Synthesis of nanopowders with low agglomeration by elaborating Φ values for producing Gd2O3-MgO nanocomposites with extremely fine grain sizes and high mid-infrared transparency

Refining ceramic microstructures to the nanometric range to minimize light scattering provides an interesting methodology for developing novel optical ceramic materials. In this work, we reported the fabrication and properties of a new nanocomposite optical ceramic of Gd₂O₃-MgO. The citric acid sol-gel combustion method was adopted to fabricate Gd₂O₃-MgO nanocomposites with fine-grain sizes, dense microstructures and homogeneous phase domains. Nanopowders with low agglomeration and improved sinterability can be obtained by elaborating Φ values. Further refining of the microstructure of the nanocomposites was achieved by elaborating the hot-pressing conditions. The sample sintered at 65 MPa and 1300 °C showed a quite high hardness value of 14.3 ± 0.2 GPa, a high transmittance of 80.3 %–84.7 % over the 3?6 μm wavelength range, due mainly to its extremely fine-grain size of Gd₂O₃ and MgO (93 and 78 nm, respectively) and high density.     

BMS Derivatives C7-Linked to β-Cyclodextrin and Hyperbranched Polyglycerol Retain Activity against R5-HIV-1NLAD8 Isolates and Can Be Deemed Potential Microbicides

Amides from indole-3-glyoxylic acid and 4-benzoyl-2-methylpiperazine, which are related to entry inhibitors developed by Bristol-Myers Squibb (BMS), have been synthesized with aliphatic chains located at the C7 position of the indole ring. These spacers contain an azido group suitable for the well-known Cu(I)-catalyzed (3+2)-cycloaddition or an activated triple bond for the nucleophilic addition of thiols under physiological conditions. Reaction with polyols (β-cyclodextrin and hyperbranched polyglycerol) decorated with complementary click partners has afforded polyol-BMS-like conjugates that are not cytotoxic (TZM.bl cells) and retain the activity against R5-HIV-1_NLAD8 isolates. Thus, potential vaginal microbicides based on entry inhibitors, which can be called of 4^th generation, are reported here for the first time.     

Achieving fabrication of highly transparent Y2O3 ceramics via air pre-sintering by deionization treatment of suspension

An easy albeit quite effective deionization suspension treatment was adopted to alleviate the detrimental effects related to the hydrolysis of Y₂O₃ in an aqueous medium. Fabrication of highly transparent Y₂O₃ ceramics with a fine grain size via air pre-sintering and post–hot isostatic pressing (HIP) treatment without using any sintering additive was achieved using the treated suspensions. The hydrolysis issue of Y₂O₃ powder in an aqueous medium was effectively alleviated by using deionization treatment, and a well-dispersed suspension with a low concentration of dissolved Y³⁺ species was obtained. The dispersed suspensions were consolidated by the centrifugal casting method, and the green bodies derived from the suspension of 35.0 vol% solid loading showed an improved homogeneity with a relative density of 52.1%. Fully dense Y₂O₃ transparent ceramic with high transparency was obtained by pre-sintering consolidated green compacts at a low temperature of 1400°C for 16 h in air followed by a post-HIP treatment at 1550°C for 2 h under 200 MPa pressure. The sample had a fine average grain size of 690 nm. The in-line transmittance of the sample reached 83.3% and 81.8% at 1100 nm and 800 nm, respectively, very close to the theoretical values of Y₂O₃.     

Tactile colour pictogram to improve artwork appreciation of people with visual impairments

A recent development in tactile technology enables an improvement in the appreciation of the visual arts for people with visual impairment (PVI). The tactile sense, in conjunction with, or a possibly as an alternative to, the auditory sense, would allow PVIs to approach artwork in a more self‐driven and engaging way that would be difficult to achieve with just an auditory stimulus. Tactile colour pictograms (TCPs), which are raised geometric patterns, are ideographic characters that are designed to enable PVIs to identify colours and interpret information by touch. In this article, three TCPs are introduced to code colours in the Munsell colour system. Each colour pattern consists of a basic cell size of 10 mm × 10 mm to represent the patterns consistently in terms of regular shape. Each TCP consists of basic geometric patterns that are combined to create primary, secondary, and tertiary colour pictograms of shapes indicating colour hue, intensity and lightness. Each TCP represents 29 colours including six hues; they were then further expanded to represent 53 colours. Two of them did not increase the cell size, the other increased the cell size 1.5 times for some colours, such as yellow‐orange, yellow, blue, and blue‐purple. Our proposed TCPs use a slightly larger cell size compared to most tactile patterns currently used to indicate colour, but code for more colours. With user experience and identification tests, conducted with 23 visually impaired adults, the effectiveness of the TCPs suggests that they were helpful for the participants.     

Rheological phase reaction synthesis and electrochemical performance of LiFe2/3Mn1/3PO4/C cathode for lithium-ion batteries

LiFe_2/3Mn_1/3PO₄/C composite was prepared by the rheological phase reaction using LiH₂PO₄, Li₂CO₃, FePO₄, Mn(Ac)₂·4H₂O and ascorbic acid as starting materials. The crystal structure and morphology of as-synthesized sample were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The analysis of XRD results showed that the obtained sample was single-phase with orthorhombic olivine-type structure (Pnma space group). SEM micrographs revealed that the sample was aggregates, with an irregular morphology. The initial discharge capacity was 166.9, 149.1, 139.6, 112.8, 82.93 mAh g^??1 at the rate of 0.1, 0.5, 1, 2, and 10 C, respectively. And when the rate was 0.1, 0.5, 1, 2, and 10 C, the capacity retention was 92.2%, 90%, 92.9%, 97.6%, 91.5% after 50, 100, 200, 200, 500 cycles, respectively.

     

Effect of Drosophila suzukii on Blueberry VOCs: Chemical Cues for a Pupal Parasitoid,Trichopria anastrephae

Journal of Chemical Ecology - Biocontrol agents such as parasitic wasps use long-range volatiles and host-associated cues from lower trophic levels to find their hosts. However, this chemical...     

Densification and joining of a (HfTaZrNbTi)C high-entropy ceramic by hot pressing

A bulk (Hf_0.2Ta_0.2Zr_0.2Nb_0.2Ti_0.2)C high-entropy ceramic (HEC) with a high density was prepared by hot pressing (HP), and through a robust joining technique, large-sized piece was fabricated. A hot-pressed carbide HEC with a single-phase and homogeneous composition was obtained at the sintering temperatures from 1800 to 1950 °C for 30 min under a pressure of 30 MPa. The influence of sintering temperature on the mechanical properties of the HEC was investigated, and the flexural and compressive strengths were reported. Additionally, the feasibility of active brazing of this HEC was studied and solid joints with high shear strength were obtained by atomic diffusion and chemical reaction at the interface, providing a key approach to fabricate complex components of HECs.     

Modeling approaches and performance for estimating personal exposure to household air pollution: A case study in Kenya

This study assessed the performance of modeling approaches to estimate personal exposure in Kenyan homes where cooking fuel combustion contributes substantially to household air pollution (HAP). We measured emissions (PM_2.5, black carbon, CO); household air pollution (PM_2.5, CO); personal exposure (PM_2.5, CO); stove use; and behavioral, socioeconomic, and household environmental characteristics (eg, ventilation and kitchen volume). We then applied various modeling approaches: a single-zone model; indirect exposure models, which combine person-location and area-level measurements; and predictive statistical models, including standard linear regression and ensemble machine learning approaches based on a set of predictors such as fuel type, room volume, and others. The single-zone model was reasonably well-correlated with measured kitchen concentrations of PM_2.5 (R² = 0.45) and CO (R² = 0.45), but lacked precision. The best performing regression model used a combination of survey-based data and physical measurements (R² = 0.76) and a root mean-squared error of 85 µg/m³, and the survey-only-based regression model was able to predict PM2.5 exposures with an R² of 0.51. Of the machine learning algorithms evaluated, extreme gradient boosting performed best, with an R² of 0.57 and RMSE of 98 µg/m³.     

Coagulation process in Manchega sheep milk from Spain: A path analysis approach

Characteristics of sheep milk are of great interest for the dairy industry, as almost the totality of production is intended for cheesemaking. However, the existing relationships between these variables are complex. This study assessed composition, hygienic quality, coagulation properties, and curd yield of 1,200 individual Manchega sheep milk samples. The aim was to compare the effect of composition and hygienic quality on coagulation and curdling, and to evaluate the relationship between curd yields and the coagulation process and the effect of other features by using path analysis methodologies. Outcomes proved path analysis to be a useful and effective tool to assess these relationships through direct and indirect paths within the same model. Results showed that the factors that had a direct influence on milk coagulation were lactose concentration, casein content, and initial pH of milk. Contrastingly, somatic cells did not seem to have any effect (direct or indirect) on the coagulation process. Factors that directly affected curd yield were fat content, lactose concentration, casein content, and curd moisture. However, technological parameters showed little effect over curd yield.