Penetration Of Acid Research Articles

DYNAMICS OF SMOKE INGREDIENTS PENETRATION INTO THE INTERIOR OF CHICKEN MEAT PRODUCTS DURING BOILING/SMOKING AND DRYING

During processing in meat, numerous activities occur. Those activities can have a positive or negative impact on the properties of aw materials and finished products. The aim of this study was to determine the dynamics of smoke components penetration (total phenols and organic acids) during boiling/smoking and drying of chicken meat at different thermal regimes.The dynamics of total phenol and total organic acidspenetrationinto meat samples was monitored during all stages of production (cooking/smoking, drying and storage). Eight experimental groups were analyzed. Samples in four experimental groups (EG I-IV) were subjected to boiling and smoking, and other four groups (EG V-VIII) to drying with different parameter values: boiling/smoking temperature 55-75°C, process duration 80-110 minutes, drying temperature 14-18°C, with air circulation 40-50 m3/min and relative humidity 85-88% in appropriate conditions.Based on the obtained results, the statistically significant influence of different heat treatments and their technological parameters on the dynamics of phenol and organic acid penetration was established (p<0.05). Temperature stood out as an important technological parameter with the greatest impact. The results show that due to elevated temperatures during heat treatments there is an increase in the concentration of total phenols and organic acids. Furthermore, it was concluded that the investigated processing procedures of chicken meat had an impact on the dynamics of penetration of smoke components.KEYWORDS:phenols, organic acids, boiling, smoking, drying

Numerical investigation into the acid flow and reaction behavior in the tight, naturally fractured carbonate reservoir during acid fracturing

Tight naturally fractured carbonate reservoirs require acid fracturing to build the connectivity between the wellbore and natural fractures (NFs), where hydrocarbon is stored. The high leakoff nature of the NF complicates the acid flow and etching pattern, raising the difficulty in acid fracturing design and optimization. To explore the acid flow and reaction behavior in such reservoirs, an acid fracturing model accounting for the NF distribution is developed, which consists of a fracture surface characterization model, a fracture propagation model, and an acid-etching model. Based on the model, the effects of injection parameters and the NF properties on the effectiveness of acid fracturing are investigated. Then, strategies for acid fracturing the tight naturally fractured carbonate reservoirs are proposed. Results show that high pumping rates and retarded acids with low hydrogen ion (H+) diffusion coefficient is conducive to achieving a long acid penetration distance, while a low pumping rate and acids with a high H+ diffusion coefficient facilitates the NF etching. Therefore, a large stimulated area can be achieved by applying a multi-stage alternating injection of the crosslinked acid with a high pumping rate followed by the gelled acid with a low injection rate. NFs impact acid fracturing in two distinct ways: enhancing the non-uniform etching of the fracture surface and reducing the effective acid-etched fracture length through high leakoff. When NF density is high, leakoff control techniques should be employed; and when the NF inclination is high, non-uniform etching techniques should be used to generate acid-etched channels in flow barriers.

Evaluation of the safety and efficacy of skin penetration enhancer Putocrin®.

Substances that can efficiently enhance skin penetration while exerting no adverse effect are useful for drug and cosmetics formulation. To investigate the safety and enhance skin penetration efficacy of Putocrin®, a combination containing 2% isosorbide dimethyl ether, 1% pentanediol, and 0.5% inositol. An invitro keratinocyte cell assay using 3-(4,5-dimethylthiazolyl-2)-2,5 diphenyltetrazolium bromide (MTT), and an invitro EpiKutis® skin study adopted hematoxylin and eosin staining, immunostaining, and liquid chromatography-mass spectrometry (LC-MS) analysis were carried out to investigate the safety of Putocrin®. A pigskin-Franz cell system experiment applied high-performance liquid chromatography (HPLC) to compare the skin penetration efficiency of fluorescein isothiocyanate (Fitc)-labeled tranexamic acid with or without the assistance of Putocrin®. The safety and efficacy of Putocrin® was further evaluated on zebrafish embryos. The MTT assay showed that Putocrin® at concentration ≤2.5% did not significantly affect cell viability. The invitro EpiKutis® skin study revealed that 2.5% Putocrin® did not affect skin morphology, filaggrin content, ceramide/protein, or fatty acid/protein ratios, but significantly increased loricrin content by 86.00% (p < 0.001). The pigskin-Franz cell penetration experiment demonstrated that Fitc-labeled tranexamic acid could barely penetrate the skin (with penetration rate of 1.121%), while Putocrin® significantly enhanced the penetration rate up to 83.983%, which was close to unlabeled tranexamic acid (90.013%). The zebrafish embryo study showed that 2.5% Putocrin® did not exert observable toxicity and obviously assisted the skin penetration of Fitc-labeled tranexamic acid into fish embryos. These results indicate the strong enhancing skin penetration potency of Putocrin®. This study demonstrated the safety as well as the strong enhancing skin penetration potency of Putocrin® for cosmetics formulation use.

DEVELOPMENT OF AN ALGORITHM FOR CALCULATING THE RATE CONSTANT OF HYDROCHLORIC ACID REACTION WITH A CARBONATE ROCK FORMATION

One of the main factors reducing acid stimulation efficiency is the intensive reaction of active acid in the immediate vicinity of the wellbore, which leads to insufficient completeness of reservoir rock dissolution in the remote reservoir zone. The reservoir hydrodynamic characteristics are not being improved properly, and the efficiency of oil production stimulation measures does not reach the planned values.To get high results of acid treatments it is necessary to achieve deep penetration of acid into the formation thickness. The reaction rate constant is used to compare the reactivity of different acid compositions and to select the most suitable acid composition for the geological and physical conditions of the treated object, which provides the highest treatment efficiency. It relates the initial substances concentrations with reaction products formation rate. To determine the reaction rate constant, a volumetric apparatus was created and methodological aspects were developed to work on it, allowing to minimize the measurement error and to achieve the greatest accuracy in determining the kinetic parameters of the reaction. But in the course of further investigations in the work of the existing algorithm for experimental data processing, a number of significant deficiencies distorting the results of calculations were revealed. The aim of the research is to develop a new improved algorithm for reaction rate constant calculation, which will improve the understanding of the process of determining the kinetic parameters of acid reaction with carbonate rock.To achieve this aim, the authors conducted a series of experiments according to the unified methodology, the results of which revealed ways to eliminate the identified deficiencies using a new algorithm. It includes obtaining and saving initial data, subsequent treatment and direct calculation of reaction kinetic parameters with results saving.The developed algorithm makes it possible to unify and automate the process of determining the kinetic parameters of the acid reaction with the formation rock, as well as to determine the reaction characteristics with higher accuracy and reduce the influence of the human factor on the research results, thus reducing the errors of the calculation results.

Thermal buckling analysis of reinforced composite conical shells in acidic environments: Numerical and experimental investigation on the effects of nanoparticles

This study investigates the effects of acid penetration and temperature on the buckling behavior of conical composite shells, to enhance structural integrity and longevity in corrosive environments. The study explores the impact of acid exposure on thermal properties and examines the efficacy of incorporating nano-silica and nano-clay in preventing buckling. Additionally, it analyzes the influence of nanoparticles on the thermal, moisture, and mechanical properties of the composite material. Experimental assessments are conducted to measure material properties during exposure to a sulfuric acid solution, providing a comprehensive understanding of the material's behavior under extreme conditions. However, due to the complexity of investigating the combined effects of temperature, acid, and nanoparticles on composite shell buckling, a combined numerical and experimental approach is adopted to predict the critical buckling load. To this end, equations of conical shells under hygrothermal loading are derived, and the critical buckling load is determined through pre-buckling analysis. The Generalized Differential Quadrature (GDQ) method is employed to solve the hygrothermal buckling of the composite shell using experimentally obtained material properties. Comparative results are presented for different nanoparticles, shell geometries, and exposure times in acidic environments. The experiments reveal that adding nanoparticles enhances mechanical properties and reduces thermal and moisture expansion coefficients. Conversely, the acidic conditions deteriorate these properties. Numerical analysis demonstrates that incorporating nanoparticles significantly increases the critical buckling temperature, with nano-silica and nano-clay particles resulting in an 11.5 % and 34.2 % increase, respectively. However, acidic environments decrease the critical buckling temperature, with reductions of 32 % for unreinforced, 29 % for nano-silica reinforced, and 46 % for nano-clay reinforced composites after three months of exposure.

Improving Water Solubility and Skin Penetration of Ursolic Acid through a Nanofiber Process to Achieve Better In Vitro Anti-Breast Cancer Activity.

Woman's breast cancer has always been among the top ten causes of cancer death, and nearly 2% to 5% of locally advanced breast cancers develop a fungating breast wound. Fungal breast cancer leads to skin ulcers, wound ruptures, and other bacterial infections in patients. Ursolic acid (UA), a natural pentacyclic triterpene compound, is widely distributed in many fruits. Previous studies demonstrated that UA has anti-breast cancer, antifungal, and improved wound-healing effects. UA, however, had poor water solubility and low bioavailability, restricting its clinical application. Nanofibers have the advantages of rapid dissolution, improved stability, and bioavailability of active ingredients. We had successfully prepared ursolic acid nanofibers (UANFs) and effectively improved their water solubility and skin penetration. UANFs can increase water solubility by improving the physicochemical properties, including increased surface area, intermolecular bonding with excipients, and amorphous transformation. Furthermore, UANFs had better anti-breast cancer activity than raw UA. UANFs inhibited the expression of phospho-signal transducer and activator of transcription 3 (STAT3) and phospho-extracellular regulated protein kinases (ERK)1/2, and induced cleaved caspase-3 protein expression, but had no effect on the raw UA treatment. In summary, UANFs enhanced the skin absorption of UA and improved its anti-breast cancer efficacy. We expect that UANFs can be used as an anti-breast cancer treatment and reduce the discomfort of breast cancer patients during dressing changes, but more detailed efficacy and safety trials still need to be conducted in further studies.

Evaluating Use of Hydraulic Modified Sulfur Powder in Concrete Pavements: Laboratory Testing and Field Application

This study comprehensively evaluates the field applicability of hydraulic modified sulfur (HMS) as a concrete additive. We assessed the microstructural characteristics, mechanical properties, and durability performance of HMS at various replacement ratios in a laboratory setting. In addition, a field study was conducted by removing an existing conventional concrete pavement measuring (6000 × 12,000 × 70 mm, W × L × T) and overlaying it with HMS concrete. The experimental results revealed that HMS enhanced the mechanical and durability performance when used as a cement replacement at rates below 9%. These results satisfied the quality control standards and performance criteria specified in the Korean standard specification for cement-concrete pavements. The comparative analysis revealed that HMS concrete outperformed conventional concrete mixtures by 62.6% in sulfuric acid penetration depth, 14.8% in compressive strength retention after sulfuric acid immersion, and 53.1% in chloride-ion penetration resistance. Furthermore, no anomalies were detected during the 3-month follow-up period.

Design and Synthesis of a Robust and Multifunctional Superhydrophobic Coating with a Three-Dimensional Network Structure on a Paper-Based Material.

A fundamental challenge in artificial superhydrophobic papers is their poor resistance to mechanical abrasion, which limits their practical application in different fields. Herein, a robust and multifunctional superhydrophobic paper is successfully fabricated via a facile spraying method by combining silver nanowires and fluorinated titania nanoparticles through a common paper sizing agent (alkyl ketene dimer) onto paper. It is shown that the surface of the paper-based material presents a three-dimensional network structure due to the cross-linking of silver nanowires with a high aspect ratio. Further hydrophilic and hydrophobic performance test results show that it exhibits exceptional water repellency, with a desirable static contact angle of 165° and roll-off angle of 6.2°. The superhydrophobic paper showcases excellent mechanical durability and maintains its superhydrophobicity even after enduring 130 linear sandpaper abrasion cycles or high-velocity water jetting impact benefited from interfacial van der Waals and hydrogen bonding. Simultaneously, the robust superhydrophobic surface can effectively prevent the penetration of acid or alkali solutions, as well as UV light, resulting in excellent chemical stability. Additionally, the superhydrophobic paper offers supplementary features such as self-cleaning, electrical conductivity, and antibacterial capability. Further development of this strategy paves a way toward next-generation superhydrophobic paper composed of nanostructures and characterized by multiple (or additional) functionalities.

Acid resistance of hydroxyapatite dental films fabricated through powder jet deposition

This study proposes a novel dental treatment method using powder jet deposition (PJD). PJD can be employed to fabricate hydroxyapatite (HA) films directly on human enamel by blasting fine HA particles. Acid resistance tests were performed on HA films fabricated with two blast angles (α = 60° and 90° with two samples each) and using human enamel (with one sample) to evaluate the usefulness of the HA films in acidic intraoral environments. All samples were dissolved in acid, and their volume gradually decreased over the test time tacid. Transmission electron microscopy images showed that the grain boundaries near the acid-exposed surface of the HA films were densely modified and prevented acid penetration, whereas the human enamel grains became finer owing to the acid–base reaction. Thus, the HA films lost lesser volume than the human enamel did, indicating higher acid resistance. However, one film fabricated at α = 60° partially peeled off during tacid = 6–9 h. Analysis of the PJD phenomenon through smoothed particle hydrodynamics indicated that the tensile residual stresses promoting crack propagation and delamination increased as α became more acute, causing HA film peeling. Therefore, particles should be blasted in multiple directions to avoid stress bias.

Investigating the Anti-Inflammatory Properties and Skin Penetration Ability of Cornelian Cherry (Cornus mas L.) Extracts.

Plant extracts can be a valuable source of biologically active compounds in many cosmetic preparations. Their effect depends on the phytochemicals they contain and their ability to penetrate the skin. Therefore, in this study, the possibility of skin penetration by phenolic acids contained in dogwood extracts of different fruit colors (yellow, red, and dark ruby red) prepared using different extractants was investigated. These analyses were performed using a Franz chamber and HPLC-UV chromatography. Moreover, the antioxidant properties of the tested extracts were compared and their impact on the intracellular level of free radicals in skin cells was assessed. The cytotoxicity of these extracts towards keratinocytes and fibroblasts was also analyzed and their anti-inflammatory properties were assessed using the enzyme-linked immunosorbent assay (ELISA). The analyses showed differences in the penetration of individual phenolic acids into the skin and different biological activities of the tested extracts. None of the extracts had cytotoxic effects on skin cells in vitro, and the strongest antioxidant and anti-inflammatory properties were found in dogwood extracts with dark ruby red fruits.

Enhancing Tranexamic Acid Penetration through AQP-3 Protein Triggering via ZIF-8 Encapsulation for Melasma and Rosacea Therapy.

The systemic use of tranexamic acid (TA) as an oral drug can bring adverse reactions, while intradermal injection leads to pain and a risk of infection. Moreover, it is difficult for highly hydrophilic TA to penetrate the skin barrier that contains lots of hydrophobic lipid compounds, which poses enormous restrictions on its topical application. Current transdermal TA delivery strategies are suffering from low drug load rates, plus their synthesis complexity, time-consumption, etc. adding to the difficulty of TA topical application in clinical therapeutics. To increase the penetration of TA, a novel approach using TA-loaded ZIF-8 (TA@ZIF-8) is developed. The encapsulation efficiency of TA@ZIF-8 reaches ≈25% through physical adsorption and chemical bonding of TA indicates by theoretical simulation and the improved TA penetration is elevated through activating the aquaporin-3 (AQP-3) protein. Additionally, in vivo and in vitro experiments demonstrate the preponderance of TA@ZIF-8 for penetration ability and the advantages in intracellular uptake, minor cytotoxicity, and inhibition of melanogenesis and inflammatory factors. Moreover, clinical trials demonstrate the safety and efficacy of TA@ZIF-8 in the treatment of melasma and rosacea. This work presents a potential topical application of TA, free from the safety concerns associated with systemic drug administration.

Boosting the acid penetration barrier of epoxy-silica organic-inorganic hybrid coating via adjusting its molecular structures: Experimental and molecular dynamics simulation study

The permeability barrier property of coatings against corrosive media determines their service life. Herein, the molecular structure of epoxy-silica organic-inorganic hybrid (OIH) coating is regulated to endow the coatings with enhanced barrier properties by a simple sol-gel method. Experiments show that the coating with 8% Si-O-Si structure has the best acid penetration resistance after 45 days of immersion in 10 wt.% H2SO4 solution. In addition, molecular dynamics simulation results show that the molecular structure of OIH affects the densification of the coating, forming a highly cross-linked network structure that inhibits the diffusion and destructive effects of corrosive media and thus affects the acid penetration resistance of the coating.

Effect of Polytetrafluorethylene Content in Fe‐N‐C‐Based Catalyst Layers of Gas Diffusion Electrodes for HT‐PEM Fuel Cell Applications

AbstractFe‐N‐C catalysts are a promising alternative to replace cost‐intensive Pt‐based catalysts in high temperature polymer electrolyte membrane fuel cell (HT‐PEMFC) electrodes. However, the electrode fabrication needs to be adapted for this new class of catalysts. In this study, gas diffusion electrodes (GDEs) are fabricated using a commercial Fe‐N‐C catalyst and different polytetrafluorethylene (PTFE) binder ratios, varying from 10 to 50 wt % in the catalyst layer (CL). The oxygen reduction reaction performance is investigated under HT‐PEMFC conditions (160 °C, conc. H3PO4 electrolyte) in a half‐cell setup. The acidophilic character of the Fe‐N‐C catalyst leads to intrusion of phosphoric acid electrolyte into the CL. The strength of the acid penetration depends on the PTFE content, which is visible via the contact angles. The 10 wt % PTFE GDE is less capable to withdraw product water and electrolyte and results into the lowest half‐cell performance. Higher PTFE contents counterbalance the acid drag into the CL and impede flooding. The power density at around 130 mA mgCatalyst−2 increases by 34 % from 10 to 50 wt % PTFE.

Microneedling Radiofrequency Enhances Poly-L-Lactic Acid Penetration That Effectively Improves Facial Skin Laxity without Lipolysis.

Microneedle fractional radiofrequency (MFR) is commonly used for skin laxity treatment, and poly-L-lactic acid (PLLA) can stimulate collagen synthesis in the body. However, the synergy of their combination for skin rejuvenation has not been proven. The authors aimed to evaluate the combined efficacy of PLLA and MRF and the potential mechanism underlying skin laxity. This prospective, randomized study included C57BL/6 mice treated with MFR, MFR plus PLLA, and carbon dioxide laser plus PLLA and 32 patients who underwent split-face treatments with MFR or MFR plus PLLA twice every 2 months. The Global Aesthetic Improvement Scale, Facial Laxity Rating scale of the whole face, the Echelle d'Evaluation Clinique des Cicatrices d'Acne grading scale of acne scars, and VISIA parameters on both treated sides were evaluated. Dermatologic changes were measured by ultrasonography in the submental space, and adverse events were documented. PLLA was delivered by channels produced by MFR but not carbon dioxide laser in the mouse model. Thirty patients were treated with split-face MFR plus PLLA or MFR, revealing an improvement in VISIA wrinkle percentile (0.020) compared with the age-matched controls (0.000). The thickness of the dermis increased, whereas the fat layer did not change significantly. No adverse effects were observed. PLLA can be delivered through microchannels produced by MFR. PLLA enhances the efficacy of MFR for skin laxity without lipolysis.

Impact of Alccofine on the strength and durability properties of concrete

The use of concrete in construction is widespread throughout the world. Essentially, it consists of a binder phase and an aggregate phase. In construction, supplementary cementitious materials (SCMs) have revolutionized the industry. The search for a cementitious material to replace cement is being carried out throughout the world in the modern era. In addition to reducing CO2 emissions, this can reduce other climatic changes, such as an increase in global average temperature. An analysis of the influence of Alccofine-1203 (ALC-1203) on the mechanical and durability characteristics of concrete of M30 grade is presented in this study. A total of six concrete mixes with varying concentrations of Alccofine and cement were prepared for the study. This research examines the strength and durability of concrete containing Alccofine, a supplemental cementitious material. The addition of varying quantities of Alcofine to concrete mix was investigated in a series of laboratory studies. It has been determined that using Alccofine as a substitute may improve the strength significantly. At a replacement level of 15%, Alccofine enhanced the compressive strength to the greatest extent. Moreover, it reduced porosity, improving durability features such as resistance to acid, sulphate, and chloride ion penetration. In addition, adding Alccofine resulted in a denser microstructure, which increased mechanical properties and durability. According to the study results, adding a supplemental material could enhance its strength and durability.

The decisive role of the abrasion stress in concrete corrosion during acid attack – Comparison of resistance of different concrete types

Biogenic-produced sulfuric acid (BSA) attack, described as microbially induced concrete corrosion (MICC), reduces lifespan of concrete elements in sewage systems worldwide. Wastewater containing solids (e.g., sand) may cause abrasive stress to the concrete with increased flow intensity and thus accelerate the development of corrosion at the sewage/air interface in the tidal zone. The impact of drying and wetting cycles is also important; therefore, all these factors were included in the testing method. Overall, this paper evaluates the development and extent of corrosion after a pure chemical acid attack combined with a mechanical abrasion in the form of brushing. To simulate the wetting and drying cycles of corrosion, samples were partially immersed in an aggressive solution. The investigation comprised comparing the acid and abrasion resistance of three types of concretes – ordinary Portland cement concrete (OPC), sulfate-resistant concrete (SRC), and white ordinary Portland cement concrete (WOPC). The impact of abrasion on the individual parameters of corrosion, e.g., the amount of leached calcium, acid consumption, and damage depths, were also discussed. The results showed that mechanical abrasion in the form of brushing promotes acid penetration; however, there are differences depending on the type of concrete.

Analysis of biopolymer modified oil cement under supercritical CO2

Storing CO2 in deep underground reservoirs is key to reducing emissions to the atmosphere and standing against climate change. However, the risk of CO2 leakage from geological reservoirs to other rock formations requires a careful long-term analysis of the system. Mostly, oil well cement used for the operation must withstand the carbonation process that changes its poromechanical behavior over time, possibly affecting the system’s integrity.The use of nanoadditives for cement, such as bacterial nanocellulose (BNC), has been increasing in recent years. This biopolymer has particular properties that can improve cement performance, like high mechanical properties and thermal resistance. For this reason, and in light of the problems that carbonation may pose in the long term in the context of geological storage of CO2 studies were carried out under supercritical CO2 conditions analyzing the behavior of cement with nanocellulose additions.Rheological, mechanical, thermal, and microstructural tests were performed on samples with different percentages of BNC [1]. Subsequently, cylindrical specimens were subjected to supercritical CO2 conditions (20 MPa and 90 °C) with different percentages of nanocellulose using two curing methods, one long-term curing at low temperature [2] and one short-term curing at high temperature [3].These results showed that BNC produces an increase in slurry viscosity but retains a greater amount of water which aids in its subsequent hydration. This could be observed in its microstructure, where a greater amount of hydration products, a higher degree of hydration, and a decrease in porosity were observed. It is likely that this increase in hydration was the reason that cements with nanocellulose had a uniaxial compressive strength up to 20% higher than neat cement. It was also observed that higher BNC contents improve the thermo-mechanical behavior under oscillating bending stress. After carbonation, the microstructure shows that the capillary porosity decreases steadily to values of 5%, which reduces the penetration of carbonic acid into the sample. All cements showed a reduction in mechanical strength, but cements with BNC had a lower degree of carbonation and better mechanical behavior, because of the lower capillary porosity prior to carbonation (Figure 1). However, these effects were not observed when the cement was subjected to a curing process under unfavorable conditions at high temperatures. In this case, the large increase in porosity dulls the short-term hydration effects and the strength of cements with nanocellulose is lower prior to the carbonation process. After carbonation, a relative increase in the strength of the samples with BNC is higher, however, it is still below the strength of neat cement [4]. These experimental studies were simulated using a coupled chemo-hydro-mechanical model. The model simulates the carbonation front advance in cement subjected to supercritical CO2 and the changes generated by the chemical reactions using the classic balance equations of continuum mechanics relative to mass, momentum, entropy, and energy. Simultaneous dissolution of portlandite and C-S-H, dissolution of calcite, and a damage model were considered. The carbonation progress of the samples was represented and an extrapolation was made to an oil well based on the parameters obtained from the experiments and simulations.&#x0D;

In Situ X-ray imaging of HT-PEMFC hot-pressing using contrast enhancement

A contrast enhancement agent is used to visualise phosphoric acid penetration and distribution in high-temperature polymer electrolyte membrane fuel cells. This new method is demonstrated in the investigation of hot-pressing parameters on phosphoric acid penetration and distribution. In situ radiography of the hot-press process showed acid plumes breaking through the catalyst layer, microporous layer (MPL) and gas diffusion layer (GDL). The phosphoric acid volume and distribution within the MPL and GDL are quantified, and their dependence on hot-press pressure, duration and compression control are analysed. Increasing hot-press pressure and duration was found to increase acid penetration and delamination of the membrane and catalyst layers. The absence of a compression control gasket also led to significant infiltration into the MPL and GDL. Penetration occurred first at the anode for all tests, which was attributed to a higher number of cracks and greater degree of crack connectivity. Phosphoric acid entered the MPL and GDL either through initial breakthrough of the catalyst layer, or from acid pooling on the GDL surface and being compressed into the fibres. This work provides a novel method to improve visualisation of phosphoric acid and highlights the acid loss mechanisms resulting from hot-press conditions.

Understanding acid hydrolysis of corn stover during densification pretreatment for quantitative predictions of enzymatic hydrolysis efficiency using modified pretreatment severity factor

DLCA(sa) pretreatment (densifying lignocellulosic biomass with sulfuric acid followed by autoclave treatment), featured with low treatment temperature and densification, demonstrate high efficiency in biomass pretreatment. In this study, the effects of temperature, acid loading, time on the hydrolysis of xylan, cellulose and lignin during DLCA(sa) pretreatment were systematically investigated. It was shown that DLCA(sa) pretreatment can effectively solubilize xylan, achieving an 84% xylose recovery under mild conditions (130 °C, 30 min, and 0.125 g/g acid loading). The conventional pretreatment severity factor correlated and further modified to improve the accuracy in evaluating the xylan hydrolysis. Additionally, a mathematical model based on the xylan hydrolytic kinetics was proposed to predict the enzymatic hydrolysis. Kinetic model suggested that mechanical densification facilitates the penetration of acid into the biomass matrix, leading to increased accessibility of xylan to acid catalysis.

Effect of hyaluronic acid encapsulation in a silica hydrogel matrix on drug penetration through the skin

It has been found that the encapsulation of high molecular weight hyaluronic acid in a biologically relevant silica hydrogel matrix provides its accelerated penetration into the skin compared to free acid. The developed hybrid hydrogels, in which high molecular weight hyaluronic acid retains its pronounced anti-inflammatory properties and strong hydrating effect, can become the basis for new, more effective soft formlations for the treatment of inflammatory skin diseases, as well as for products used in the beauty industry. It has been shown that the penetration of hyaluronic acid from the hybrid hydrogels depends on the conditions of their synthesis, the average molecular weight and the loading of the acid.