Search Results (3)

The present study develops and optimizes a jet-cutting encapsulation method using a laboratory-scale encapsulator to incorporate herbal dietary supplements into fermented milk products. Sodium alginate and pullulan were selected as core and coating polymers, respectively, after rheological screening demonstrated that 1% alginate (η ≈ 350–450 Pa·s at 22–25 °C) and 2% pullulan (η ≈ 400 Pa·s at 25–30 °C) provide a balance between atomization, shell integrity, and fluidity. Under optimized conditions, capsules of 1.00 ± 0.05 mm diameter and high sphericity (aspect ratio 1.08 ± 0.03) were produced. In vitro gastrointestinal simulation confirmed capsule stability in simulated gastric fluid (pH 2.0) and complete disintegration within 120 min in simulated intestinal fluid (pH 7.2). Inclusion of 8% (w/w) capsules in a fermented milk beverage preserved appearance, texture, flavor, and color while increasing viscosity from 2.0 to 4.0 Pa·s. Titratable acidity rose from 87 °T at 24 h to 119 °T at 120 h, with sensory quality remaining acceptable; substantial gas formation and excessive sourness occurred only after 168 h, defining a 5-day refrigerated shelf life. These findings demonstrate that the 1% alginate–pullulan capsule system successfully protects plant extracts during gastric transit and enables targeted intestinal release, while maintaining the sensory and rheological properties of the fortified fermented milk product. Full article

The oil and gas industry is involved with severe corrosive/sour environmental conditions due to H₂S, CO₂, and moisture content. The National Association of Corrosion Engineers (NACE) has developed standards to enable users to select suitable materials for given sour conditions which utilize laboratory testing. A failed piping sample (API-5L-X65) was removed from a pipeline after 15 years of service. Optical microscopy was used to compare the microstructure of the corroded sample near the exposed surface to both the service environment, and further away from it. Moreover, pitted samples were analyzed using a scanning electron microscope coupled with energy dispersive X-ray (SEM/EDS) to understand the deposits’ morphology. Furthermore, XPS analysis proves the presence of a significant content of sulfur compound. Additionally, the mechanical properties of both corroded and non-corroded samples were evaluated and compared. Micro-hardness was carried out on the cross-section of the removed sample to understand any evident hardness variation from the inner diameter (ID) to the outer diameter (OD) of the piping. All the results suggest that prolonged service exposure has resulted in the development of micro defects, resulting in the reduction of strength and impact toughness, and the reduction in the hardness at the exposed surface of the corroded piping. Understanding the corrosion mechanism of pipelines exposed to sour media in the long-term helps in repair/replacement planning and extending the usable design life of the material, and paving the way for the oil and gas industry to develop additional ways to monitor the changes in the critical materials’ properties when exposed to sour service. Full article

Hydrogen sulfide (H₂S) is a hazardous, colorless, flammable gas with a distinct rotten-egg smell at low concentration. Exposure to a concentration greater than 500 ppm of H₂S can result in irreversible health problems and death within minutes. Because of these hazards, operations such as oil and gas processing and sewage treatment that handle or produce H₂S and/or sour gas require effective and well-designed hazard controls, as well as state-of-the-art gas monitoring/detection mechanisms for the safety of workers and the public. Laboratories studying H₂S for improved understanding must also develop and continually improve upon lab-specific safety standards with unique detection systems. In this study, we discuss various H₂S detection methods and hazard control strategies. Also, we share our experience regarding a leak that occurred as a result of the failure of a perfluoroelastomer O-ring seal on a small stirred autoclave vessel used for studying H₂S hydrate dissociation/formation conditions in our laboratory, and discuss how our emergency response plan was activated to mitigate the risk of exposure to the researchers and public. Full article