Improvement of glycerin removal from crude biodiesel through the application of a sulfonated polymeric adsorbent material

The proposal of suitable processes for glycerin removal from crude biodiesel is an important task for making the overall biodiesel production process environmentally friendly and economically viable. In this article, we propose a dry purification process for biodiesel treatment with different polymeric materials [chitosan, cellulose acetate, poly(vinyl alcohol) (PVA), and sulfonated PVA]. Except for pure PVA, all of the proposed materials were able to reduce the free glycerin content of crude biodiesel from 0.03 wt % to values lower than 0.02 wt %. When the PVA was sulfonated, the glycerin removal increased from 12 to 82% compared that of pure PVA. The glycerin content in the biodiesel sample treated with sulfonated PVA was 0.0055 wt %. Mid‐IR spectrometric analysis showed that the sulfonation of PVA increased the band due to H? O? H stretching vibrations; this enabled greater hydrogen bonding between glycerol and the ? SO₃? groups of the sulfonated adsorbent. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45330.     

Exploring residential satisfaction in shrinking cities: a decision-tree approach

The number of cities experiencing population decline has been increasing worldwide. Despite the existence of theoretical propositions of shrinkage as an opportunity to increase levels of residential satisfaction, the issue has not been addressed empirically. This article contributes to fill this gap by assessing, through survey, the residential satisfaction of inhabitants of four shrinking Portuguese cities.

Data were analysed by means of a tree-decision approach: the Chi-squared Automatic Interaction Detection analysis. A sense of safety is the feature that best discriminates inhabitants’ level of residential satisfaction. The results show that shrinkage due to deindustrialisation processes is detrimental to residential satisfaction.     

Precursor system of liquid crystalline phase containing propolis microparticles for the treatment of periodontal disease: development and characterization

Precursor systems of liquid crystalline phase were prepared using the surfactant PPG-5-Ceteth-20, isopropyl myristate, and water; gelatin microparticles containing propolis were then added into these systems. Homogeneity of dispersion, the in-system microparticle morphology, and sedimentation behavior of each formulation were evaluated. The rheological and mechanical properties (hardness, compressibility, and adhesiveness), the work of syringing, and the propolis release profile were also evaluated. All the formulations exhibited pseudoplastic flow and thixotropy, and they displayed storage modulus, loss modulus, dynamic viscosity, and loss tangent that depended on temperature, frequency, and composition. Mechanical properties varied significantly among the formulations being affected by changes in the composition and temperature. Raising the concentration of surfactant and adding propolis microparticles significantly decreased the work of syringing. The drug release was non-Fickian (anomalous) and there was no significant difference between the tested systems in the times required for 10%, 30%, and 50% release of the initial drug loading.     

Preparation of monoglycerides by guanidine-catalyzed processes

Glycerolysis of methyl stearate and tristearin has been carried out in the presence of alkylguanidines—strong nonionic bases—as catalysts. When applied at 10 mol%, 1,5,7-triazabicyclo [4.4.0]dec-5-ene, 1,2,3-tricyclohexylguanidine, and 1,3-dicyclohexyl-2-n-octylguanidine give monoglycerides in more than 90% selectivity, in a maximum of 6 h reaction time.     

Performance strategies affect mammary gland development in prepubertal heifers

In Brazil, the majority of dairy cattle are Holstein × Gyr (H×G). It is unknown whether excessive energy intake negatively affects their mammary development to the same extent as in purebred Holsteins. We hypothesized that mammary development of H×G heifers can be affected by dietary energy supply. We evaluated the effect of different average daily gains (ADG) achieved by feeding different amounts of a standard diet during the growing period on biometric measurements, development of mammary parenchyma (PAR) and mammary fat pad (MFP), and blood hormones. At the outset of this 84-d experiment, H×G heifers (n = 18) weighed 102.2 ± 3.4 kg and were 3 to 4 mo of age. Heifers were randomly assigned to 1 of 3 ADG programs using a completely randomized design. Treatments were high gain (HG; n = 6), where heifers were fed to gain 1 kg/d; low gain (LG; n = 6), where heifers were fed to gain 0.5 kg/d; and maintenance (MA; n = 6), where heifers were fed to gain a minimal amount of weight per day. Heifers were fed varying amounts of a single TMR to support desired BW gains. Over the 84 d, periodic biometric and blood hormone measurements were obtained. On d 84, all heifers were slaughtered and carcass and mammary samples were collected. At the end, HG heifers weighed the most (181 ± 7.5 kg), followed by LG (146 ± 7.5 kg) and MA (107 ± 7.5 kg) heifers. The ADG were near expected values and averaged 0.907, 0.500, and 0.105 ± 0.03 kg/d for HG, LG, and MA, respectively. In addition, body lengths, heart girths, and withers heights were affected by dietary treatment, with MA heifers generally being the smallest and HG heifers generally being the largest. Body condition scores differed by treatment and were highest in HG and lowest in MA heifers; in vivo subcutaneous fat thickness measurement and direct analysis of carcass composition supported this. The HG heifers had the heaviest MFP, followed by LG and then MA heifers. Amount of PAR was highest in LG heifers and was the same for HG and MA heifers. The percentage of udder mass occupied by PAR was lowest in HG heifers, differing from LG and MA heifers. Composition of MFP was not evaluated. Regarding PAR composition, no differences in ash or DM were found. On the other hand, CP concentration of PAR for HG heifers was lower than that for LG heifers, which was lower than that for MA heifers. Regarding the fat content, HG treatment was higher than LG and MA treatment, which did not differ from each other. In PAR, differences in relative abundance of genes related to both stimulation and inhibition of mammary growth were observed to depend on dietary treatment, sampling day, or both. The same can be said for most of the blood hormones that were measured in this experiment. In this experiment, high ADG achieved by feeding different amounts of a standard diet during the growing period negatively affected mammary development.     

Short communication: Identification of Corynebacterium bovis by MALDI-mass spectrometry

Corynebacterium bovis is a mastitis-causing microorganism responsible for economic losses related to decrease in milk production. The aim of the study was identify Corynebacterium spp. strains recovered from milk samples of subclinical mastitis by using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Samples were collected during a 10-mo mastitis-monitoring program in a high-production dairy farm. In this study, 80 strains were analyzed; from these 54 (67.5%) were identified at species level as Corynebacterium bovis, 24 (31.2%) isolates were identified at the genus level as Corynebacterium spp., and only 1 (1.35%) isolated had unreliable identification. Results demonstrated that MALDI-MS could be an important technique for the identification of Corynebacterium spp. in milk.     

Interaction intimacy organizes networks of antagonistic interactions in different ways

Interaction intimacy, the degree of biological integration between interacting individuals, shapes the ecology and evolution of species interactions. A major question in ecology is whether interaction intimacy also shapes the way interactions are organized within communities. We combined analyses of network structure and food web models to test the role of interaction intimacy in determining patterns of antagonistic interactions, such as host–parasite, predator–prey and plant–herbivore interactions. Networks describing interactions with low intimacy were more connected, more nested and less modular than high-intimacy networks. Moreover, the performance of the models differed across networks with different levels of intimacy. All models reproduced well low-intimacy networks, whereas the more elaborate models were also capable of reproducing networks depicting interactions with higher levels of intimacy. Our results indicate the key role of interaction intimacy in organizing antagonisms, suggesting that greater interaction intimacy might be associated with greater complexity in the assembly rules shaping ecological networks.     

Heat Conduction Analytical Solutions to be Applied in Boundary Conditions Obtained from Discrete Data

Analytical solutions have varied uses. One is to provide solutions that can be used in verification of numerical methods. Another is to provide relatively simple forms of exact solutions that can be used in estimating parameters, thus, it is possible to reduce computation time in comparison with numerical methods. In this paper, an alternative procedure is presented. Here is used a hybrid solution based on Green＇s function and real characteristics （discrete data） of the boundary conditions.     

Spin injection in n-type resonant tunneling diodes

We have studied the polarized resolved photoluminescence of n-type GaAs/AlAs/GaAlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. Under resonant tunneling conditions, we have observed two emission lines attributed to neutral (X) and negatively charged excitons (X⁻). We have observed a voltage-controlled circular polarization degree from the quantum well emission for both lines, with values up to −88% at 15 T at low voltages which are ascribed to an efficient spin injection from the 2D gases formed at the accumulation layers.