B Cells with a Senescent-Associated Secretory Phenotype Accumulate in the Adipose Tissue of Individuals with Obesity

Senescent cells accumulate in the adipose tissue (AT) of individuals with obesity and secrete multiple factors that constitute the senescence-associated secretory phenotype (SASP). This paper aimed at the identification of B cells with a SASP phenotype in the AT, as compared to the peripheral blood, of individuals with obesity. Our results show increased expression of SASP markers in AT versus blood B cells, a phenotype associated with a hyper-metabolic profile necessary to support the increased immune activation of AT-derived B cells as compared to blood-derived B cells. This hyper-metabolic profile is needed for the secretion of the pro-inflammatory mediators (cytokines, chemokines, micro-RNAs) that fuel local and systemic inflammation.     

Valorization of Al slag in the production of green ceramic tiles: Effect of experimental conditions on microstructure and crystalline phase composition

This work reports the results of an investigation aimed at the development of sintered glass-ceramic tiles by the sinter-crystallization of mixtures composed of aluminum slag and reclaimed packaging glass. The thermal behaviors of mixtures incorporating 50 and 60 wt% Al slag were established by differential thermal analysis (DTA). Green compacts were sintered in a temperature range of 800°C-1050°C and then soaked for 10-60 minutes. The mineralogical characterizations of the sintered materials were obtained by X-ray diffraction (XRD). The achieved results indicated that the sintering of aluminum slag and packaging glass reclaimed led to a glass-ceramic material composed mainly of needle-like crystals of wollastonite (CaSiO₃). The bloating of samples during firing was evaluated according to a Cougny predictive diagram. After initial observations and according to bending strength characterizations, sintered tiles prepared from aluminum slag and glassy sand are appropriate for floor pavement and wall covering.     

Producing High-Quality Titanium Alloy by a Cost-Effective Route Combining Fast Heating and Hot Processing

Powder metallurgy is a very attractive method for producing titanium alloys, which can be near-net-shape formed and have freedom in composition selection. However, applications are still limited due to product affordability. In this paper, we will discuss a possible cost-effective route, combining fast heating and hot processing, to produce titanium alloys with similar or even better mechanical properties than that of ingot metallurgy titanium alloys. Two titanium alloys, Ti-5Al-5V-5Mo-3Cr (Ti-5553) and Ti-5Fe, were successfully produced from HDH titanium powder and other master alloy powders using the proposed processing route. The effect of the processing route on microstructural variation and mechanical properties have been discussed.     

Esterification of ethenyl benzene and its derivatives with acetic acid in the presence of perchloric acid as a catalyst

The esterification process of ethenyl benzene and its derivative compounds (p-methyl, p-methoxy, p-chloro, m-methyl, m-nitro and m-chloro, respectively) was carried out with acetic acid and using perchloric acid as a catalyst. From the effects of the variables studied it could be concluded that: the temperature and the catalyst concentration influence positively over the olefin conversion, whereas the initial olefin concentration exert no effect over the same; and that the presence of perchloric salts exerts a different influence, depending on the temperature and on the catalyst concentration. It has been proven that the substituted radicals in the m- or p- positions exert an important influence over the conversion of the studied olefins, presenting growing reactivity in the following order: m-nitro ethenyl benzene, m-chloro ethenyl benzene, p-chloro ethenyl benzene, m-methyl ethenyl benzene, ethenyl benzene, p-methyl ethenyl benzene and p-methoxy ethenyl benzene. Finally, a kinetic and thermodynamic study has been done and the corresponding parameters have been calculated, with an adequate fitting.     

Use of infrared thermography for the evaluation of heat losses during coal storage

The exothermic processes during coal storage reduce the calorific value of the coal which in turn results in financial losses. An accurate and easy calculation of the losses may be an efficient tool to evaluate the effectiveness of the measures taken to reduce the spontaneous heating of coal and to predict the appearance of hot spots. This study was carried out with ‘Mezcla' coal used at Endesa power station in Andorra–Teruel (Spain). For this purpose, laboratory measurements relating to spontaneous heating properties and field measurements were carried out. Three experimental coal piles were built, a high porosity pile, a periodically compacted pile and a pile with a low angle slope in the prevailing wind direction. A method to determine the coefficient of total losses was developed and the coefficients of calorific losses and total losses were also found. Temperatures were measured by infrared thermography and by thermocouples and a good agreement between them was found. The use of a mathematical model, developed by ASINEL, allowed to calculate the heat fluxes due to spontaneous heating and a new coefficient of calorific losses, the similarity of this coefficient with the experimentally found revealed the effectiveness of this method to quantify heat emissions. The self-heating behaviour of the pile was also followed by an infrared thermographic camera which allowed the detection of heat fluxes.     

Simulation of an air conditioning absorption refrigeration system in a co-generation process combining a proton exchange membrane fuel cell

In this work, a computer simulation program was developed to determine the optimum operating conditions of an air conditioning system during the co-generation process. A 1 kW PEMFC was considered in this study with a chemical/electrical theoretical efficiency of 40% and a thermal efficiency of 30% applying an electrical load of 100%. A refrigeration-absorption cycle (RAC) operating with monomethylamine–water solutions (MMA–WS), with low vapor generation temperatures (up to 80 °C) is proposed in this work. The computer simulation was based on the refrigeration production capacity at the maximum power capacity of the PEMFC. Heat losses between the fuel cell and the absorption air conditioning system at standard operating conditions were considered to be negligible. The results showed the feasibility of using PEMFC for cooling, increasing the total efficiency of the fuel cell system.     

NUMERICAL SIMULATION OF THE EFFECTS OF BUOYANCY FORCES AND FLOW CONTROL DEVICES ON FLUID FLOW AND HEAT TRANSFER PHENOMENA OF LIQUID STEEL IN A TUNDISH

Fluid flow and heat transfer of liquid steel in a tundish of a continuous slab caster was numerically simulated. The importance of natural flow convection was established through a dimensionless number given by the ratio Gr/Re². Buoyancy forces proved to be as important as inertial ones, especially in the extremes of the tundish far from the entering liquid jet. The usual flow control devices like weirs and dams were not as effective as turbulence inhibitors, a kind of impact pad with lips, interior squared angles, and a square cross section. The simulations indicated that this device helps to decrease fluid turbulence in the zone of the entering liquid jet and has damping effects of step inputs of cold or hot steel, allowing for better control of the casting temperature.     

Fluorometric determination of chemically available lysine: adaptation, validation and application to different milk products

A spectrophotometric method based on the reaction between available lysine and ortho-phthaldialdehyde (OPA) was adapted and validated for fluorometric determination of the chemically available lysine contents in milk matrices (UHT and conventional in-bottle sterilized cow milk, milk-based infant formulas and infant formula ingredients). The values of the analytical parameters show its usefulness as a routine method (linearity, r = 0.9992; detection limit, 0.0066 mg/mL assay; accuracy, 99-108%; precision, intra-day 2.1-5.9% and inter-day 3.5 10.2%). No statistically significant differences (p < 0.05) were found between the values obtained with the adapted method and those obtained applying the 1-fluoro-2,4-dinitrobenzene (FDNB) (Carpenter) technique. The OPA method was used to measure the chemically available lysine contents in UHT and sterilized milk marketed in Spain, to study the evolution of chemically available lysine during the shelf-life of UHT milks, and finally the quality of name- and store-brand UHT milks was also compared. No statistically significant differences (p < 0.05) were found between either the available lysine contents of the same type of UHT or sterilized milk or between store- and name-brand UHT milks. Statistically significant differences (p < 0.05) were found between the chemically available lysine contents in UHT and sterilized milk. Losses of chemically available lysine ranging from 2.7 to 29% were obtained during the shelf-life of UHT milk.     

Content of free phenolic compounds in bananas from Tenerife (Canary Islands) and Ecuador

Determination of free gallic acid and catechin (cianidanol) in banana samples was optimized using a high-performance liquid chromatographic (HPLC) method with on-line photodiode array detection. This method was applied for cultivars of bananas (Gran Enana and Pequeña Enana) harvested in Tenerife (Canary Islands) and for bananas (Gran Enana) from Ecuador. The contents of catechin and gallic acid in bananas from Ecuador were higher (P<0.05) and lower than in bananas produced in Tenerife. Variations in the contents of these polyphenolic compounds in the bananas from Tenerife according to cultivation method (greenhouse and outdoors), farming style (conventional and organic) and region of production (north and south) were observed.     

Transmission Electron Microscopy-Based Analysis of Electrically Conductive Surface Defects in Large Area GaSb Homoepitaxial Diodes Grown Using Molecular Beam Epitaxy

We investigate a mechanism causing shorting of large area GaSb diodes grown on GaSb substrates using molecular beam epitaxy (MBE). The source of these shorts is determined to be large crystallographic defects on the surface of the diodes that are formed around droplets of gallium ejected from the gallium Knudsen cells during MBE. The gallium droplets cause defects in the crystal structure, and, as the epitaxy continues, the gallium is incorporated into the surrounding material. The shape of the defects is pyramidal with a central void extending from the epi-surface to the gallium core. Processing a GaSb diode with these surface defects results in the top-side contact metal migrating into the defect and shorting the diode. This prevents realization of large area diodes that are critical to applications such as photovoltaics and detectors. The diodes in this study are electrically characterized and the defect formation mechanism is investigated using cross-section transmission electron microscopy and electron dispersive spectroscopy.