Selected primary and secondary metabolites in fresh persimmon (Diospyros kaki Thunb.): A review of analytical methods and current knowledge of fruit composition and health benefits

Diospyros kaki Thunb. (Ebenaceae) is a widely cultivated tree species in some countries of Asia, while in other continents persimmons are mostly considered “exotic” fruits. Peculiar characteristics of this species are a complex sex expression, parthenocarpy and fruit astringency at harvest time, associated with a different composition in polymerized flavan-3-ols. Analytical methods for determining sugars, vitamin C, carotenoids and polyphenols in persimmons were critically reviewed in order to evaluate the overall significance of literature results; the nutritional and nutraceutical properties, together with the health benefits of both astringent and non astringent cultivars, were also overviewed. To these aims, the available literature from the last twenty years and the most important formerly published papers were investigated using SciFinder^®, Elsevier SciVerse, AGRIS, and PubMed search engines. Persimmons resulted rich in sugars (about 12.5 g/100 g FW), being fructose, glucose and sucrose the major components, and in total vitamin C, for which 100-150 g of fresh persimmon supplies the recommended daily amount. Astringent varieties supply higher amounts of sugars than nonastringent ones; conversely, higher concentrations of total vitamin C were found in nonastringent cultivars. The main carotenoid components are ??-cryptoxantin (193 ??g/100 g FW), ??,??-carotene (113 ??g/100 g FW) and ??,??-carotene (30 ??g/100 g FW). Persimmons are also a good source of polyphenolic compounds such as p-coumaric acid, catechin, epicatechin, epigallo catechin, and condensed proanthocyanidins. This chemical composition, together with in vivo and in vitro studies, suggests a relevant role of persimmon in the protection against free radicals and in the prevention of some human diseases.     

Stochastic modeling of asphaltenes deposition and prediction of its influence on friction pressure drop

Abstract

When dealing with heavy and extra-heavy crude oils, petroleum industry faces the deposition and incrustation of solids on pipelines walls during fluids transportation. Such a deposition phenomenon is supposed to be caused by asphaltenes aggregation. In this work, is presented a stochastic model that predicts the behavior of friction pressure drop with respect to asphaltenes concentration and the deposition and detaching velocities through the principles of fractal geometry and differential fractional calculus. Results show that at higher values of asphaltenes total concentration and deposition velocity, the friction pressure losses are also increased, which is an expected behavior because of the thickness and morphology of the asphaltenes deposited layer.     

One‐way mesoscale‐microscale coupling for simulating a wind farm in North Texas: Assessment against SCADA and LiDAR data

One‐way nested mesoscale to microscale simulations of an onshore wind farm have been performed nesting the Weather Research and Forecasting (WRF) model and our in‐house high‐resolution large‐eddy simulation code (UTD‐WF). Each simulation contains five nested WRF domains, with the largest domain spanning the north Texas Panhandle region with a 4 km resolution, while the highest resolution (50 m) nest simulates microscale wind fluctuations and turbine wakes within a single wind farm. The finest WRF domain in turn drives the UTD‐WF LES higher‐resolution domain for a subset of six turbines at a resolution of ～5 m. The wind speed, direction, and boundary layer profiles from WRF are compared against measurements obtained with a met‐tower and a scanning Doppler wind LiDAR located within the wind farm. Additionally, power production obtained from WRF and UTD‐WF are assessed against supervisory control and data acquisition (SCADA) system data. Numerical results agree well with the experimental measurements of the wind speed, direction, and power production of the turbines. UTD‐WF high‐resolution domain improves significantly the agreement of the turbulence intensity at the turbines location compared with that of WRF. Velocity spectra have been computed to assess how the nesting allows resolving a wide range of scales at a reasonable computational cost. A domain sensitivity analysis has been performed. Velocity spectra indicate that placing the inlet too close to the first row of turbines results in an unrealistic peak of energy at the rotational frequency of the turbines. Spectra of the power production of a single turbine and of the cumulative power of the array have been compared with analytical models.     

Physicochemical and Sensory Properties of Cold Pressed Oils from Florida Hamlin and Valencia Oranges Affected by Huanglongbing

Cold pressed oils from huanglongbing (HLB) symptomatic (SY) and asymptomatic (AS) Hamlin and Valencia oranges were assessed for 2 y (2014 to 2015 and 2015 to 2016 seasons) with 2 harvest dates for each orange variety per year. Physicochemical properties (optical rotation, aldehyde content, ultraviolet [UV] absorbance, refractive index, and specific gravity) mandated by the United States Pharmacopeia (USP) for orange oil quality were assessed. Hamlin and Valencia oils showed minor differences in physicochemical properties based upon disease stage. However, all Hamlin oils had aldehyde contents below the USP minimum and Valencia oil from late season SY oranges had specific gravities above the USP maximum. Significant differences based on harvest year were seen for aldehyde content, refractive index, optical rotation, and UV absorbance. While none of these changes led to an oil being out of USP specifications, they indicate a need to monitor the quality of oil every year to ensure a consistent product. Flavor taste panels were performed both years by adding 0.035% oil samples to a uniform orange juice base. Aroma panels were done by smelling pure oil. There were no significant differences between SY and AS oils for flavor, although panelist race was a significant factor in several of the panels. There were significant differences between the aroma of SY and AS oils for both 2015 to 2016 Hamlin Early and Valencia Late samples. Overall, these results show HLB can have an effect on the aroma and USP mandated physicochemical properties of Florida orange oils, although flavor may be unaffected by this plant disease.     

Computational Study of Impingement Jet Drying of Seeds Using Superheated Steam Based on Kinetic Theory of Granular Flow

A Eulerian model including the kinetic theory of granular flow (KTGF) and mass transfer in the period of saturated wet surface has been developed to simulate continuous drying of particulate solids using superheated steam in a radial impingement jet system. When applying this type of drying processes, the preliminary results obtained show good predictive ability of the Eulerian modeling based on KTGF. It is concluded that the present study and other works of modeling can be used to study the dynamics and control of this drying process and thus would facilitate the equipment design and scaling.     

Influence of silica and coupling agent loading on thermal, morphological and mechanical properties of hybrid membranes

Hybrid polyetherimide-silica (PEI-SiO₂) membranes were synthesized via the sol–gel method through the hydrolysis of tetraethoxysilane (TEOS) with 3-aminopropyltriethoxysilane (APTEOS) as a coupling agent. The effects of silica content and the APTEOS/TEOS ratio in thermal, morphological and mechanical properties of the hybrid membranes were studied. Although many studies report improvements in the structure or properties of composite materials when a coupling agent is used, these contributions do not investigate the effect of the coupling agent loading on the properties of the new material synthesized. In this study, we prepared hybrid membrane with a fixed amount of APTEOS modifying TEOS content to analyze the silica content effect. Conversely, to determine the coupling agent effect, hybrid membranes were prepared varying the APTEOS content while the amount of TEOS was kept constant. All hybrid membranes have a dense and uniform internal structure and exhibit good thermal resistance with a degradation temperature above 544 °C. Membranes with 10 wt% of silica showed better tensile strength with a high modulus and low rupture elongation indicating an effective load transfer between the phases. Concerning the coupling agent effect, the maximum modulus was observed for membranes with 10 wt% of APTEOS, suggesting a greater interaction between the organic and inorganic phases.     

Geological and geophysical investigations at Sierra del Medio massif,Argentina

Geological investigations were performed at Sierra del Medio (Cushamen County, Chubut Province in Central Patagonia), a mountainous massif of about 25 km by 8 km of migmatic origin, which emerges from a depressed tectonic trench or graben called Pampa de Gastre. The most ancient rocks belong to biotitic and amphibolic schist that passed almost entirely to tonalitoid migmatites with a second process producing granitic rocks. Boreholes were drilled on the basis of conclusions from Landsat satellite imagery and aerial photographic sets, followed by field work on geological, petrographic, geophysical and hydrogeological features at surface, structural interpretation supported by geostatistical computations. Two sets of boreholes were drilled to investigate, subsurface rock behaviour at 300 m depth and 800 m depth respectively, beginning at peripheral places and ending at the central part or selected site. Basic purposes of boreholes were to define structural and petrographic features of the rock massif by a good comprehension of master joints and faulting distribution with its belts of alteration, mylonitization or brecciation, mechanical properties of samples, chemical composition and variations, petrographic facies and mineralogy. Boreholes provided data to investigate joints, faults and dikes as general discontinuities for hydraulic research such as permeability or effective hydraulic conductivity, and their geostatistical modelling. Boreholes are also being prepared for geophysical logging from which thermal logs have already been completed.     

The role of online seller reviews and product price on buyers' willingness-to-pay: a risk perspective

Third-party interpersonal communications such as online seller reviews play an important role in buyers’ purchase decisions in online markets. Although it is empirically clear that seller reviews (volume and valence) and product price contribute to buyers’ willingness-to-pay (WTP) differently across various studies, it is theoretically less understood why such effects qualitatively differ (e.g., positive vs negative), rendering unclear managerial implications for online marketers. In this paper, we study the role of online seller reviews and product price in buyers’ WTP. We offer a conceptual framework from a risk perspective in which we argue that the different effects of seller reviews and product price on buyers’ WTP may emerge simultaneously in an online market. We highlight two important drivers for such qualitatively different effects: a difference in buyers’ risk attitudes (averse, neutral, or seeking) and a difference in WTP measures (absolute or relative). We test our hypotheses and find good support for them both internally (an experimental study) and externally (an empirical study). Our research enhances the understanding of the relationship between online user reviews and online price dispersions while shedding light on better management of online user reviews for market makers.     

Information systems and performance: the role of technology,the task and the individual

Organisations require good performance from individuals to achieve their objectives. In view of the growing presence of technology, it becomes necessary to understand performance in the context of information systems. However, the research streams that study performance (e.g. industrial psychology or the impact of technology on performance) focus primarily on a single component (the individual or the technology). The systemic perspective, for its part, considers all three components (technology, the individual and the task) and their relationships in order to explain performance. From this perspective, this article develops a research model where individual (knowledge of the task and the technology), task (ease) and technology (usefulness and ease) factors determine performance. Links are also established between these factors. Data were collected from 246 individuals and the results show that the proposed links are significant. This research highlights that management should take into account all three components to boost performance. The study emphasises in which factors of these components special care should be taken. The lack of improvement in performance after the introduction of an information system may not be solved merely by tackling the features of the technology but also by simplifying the tasks or reviewing the users’ knowledge gaps.     

Engineering 2-oxoglutarate dehydrogenase to a 2-oxo aliphatic dehydrogenase complex by optimizing consecutive components

Multienzyme complexes have the potential for green catalysis of sequential reactions. The Escherichia coli 2-oxoglutarate dehydrogenase complex (OGDHc) was converted from a 2-oxoglutarate dehydrogenase to a 2-oxo aliphatic dehydrogenase complex by engineering consecutive components. OGDHc catalyzes succinyl-CoA synthesis in the Krebs cycle. OGDHc is composed of three components: E1o, 2-oxoglutarate dehydrogenase; E2o, dihydrolipoylsuccinyl transferase; E3, dihydrolipoyl dehydrogenase. There are three substrate checkpoints. One is in E1o and two in E2o. OGDHc was reprogrammed to accept alternative substrates by evolving the E1o and E2o components. Wt-ODGHc does not accept aliphatic substrates. E1o was previously engineered to accept a non-natural aliphatic substrate, 2-oxovalerate (2-OV). E2o also required engineering to accept 2-OV in the overall reaction. Hence, saturation mutagenesis libraries of E2o were screened for 2-OV activity. E2o-S333M, E2o-H348F, E2o-H348Q, and E2o-H348Y were identified to show activity for 2-OV in the reconstituted complex. Variants also displayed activity for larger aliphatic substrates.