In the present study, a new technique of utilizing nanofluid as a secondary fluid in a secondary loop of refrigeration system is examined. This secondary loop serves for providing cooling in specific ...applications such as walk-in coolers and freezers. The secondary loop is obtained across the evaporator section wherein the refrigerant R134a extracted heat from the nanofluid. The evaporator here is classified as shell and coil heat exchanger where nanofluid flowed in the shell side and refrigerant flowed in the coil. A compressor, expansion valve and water cooled condenser are the major integral parts of the system. Experiments were conducted for various volume concentrations of Al2O3 nanofluid (0-15%), mass flow rates (40-80 g/s) and nanofluid inlet temperatures (30-40 °C). The modified system exhibited superior performance when Al2O3 nanofluid was employed in the secondary loop as compared to base fluid (distilled water) while operating at the same mass flow rate and inlet temperature. A maximum COP of 6.5 was achieved for nanofluid inlet temperature 40 C at mass flow rate 80 g/s and volume concentration 15%. The enhancement in refrigeration effect and coefficient of performance is attributed to micro conduction effect due to the rise in thermal conductivity of nanofluid as compared to distilled water.
Fungal contamination of food and animal feed, especially by mycotoxigenic fungi, is not only a global food quality concern for food manufacturers, but it also poses serious health concerns because of ...the production of a variety of mycotoxins, some of which present considerable food safety challenges. In today's mega‐scale food and feed productions, which involve a number of processing steps and the use of a variety of ingredients, fungal contamination is regarded as unavoidable, even good manufacturing practices are followed. Chemical preservatives, to some extent, are successful in retarding microbial growth and achieving considerably longer shelf‐life. However, the increasing demand for clean label products requires manufacturers to find natural alternatives to replace chemically derived ingredients to guarantee the clean label. Lactic acid bacteria (LAB), with the status generally recognized as safe (GRAS), are apprehended as an apt choice to be used as natural preservatives in food and animal feed to control fungal growth and subsequent mycotoxin production. LAB species produce a vast spectrum of antifungal metabolites to inhibit fungal growth; and also have the capacity to adsorb, degrade, or detoxify fungal mycotoxins including ochratoxins, aflatoxins, and Fusarium toxins. The potential of many LAB species to circumvent spoilage associated with fungi has been exploited in a variety of human food and animal feed stuff. This review provides the most recent updates on the ability of LAB to serve as antifungal and anti‐mycotoxigenic agents. In addition, some recent trends of the use of LAB as biopreservative agents against fungal growth and mycotoxin production are highlighted.
The motive of the current analysis is to examine the role of gyrotactic microorganisms to reveal their behaviour in heat and mass transfer in time-dependent MHD flow of Cross fluid accounted through ...nanoparticles. Non-linear thermal radiative, viscous dissipation, Soret and Dufour effect are also scrutinised with constraining conditions. By applying the suitable alteration the system of PDEs is transmuted into ODEs. The transmuted ODE's are utilised through RK-4 along with shooting techniques. Moreover, the impact of various emerging variables on the velocity, temperature, concentration and density of motile microorganisms are deliberated numerical and graphical. The outcomes are presented through plots and tables. Further, the outcomes illustrated that enhancements in the value of Weissenberg number We result in a reduction in motile density microorganism while the opposite effect is examined in the velocity slip effect. In addition, an intensifying microorganism profile is observed with velocity slip effect, Peclet number. Comparisons have been prepared with previously published literature and found an outstanding agreement.
The past two decades have witnessed a global surge in the application of probiotics as functional ingredients in food, animal feed, and pharmaceutical products. Among food industries, the dairy ...industry is the largest sector where probiotics are employed in a number of dairy products including sour/fermented milk, yogurt, cheese, butter/cream, ice cream, and infant formula. These probiotics are either used as starter culture alone or in combination with traditional starters, or incorporated into dairy products following fermentation, where their presence imparts many functional characteristics to the product (for instance, improved aroma, taste, and textural characteristics), in addition to conferring many health‐promoting properties. However, there are still many challenges related to the stability and functionality of probiotics in dairy products. This review highlights the advances, opportunities, and challenges of application of probiotics in dairy industries. Benefits imparted by probiotics to dairy products including their role in physicochemical characteristics and nutritional properties (clinical and functional perspective) are also discussed. We transcend the traditional concept of the application of probiotics in dairy products and discuss paraprobiotics and postbiotics as a newly emerged concept in the field of probiotics in a particular relation to the dairy industry. Some potential applications of paraprobiotics and postbiotics in dairy products as functional ingredients for the development of functional dairy products with health‐promoting properties are briefly elucidated.
This paper presents a novel idea of utilizing nanofluid as external cooling jacket around the condenser of an air conditioner. Experimental investigations were carried out to study the influence of ...two types of nanofluids namely, copper and aluminum oxide nanofluids on the performance of an air conditioner. The nanofluids were used to enhance the heat transfer by means of providing an external nanofluid medium around the condenser section. Both Cu and Al2O3 nanofluids were prepared in three volume fractions of 1%, 2% and 5% with water as the base fluid. The performance of the air conditioner was evaluated by comparing the coefficient of performance when the system is operated with and without nanofluid. Experimental results indicate that employment of Cu and Al2O3 nanofluids causes a significant enhancement in the COP. As the volume fraction was increased, the performance was found to increase. For the highest volume fraction of 5%, Al2O3 nanofluid was found to enhance the COP by a maximum of 22.1% while copper nanofluid exhibited a more significant enhancement by 29.4%.
Having access to accurate and recent
of infrastructure assets benefits the renovation, maintenance, condition monitoring, and construction planning of infrastructural projects. There are many cases ...where such a digital twin does not yet exist, such as for legacy structures. In order to create such a digital twin, a mobile laser scanner can be used to capture the geometric representation of the structure. With the aid of
, the scene can be decomposed into different object classes. This decomposition can then be used to retrieve cad models from a cad library to create an accurate digital twin. This study explores three deep-learning-based models for semantic segmentation of point clouds in a practical real-world setting: PointNet++, SuperPoint Graph, and Point Transformer. This study focuses on the use case of catenary arches of the Dutch railway system in collaboration with Strukton Rail, a major contractor for rail projects. A challenging, varied, high-resolution, and annotated dataset for evaluating point cloud segmentation models in railway settings is presented. The dataset contains 14 individually labelled classes and is the first of its kind to be made publicly available. A modified PointNet++ model achieved the best mean class Intersection over Union (IoU) of 71% for the semantic segmentation task on this new, diverse, and challenging dataset.
Abstract
The microbial world represents a phenomenal diversity of microorganisms from different kingdoms of life, which occupy an impressive set of ecological niches. Most, if not all, microorganisms ...once colonize a surface develop architecturally complex surface-adhered communities, which we refer to as biofilms. They are embedded in polymeric structural scaffolds and serve as a dynamic milieu for intercellular communication through physical and chemical signalling. Deciphering microbial ecology of biofilms in various natural or engineered settings has revealed coexistence of microorganisms from all domains of life, including Bacteria, Archaea, and Eukarya. The coexistence of these dynamic microbes is not arbitrary, as a highly coordinated architectural setup and physiological complexity show ecological interdependence and myriads of underlying interactions. In this review, we describe how species from different kingdoms interact in biofilms and discuss the functional consequences of such interactions. We highlight metabolic advances of collaboration among species from different kingdoms, and advocate that these interactions are of great importance and need to be addressed in future research. Since trans-kingdom biofilms impact diverse contexts, ranging from complicated infections to efficient growth of plants, future knowledge within this field will be beneficial for medical microbiology, biotechnology, and our general understanding of microbial life in nature.
Most of the biofilms that abound in nature are comprised of members from different kingdoms of life (Bacteria, Archaea, and Eukarya) which interact with each other and shape the community-level functions and resilience. The authors have provided mechanistic insights into various transkingdom interactions that prevail in these biofilms, including interactions between viruses and bacterial biofilms.
The use of sourdough as a leavening agent in bread making is a very old method that can be traced back to ancient times. Sourdoughs harbor a complex microbiota that is affected by multiple factors ...including factors related to cereal plants, grains, and sourdough processing techniques. Lactobacillus sanfranciscensis is the key autochthonous bacterium of the traditional sourdough microbiota and it is said to be “sourdough adapted” species. Despite the great dominance of this bacterium in sourdoughs, the origin of this species still remains unclear. Lactobacillus sanfranciscensis positively influences all aspects of sourdough and fermented foods. However, the positive influence of this species on sourdough is a strain‐dependent characteristic. The first purpose of this review was to discuss factors affecting the microbiota of sourdoughs with particular emphasis on reasons behind the remarkable prevalence of L. sanfranciscensis in this ecological niche. The second objective was to discuss the genotypic and phenotypic classification of L. sanfranciscensis strains and the influence of this species on technological and functional characteristics of sourdough including its influence on rheological properties of dough and bread characteristics, texture, aroma, and shelf‐life through the inhibition of fungal growth.
Kefir milk, known for its high nutritional value and health benefits, is traditionally produced by fermenting milk with kefir grains. These grains are a complex symbiotic community of lactic acid ...bacteria, acetic acid bacteria, yeasts, and other microorganisms. However, the intricate coexistence mechanisms within these microbial colonies remain a mystery, posing challenges in predicting their biological and functional traits. This uncertainty often leads to variability in kefir milk's quality and safety. This review delves into the unique structural characteristics of kefir grains, particularly their distinctive hollow structure. We propose hypotheses on their formation, which appears to be influenced by the aggregation behaviors of the community members and their alliances. In kefir milk, a systematic colonization process is driven by metabolite release, orchestrating the spatiotemporal rearrangement of ecological niches. We place special emphasis on the dynamic spatiotemporal changes within the kefir microbial community. Spatially, we observe variations in species morphology and distribution across different locations within the grain structure. Temporally, the review highlights the succession patterns of the microbial community, shedding light on their evolving interactions.Furthermore, we explore the ecological mechanisms underpinning the formation of a stable community composition. The interplay of cooperative and competitive species within these microorganisms ensures a dynamic balance, contributing to the community's richness and stability. In kefir community, competitive species foster diversity and stability, whereas cooperative species bolster mutualistic symbiosis. By deepening our understanding of the behaviors of these complex microbial communities, we can pave the way for future advancements in the development and diversification of starter cultures for food fermentation processes.
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•The complexation of SLP with mannan was predicted by molecular docking and molecular dynamics simulation.•The quenching mechanism of mannan to SLP belonged to static with ...high-affinity.•The interaction between mannan and SLP was mainly driven by Hydrophobic forces.•Mannan induced conformational changes of SLP structure.•The SLP-mannan complex was stable and compact.
Tibet kefir grain (TKG) formation is mainly dependent on the aggregation of lactobacillus and yeasts. The interaction of surface layer protein (SLP) and yeast mannan plays an important role in mediating the co-aggregation of Lactobacillus kefiri with Saccharomyces cerevisiae. The interaction mechanism of the two was researched through multispectral spectroscopy, morphology observation and silico approaches. Fluorescence spectra data revealed that mannan was bound to SLP through a spontaneous binding process. The particle size of the binding complex increased as the mannan concentration increased. Synchronous fluorescence spectroscopy and circular dichroism (CD) spectra showed the conformational and microenvironment alteration of SLP treated with mannan. Molecular docking results indicated that hydrophobic interactions played major roles in the formation of SLP-mannan complexes. These findings provide a deeper insight into the interactions of protein and polysaccharide, and this knowledge is valuable in the application of SLP and mannan in co-fermentation systems.
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