High-density metals and arsenic in algae of storm emissions from the coastal area of the Severny island of the Novaya Zemlya archipelago

Purpose of the Study is to assess the potential hazard in terms of the content of high-density metals (HDMs) and arsenic (As) for the consumption of objects of the Arctic algal flora presented in storm emissions in places of probable disembarkation of a crew, the ship has come in a distress or a disaster in the water area of the northern seas of the Russian Federation.Materials and methods. The elemental composition of samples of the plants thrown by the wind-wave impact on the coastal area of the Severny island of the Novaya Zemlya archipelago. Before making the analysis, thallus fragments were dried at 80° C to constant weight to determine their dry weight with an accuracy of 1 mg. The material mineralization was carried out using a microwave mineralizer according to the standard technique. The elementary analysis was performed using MGA-915M atomic spectrometer. The data obtained were compared with the maximum permissible levels established by the current regulatory documents. According to the results of measurements, series of decreasing concentrations of HDMs in algae samples were built according to the places of collection and species.Results and Discussion. It has been found that the lowest content of HDMs and arsenic in the wind-wave emissions of algae on the Severny Island in the Russkaya Gavan Bay of the Novaya Zemlya archipelago belongs to both Laminaria digitata and vegetative parts of the thallus of most of the other ejected algae. These plants can be used for food in extreme situations by the crews of a ship (an aircraft, etc.) who has come in a distress or a disaster.

Bioplastic Production from Eucheuma Cottoni

Plastic waste has become a global problem because it causes environmental pollution. This is because plastic waste is difficult to decompose. There have been numerous solutions proposed, one of which is theuse of bioplastics. In this research, the bioplastics were made from third- generation biomass, namely the eucheuma cottoni. Eucheuma cottoni is contains biopolymer carrageenan, a carbohydrate with unit structures consisting of d-galactose and 3,6 anhydrogalactose with glycosidic bonds. Goal this research is study the effects of sorbitol plasticizer content and bioplastics manufacturing temperature on bioplastics, tensile strength, elongation, and biodegradation rate. The bioplastics were made by extracting 10 grams of eucheuma cottoni powder in 200 ml of distilled water. The algae extract was added with sorbitol (plasticizer) and heated at various temperatures from 45°C until 60°C. The mixture was poured into a mold tin and dried in the oven to a constant weight. The resulting bioplastics were then characterized to determine the tensile strength and biodegradation rate. The results showed that increasing the plasticizer content from 3.5% reduced the tensile strength, however, it increased the elongation and biodegradation rate. The optimal plasticizer content was 4% with a tensile strength value of 4.8309 Mpa, elongation of 24.1548%, and biodegradation rate of 26.9392%. The temperature variable showed that increasing the temperature of making bioplastics could reduce tensile strength, increase elongation and biodegradation rate of bioplastics. The optimum temperature for making bioplastics at 45oC obtained a tensile strength of6.28 Mpa and an elongation of 20.67%. The biodegradation rate was 39.6665%, and the best sorbitol content was received at 4%.

Effect of Two Drying Methods on the Bioactive Cashew Apple Varieties Consumed in the City of Garoua (Northern Cameroon)

Aims: The cashew tree (family Anacardiaceae) grows widely in many parts of African countries, including Cameroon. Its fruit and nut are used for food and several studies have shown their beneficial effects on health. This work aimed to evaluate the impact of two drying methods on the content of bioactive compounds and antioxidant activity. Methodology: Four varieties (VAR 1, VAR 2, VAR 3, VAR 4) of cashew apple samples were collected and drying using sun-dried and oven-dried to a constant weight, and then ground in a blender to a powder, the fresh one was cut up and crushed in a blender. All sample were reconstituted with distilled water and polyphenols, flavonoids, alkaloids contents, and antioxidant activity through different mechanisms (DPPH radical, FRAP and TAC assays) were assessed. Results: Alkaloids ranged from 1.50 mg EQui/g MF to 5.69 mg EQui/g DM for fresh and oven-dried VAR 1 respectively, polyphenols ranged from 786.15 mg EAG/g MF to 2836.92 mg EAG/g DM for fresh and oven-dried VAR 1 respectively, flavonoids ranged from 8.18 mg EAG/g MF to 295.45 mg EAG/g DM for fresh and oven-dried VAR 2 respectively. TAC values ranged from 13.09 mg EAA/g MF to 67.06 mg EAA/g for fresh and oven-dried VAR3 and VAR2 respectively. The highest DPPH radical scavenging value (86.25%) was obtained with fresh VAR 4 and the lowest (25.67%) with fresh VAR 1. The highest ferric reducing antioxidant power (FRAP) was obtained with fresh VAR 1 and VAR 3 (0.27 mg AAE/g MF) and the lowest with VAR 3 and VAR 4 oven-dried (0.23 mg AAE/g MF). Conclusion: In conclusion, the different cashew varieties studied in this work are a good source of antioxidants. The drying method significantly affects bioactive compounds and antioxidant activities. A weak but not significant correlation was obtained between the number of bioactive compounds and antioxidant activities.

Comparison of the Natural Vibration Frequencies of Timoshenko and Bernoulli Periodic Beams

This paper deals with the linear natural vibrations analysis of beams where the geometric and material properties vary periodically along the beam axis. In contrast with homogeneous prismatic beams, the frequency spectra of such beams are irregular as there exist enlarged intervals between some adjacent frequencies. Presented here are two averaged models of beams based on the tolerance modelling approach. The assumptions of classical Euler–Bernoulli and Timoshenko–Ehrenfest beam theories are adopted as the foundations. The resulting mathematical models are systems of differential equations with constant, weight-averaged coefficients. This makes it possible to apply any classical method of solution suitable for homogeneous beams, such as Galerkin orthogonalization. Here, emphasis is placed on the comparison of natural frequencies neighbouring the frequency band-gaps that are obtained from these two theories. Two basic cases of material and geometric property distribution in a periodicity cell are studied, and the natural frequencies and mode shapes are obtained for a simply supported beam. The results are supported by a comparison with the finite element method and partially exact solutions.

The Influence of Silica Nanoparticles on the Thermal and Mechanical Properties of Crosslinked Hybrid Composites

This paper presents the synthesis and physicochemical characterization of a new hybrid composite. Its main goals are evaluating the structure and studying the thermal and mechanical properties of the crosslinked polymeric materials based on varying chemical properties of the compounds. As an organic crosslinking monomer, bisphenol A glycerolate diacrylate (BPA.GDA) was used. Trimethoxyvinylsilane (TMVS) and N-vinyl-2-pyrrolidone (NVP) were used as comonomers and active diluents. The inorganic fraction was the silica in the form of nanoparticles (NANOSiO2). The hybrid composites were obtained by the bulk polymerization method using the UV initiator Irqacure 651 with a constant weight ratio of the tetrafunctional monomer BPA.GDA to TMVS or NVP (7:3 wt.%) and different wt.% of silica nanoparticles (0, 1, 3%). The proper course of polymerization was confirmed by the ATR/FTIR spectroscopy and SEM EDAX analysis. In the composites spectra the signals correspond to the C=O groups from NVP at 1672–1675 cm−1, and the vibrations of Si–O–C and Si–O–Si groups at 1053–1100 cm−1 from TMVS and NANOSiO2 are visible. Thermal stabilities of the obtained composites were studied by a differential scanning calorimetry DSC. Compared to NVP the samples with TMVS degraded in one stage (422.6–425.3 °C). The NVP-derived materials decomposed in three stages (three endothermic effects on the DSC curves). The addition of NANOSiO2 increases the temperature of composites maximum degradation insignificantly. Additionally, the Shore D hardness test was carried out with original metrological measurements of changes in diameter after indentation in relation to the type of material. The accuracy analysis of the obtained test results was based on a comparative analysis of graphical curves obtained from experimental tests. The values of the changes course of similarity in the examined factors, represented by those of characteristic coefficients were determined based on the Fréchet’s theory.

Hybrid drying of ultrasound assisted osmotic dehydration (UOAD) and hot air drying of Eucalyptus deglupta

Eucalyptus deglupta is one of the promising medicinal plants from Mytracea family consisting of bioactive compounds that are to be used in medications. The bioactive compounds present in Eucalyptus deglupta were extracted at the best yield using a hybrid drying method consisting of ultrasound assisted osmotic dehydration (UOAD) and hot air drying in this study. The drying conditions of UAOD were optimised with response surface methodology (RSM) to attain the highest antioxidant activity via of DPPH radical scavenging assay. Four parameters were optimised with response surface methodology, namely concentration of sucrose (v/w), temperature (°C), duration of drying and intensity of ultrasound (%) ranged from 30% to 50%, 20°C to 60°C, 40 min to 100 min and 60% to 100%, respectively. A series of 27 combinations of the UAOD drying conditions were performed and followed by hot air drying performed at 60°C until a constant weight was achieved. A moderate scavenging activity of DPPH assay (56.12%) was achieved at a concentration of sucrose, temperature, duration of drying and intensity of ultrasound of 50%, 40°C, 100 min and 264 W, respectively.

DRYING KINETICS OF FISH (Clarias gariepinus) SMOKED WITH BIOGAS

This is aimed at studying the aeration kinetics of catfish (Clarias gariepinus) smoked directly with biogas. Five live fresh fishes (Clarias gariepinus) were obtained from Fishery and Aquaculture Technology Department in FUTA, Ondo State, Nigeria at the age of 4 months with average weight of 900g each. The fishes were killed, de-gutted, thoroughly washed with water, cut into pieces of 3cm length. The chunks were laid in a single layer on a mesh directly exposed to biogas flame obtained from bio-decomposition of poultry waste and the weight was being monitored at 15 minutes interval until constant weight was observed. The study showed that the time taken for drying of Clarias gariepinus to reach the humidity point of around 12.43% (db.) was two and a half hours. The drying data was subjected to 10 thin-layer drying models. The compared the performances of the models using the determination of coefficient (R2), reduced chi­square (x2) and root mean square error (RMSE) between the calculated and predicted moisture ratios. The results showed that Henderson and Pabis modified model (highest R2 and lowest x2 and RMSE of 0.998, 0.00021 and 0.01386 respectively) was found to satisfactorily describe the biogas drying curves of Clarias gariepinus.

Binomial Number System

This paper presents and first scientifically substantiates the generalized theory of binomial number systems (BNS) and the method of their formation for reliable digital signal processing (DSP), transmission, and data storage. The method is obtained based on the general theory of positional number systems (PNS) with conditions and number functions for converting BNS with a binary alphabet, also allowing to generate matrix BNS, linear-cyclic, and multivalued number systems. Generated by BNS, binomial numbers possess the error detection property. A characteristic property of binomial numbers is the ability, on their basis, to form various combinatorial configurations based on the binomial coefficients, e.g., compositions or constant-weight (CW) codes. The theory of positional binary BNS construction and generation of binary binomial numbers are proposed. The basic properties and possible areas of application of BNS researched, particularly for the formation and numbering of combinatorial objects, are indicated. The CW binomial code is designed based on binary binomial numbers with variable code lengths. BNS is efficiently used to develop error detection digital devices and has the property of compressing information.

Influence of different anionic charges in lead compounds in the remediation of lead by Eleusine indica (Gaertn)

The study was carried out to investigate the remediative capacity of Eleusine indica in lead-polluted soil. Soil samples were collected near student hostel (hall 5) in the University of Benin. The soil samples were sun dried to constant weight and was pulverized with wooden roller and sieved with a hand sieve of 2 mm mesh size. The sieved soil was spiked with 0.625 g lead nitrate (PbNO3), lead sulphate (PbSO4), lead carbonate (PbCO3), lead acetetrahydrate (PbC2H6) and lead chloride (PbCl2) separately in three replicate using aqueous standard solutions. Tillers of Eleusine Indica were placed in the metal polluted soil immediately and the experiment was allowed to stay for 15 weeks. The result showed that the uptake efficiency for Eleusine indica in both shoots and roots for lead nitrate was 0.016% and 0.8%, lead sulphate 0.016 % and 0.352 %, lead carbonate 0.064% and 0.496 %, lead acetetrahydrate 0.032 % and 0.688 %, and lead chloride 0.08 % and 0.72 % respectively, indicating that the plant might have sequestered the metal in the soil rather than accumulating it in the leaves. This was evident in the presentation of the metal sequestration factor of over 70 % irrespective of the nature of the metal. Microbial count of soil before and after contamination with lead nitrate was 19000 and 4000 cfu/g indicating a reduction. The study therefore revealed that Eleusine indica is a high efficient plant in sequestering lead in polluted soil.