In this paper, we describe an experimental study on the hot alkali extraction of hemicelluloses from wheat straw and corn stalks, two of the most common lignocellulosic biomass constituents in Romania. The chemical compositions of the raw materials were determined analytically, and the relevant chemical components were cellulose, hemicelluloses, lignin, and ash. Using the response surface methodology, the optimum values of the hot alkaline extraction parameters, i.e., time, temperature, and NaOH concentration, were identified and experimentally validated. The physicochemical characterization of the isolated hemicelluloses was performed using HPLC, FTIR, TG, DTG, and 1H-NMR spectroscopy. The main hemicellulose components identified experimentally were xylan, arabinan, and glucan. The study emphasizes that both corn stalks and wheat straw are suitable as raw materials for hemicellulose extraction, highlighting the advantages of alkaline pretreatments and showing that optimization methods can further improve the process efficiency.

The alkaline extraction of hemicelluloses from a mixture of three varieties of wheat straw (containing 40.1% cellulose, 20.23% xylan, and 26.2% hemicellulose) was analyzed considering the following complementary pre-treatments: freeze–thaw cycles, microwaves, and ultrasounds. The two cycles freeze–thaw approach was selected based on simplicity and energy savings for further analysis and optimization. Experiments planned with Design Expert were performed. The regression model determined through the response surface methodology based on the severity factor (defined as a function of time and temperature) and alkali concentration as variables was then used to optimize the process in a multi-objective case considering the possibility of further use for pulping. To show the properties and chemical structure of the separated hemicelluloses, several analytical methods were used: high-performance chromatography (HPLC), Fourier-transformed infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (¹H-NMR), thermogravimetry and derivative thermogravimetry analysis (TG, DTG), and scanning electron microscopy (SEM). The verified experimental optimization result indicated the possibility of obtaining hemicelluloses material containing 3.40% glucan, 85.51% xylan, and 7.89% arabinan. The association of hot alkaline extraction with two freeze–thaw cycles allows the partial preservation of the hemicellulose polymeric structure.

The increasing incidence of skin diseases, against the background of increased pollution, urbanism, poor habits in lifestyle, work, rest, diet and general medication, led to the development of products with a protective effect. These new types of dermatocosmetic preparations ensure maximum benefits with minimal formulation. Antioxidants are, nowadays, ingredients that stand out with a proven role in skin protection from oxidative stress and its effects. Thus, research has shown that light-textured formulas, quickly absorbed into the skin, with optimum hydration and protection against excessive free radicals, uphold the skin integrity and appearance. This article aims to evaluate essential criteria for a newly marketed product: stability, rheological properties and microbiological characteristics of oil-in-water emulsions based on a mixture of 3% resveratrol 0.5% ferulic acid and 1mL alcoholic extract of Saffron. The tests led to the conclusion that O / W dermatocosmetic emulsions, based on 3% resveratrol and 0.5% ferulic acid, or also 1mL alcoholic extract of Saffron, show resistance to microbiological contamination, good rheological properties (viscoelastic behavior, structural stability, acceptable shearing behavior) that reveal satisfactory texture and high physical stability during storage. These results encourage the transition to dermatological testing as the final stage in considering a new commercial product.

The need for biodegradable and environmentally friendly materials is increasing due to resource shortages and rising levels of environmental pollution. Agro-food waste, which includes coffee grounds, is of great interest in the production of composite materials due to its low cost, low density, easy availability, non-abrasive nature, specific properties such as reduced wear on the machinery used, the absence of residues and toxic products, and biodegradable characteristics. The composite materials developed that include coffee grounds exhibit good characteristics. This field is evolving and requires further improvements, but, at this moment, it can be stated that coffee grounds are not just waste but can be transformed into a highly efficient material applicable in various domains. In this study, composite materials were prepared using paper pulp as a matrix, coffee grounds as a filler material, and water as a binding agent. The obtained composite materials were evaluated through thermal analysis, SEM, EDX, ATR-FTIR, and rheological behavior analysis. The composite materials created from paper pulp and coffee grounds proved to be effective for use in the production of seedling pots. The seedling pots created in this study are produced at a low cost, are environmentally friendly, exhibit thermal stability, have good stability over time, and have good resistance to deformation.

Knowing the thermodynamic and transport properties of liquid systems is very important in engineering for the development of theoretical models and for the design of new technologies. Models that allow accurate predictions of thermodynamic and transport properties are needed in chemical engineering calculations involving fluid, heat, and mass transfer. In this study, the modeling of viscosity deviation for binary and ternary systems containing benzyl alcohol, n-hexanol, and water, less studied in the literature, was carried out using Redlich and Kister (R-L) models, multiple linear regression (MLR) models and artificial neural networks (ANN). The viscosity of the binary and ternary systems was experimentally determined at the following temperatures: 293.15, 303.15, 313.15, and 323.15 K. Viscosity deviation was calculated and then correlated with mole fractions, normalized temperature, and refractive index. The neural model that led to the best performance in the testing and validation stages contains 4 neurons in the input layer, 12 neurons in the hidden layer, and one neuron in the output layer. In the testing stage for this model, the standard deviation is 0.0067, and the correlation coefficient is 0.999. In the validation stage, a deviation of 0.0226 and a correlation coefficient of 0.996 were obtained. The MLR model led to worse results than those obtained with the neural model and also with the R-L models. The standard deviation for this model is 0.099, and the correlation coefficient is 0.898. Its advantage over the R-L type models is that the influence of both composition and temperature are included in a single equation.

Compounds from plant extracts make dermatocosmetic products more effective as they avoid the adaptation and resistance of the organism and achieve a synergistic effect of the molecular properties of interest. Acmella oleracea extract is considered to have great potential in preventing oxidative damage and improving the appearance of the skin. The purpose of this article is to support the product formulated by preliminary studies of two types of O/W emulsions with 3% and 5% concentrations of Acmella oleracea extract. Physico-chemical methods were performed to evaluate the stability, microbiological control, rheological behavior and diffusion through the membrane. Good homogeneity, structural strength and flexibility, adequate skin diffusion, and high physico-chemical and microbiological stability were confirmed. The conclusions lead to the idea that these results require further in vivo studies as well as studies of toxicity and cytotoxicity to obtain the necessary data to place this product on the market.