•Polymers used for packaging such as chitosan, starch, polylactic acid, polyvinyl alcohol and poly caprolactone.•The most favorable nanomaterials are nanoclays, zinc oxide, titanium dioxide and ...silver nanoparticles.•The barrier properties of prepared packaging films against oxygen, carbon dioxide water vapor should be improved.•The mechanical, thermal stability and antibacterial activity of the packaging films should be enhanced.
Bionanocomposites materials open a chance for the usage of novel, high performance, lightweight, and ecofriendly composite materials making them take place the traditional non-biodegradable plastic packaging materials. Biopolymers like polysaccharides such as chitosan (CS), carboxymethyl cellulose (CMC), starch and cellophane could be used to resolve environmental hazards owing to their biodegradability and non-toxicity. In addition these advantages, polysaccharides have some disadvantages for example poor mechanical properties and low resistance to water. Therefore, nanomaterials are used to improve the thermal, mechanical and gas barrier properties without hindering their biodegradable and non-toxic characters. Furthermore, the most favorable nanomaterials are layered silicate nanoclays for example montmorillonite (MMT) and kaolinite, zinc oxide (ZnO-NPs), titanium dioxide (TiO2-NPs), and silver nanoparticles (Ag-NPs). In packaging application, the improvement of barrier properties of prepared films against oxygen, carbon dioxide, flavor compounds diffusion through the packaging films. Wide varieties of nanomaterials are suitable to offer smart and/or intelligent properties for food packaging materials, as demonstrated by oxygen scavenging capability, antimicrobial activity, and sign of the level of exposure to various harmful features for instance oxygen levels or insufficient temperatures. The compatibility between nanomaterials and polymers matrix consider the most challenge for the preparation of bionanocomposites as well as getting whole distribution of nanoparticles into the polymer matrix. We keen in this review the development of packaging materials performance and their mechanical, degradability and thermal stability as well as antibacterial activity for utilization of bionanocomposites in different packaging application is considered.
•Developments in the efficacy of food packaging to prevent foodborne pathogens and reduce environmental waste.•Biodegradable packaging plays an important role in maintaining the health of ...ecosystems.•The incorporation of nanomaterial in biopolymers improves barrier and mechanical properties.•The incorporation of nanomaterials in packaging materials enhances the shelf life of packaged foodstuff.
Improvements in the effectiveness of packaging materials can help to prevent foodborne pathogens and reduce environmental waste. Traditionally, food is packaged in plastic that is rarely recyclable, negatively impacting the environment. Biodegradable packaging materials play an important role in maintaining the health of ecosystems. However, there are limitations in the utilization of bio-based materials, including poor barrier and mechanical properties which frequently cause a shorter shelf life compared to conventional food packaging materials. The incorporation of different nanomaterial in bio-based polymers such as (Chitosan, potato starch, carboxymethyl cellulose (CMC), corn starch and Arabic gum) can improve the various properties packaging materials by enhancing the antimicrobial activity, therefore preventing foodborne pathogens, correspondingly bringing notable enhancement in the bio-based materials properties as food packaging materials. This review deliberates the potential of using bionanocomposite films to solve the issues of both environmental waste and to reduce the spoilage of food products.
Preparation of natural hazards maps are vital and essential for urban development. The main scope of this study is to synthesize natural hazard maps in a single multi-hazard map and thus to identify ...suitable areas for the urban development. The study area is the drainage basin of Xerias stream (Northeastern Peloponnesus, Greece) that has frequently suffered damages from landslides, floods and earthquakes.
Landslide, flood and seismic hazard assessment maps were separately generated and further combined by applying the Analytical Hierarchy Process (AHP) and utilizing a Geographical Information System (GIS) to produce a multi-hazard map. This map represents the potential suitability map for urban development in the study area and was evaluated by means of uncertainty analysis.
The outcome revealed that the most suitable areas are distributed in the southern part of the study area, where the landslide, flood and seismic hazards are at low and very low level. The uncertainty analysis shows small differences on the spatial distribution of the suitability zones. The produced suitability map for urban development proves a satisfactory agreement between the suitability zones and the landslide and flood phenomena that have affected the study area. Finally, 40% of the existing urban pattern boundaries and 60% of the current road network are located within the limits of low and very low suitability zones.
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•Individual landslide, flood and seismic hazard assessment maps are produced.•Natural hazard maps are created and correlated via multi-criteria analysis.•Suitable sites for urban development are selected using multi-hazard map.•Suitable area for urban development is located in the southern part of the study area.•Almost 40% of the urban area is located in the low to very low susceptibility zones.
At present, renewable and biodegradable biocomposites materials have drawn much attention as promising green materials in different domains of application such as intelligent food packaging, ...biomedical and drug delivery, bio-membranes, automotive, as well as in industrial composting applications. The current review deals with the advances in preparation methods and technical applications of these biocomposites. Different biomass materials obtained from renewable resources such as coffee grounds (CG), nanocellulose and date stones are developed to be used as smart reinforcing agents in biodegradable biopolymers for improving their overall properties. Conversely, some drawbacks are associated with the use of lignocellulosic materials as reinforcing agents, especially their high humidity absorption, poor wettability, and incompatibility with most biopolymers. Thus, novel processing techniques and different aspects are proposed in this review to produce high performance lignocellulosic reinforced materials with better properties. Facial and green modification of organoclay (OC) by antibacterial natural rosin and stearic acid to obtain toxicity-free expanded OC is also discussed. Green modification using OC can also be used as compatibilizing and reinforcing material for different incompatible biopolymers such as chitosan, carboxy methyl cellulose (CMC) and polylactic acid (PLA). Ultimately, the future vision on the challenges and the environmental issues towards CO2 emission which is associated to the risk assessment of these bionanomaterials are also discussed.
•The present review deals with the advances in the preparation & technical applications biocomposites materials.•Renewable resources such as coffee grounds, nanocellulose & date stones using as smart reinforcing agent in biocomposites.•Green modification of organoclay by antibacterial natural rosin& stearic acid to obtain toxicity-free expanded organoclay.•Future vision on the challenges and the environmental issues towards CO2 emission.
5-bromopyridine-2,3-diamine reacted with benzaldehyde to afford the corresponding 6-Bromo-2-phenyl-3H-imidazo4,5-bpyridine (
). The reaction of the latter compound (
) with a series of halogenated ...derivatives under conditions of phase transfer catalysis solid-liquid (CTP) allows the isolation of the expected regioisomers compounds (
-
). The alkylation reaction of (1) gives, each time, two regioisomers, N3 and N4; in the case of ethyl bromoactate, the reaction gives, at the same time, the three N1, N3 and N4 regioisomers. The structures of synthesized compounds were elucidated on the basis of different spectral data (
H NMR,
C NMR), X-Ray diffraction and theoretical study using the DFT method, and confirmed for each compound. Hirshfeld surface analysis was used to determine the intermolecular interactions responsible for the stabilization of the molecule. Density functional theory was used to optimize the compounds, and the HOMO-LUMO energy gap was calculated, which was used to examine the inter/intra molecular charge transfer. The molecular electrostatic potential map was calculated to investigate the reactive sites that were present in the molecule. In order to determine the potential mode of interactions with DHFR active sites, the three N1, N3 and N4 regioisomers were further subjected to molecular docking study. The results confirmed that these analogs adopted numerous important interactions, with the amino acid of the enzyme being targeted. Thus, the most docking efficient molecules,
and
, were tested in vitro for their antibacterial activity against Gram-positive bacteria (
) and Gram-negative bacteria (
). Gram-positive bacteria were more sensitive to the action of these compounds compared to the Gram-negative, which were much more resistant.
This experiment investigated the influence of different synbiotic processing methods on the intestinal bacterial count, morphology and histological status of developed male Mandarah chicks. Two ...hundred and ten male Mandarah line chicks aged 1 d were randomized to receive one of 7 chicks. The method and dose for 1-time synbiotics administration to the day-old chicks were as follows: G1: chicks on basal diet received no treatment (control); G2: 0.25 mL synbiotics sprayed; G3: 0.50 mL synbiotics sprayed; G4: 0.25 mL of synbiotics are added to drinking water; G5: 0.50 mL of synbiotics are added to drinking water; G6: 0.25 mL of synbiotics dripped into the mouth; and G7: 0.50 mL of synbiotics dripped into mouth drops. Lactic acid bacteria(LAB) were significantly increased (P<0.0001) compared to the control group and other treated groups and had the maximum values after the use of synbiotics via drinking water (0.25 or 0.50 mL). Furthermore, when comparing the treated birds (G4, G5) with the control birds, the Escherichia coli concentration in the drinking water containing synbiotics was significantly lower. In addition, treated chickens at (G7) showed a higher duodenum, ileum villus height (VH), and VH. - Ileum crypt depth (CD) ratio compared to other groups. In addition, birds treated with 0.50 mL of synbiotics in drinking water (G5) performed better in duodenum, ileum, CD and VH. - CD ratio than the other groups. Meanwhile, intestinal tract length and visceral pH did not differ significantly between groups. It can be concluded that the use of 0.25 mL of synbiotics in drinking water can improve the overall health of birds.
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•ZnO-NPs prepared via green chemistry and added to CH/CMC blend by different ratios.•Morphological, mechanical, antimicrobial properties of the bionanocomposite films were ...evaluated.•Soft white cheese was manufactured and packaged using the bionanocomposite films.•The obtained bionanocomposite extend the shelf life of cheese during storage period.
A novel bionanocomposites packaging material prepared using chitosan (CH), carboxymethyl cellulose (CMC), and zinc oxide nanoparticles (ZnO-NPs), namely CH/CMC/ZnO bionanocomposites, was prepared by casting method. The CH/CMC/ZnO bionanocomposites were investigated using FT-IR, TEM, SEM, XRD, and TGA. The acquired bionanocomposites exhibited improved mechanical and thermal properties compare with the biocomposites (CH/CMC) blend. The soft white cheese were manufactured, packaged within the prepared bionanocomposites films and stored at 7°C for 30days. The influence of packaging material on packaged cheese (rheological properties, colour measurements, moisture, pH and titratable acidity) were assessed. Furthermore, the effect of packaging material on the total bacterial counts, mold & yeast and coliform in cheese was evaluated. The prepared bionanocomposites displayed good antibacterial activity against gram positive (Staphylococcus aureus), gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria and fungi (Candidia albicans). Moreover, the packaging films assisted in increasing the shelf life of white soft cheese. Therefore, it can be used in food packaging applications.
In this paper we describe the preparation of a new bionanocomposite based on carboxymethyl cellulose (CMC), Arabic gum (AG) and gelatin (GL), incorporating garlic extract (GE) and TiO
2
nanoparticles ...(TiO
2
-NPs). The prepared bionanocomposites were evaluated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Energy Dispersive X-ray Analysis (EDX), and scanning electron microscopy (SEM), and were evaluated for their antimicrobial effect. The permeability and thermal and mechanical properties of the films were assessed. The water vapor transmission rate (WVTR), oxygen transmission rate (OTR), and mechanical, thermal and antimicrobial properties of the prepared bionanocomposite films were enhanced by the addition of GE and TiO
2
-NPs. The effects of GE and TiO
2
-NPs in combination incorporated into a CMC/AG/GL blend as an edible coating on the quality of fresh Nile tilapia fish fillets during refrigerated storage were evaluated. The microbiological status and weight loss of fresh Nile tilapia fish fillets were periodically tested for 21 days during storage at 4 °C. The results indicated that GE combined with TiO
2
-NPs has a synergistic influence on the enhancement of the preservation properties of CMC/AG/GL/GE-TiO
2
bionanocomposites for refrigerated tilapia fish fillets, which could control microbial growth, and decrease weight loss during the storage of tilapia fish fillets.
In current work a new bionanocomposite based on carboxymethyl cellulose, Arabic gum and gelatin, incorporating garlic extract and TiO
2
nanoparticles as an edible coating for preserving the fresh Nile tilapia fish fillets during cold storage.
Mountain areas in the southern western corner of the Kingdom of Saudi Arabia (KSA) frequently suffer from various types of landsides induced by rainstorms and anthropogenic activities. To mitigate ...these problems, landslide susceptibility mapping and classification is important to develop quick and safe mitigation or remediation measures and to help the decision making in future planning by identifying the most vulnerable areas. This paper summarizes the findings of a landslide susceptibility analysis in the Ar-Rayth area, Jizan, KSA, using an analytical hierarchy process (AHP), frequency ratio (FR), and logistic regression (LR) models with the aid of GIS tools and remote sensing data. The landslide inventory map was prepared according to historical data, interpretation of high-resolution satellite images (Geo-Eye 0.5 m resolution and QuickBird 0.6 m resolution), topographic maps (1:10,000), and verified by field investigations. An inventory map with 253 landslides locations was extracted from many sources. The landslide inventory was randomly divided into two datasets: 75 % for training the models and 25 % for validation. An enhanced thematic mapper plus 15 m satellite image acquired in 2006 was used for determining the Normalized Difference Vegetation Index. A contour map (1:10,000 with a 10 m contour interval) was converted to digital elevation model 10 m resolution and subsequently converted to slope, slope aspect, curvature, elevation, and drainage networks. Geological data obtained with the help of satellite images were used to prepare lithological units and lineaments. Roads were digitized from the high-resolution image and a rainfall map was prepared from the rainfall gauges distributed throughout the study area. All these data were used to construct a spatial database using GIS and image processing. Three landslide susceptibility maps were constructed; one on the basis of a heuristic method using an AHP, the other two on the basis of landslide inventories and causative factors, using FR and LR. Furthermore, each causative factor’s weight was determined according to these three models and landslide susceptibility indices were calculated. For verification, receiver operating characteristic curves were calculated and the areas under the curve (AUC) for success rate are 0.755, 0.828, and 0.749 and for prediction rate are 0.708, 0.781, and 0.727 for the AHP, FR, and LR, respectively. In addition, the percentage of existing training landslides data in high and very high zones of the susceptibility maps is of 73.2, 85.31, and 88.59 % and for the validation landslides data is 73.2, 85.31, and 88.59 % for the AHP, FR, and LR, respectively. The findings indicated that the values of AUC are above 0.7 for both success and prediction rate which indicate these three models are suitable for susceptibility analysis. Also, percent of training and validation landslides data of high and very high zones indicate that LR model is more accurate followed by FR model and AHP model.
► In this study we prepare Ag nanoparticles by novel method as antibacterial additive. ► Prepared Ag nanoparticles characterize by using XRD, UV and TEM. ► Ag nanoparticles impregnated into PS ...solution and coated carton by different ratio. ► We find that the coated carton shows good antibacterial and mechanical properties.
Polymer nanocomposites and paper constitute a new class of packaging materials. In this study silver nanoparticles were prepared by novel method as antibacterial additive, where, synthetic takes place with aid of a novel, non-toxic, and eco-friendly biological materials namely rice straw (RS) powder. The prepared Ag nanoparticle was examined by transmission electron microscope (TEM), X-ray diffraction pattern (XRD) and UV-spectroscopy. The silver nanoparticles were then embedded into commercial polystyrene solution. The recycled carton paper was coated by the polystyrene nanocomposites containing different concentration of silver nanoparticles, namely 2, 4, 6 and 8% based on polystyrene. The prepared recycled carton sheets were characterized by scanning electron microscope (SEM). The mechanical properties, water vapor permeability and antibacterial effect of recycled carton sheets were also investigated.
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