Cellular Glass Manufactured by Microwave Irradiation of Residual Glass, Eggshell and Borax

The paper presents an improved method of manufacturing cellular glass using residual glass (91 %), sodium borate (5 %), eggshell waste (4 %) and added water (9 %). Compared to methods using eggshell as an expanding agent producing cellular glass with low compression strength, the technique adopted by the authors is original by the addition of sodium borate, which contributes to increasing the compression strength and the use of the unconventional electromagnetic wave heating method, which ensures very economical specific energy consumption. The optimal variant of cellular glass had the following characteristics: density of 0.40 g/cm3, porosity of 81 %, heat conductivity of 0.086 W/m·K, compression strength of 4.3 MPa and the cell dimension between 0.3-0.9 mm. The specific energy consumption of the process was 0.80 kWh/kg. The product has adequate features for using as a heat insulation material under conditions of quite high mechanical loading.

Assessing the Enzymatic Hydrolysis of Salmon Frame Proteins through Different By-Product/Water Ratios and pH Regimes

The enzymatic hydrolysis of fish by-product proteins is traditionally carried out by mixing ground by-products with water. In addition, pH control is used to avoid pH drops. Higher costs are involved due to the use of pH control systems and the consequent energy cost in the drying stage. This work aimed to evaluate the effect of these conditions on the hydrolysis of salmon frame (SF) proteins, including the SF hydrolysis without added water. SF hydrolysis by subtilisin at 50, 75, and 100% SF under different pH regimes were evaluated by released α-amino (α-NH) groups, total nitrogen, degree of hydrolysis, and estimated peptide chain length (PCL) at 55 °C. The concentration of released α-NH groups was higher in the conditions with less added water. However, the nitrogen recovery decreased from 50 to 24% at 50 and 100% SF, respectively. Changing the SF/water ratio had a more significant effect than changing the pH regime. Estimated PCL changed from 5–7 to 7–9 at 50 and 100% SF, respectively. The operating conditions affected the hydrolysis performance and the molecular characteristics of the hydrolysate.

Structure Dynamic Response of Amphibious Aircraft Induced by Water-Taxiing

The significant dynamic response under the combined impact of aerodynamic and hydrodynamic forces could be likely to appear because of the structural flexibility, when taxiing on the water surface for amphibious aircraft. Meanwhile, the modal characteristics of the structure are also affected by the additional motion of water. These require that the influence of the structural elasticity and the coupling effect between water and structure should be considered in dynamic response analysis of water-taxiing. According to the peculiarities of the amphibious aircraft, structural dynamics model is based on the distribution of stiffness and mass, Virtual Mass Theory is utilized to solve the wet modes on the water surface, rational function approximations of unsteady aerodynamic force in time-domain are constructed by the Minimum-State Approximation Formula, and loose coupling method is employed to simulate the hydrodynamic elastic response under the encounter of amphibian with single wave and repeated waves, respectively. Analysis of dynamic characteristics during the water-taxiing of the amphibious aircraft has been achieved in this work. The results show that wet natural frequencies of the aircraft have different degrees of decline compared with the dry frequencies because of the influence of added water on the hull, and the response amplitude of dynamic loads obtained by using the wet modes have some certain extent decrease compared with the dry modes. The dynamic amplitude of different locations changes in different degree relatives to the center of gravity position, which reflects the influence of structural elasticity. Due to the excitation of single wave and repeated waves, the structural vibration amplitude will increase rapidly, but the amplitude shows a certain divergence trend under the action of repeated waves with a given oscillation frequency, which is more severe for structural strength design.

The added water control system based on neural network model and double parameter corrected for loosening and conditioning cylinder

In order to improve the stability of outlet moisture in the of loosening and conditioning cylinder, we concentrate on loosening and conditioning cylinder, and design the prediction model of the added water volume based on neural network technology and the double parameter corrected control system of material balance and moisture deviation for loosening and conditioning cylinder by using historical production data. Taking the set value of inlet and outlet moisture of the loosening and conditioning cylinder as the input factor and the added water volume as the output factor, the prediction model of the added water volume was to predict the total volume of the added water. When there was a big deviation between the actual value and the set value of outlet moisture, the double parameter corrected control system of material balance and moisture deviation was used to correct the deviation, so as to improve the outlet moisture stability and the control accuracy of the added water volume. Using Cigarette brand “diamond (hard-case Yingbin)” produced by Zhangjiakou cigarette factory to built model and analysis, the results showed that after the improvement, the standard deviation of output moisture of loosening and conditioning cylinder reduced by 0.27%, and the control stability and the control level of production process were improved.

Chemical Composition and Screening of Aflatoxin M1 in Cows’ Milk in Gadarif Town, Sudan

Background: Milk is a perfect complete perishable food that could be adulterated or contaminated by wide varieties of substance throughout the chain of its production. Of these aflatoxins M1 was considered as an important health risk associated with the milk. The objectives of this study are to analyse milk samples, for chemical composition and detection of aflatoxin M1. Method: One hundred milk samples were collected from different sources randomly; 35 samples from farms, 35 samples from sale points and 30 samples from groceries in Gedarif town. Milk-Kana was used for determination of chemical composition (fat, solids not fat, lactose and protein and analysis of freezing point, density and added water) and Unisensor kits were used as screening method for detection of aflatoxin M1 in milk. Results: The chemical composition of milk samples collected from farms, sales points and groceries showed lower content of the fat (3.4±1.3%, 3.4±1.3% and 3.5±1.25%), solids not fat (7.7±1.1%, 8.1±1.7% and 8±1%), lactose (4.2±0.6%, 4.4±0.8% and 4.3±0.5%) and protein (3±0.4%, 3±0.5% and 3±0.4%). The freezing point of milk samples revealed -.503±.079, -.524±.007 and -.522±.099 °C, while the density showed 0.025±0.003, 0.026±0.005 and 0.026±0.003 gm/cm3, respectively. Moreover the added water was found as 10.6±11.6%, 10.6±10.4% and 8.7±8.2% in the samples collected from farms, sale points and groceries, respectively. The occurrence of aflatoxin M1 in raw milk samples were found in 22(27.50%) of the samples. The presence of aflatoxin contamination was high in milk samples collected from sales points (15.0%) followed by farms (11.25%) compared to those obtained from groceries (1.25%). Conclusion: The lower chemical composition of milk ns the high added water suggested adulteration of milk. Moreover the presences of aflatoxin M1 in the milk samples might indicate that the cow milk was contaminated with aflatoxins through feed. Hence this study recommended that good hygienic practices should be considered in Gadarif town. Similarly regulations and lows for selling the milk should be implemented by the official authorities.

Determination of Technological Parameters and Characterization of Microbiota of the Spontaneous Sourdough Fermentation of Hull-Less Barley

The development of microorganisms of sourdough and biodiversity of microbiota can be influenced by changing the parameters of the technological process such as the ratio of flour and added water, the fermentation temperature and time. The Box–Behnken design methodology was used to determine the optimal parameters for the three-phase spontaneous backslopping fermentation process of hull-less barley sourdough, as well as to characterize the microbiological diversity. The optimized parameters of backslopping fermentation are flour and water ratio 1:1.13, temperature 30 °C, time 24 h in the 1st backslopping; the inoculate, flour and water ratio 1:1:1.3, temperature 31 °C, time 14 h in the 2nd backslopping, and the inoculate, flour and water ratio 1:1:1.5, and temperature 28.5 °C, time 12 h in the 3rd step of backslopping. In the controlled spontaneous fermentation environment in three backslopping steps, the microbiological research of hull-less barley sourdough has confirmed the dominance of species Pediococcus pentosaceus in the 3rd backslopping step of spontaneous fermentation. The developed spontaneous hull-less barley sourdough is consistent with the number of lactic bacteria and yeasts in line with that seen by the active sourdough.

Recycling of Nonwoven Polyethylene Terephthalate Textile into Thermal and Acoustic Insulation for More Sustainable Buildings

The construction and building sector is responsible for a large share of energy and material used during the life cycle of a building. It is therefore crucial to apply a circular economy model within the process wherever possible to minimize the impact on the environment. In this paper, the possibility of producing thermal and acoustic boards from industrial nonwoven waste textile is studied and presented. The nonwoven polyester textile obtained directly from the production line in the form of strips and bales was first shredded into smaller fractions and then in the form of pile compressed with a hot press to form compact thermal insulation boards. The first set of specimens was prepared only from waste polyester nonwoven textile, whereas the second set was treated with sodium silicate in order to check the material’s reaction to fire performance. The experimental work was conducted to define the acoustic properties, reaction to fire behavior and thermal conductivity of the produced specimens. The obtained results show that the thermal conductivity coefficient of specimens without added water glass dissolution is near to the values of conventional materials used as thermal insulation in buildings. The reaction to fire testing proved that the addition of water glass actually propagates the progressive flame over the entire product. It can be concluded that the presented thermal insulation can be used as an adequate and sustainable solution for building construction purposes.

Occurrence of adulterants and preservatives in the Milk Sold in Rural areas of Omdurman, Sudan

In the present investigation, the chemical composition of milk was determined and the detection of the presence of some additives and preservatives in raw cow milk obtained from rural area of Omdurman city Sudan was done. The milk samples (n= 120) were obtained from rural areas of North and South Omdurman. Significantly, (P≤0.05) higher values for the chemical constituents of the examined raw milk samples were reported in the samples from South Omdurman compared to those from North Omdurman. In addition, the results showed that the added water was found in 16.7% of the examined milk samples. Also, formaldehyde was used as a preservative in 19.2% of the samples, while boric acid was used as preservative in 25% of the milk samples in South Omdurman. However, sodium bicarbonate, hydrogen peroxide and starch were not detected. It was concluded that milk distributed in North and South Omdurman contains some adulterants. Hence control and monitoring programs should be directed towards the hygienic quality of milk during production and marketing.