On the extraction of gas from multilayered rock

his paper presents some simple analytical and numerical models which describe the dynamics of gas flowing from a multilayered low-permeability porous rock into a fracture. The models account for the vertical flow between relatively high- and low-permeability layers. The motion of gas in a permeable rock is governed by a nonlinear diffusion equation for the gas pressure. We analyse the gas flow described by this equation in both bounded and unbounded domains. In both cases simple scalings laws are developed to determine the fluxes and the dimensions of the regions within the rock which may be depleted over a given time scale. These are compared with the results of a full numerical model

Research subjects studied by the Cluj accounting school in the „Brasov period”

This article focuses on the works published in the field of accounting during the Second World War and in the post-war period in Transylvania. More exactly, this work presents the research themes studied when the Academy of High Commercial and Industrial Studies, which was the first form of Higher education in the economic field in Transylvania, functioned in Brasov. We wanted to surprise in this paper the apparition of the Academy in Cluj, the reason of moving in Brasov and the “Brasov period”

The development of 3-D, in vitro, endothelial culture models for the study of coronary artery disease

The response of the vascular endothelium to wall shear stress plays a central role in the development and progression of atherosclerosis. Current studies have investigated endothelial response using idealized in vitro flow chambers. Such cell culture models are unable to accurately replicate the complex in vivo wall shear stress patterns arising from anatomical geometries. To better understand this implication, we have created both simplified/tubular and anatomically realistic in vitro endothelial flow models of the human right coronary artery. A post-mortem vascular cast of the human left ventricular outflow tract was used to create geometrically accurate silicone elastomer models. Straight, tubular models were created using a custom made mold. Following the culture of human abdominal aortic endothelial cells within the inner lumen, cells were exposed to steady flow (Re = 233) for varying time periods. The resulting cell morphology was analyzed in terms of shape index and angle of orientation relative to the flow direction. In both models a progressive elongation and alignment of the endothelium in the flow direction was observed following 8, 12, and 24 hours. This change, however, was significantly less pronounced in the anatomical model (as observed from morphological variations indicative of localized flow features). Differences were also observed between the inner and outer walls at the disease-prone proximal region. Since morphological adaptation is a visual indication of endothelial shear stress activation, the use of anatomical models in endothelial genetic and biochemical studies may offer better insight into the disease process

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

Two alternating polyfluorene polyrotaxanes (3·TM-βCD and 3·TM-γCD) have been synthesized by the coupling of 2,7-dibromofluorene encapsulated into 2,3,6-tri-O-methyl-β- or γ-cyclodextrin (TM-βCD, TM-γCD) cavities with 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol) ester. Their optical, electrochemical and morphological properties have been evaluated and compared to those of the non-rotaxane counterpart 3. The influence of TM-βCD or TM-γCD encapsulation on the thermal stability, solubility in common organic solvents, film forming ability was also investigated. Polyrotaxane 3·TM-βCD exhibits a hypsochromic shift, while 3·TM-γCD displays a bathochromic with respect to the non-rotaxane 3 counterpart. For the diluted CHCl3 solutions the fluorescence lifetimes of all compounds follow a mono-exponential decay with a time constant of ≈0.6 ns. At higher concentration the fluorescence decay remains mono-exponential for 3·TM-βCD and polymers 3, with a lifetime τ = 0.7 ns and 0.8 ns, whereas the 3·TM-γCD polyrotaxane shows a bi-exponential decay consisting of a main component (with a weight of 98% of the total luminescence) with a relatively short decay constant of τ1 = 0.7 ns and a minor component with a longer lifetime of τ2 = 5.4 ns (2%). The electrochemical band gap (ΔEg) of 3·TM-βCD polyrotaxane is smaller than that of 3·TM-γCD and 3, respectively. The lower ΔEg value for 3·TM-βCD suggests that the encapsulation has a greater effect on the reduction process, which affects the LUMO energy level value. Based on AFM analysis, 3·TM-βCD and 3·TM-γCD polyrotaxane compounds exhibit a granular morphology with lower dispersity and smaller roughness exponent of the film surfaces in comparison with those of the neat copolymer 3

Sediment dynamics of a nearshore sandbank: Results from TELEMAC-2D, TOMAWAC and SISYPHE modelling

Water Qualit

Development of functional beverage from wheat grass juice

The juice from wheat grass is called "green blood" and is an excellent detoxifying, facilitating the elimination of toxins and fats from body. In the form of fresh juice, it has high concentrations of chlorophyll, active enzymes, vitamins and other nutrients. The aim of this work was the development and characterization of a functional beverage from green wheat juice by adding apple and limes. The antioxidant capacity, vitamin C, polyphenols and flavonoids content were quantified by using spectrophotometry. The final product was pasteurized and evaluated by the content of bioactive compounds during storage at intervals of 7 and 14 days. During storage there were found slight decreases of the contents of bioactive compounds. The juice obtained has a sweet-sour taste, a unique flavor and a very pleasant smell. This product targets all categories of consumers and represents an ideal morning snack for those who are concerned about a healthy lifestyle

STUDY REGARDING THE USE OF SALVIA OFFICINALIS ESSENTIAL OIL IN FOOD PRODUCTS WITH A HIGH FAT CONTENT (MAYONNAISE)

In the last years, through the emerging technologies for food processing, new ways are proposed for replacing the synthetic antioxidants with natural occurring compounds extracted from plants and which exert a high antioxidant activity. Therefore, the aim of the present study was to assess the addition of Salvia officinalis essential oil and its impact on the physicochemical characteristics of homemade mayonnaise. The product was monitored for four months in order to highlight the possible physicochemical changes, by determining the peroxide, the free fatty acids and the pH values. During storage, the pH of all investigated samples, except mayonnaise sample containing 2 μl/g of sage essential oil, slightly increased. The peroxid values for all samples increased during storage period and were higher than the one obtained for the control sample. Also, an increase in the free fatty acids content was noticed for all studied samples. Following the results obtained it can be stated that Salvia officinalis essential oil could be useful to control the development of rancidity and to maintain the quality and extend the shelf life of mayonnaise

Screen or No Screen? Lessons Learnt from a Real-World Deployment Study of Using Voice Assistants With and Without Touchscreen for Older Adults

While voice user interfaces offer increased accessibility due to hands-free and eyes-free interactions, older adults often have challenges such as constructing structured requests and perceiving how such devices operate. Voice-first user interfaces have the potential to address these challenges by enabling multimodal interactions. Standalone voice + touchscreen Voice Assistants (VAs), such as Echo Show, are specific types of devices that adopt such interfaces and are gaining popularity. However, the affordances of the additional touchscreen for older adults are unknown. Through a 40-day real-world deployment with older adults living independently, we present a within-subjects study (N = 16; age M = 82.5, SD = 7.77, min. = 70, max. = 97) to understand how a built-in touchscreen might benefit older adults during device setup, conducting self-report diary survey, and general uses. We found that while participants appreciated the visual outputs, they still preferred to respond via speech instead of touch. We identified six design implications that can inform future innovations of senior-friendly VAs for managing healthcare and improving quality of life

How do Older Adults Set Up Voice Assistants? Lessons Learned from a Deployment Experience for Older Adults to Set Up Standalone Voice Assistants

While standalone Voice Assistants (VAs) are promising to support older adults' daily routine and wellbeing management, onboarding and setting up these devices can be challenging. Although some older adults choose to seek assistance from technicians and adult children, easy set up processes that facilitate independent use are still critical, especially for those who do not have access to external resources. We aim to understand the older adults' experience while setting up commercially available voice-only and voice-first screen-based VAs. Rooted in participants observations and semi-structured interviews, we designed a within-subject study with 10 older adults using Amazon Echo Dot and Echo Show. We identified the values of the built-in touchscreen and the instruction documents, as well as the impact of form factors, and outline important directions to support older adult independence with VAs