at eldercare facilities in Colima, Mexico. Association between blood serum ferritin levels and nutritional status determined by Body Mass Index was evaluated. Ferritin levels were determined by means of chemiluminescence of blood samples obtained from subjects under control conditions. Descriptive statistics were used to analyze demographic characteristics. Student's t test and chi-square test were used to compare ferritin levels and Body Mass Index, respectively, between sexes. Statistical significance was considered to exist when P≤ 0.05. Pearson's correlation was used to establish the relation between Body Mass Index and serum ferritin levels. RESULTS: Mean serum ferritin levels were 59.9489 ng/mL in women and 86.9266 ng/mL in men (P= 0.12). In regard to Body Mass Index there was statistical significance between normal vs overweight/obesity (P = 0.008), but not between normal vs underweight (P = 0.34). Body Mass Index/serum ferritin correlation was not statistically significant (Pearson's r = 0.003). CONCLUSIONS: The quantification of a single serum indicator is insufficient for determining nutritional status in the older adult.

Regulation of proteinases during mouse peri-implantation development: urokinase-type plasminogen activator expression and cross talk with matrix metalloproteinase 9.

Trophoblast cells express urokinase-type plasminogen activator (PLAU) and may depend on its activity for endometrial invasion and tissue remodeling during peri-implantation development. However, the developmental regulation, tissue distribution, and function of PLAU are not completely understood. In this study, the expression of PLAU and its regulation by extracellular matrix proteins was examined by RT-PCR, immunocytochemistry, and plasminogen-casein zymography in cultured mouse embryos. There was a progressive increase in Plau mRNA expression in blastocysts cultured on gestation days 4-8. Tissue-type plasminogen activator (55 kDa) and PLAU (a triplet of 40, 37, and 31 kDa) were present in conditioned medium and embryo lysates, and were adsorbed to the culture plate surface. The temporal expression pattern of PLAU, according to semi-quantitative gel zymography, was similar in non-adhering embryos and embryos cultured on fibronectin, laminin, or type IV collagen, although type IV collagen and laminin upregulated Plau mRNA expression. Immunofluorescence revealed PLAU on the surface of the mural trophectoderm and in non-spreading giant trophoblast cells. Exogenous human plasminogen was transformed to plasmin by cultured embryos and activated endogenous matrix metalloproteinase 9 (MMP9). Indeed, the developmental expression profile of MMP9 was similar to that of PLAU. Our data suggest that the intrinsic developmental program predominantly regulates PLAU expression during implantation, and that PLAU could be responsible for activation of MMP9, leading to localized matrix proteolysis as trophoblast invasion commences.

Ultrasonic wave propagation in cementitious materials: a multiphase approach of a self-consistent multiple scattering model.

This paper examines ultrasonic wave propagation through strongly heterogeneous materials such as cementitious materials, and deals meanly with the formulation of a multiphase approach of a self-consistent multiple scattering model, the so-called dynamic generalized self-consistent model (DGSCM) proposed by Yang [J. Appl. Mech. 70(2003) 575-582]. This extended model can describe the influence of the size and volume fraction of aggregates on cementitious materials, as well as the interaction, contribution, and influence of entrapped air voids together with the aggregates on frequency-dependent parameters such as the phase velocity and the attenuation coefficient. To show the performance of this approach, theoretical predictions were compared with experimental ultrasonic measurements over a wide frequency range from several mortar specimens with different features in their microstructure properties and concentrations of aggregates up to 60%. The multiphase approaches of both the DGSCM and the Waterman-Truell model (WT) were also compared. The obtained results of the multiphase DGSCM were found to be significantly better than those obtained from the N-phase WT model for ultrasonic measurements from cementitious materials at high aggregate concentrations. The feasibility of material characterization using the multiphase approach of DGSCM was also discussed.

On the measurement of frequency-dependent ultrasonic attenuation in strongly heterogeneous materials.

This paper deals with the measurement of frequency-dependent ultrasonic attenuation in strongly heterogeneous materials, such as cementitious materials. To improve the measurement of this parameter on this kind of materials, a linear swept-frequency signal is used to drive an emitter transducer to conduct a through-transmission inspection in immersion. To filter out undesirable frequency content, time-frequency filtering and detection process are performed. The use of this method has been compared with two excitation techniques, the broadband and the narrowband pulses. The results obtained using the swept-frequency excitation together with the time-frequency filtering, allows the determination of the attenuation curves with high accuracy over a wide frequency range without the need for complicated equipment, and improves the effective bandwidth by using a unique pair of transducers.

Matrix metalloproteinases 2 and 9 in central nervous system and their modification after vanadium inhalation.

Vanadium (V) derivatives are well-known environmental pollutants and its toxicity has been related with oxidative stress. Toxicity after vanadium inhalation on the substantia nigra, corpus striatum, hippocampus and ependymal epithelium was reported previously. The purpose of this study was to analyse the role of matrix metalloproteinases 2 (MMP-2) and 9 (MMP-9) in the changes observed in brain tissue after chronic V inhalation. Mice were exposed to vaporized, vanadium pentoxide 0.02 m in deionized water for 1 h twice a week, and killed at 1 h, 1, 2 and 4 weeks after exposure. The brain was removed and the olfactory bulb, prefrontal cortex, striatum and hippocampus were dissected and the MMP content was obtained by zymography. The results showed that MMP-9 increased in all the structures at the end of the exposure, although in the hippocampus this increment was evident after 1 week of exposure. When MMP-2 was analysed in the olfactory bulb and prefrontal cortex it remained unchanged throughout the whole exposure, while in the hippocampus it increased at week 4, while in the striatum MMP-2 increased from the second week only, through the whole experiment. These results demonstrate that V increased MMPs in different structures of the CNS and this change might be associated with the previously reported modifications, such as dendritic spine loss and neuronal cell death. The modifications in MMPs could be related with blood-brain barrier (BBB) disruption which was reported previously. Oxidative stress might also be involved in the activation of these gelatinases as part of the different mechanisms which take place in V toxicity in the CNS.

Porosity estimation of aged mortar using a micromechanical model.

Degradation of concrete structures located in high humidity atmospheres or under flowing water is a very important problem. In this study, a method for ultrasonic non-destructive characterization in aged mortar is presented. The proposed method makes a prediction of the behaviour of aged mortar accomplished with a three phase micromechanical model using ultrasonic measurements. Aging mortar was accelerated by immersing the probes in ammonium nitrate solution. Both destructive and non-destructive characterization of mortar was performed. Destructive tests of porosity were performed using a vacuum saturation method and non-destructive characterization was carried out using ultrasonic velocities. Aging experiments show that mortar degradation not only involves a porosity increase, but also microstructural changes in the cement matrix. Experimental results show that the estimated porosity using the proposed non-destructive methodology had a comparable performance to classical destructive techniques.

Time-varying prediction filter for structural noise reduction in ultrasonic NDE.

Predominant physical phenomenon in highly scattering materials is the attenuation due to dispersion. Therefore, received echo has high frequencies more severely attenuated than low frequencies and the structural noise can be modeled as a non-stationary random process. Most of the proposed techniques for enhancing the flaw visibility do not exploit the frequency dependency of the incoming flaw signal, assuming homogeneous behaviour of the insonified material. In this work, a new technique based on exploiting the non-stationary nature of the incoming UT signal is presented. Proposed technique is based on the prediction error obtained with a linear and time-varying parametric model of the noise. By this method, when the analyzed UT echo has only structural noise, the prediction error is low, however, if it contains a flaw, high prediction error occurs because a flaw is a non-predictable alteration of the material structure. Experiments with stainless steel show that this method has an excellent performance on SNR enhancement.

Speckle reduction by energy time-frequency filtering.

Structural noise is a very important limitation to the visibility of flaw echoes in ultrasonic testing and evaluation of highly scattering materials. In order to enhance the signal-to-noise ratio, different algorithms have been developed. One of these techniques is based on filtering the spectrum low band of the received echo to obtain a significant improvement of the defect visibility. Based on this idea, in this work a new time-frequency technique is presented. In this method, block-processing autoregressive techniques are used to estimate the instantaneous center frequency of the traveling wave. From this information, a time-frequency filter is designed tuned at half the estimated instantaneous center frequency. Experimental results and the comparison with the non-time-frequency filtering technique are also included, showing that the proposed method has an excellent performance on SNR enhancement.

Effect of the fluid in the inclusions of cement paste on the ultrasonic velocity.

The durability of cement composites significantly depends on the movement of the fluids into the material through the porous system. The aqueous phase contained in the pores can cause irreversible damage from the dimensional stability viewpoint. In this sense, methods for non-destructive characterization of both, the porous structure and water content should be investigated. In this work, the effect of the fluid in the inclusions of the cement paste on the ultrasonic velocity is studied. Firstly, a theoretical analysis based on the micromechanical model, considering the microstructural information of the matrix and the fluid filling the pores, is presented. Some experimental work is made later using cement paste samples, whose porous structure is maintained dry or saturate with water. In both cases, the ultrasonic velocity is measured and compared to the one predicted by the micromechanical model. Using this technique, the ultrasonic velocity can be predicted with errors below 2% in the cases of dry or water saturated cement paste.

Application of micromechanics to the characterization of mortar by ultrasound.

Mechanical properties of concrete and mortar structures can be estimated by ultrasonic non-destructive testing. When the ultrasonic velocity is known, there are standardized methods based on considering the concrete a homogeneous material. Cement composites, however, are heterogeneous and porous, and have a negative effect on the mechanical properties of structures. This work studies the impact of porosity on mechanical properties by considering concrete a multiphase material. A micromechanical model is applied in which the material is considered to consist of two phases: a solid matrix and pores. From this method, a set of expressions is obtained that relates the acoustic velocity and Young's modulus of mortar. Experimental work is based on non-destructive and destructive procedures over mortar samples whose porosity is varied. A comparison is drawn between micromechanical and standard methods, showing positive results for the method here proposed.

Time-frequency Wiener filtering for structural noise reduction.

In order to enhance the defect in relation to background noise of large grained materials different algorithms have been developed. Wiener filtering techniques have proved to be efficient for the SNR enhancement of ultrasonic signals coming from highly scattering materials. These processing algorithms are based on designing a filter that has large gain at frequencies where the SNR is high and low gain at frequencies where SNR is small. However, this technique does not consider two important ultrasonic effects: the finite-time duration of the flaw UT signal coming from a defect and the distortion of the frequency components of the traveling wave-front due to the dispersion. In this work, a time-frequency Wiener filter is proposed that takes into account these two characteristics. Experimental results are presented, showing that the proposed time-frequency algorithm has an excellent performance on SNR enhancement.

Evaluation of the Reveal quick test for Salmonella detection in raw chicken meat.

Salmonella belongs to the Enterobacteriaceae family, and is the cause of illnesses such as enteric fevers, enteritis and septicemia. Accordingly, a necessity exists of researching and developing new techniques,--which must be sensible, specific, economic and fast--for genus determination; all this related to the culture technique (official technique). In the present work, 80 samples of chicken were analyzed for Salmonella both by the Reveal equipment and by the culture technique with and without a pre-enrichment step (reference technique). Samples were collected in established markets in Netzahualcóyotl City and Chimalhuacán, Estado de México; and analyzed by the culture technique, from which 15 Salmonella strains were isolated. 14 of those strains were obtained when the pre-enrichment step was implemented. Meanwhile, using the Reveal equipment (new technique), the presence of 16 Salmonella strains was identified. The statistical method used, defined as a method of predictive values, calculates the sensitivity and specificity of the Reveal test in relation with the culture technique. It also determines the positive predictive value (PPV), that represents the probability that the microorganism is truly present when the Reveal test scores positive; and the negative predictive value (NPV), that represents the probability that the microorganim is not present when the Reveal test scores negative.

The biotransformation of 18-hydroxy-9-epi-ent-pimara-7,15-diene by Gibberella fujikuroi.

Incubation of 18-hydroxy-9-epi-ent-pimara-7,15-diene with the fungus Gibberella fujikuroi gave the compounds 18-hydroxy-7 alpha,8 alpha-epoxy-9-epi-ent-pimara-15-ene, 18-hydroxy-7-oxo-ent-pimara-15-ene, 6 beta, 18-dihydroxy-7 alpha, 8 alpha-epoxy-9-epi-ent-pimara-15-ene, 9 beta,18-dihydroxy-7 alpha, 8 alpha-epoxy-ent-pimara-15-ene and 6 beta, 14 alpha, 18-trihydroxy-9-epi-ent-pimara-7,15-diene. Oxidation of C-19, which is characteristic of the biosynthesis pathway of the gibberellins is not produced.

Paramyosin is a major target of the human IgA response against Schistosoma japonicum.

Human resistance and susceptibility to schistosomiasis is associated with age and specific antibody isotype responses against worm (SWAP) and egg (SEA) antigens. In a cross-sectional study of 176 individuals infected with Schistosoma japonicum in the Philippines, strikingly similar isotype response patterns against SWAP and SEA was observed when compared to other endemic areas. Interestingly, IgA titres to SWAP correlated with older age among S. japonicum-infected individuals (n = 176, P < 0.01), suggesting a role for this isotype in protective immunity. To identify the molecular targets of human IgA, 17 high-IgA/SWAP responders were identified from the said population. IgA antibodies from the majority (14/17) of these individuals recognized a band of 97 kDa (Sj97), comigrating in immunoblots with the myofibrillar protein paramyosin. The antigen was confirmed as paramyosin by expressed sequence tag (EST)-analysis of four clones obtained by screening an adult S. japonicum cDNA library with pooled IgA antisera and mouse antiparamyosin polyclonal antibodies. The identification of paramyosin as a major target of human IgA raises its potential as a vaccine candidate that targets mucosal immune responses. Since this antigen is exposed on the parasite surface only during the lung stages, we propose that human IgA contributes to parasite attrition during schistosome migration in the lungs.