Heat Treatment Improves Olive Oil Extraction

To determine the effect of hot water pre-treatment on olive oil extraction, six cultivars of olive fruit (Olea europaea L. cvs. “Arbequina”, “Hojiblanca”, “Lechín”, “Manzanilla”, “Picual”, and “Verdial”) were heated at 50, 55, and 60 °C prior to laboratory scale oil extraction. Heat treatment resulted in higher oil extraction than unheated control samples. Quality parameters of the oils were not significantly (P < 0.05) affected by these treatments; however, oil stability and bitterness intensity were reduced and pigment content was increased through pre-heat treatment. This process may be incorporated economically into olive oil processing.     

Polyester–polycarbonate blends. VI. Branched aliphatic polyesters

Polycarbonate blends with poly(pivalolactone) were found to be completely immiscible based on the glass transitional behavior observed by thermal analysis. Crystallinity of the poly(pivalolactone) was unaffected by blending with polycarbonate. The heat of mixing of low molecular weight analogs of this system, ethyl pivalate and diphenyl carbonate, were found to be endothermic, in contrast to exothermic mixing observed for similar linear esters. Methyl branching adjacent to the ester carbonyl is believed to shield the specific interaction of this unit with the aromatic carbonate structure which leads to exothermic mixing and miscibility of similar unbranched esters with polycarbonate. Blends of poly(2,2-dimethyl-1,3-propylene succinate) were found to be partially miscible with polycarbonate because the shielding is not so great since the methyl groups are further removed from the ester group.     

Systematic integrated process design and control of binary element reactive distillation processes

Integrated process design and control of reactive distillation processes is considered through a computer‐aided framework. First, a set of simple design methods for reactive distillation column (RDC) that are similar in concept to nonreactive distillation design methods are extended to design‐control of RDCs. These methods are based on the element concept where the reacting system of compounds is represented as elements. When only two elements are needed to represent the reacting system of more than two compounds, a binary element system is identified. It is shown that the same design‐control principles that apply to a nonreacting binary system of compounds are also valid for a reactive binary system of elements for distillation columns. Application of this framework shows that designing the reactive distillation process at the maximum driving force results in a feasible and reliable design of the process as well as the controller structure. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3137–3154, 2016     

Toward the accurate modeling of amorphous nonlinear materials—polymer stress relaxation (I)

We expand our analytical modeling strategy for polymer non‐linear stress relaxation (A) to specify the remaining steps to accurately deal with the nonaffine nature of the materials’ local strains and stresses relative to their average overall values, and (B) to make it consistent with a new cooperative theory of amorphous materials dynamics, providing a model of tunable fragility that sheds light to most aspects of the behavior, including the glass transition. The stress relaxation models (1) describe a nonlinear (strain‐dependent) behavior that becomes linear at very low strains, (2) quantify the effect of temperature, (3) may quantify the effects of changes in free volume, and (4) ensure very fast computations of the materials’ response irrespective of the experimental time scale. The models are sensitive to the influence of different initial states of the material, as may result from varying degrees of molecular orientation and aging levels, and are able to predict from experimental stress relaxation moduli (for a poly (methylmethacrylate)—PMMA and a bis‐phenol‐A polycarbonate—PC) the values of the crossover frequency, ν_c, crossover temperature, T_c, and the minimum activation energy, in addition to the initial and long‐time plateau moduli, in agreement with independently measured values. POLYM. ENG. SCI., 56:348–360, 2016. © 2016 Society of Plastics Engineers     

Influence of the notch‐sharpening technique on styrene–acrylonitrile fracture behavior

The Centre Català del Plàstic and Universidad Rey Juan Carlos laboratories joined forces to investigate the effect of the notch‐sharpening technique on the fracture parameters of styrene–acrylonitrile. Contact notch‐sharpening techniques, such as razor tapping, razor sliding, and razor broaching, and a noncontact procedure, femtolaser, were analyzed. The fracture values of the samples with notches sharpened via contact techniques were divided into two groups: one with pop‐in and the other with no pop‐in in the load–displacement records; this resulted in the lowest and highest fracture toughnesses, respectively. The fracture parameters of the specimens with notches sharpened via a femtolaser were between those of the samples with notches sharpened via contact procedures in which pop‐in occurred and those in which it did not. To explain these results, the crack front of the nontested specimens after sharpening was investigated in depth, we identified the type of damage and measured its size and the crack tip radii. The morphology of the crack front was related to the fractographic study. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43775.     

Degradation profiles of poly(methylene oxide) and poly(glycolic acid) for inflow control devices in oil wells

The viability of the application of hydrolysable polymers, such as poly(methylene oxide) (PMO) and poly(glycolic acid) (PGA), in formation treatments in oil wells, was studied; we examined their addition to inflow control devices (ICDs), which are instruments used to control the oil‐flow profile along production intervals. Thereby, the structural and morphological changes of PMO and PGA samples exposed to common chemicals, such as hydrochloric acid (HCl) and sodium chloride (NaCl) solutions and xylene, used in the procedure were evaluated under conditions similar to those observed in southeastern Brazilian offshore oil fields (temperature range = 50–130 °C, 41.4 MPa). The aim of this study was to verify whether the polymers hydrolyzed and could be further removed from the ICDs. Techniques including high‐pressure liquid chromatography, ion chromatography, ¹³C‐NMR, differential scanning calorimetry, scanning electron microscopy, and optical microscopy were applied in this study. Xylene did not produce expressive effects in the samples. PMO was significantly affected by 15% HCl at 75 °C but was not completely dissolved after 24 h of exposure; this counter indicates its use. The PGA hydrolysis profile in NaCl brine was suitable for application around 75 °C. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43786.     

Preliminary study on the biodegradation of adipate/phthalate polyester polyurethanes of commercial‐type by Alicycliphilus sp. BQ8

Accumulation of polyurethane (PU) waste has increased considerably due to its extensive use. Even though many efforts are being carried out to develop more biodegradable PU, the use of these new materials is far from being commercially available. Here, we analyzed the susceptibility of solid polyester polyurethanes (PS‐PU) of commercial‐type, to biodegradation by Alicycliphilus sp. BQ8, a polyurethanolytic bacterial strain. Four polyester polyols were synthesized from dipropylene glycol (DPG) or diethylene glycol (DEG), and adipic acid (ADA) or phthalic anhydride (PHA), and were combined with either 4,4′‐ and 4,2′‐methylene diphenyldiisocyanate (MDI) or 2,4‐ and 2,6‐toluene diisocyanate (TDI). Synthesized polyols and PUs were characterized. PU biodegradation was assessed by the capacity of the polymers to support bacterial growth, and by scanning electron microscopy (SEM), Fourier transformed infrared (FTIR) spectroscopy, and gas chromatography/mass spectrometry (GC‐MS) analyses. Although all the synthesized PUs supported BQ8 growth, SEM analysis showed that PHA‐based PU foams were the most affected by bacterial growth. FTIR spectroscopy and GC‐MS analyses of bacterial treated PS‐PUs showed that they were attacked at ester and urethane groups, suggesting that esterase and amidase activities are involved. Extra‐cellular and membrane bound esterase activities were detected during the five days of analysis. Our results suggest that solid PHA‐based PUs might be more susceptible than ADA‐based PUs to microbial biodegradation in the environment. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42992.     

Ultrastructural aspects of mouse nerve‐muscle preparation exposed to Bothrops jararacussu and Bothrops bilineatus venoms and their toxins BthTX‐I and Bbil‐TX: Unknown myotoxic effects

Bites by Bothrops snakes normally induce local pain, haemorrhage, oedema and myonecrosis. Mammalian isolated nerve‐muscle preparations exposed to Bothrops venoms and their phospholipase A₂ toxins (PLA₂) can exhibit a neurotoxic pattern as increase in frequency of miniature end‐plate potentials (MEPPs) as well as in amplitude of end‐plate potentials (EPPs); neuromuscular facilitation followed by complete and irreversible blockade without morphological evidence for muscle damage. In this work, we analysed the ultrastructural damage induced by Bothrops jararacussu and Bothrops bilineatus venoms and their PLA₂ toxins (BthTX‐I and Bbil‐TX) in mouse isolated nerve‐phrenic diaphragm preparations (PND). Under transmission electron microscopy (TEM), PND preparations previously exposed to B. jararacussu and B. bilineatus venoms and BthTX‐I and Bbil‐TX toxins showed hypercontracted and loosed myofilaments; unorganized sarcomeres; clusters of edematous sarcoplasmic reticulum and mitochondria; abnormal chromatin distribution or apoptotic‐like nuclei. The principal affected organelles, mitochondria and sarcoplasmic reticulum, were those related to calcium buffering and, resulting in sarcomeres and myofilaments hypercontraction. Schwann cells were also damaged showing edematous axons and mitochondria as well as myelin sheath alteration. These ultrastructural changes caused by both of Bothrops venoms and toxins indicate that the neuromuscular blockade induced by them in vitro can also be associated with nerve and muscle degeneration.     

On the estimation of particle number

Two methods are proposed for estimating the number of separated particles within a solid structure per unit volume of structure, N_v. Apart from being arranged with independence of any size parameter, no special assumptions upon the size, shape and orientation of the particles are made. The first method is based on the identity N_V = (N_A)_u ? μ_u^?1, where (N_A)_u is the mean number of particle sections per unit area of a plane probe T_u which is uniform random within the structure and perpendicular to a given direction u, whereas μ_u is the mean particle caliper length along u. The second method uses N_V = A_A?V^?1, where A_A is the mean areal fraction of the particles per unit area of section, whereas v is the mean particle volume. The estimation of (N_A)_u, μ_u, and v requires the examination of parallel serial sections above and below T_u. Particle model reconstructions are not needed, however. Previous approaches to the problem are discussed.