Modeling of the relative humidity via functional networks and control of the temperature via classic controls for a bird incubator

The control of the relative humidity and the temperature is important for the birds to be born. It is not easy to control the relative humidity, but it is possible to obtain the measure of the relative humidity as a consequence of the control of the temperature in a bird incubator. In this article, (1) the mathematical model for the control of temperature in the bird incubator is presented, (2) a functional network to approximate the relative humidity behavior in the bird incubator is proposed, (3) a control for the temperature in the bird incubator is proposed, the error of the proportional control applied to the mathematical model of the temperature of the bird incubator is assured to be uniformly stable, (4) the comparison results of four classic control laws for the control of the temperature considering the proposed mathematical model of the temperature and the functional network to approximate the relative humidity behavior in the bird incubator are presented.     

He scattering on a TiO2(1 1 0) surface

We present measurements of energy-losses and neutralisation of helium ions on a TiO₂(1 1 0) surface at low keV energies. Measurements were performed in the 1–4 keV energy range. The target azimuthal orientation dependence of total scattering intensity profiles, energy-losses and probability of electron capture or loss were determined. On the basis of Marlowe simulations it is concluded that ion scattering intensities give indications about defects regarding surface bridging O atoms. Variations in energy losses for different scattering directions are reported. Ion fraction measurements were made using both incident ions and neutrals. Similar ion fractions were found indicating that He is efficiently neutralised and ions result from reionisation. These ion fractions are found to depend on the azimuthal orientation and have a minimum along the main crystallographic directions.     

Flour of hard bean (Phaseolus vulgaris) in the preparation of bread]

In order to utilize hardened beans, we proposed to find the method most indicated for the preparation of bean flour to determine their nutritional value, and to make bread of high industrial, nutritional quality, and good sensory characteristics, using blends of bean and wheat flours. Two types of flour were prepared, testing four soaking temperatures (22, 30, 40 and 50 degrees C) and two methods to remove the testa (under moist and dry conditions). At laboratory level, the dry testa removal method gave the best flour yields (mean = 85.8%) and the highest protein content (mean = 23.7%). Comparison between soaking temperature at 30 and 50 degrees C was not significant (alpha = 0.05). At pilot plant level, with soaking at 50 degrees C the flour yields were 58.0% for moist testa removal (H1) and 74.0% for dry removal (H2), with a protein content of 22.6% for H1 and 23.0% for H2. The H1 and H2 flours were added to wheat flour at 5, 10 and 15% for bread making. The addition of 5.0% gave breads with similar protein content and sensory characteristics to those of the control, wheat. A diet based on bean-flour bread resulted in greater weight gains than that with casein for gold hamsters. The study also demonstrated the importance of heat-treating of the bean flours, because when flour without previous heat treatment was administered, the animals lost weight and died. This effect was overcome by the process of baking the flours at 140 degrees C for four hours.     

Multilayer Dual-Band Filter Using a Reflector Cavity and Dual-Mode Resonators

A dual-band filter has been designed using a multilayer approach. The structure includes a reflector cavity and dual-mode resonators. The walls of the reflector cavity have been designed using metalized vias enabling the integration characteristics of standard planar microwave circuits. The principle includes the passband division of a fourth-order fully canonical form into two narrowband second-order passbands. The designed topology exhibits a dual-band response with center frequencies of 5.2 and 5.7GHz and in-between isolation of 30 dB created by two in-band transmission zeros. The enclosing cavity reduces radiation loss and increases the unloaded of the resonant modes. The hybrid design provides insertion losses better than 1.7 dB and narrow fractional bandwidths of 2.5%.     

Surface contributions to the effective optical properties of porous silicon

Porous silicon (PS) presents efficient photoluminescence and electroluminescence with potential applications in the optoelectronic industry, in particular in photovoltaic devices. It is now generally accepted that the interesting optical properties of PS are due to two combined aspects: on the one hand, the quantum confinement and on the other, the surface states. Although there has been a great effort to study PS, its transport properties are still not well understood. Due to the complex structure of PS an averaging theory to describe its effective properties is justified. In this work the effective dielectric function, effective absorption coefficient and effective refractive index are calculated using the volume averaging method for a model of periodic columns with different surface coatings simulating porous silicon. This approach allows analytical results within certain approximations and the analysis of surface contributions. The method uses parameters to characterize the bulk and the surface. We choose for the bulk c-Si, and cover it with three different possible surfaces: siloxane, a-Si : H and SiO₂. The results are compared with experimental data and other theoretical approaches for silicon wires. We obtain good agreement with some experimental results showing the important role of the surface in the effective response of porous silicon.     

Water use (and abuse) and its effects on the crater‐lakes of Valle de Santiago,Mexico

Most Mexicans live in the arid and semiarid regions that represent two‐thirds of the Mexican territory, where water is scarce. Natural, as well as human, causes are favouring the degradation of Mexican lakes. There is a clear need to develop and implement sustainable water‐use programmes at a catchment scale. However, the accelerated degradation rate of the Mexican lakes means that there will not be enough time to perform whole‐basin evaluations to establish sustainable water‐use programmes before the lakes dry up. The case of the Valle de Santiago crater‐lakes clearly illustrates the declining trend that Mexican inland aquatic resources follow. Vegetation clearance, overgrazing, abatement of phreatic waters and salinization have induced severe erosion and overall desertification (land degradation) in the basin for what, it seems, a long time (i.e. prehispanic times). In this way, human activities could be provoking at least the following negative consequences: a hotter and drier local climate, water scarcity, dust storms and soil salinization. The aquatic (surface and groundwater) resources of the Valle de Santiago basin have been seriously threatened. Two of the four crater‐lakes have already dried up and phreatic mantle abatement reaches up to 2.5 m per year. In spite of these facts, no sustainable water‐use programme has been established yet. The future scenery of this Mexican basin looks alarmingly like many other basins in the central and northern Mexican territories.     

High pressure densities of carbon dioxide + dipentaerythritol hexaheptanoate: New experimental setup and volumetric behavior

To perform an appropriate selection of the lubricants in air conditioned systems working with carbon dioxide as refrigerant, the thermodynamic behavior of the CO₂ + lubricant systems must be well known. In this work we present a new setup to prepare compressed gas–liquid mixtures and to determine the high pressure density by using an automated densimeter HPM and two syringe pumps. To analyze the reliability of the procedure proposed, we have determined the densities and mixing volumes of four CO₂ + n-decane mixtures. We have found a good agreement with previous literature data. In addition new density values are reported for the binary system CO₂ + dipentaerythritol hexaheptanoate (DiPEC7) at several temperatures and pressures from 10 MPa to 120 MPa.     

A defective Vkappa A2 allele in Navajos which may play a role in increased susceptibility to haemophilus influenzae type b disease

The antibody response to H. influenzae type b (Hib) is pauciclonal, and is dominated by antibodies using the VkappaA2 gene. Navajos have a 5-10-fold increased incidence of Hib disease compared with control populations. We hypothesized that a polymorphism in one of the genes in this oligoclonal response may lead to increased disease susceptibility. Since the predominant A2+ anti-Hib antibodies have high avidity for Hib and can be unmutated, the A2 Vkappa gene was analyzed. Over half of the Navajos studied, but only one control individual, had a new allele of A2, termed A2b, with three changes from the published A2 germline sequence. One of the changes was in the recombination signal sequence, suggesting that the A2b allele might not undergo V-J rearrangement very frequently. This possibility was confirmed by analyzing the relative frequency of non-productive A2 rearrangements in A2a/b heterozygous Navajos. Many fewer A2b rearrangements were observed, showing that the A2b allele is defective in its ability to undergo rearrangement. The prevalence of this allele in Navajos may play a role in their increased susceptibility to invasive Hib disease. If so, it would underscore the importance of the germline Ig repertoire for protective antibody responses to pathogenic bacteria in unimmunized children.     

Biobased polyester obtained from bifunctional monomers through metathesis of fatty acids as precursor to synthesis of polyurethanes

Biobased unsaturated aliphatic polyesters and polyurethanes were obtained from fatty acid monomers with double functionality synthesized through cross-metathesis of oleic acid and oleic alcohol. The chemical structure and thermal behavior of the monomers and polymers were analyzed by several physicochemical tests, and oscillatory rheometry and optical microscopy were used to determine their rheological properties and to observe the crystal formation of the obtained polyesters, respectively. It has been found that the polyesterification reaction depends on reaction temperature and to a lesser degree on both the reaction time and catalyst addition. The melt temperature and enthalpy of the obtained biobased polymers show that the monomer chain length has an effect on both the crystallinity and thermal transitions of the polymers, as can be explained by a group contribution analysis showing excellent correlation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47095.