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Abstract

To estimate and model explosion pressure rise in closed volumes, industrial applications require a simple method. Ideal gas model is capable to assume pressure rise values to 10% above to initial pressure. However, most of the explosion venting devices opens higher than this pressure range.

Extension of ideal gas model was carried out in this paper. Authors made some experimental studies in 20 L explosion sphere at ambient temperature and atmospheric initial pressure, with propane-air mixtures at different concentrations between 2.8 and 6.3 vol%. They measured pressure values inside the chamber during explosion and recorded at 9,600 Hz. Based on experimental studies, authors extended ideal gas model application range to 1.5 barg.

Open access

Abstract

The effect of processing parameters on microencapsulation of oregano essential with maltodextrin:gum arabic using a disk atomiser spray-dryer was evaluated. By means of response surface methodology, the feed flow rate and inlet air temperature were optimised. Powder yield, moisture content, essential oil retention, and antioxidant activity of microparticles were evaluated. The best conditions to produce microencapsulated oregano essential oil were 0.6 L h−1 for feed flow rate and 200 °C for inlet air temperature. With this combination a microencapsulated powder with 89.8% powder yield, 2.1% moisture content, 92.1% essential oil retention, 76 s solubilisation time, 12.9 g of water/100 g of dry matter, 0.3371 g mL−1 bulk density, 0.5826 g mL−1 tapped density, and 8.2 μm of average particle size was produced. The microencapsulation of oregano essential oil preserves the antioxidant and antimicrobial activities of its bioactive compounds.

Restricted access

Abstract

This study evaluated the effect of surfactant-assisted enzymatic extraction on the quality of tiger nut milk (TNM). TNM was extracted from tiger nuts using different concentrations of xylanase (0.010–0.100%) and Tween 20 (0.005–0.010%). The yield, stability, nutritional, antioxidant, and sensory properties of the samples were determined. The yield of TNM significantly increased, by 32.72–50.67%, following surfactant-assisted enzymatic extraction. Optimum yield and stability of TNM were obtained using 0.010% xylanase and Tween 20. Enzymatic extraction significantly increased total sugar and flavonoids, however, starch, dietary fibre, protein, carotenoids, lycopene, total phenolic content, and antioxidant properties reduced significantly. The incorporation of Tween 20 stabilised these parameters. There was no significant difference in panellists' preference for the control (sample extracted without enzyme and surfactant), enzymatically-extracted, and surfactant-assisted enzymatic extracted samples in mouthfeel and aroma, however, the surfactant-assisted enzymatic extracted sample was most preferred in colour, consistency, taste, and overall acceptability. Using surfactant-assisted enzymatic extraction could prove invaluable for the production of TNM.

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Abstract

Cultivation of specialty mushrooms on lignocellulosic wastes represents one of the most economical organic recycling processes. Compared with other cultivated mushrooms, very little is known about the nature of the lignocellulolytic enzymes produced by the edible fungus Calocybe indica, its enzymatic activity profiles during submerged and solid state fermentation. The intracellular activity of laccase (7.67 U mg−1), manganese peroxidase (7.48 U mg−1), cellobiohydrolase (5.46 U mg−1), and endoxylanase (4.21 U mg−1) was best obtained in C. indica on 14th and 21st day of incubation. The extracellular activity of laccase (11.57 U mL−1), lignin peroxidase (8.45 U mL−1), and endoxylanases (6.22 U mL−1) were found to be highest on the 14th day. Ligninolytic enzyme activity was substantial during substrate colonisation but quickly dropped during fruiting body development. C. indica, on the other hand, showed relatively modest hydrolase activity during substrate colonisation. The activity of hydrolytic enzymes increased dramatically when primordia formed and peaked at the mature fruiting body stage. The yield of the crude enzyme-treated wheat straw utilised for mushroom production was 52.47%. These findings showed that the activities of lignocellulolytic enzymes were regulated in line with developmental phase of growth of C. indica.

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Abstract

This study aims to formulate the optimal pectin-curcumin-lemongrass oil emulsion (PE) for coating of chicken fillet at 50:50%, 70:30%, and 90:10%, based on microbial growth inhibition, freshness consistency, and fat absorption during frying. Throughout the 7 days of storage, chicken fillet coated with 70:30% PE showed significant (P < 0.05) suppressive activity against psychrophilic bacteria (8.09 ± 0.00 log10 CFU g−1) compared to non-coated sample (8.27 ± 0.06 log10 CFU g−1). In contrast, 90:10% PE coating inhibited the growth of yeasts or moulds on chicken fillet at 8.24 ± 0.28 log10 CFU g−1, compared to non-coated sample (9.16 ± 0.14 log10 CFU g−1). The 70:30% PE coating showed a better fillet's toughness (18.30 ± 1.32 N mm−1 s−1) and firmness (1.49 ± 0.22 N mm−1) when compared to fillet without coating. After 7 days of storage, coated and uncoated samples showed the same total colour difference (E value) indicating PE coating preserved the texture of fillet and colour. Both coated samples (70:30% and 90:10%) reduced fat uptake during frying by 13.70%–14.25%. The application of PE coating at 90:10% was effectively functioned as an excellent coating to preserve the quality and safety of fillet.

Restricted access
Acta Alimentaria
Authors:
M. Reyzov
,
M. Eftimov
,
S. Gancheva
,
M. Todorova
,
M. Zhelyazkova-Savova
,
M. Tzaneva
, and
S. Valcheva-Kuzmanova

Abstract

Metabolic syndrome (MS) is a serious health condition. The purpose of this study was to investigate the effects of polyphenol-rich Aronia melanocarpa fruit juice (AMFJ) on glucose tolerance, triglyceride levels, and adipose tissue in rats with MS induced by high-fat high-fructose (HFHF) diet. Fifty rats were allocated in 5 groups: control, MS, MS+AMFJ2.5, MS+AMFJ5, and MS+AMFJ10. In the course of 10 weeks, the control group was on a regular rat diet while the other groups received HFHF diet. During the experiment, control and MS groups were treated daily orally with distilled water (10.0 mL kg−1) and the other three groups – with AMFJ at doses of 2.5, 5.0, and 10.0 mL kg−1, respectively. In MS rats, glucose intolerance, hypertriglyceridemia, visceral obesity, and increased adipocyte size were observed. In AMFJ-treated groups, the serum glucose and triglycerides, as well as visceral fat and adipocyte size decreased significantly and did not differ from those of the control group. AMFJ at doses 2.5 and 5.0 mL kg−1 showed an anti-apoptotic activity in adipocytes, while at the dose of 10 mL kg−1 a pro-apoptotic effect was detected. In conclusion, AMFJ could antagonise most of the negative consequences of HFHF diet on carbohydrate and lipid metabolism in a rat MS model.

Open access

Abstract

This study aims to select the suitable density of the material according to the mechanical properties needed by the 3D-printing application in which it will be used. 3D-printed carbon fiber filaments with different printing densities have been tensile, and a fatigue test was experimented with to find the mechanical properties. Furthermore, the modulus of elasticity, yield stress, and ultimate tensile strength of the material was determined by analyzing the stress-strain curves. The result shows that the parts printed with a high infill density give better mechanical properties, more time to build the object, more strength, and heavier weight than those printed with low infill density.

Restricted access

Abstract

Accessibility is known as the ease of reaching destinations. The accessibility is determined by the spatial distribution of potential destinations, and the magnitude, quality, and character of the activities found there. However, modernization and the fast expansion of urban development transform cities' local cultural life from walkable accessible places to just car places. This has encroached into every corner of our urban environment today. In addition, the available services and systems to manage the pedestrian movement in the historic core are inadequate and inefficient, posing risks to both the traffic and the pedestrians. That affects the walkability for cities gradually. Hence, this paper aims to explore the main physical elements that contribute toward accessibility under three main categories (pedestrians, vehicles and public transport) as one of the walkability characters in Salt City in Jordan. Historical review, site analysis, and survey were the main methodology used in this study.

Open access

Abstract

Accessibility is known as the ease of reaching destinations. The accessibility is determined by the spatial distribution of potential destinations, and the magnitude, quality, and character of the activities found there. However, modernization and the fast expansion of urban development transform cities' local cultural life from walkable accessible places to just car places. This has encroached into every corner of our urban environment today. In addition, the available services and systems to manage the pedestrian movement in the historic core are inadequate and inefficient, posing risks to both the traffic and the pedestrians. That affects the walkability for cities gradually. Hence, this paper aims to explore the main physical elements that contribute toward accessibility under three main categories (pedestrians, vehicles and public transport) as one of the walkability characters in Salt City in Jordan. Historical review, site analysis, and survey were the main methodology used in this study.

Open access

Abstract

Cracking in composite steel-concrete bridge decks is a common problem in civil engineering. Before, or shortly after, the bridge is subjected to live loads; various levels of cracking can appear, mostly due to plastic shrinkage and temperature effects.

This paper presents an investigation of the behavior of cracked concrete in a composite deck slab of a railway bridge supported by steel girders using the finite element method. Eurocode 4-2 proposes a few simplified methods for calculating shrinkage and cracking effects in concrete. Through the proposed methods of analysis, an analytical simulation of a continuous composite steel-concrete bridge deck is performed and some practical recommendations for analyzing beam girders of this type are given.

Open access