scholarly journals Research of the rheological properties of water variances of polysaccharides

2021 ◽  
Vol 2 (3(58)) ◽  
pp. 40-43
Author(s):  
Oksana Tochkova ◽  
Inna Gagan ◽  
Oksana Мelnyk
Keyword(s):  
Structural Relaxation ◽  
Food System ◽  
Physicochemical Characteristic ◽  
Physicochemical Characteristics ◽  
Mutual Arrangement ◽  
Shear Stresses ◽  
Spatial Network ◽  
Ordered Structure ◽  
Aqueous Dispersions ◽  
Wide Range

The object of research is aqueous dispersions of polysaccharides. One of the most problematic factors is the insufficient study and study of the physicochemical properties of polysaccharides, in particular starch. Among natural polysaccharides, starch occupies a unique position. It has a wide range of applications across many industries and technologies. This is what determines a large number of studies of the state of starch of various botanical origin under the action of various factors that have appeared in the literature recently. Natural polysaccharides, in contrast to synthetic ones, are characterized by a partial ordered structure, formed in the process of synthesis and growth. In the course of the study, a new method of relaxation in starch mixtures was proposed. It was found that structural relaxation in time is slow and long. It was also found that the physicochemical characteristic of polysaccharides, relaxation, is explained by a partially ordered structure with the mutual arrangement of individual chains in a spatial network. It was shown that, under the action of shear stresses, the retest destroys the pseudoplastic liquid structures of aqueous dispersions of starch, followed by restoration to an equilibrium state within 17 hours. The process of recovery or structural relaxation of the spatial structures of aqueous dispersions of polysaccharides occurs due to the rearrangement of the spatial network of the polymer and is formed due to the existence of cross-linked chemical bonds. Thanks to this method of using polysaccharides, it is possible to obtain improved organoleptic, structural, mechanical and physicochemical characteristics of food products. Compared to similar thickeners (pectin, flour), native potato and corn starches provide and provide structural form to products such as sauces, puddings, pastries, minced meat, fish products, and low fat dairy products. In the food system, the role of polysaccharides is to stabilize structure and interact with other components to deliver or maintain nutrients and taste.

Pharmaceutical Co-Crystals - Design, Development and Applications

2020 ◽  
Vol 10 (3) ◽  
pp. 169-184
Author(s):  
Rachna Anand ◽  
Arun Kumar ◽  
Arun Nanda
Keyword(s):  
Physicochemical Properties ◽  
Crystal Engineering ◽  
Pharmacological Action ◽  
Physicochemical Characteristics ◽  
Research Area ◽  
Dissolution Profile ◽  
Design Development ◽  
Drug Molecule ◽  
Wide Range ◽  
Major Factors

Background: Solubility and dissolution profile are the major factors which directly affect the biological activity of a drug and these factors are governed by the physicochemical properties of the drug. Crystal engineering is a newer and promising approach to improve physicochemical characteristics of a drug without any change in its pharmacological action through a selection of a wide range of easily available crystal formers. Objective: The goal of this review is to summarize the importance of crystal engineering in improving the physicochemical properties of a drug, methods of design, development, and applications of cocrystals along with future trends in research of pharmaceutical co-crystals. Co-crystallization can also be carried out for the molecules which lack ionizable functional groups, unlike salts which require ionizable groups. Conclusion: Co-crystals is an interesting and promising research area amongst pharmaceutical scientists to fine-tune the physicochemical properties of drug materials. Co-crystallization can be a tool to increase the lifecycle of an older drug molecule. Crystal engineering carries the potential of being an advantageous technique than any other approach used in the pharmaceutical industry. Crystal engineering offers a plethora of biopharmaceutical and physicochemical enhancements to a drug molecule without the need of any pharmacological change in the drug.

2D and 3D CFD Investigations of Seabed Shear Stresses Around Subsea Pipelines

2013 ◽  
Author(s):  
Wenwen Shen ◽  
Terry Griffiths ◽  
Mengmeng Xu ◽  
Jeremy Leggoe
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Interaction Model ◽  
Suspended Sediment Transport ◽  
Shear Stresses ◽  
Parametric Function ◽  
Ample Evidence ◽  
North West ◽  
Wide Range ◽  
Subsea Pipelines

For well over a decade it has been widely recognised that existing models and tools for subsea pipeline stability design fail to account for the fact that seabed soils tend to become mobile well before the onset of pipeline instability. Despite ample evidence obtained from both laboratory and field observations that sediment mobility has a key role to play in understanding pipeline/soil interaction, no models have been presented previously which account for the tripartite interaction between the fluid and the pipe, the fluid and the soil, and the pipe and the soil. There are numerous well developed and widely used theories available to model pipe-fluid and pipe-soil interactions. A challenge lies in the way to develop a satisfactory fluid-soil interaction algorithm that has the potential for broad implementation under both ambient and extreme sea conditions due to the complexity of flow in the vicinity of a seabed pipeline or cable. A widely used relationship by Shields [1] links the bedload and suspended sediment transport to the seabed shear stresses. This paper presents details of computational fluid dynamics (CFD) research which has been undertaken to investigate the variation of seabed shear stresses around subsea pipelines as a parametric function of pipeline spanning/embedment, trench configuration and wave/current properties using the commercial RANS-based software ANSYS Fluent. The modelling work has been undertaken for a wide range of seabed geometries, including cases in 3D to evaluate the effects of finite span length, span depth and flow attack angle on shear stresses. These seabed shear stresses have been analysed and used as the basis for predicting sediment transport within the Pipe-Soil-Fluid (PSF) Interaction Model [2] in determining the suspended sediment concentration and the advection velocity in the vicinity of pipelines. The model has significant potential to be of use to operators who struggle with conventional stabilisation techniques for the pipelines, such as those which cross Australia’s North West Shelf, where shallow water depths, highly variable calcareous soils and extreme metocean conditions driven by frequent tropical cyclones result in the requirement for expensive and logistically challenging secondary stabilisation measures.

scholarly journals Blocking of Bacterial Biofilm Formation by a Fish Protein Coating

2008 ◽  
Vol 74 (11) ◽  
pp. 3551-3558 ◽  
Author(s):  
Rebecca Munk Vejborg ◽  
Per Klemm
Keyword(s):  
Biofilm Formation ◽  
Fish Muscle ◽  
Physicochemical Characteristics ◽  
Economic Problem ◽  
Bacterial Attachment ◽  
Bacterial Biofilm ◽  
Adhesive Properties ◽  
Muscle Extract ◽  
Wide Range ◽  
Inert Surfaces

ABSTRACT Bacterial biofilm formation on inert surfaces is a significant health and economic problem in a wide range of environmental, industrial, and medical areas. Bacterial adhesion is generally a prerequisite for this colonization process and, thus, represents an attractive target for the development of biofilm-preventive measures. We have previously found that the preconditioning of several different inert materials with an aqueous fish muscle extract, composed primarily of fish muscle α-tropomyosin, significantly discourages bacterial attachment and adhesion to these surfaces. Here, this proteinaceous coating is characterized with regards to its biofilm-reducing properties by using a range of urinary tract infectious isolates with various pathogenic and adhesive properties. The antiadhesive coating significantly reduced or delayed biofilm formation by all these isolates under every condition examined. The biofilm-reducing activity did, however, vary depending on the substratum physicochemical characteristics and the environmental conditions studied. These data illustrate the importance of protein conditioning layers with respect to bacterial biofilm formation and suggest that antiadhesive proteins may offer an attractive measure for reducing or delaying biofilm-associated infections.

scholarly journals Novel Affordable, Reliable and Efficient Technologies to Help Addressing the Water-Energy-Food Nexus

2019 ◽  
Vol 8 (4) ◽  
pp. 1 ◽  
Author(s):  
Francesco Meneguzzo ◽  
Federica Zabini ◽  
Lorenzo Albanese ◽  
Alfonso Crisci
Keyword(s):  
Food System ◽  
Raw Materials ◽  
Sustainable Consumption ◽  
Processing Parameters ◽  
Hydrodynamic Cavitation ◽  
Strong Basis ◽  
Global Challenge ◽  
Wide Range ◽  
System Sustainability ◽  
Experimental Trials

Improving the food system sustainability and security is becoming an urgent global challenge. In this regard, one of the most effective routes is the shift of the human diet toward healthier and more sustainable consumption, involving in particular the prevalence of plant-based raw food materials. Controlled hydrodynamic cavitation (HC) technologies could help considerably in this transition. HC techniques are gaining increased scientific interest, and are quickly spreading across a wide range of technical fields, recently showing surprising performances with biological raw materials related to the food, agricultural and forestry sectors and resources. HC processes enjoy recognized advantages in the acceleration of the processing steps of plant-based food, the extraction of valuable bioactive compounds, the reduction and the valorization of waste streams, as well as the superior efficiency in resource use, energy consumption, process yield, and exergy balance than competing processes. Thus, HC is very promising candidate to help addressing the water-energy-food nexus, and, ultimately, sustainability. Findings obtained from direct experimental trials and recent literature concerning the applications of HC to food processing, provide a strong basis for novel investigation aimed at standardization, starting from the identification of the most suitable devices and the optimal processing parameters, eventually oriented to further spreading of HC applications.

scholarly journals A Review on The Physical, Milling Quality and Physicochemical Characteristic of Hipa 6 Jete and Hipa 7

2020 ◽  
Vol 16 (2) ◽  
pp. 25
Author(s):  
Shinta Dewi Ardhiyanti ◽  
Siti Dewi Indrasari
Keyword(s):  
First Generation ◽  
Hybrid Rice ◽  
Amylose Content ◽  
Physicochemical Characteristic ◽  
Physicochemical Characteristics ◽  
Yield Potential ◽  
Physical Quality ◽  
Rice Quality ◽  
Milling Quality ◽  
Head Rice

Up to now the Agriculture Ministry of Republic of Indonesia has released 19 varieties of hybrid rice. Hipa 6 Jete and Hipa 7 varieties are two of them. Hybrid rice is a group of rice plants formed from first generation individuals (F1) derivative of a combination of crossing between certain elders. Hybrid rice superior varieties has a higher yield potential than inbred superior varieties that dominate rice cultivation areas. Rice quality is one of the factors that determine the level of consumer acceptance of a variety. The rice quality is influenced by several factors such as physical quality, cooking quality and taste quality. This paper aims to review the physical quality, milling quality and physical properties of Hipa 6 Jete and Hipa 7. The length of Hipa 6 Jete and Hipa 7 are long and the shape are slender. Based on the head rice and broken rice percentage both Hipa 6 Jete and Hipa 7 are met the medium 2 and 3 quality class (SNI 6128:2015). Based on the physicochemical characteristics both Hipa 6 Jete and Hipa 7 are classified as intermediate amylose content with soft gel consistency and with high intermediate gelatinization temperature. In cooling condition the cooked rice of Hipa 6 Jete and Hipa 7 are soft texture.

Responses of Percid Fishes and Their Habitats to Eutrophication

1977 ◽  
Vol 34 (10) ◽  
pp. 1964-1971 ◽  
Author(s):  
J. H. Leach ◽  
M. G. Johnson ◽  
J. R. M. Kelso ◽  
J. Hartmann ◽  
W. Nümann ◽  
...  
Keyword(s):  
Physicochemical Characteristics ◽  
Habitat Modification ◽  
Trophic Conditions ◽  
Relative Level ◽  
Cultural Eutrophication ◽  
Fish Yield ◽  
Species Dominance ◽  
Wide Range ◽  
Selective Mechanism ◽  
The Continuum

Percid fishes are found in lakes that cover a wide range of trophic conditions. The responses of percids and their habitats to progressive cultural eutrophication are predictable. Alterations in physicochemical characteristics of habitats precipitate changes in phytoplankton, macrophytes, zooplankton, and benthos that are ultimately deleterious. Enrichment can lead to favorable responses in percids, but somewhere in the continuum of trophic conditions the responses become unfavorable. The relative level at which the response becomes negative varies with the species according to tolerances to altered environment, adaptabilities to new habitat and forage base, and reproductive behavior. Progressive eutrophication acts as a selective mechanism that leads to a predictable sequence of fish species. Other perturbations, such as exploitation and habitat modification, can act synergistically with cultural eutrophication in accelerating the sequence. As eutrophication proceeds, the succession of species may not lead to increased fish yield because part of the nutrient load may be channeled through unharvestable food chains. Key words: Percidae, habitat, eutrophication, species dominance, food habits, parasitism, disease

Cerebral Blood Vessel Rupture During Head Impacts: A Parametric Study on Properties of SAS Trabeculae and Pia Mater

2008 ◽  
Author(s):  
M. Zoghi-Moghadam ◽  
A. Sadegh ◽  
P. Saboori
Keyword(s):  
Mechanical Properties ◽  
Blood Vessels ◽  
Shear Stresses ◽  
Cerebral Blood Vessels ◽  
Pia Mater ◽  
Head Impacts ◽  
Knowing That ◽  
Blunt Impact ◽  
Wide Range ◽  
Brain Interface

Blunt head impacts cause relative motion between the brain and skull. This increases the normal and shear stresses in the (skull/brain) interface region, which leads to the rupture of cerebral blood vessels and in particular bridging veins. Mechanical properties of meningeal layers, in particular, subarachnoid space (SAS) trabeculae and the pia mater are not well established in the literature and could have a wide range depending on an individual. In our previous studies, knowing that SAS trabeculae and pia mater are collagen-based structures, these mechanical properties have been estimated using the properties of similar collagen based tissues. However, recent study Xin Jin et al. (2008), suggests that the mechanical properties of trabeculae and the pia matter are significantly less than a collagen-based tissue. Therefore, the goal of this study is to investigate the effect of the mechanical properties of these tissue on the stress and strain of the neighboring tissues when the head is subjected to a blunt impact. Specifically, the objectives of this study is to determine the stress/strain changes of the cerebral blood vessels as a function of the mechanical properties of the SAS trabeculae and pia mater, when the loading and the boundary conditions of the local model are kept the same. Note that the variation of the properties of these tissues affects the failure of cerebral blood vessels which leads to traumatic brain injury.

scholarly journals CO2 Hydrogenation over Nanoceria-Supported Transition Metal Catalysts: Role of Ceria Morphology (Nanorods versus Nanocubes) and Active Phase Nature (Co versus Cu)

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1739 ◽  
Author(s):  
Michalis Konsolakis ◽  
Maria Lykaki ◽  
Sofia Stefa ◽  
Sόnia A. C. Carabineiro ◽  
Georgios Varvoutis ◽  
...  
Keyword(s):  
Specific Activity ◽  
Active Phase ◽  
Physicochemical Characteristics ◽  
Co2 Hydrogenation ◽  
Transition Metal Catalysts ◽  
Co2 Conversion ◽  
Reverse Water Gas Shift ◽  
Wide Range ◽  
Combined Impact

In this work we report on the combined impact of active phase nature (M: Co or Cu) and ceria nanoparticles support morphology (nanorods (NR) or nanocubes (NC)) on the physicochemical characteristics and CO2 hydrogenation performance of M/CeO2 composites at atmospheric pressure. It was found that CO2 conversion followed the order: Co/CeO2 > Cu/CeO2 > CeO2, independently of the support morphology. Co/CeO2 catalysts demonstrated the highest CO2 conversion (92% at 450 °C), accompanied by 93% CH4 selectivity. On the other hand, Cu/CeO2 samples were very selective for CO production, exhibiting 52% CO2 conversion and 95% CO selectivity at 380 °C. The results obtained in a wide range of H2:CO2 ratios (1–9) and temperatures (200–500 °C) are reaching in both cases the corresponding thermodynamic equilibrium conversions, revealing the superiority of Co- and Cu-based samples in methanation and reverse water-gas shift (rWGS) reactions, respectively. Moreover, samples supported on ceria nanocubes exhibited higher specific activity (µmol CO2·m−2·s−1) compared to samples of rod-like shape, disclosing the significant role of support morphology, besides that of metal nature (Co or Cu). Results are interpreted on the basis of different textural and redox properties of as-prepared samples in conjunction to the different impact of metal entity (Co or Cu) on CO2 hydrogenation process.

scholarly journals Cellulose Nanocrystals/Graphene Hybrids—A Promising New Class of Materials for Advanced Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1523 ◽  
Author(s):  
Djalal Trache ◽  
Vijay Kumar Thakur ◽  
Rabah Boukherroub
Keyword(s):  
Cellulose Nanocrystals ◽  
Renewable Resources ◽  
Food Packaging ◽  
Environmental Concern ◽  
Physicochemical Characteristics ◽  
Great Promise ◽  
New Class ◽  
Wide Range ◽  
Key Features ◽  
Basic Concepts

With the growth of global fossil-based resource consumption and the environmental concern, there is an urgent need to develop sustainable and environmentally friendly materials, which exhibit promising properties and could maintain an acceptable level of performance to substitute the petroleum-based ones. As elite nanomaterials, cellulose nanocrystals (CNC) derived from natural renewable resources, exhibit excellent physicochemical properties, biodegradability and biocompatibility and have attracted tremendous interest nowadays. Their combination with other nanomaterials such as graphene-based materials (GNM) has been revealed to be useful and generated new hybrid materials with fascinating physicochemical characteristics and performances. In this context, the review presented herein describes the quickly growing field of a new emerging generation of CNC/GNM hybrids, with a focus on strategies for their preparation and most relevant achievements. These hybrids showed great promise in a wide range of applications such as separation, energy storage, electronic, optic, biomedical, catalysis and food packaging. Some basic concepts and general background on the preparation of CNC and GNM as well as their key features are provided ahead.

Structural Relaxation of Open Volume in Hyper-Eutectic Zr-Cu-Al Bulk Amorphous Alloys Measured by Positron Annihilation

2017 ◽  
Vol 373 ◽  
pp. 130-133
Author(s):  
Taishi Ishiyama ◽  
Kazukui Kobayashi ◽  
Yoshihiko Yokoyama ◽  
Toyohiko J. Konno ◽  
Akihiro Iwase ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Structural Relaxation ◽  
Amorphous Alloys ◽  
Density Measurement ◽  
High Strength ◽  
Eutectic Alloys ◽  
Ordered Structure ◽  
Compositional Dependence ◽  
Scanning Calorimetry ◽  
Bulk Amorphous Alloys

The Zr-Cu-Al bulk amorphous (BA) alloys, which have no long-range ordered structure, possess various properties such as high strength and toughness with compositional dependence. In the present study, in order to estimate the natures of local structure change and relaxation behavior of hyper-eutectic BA alloys during annealing, positron annihilation measurements and density measurement have been performed for hyper-eutectic Zr-Cu-Al BA alloys with annealing. The enthalpy relaxation and structural relaxation was also measured by differential scanning calorimetry (DSC) measurement. These results show that the relaxation process of free volume containing in hyper-eutectic BA alloys is different from that in hypo-eutectic alloys.

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