State-of-art review on hybrid nanofluids Ranga Babu, J.A.; Kumar, K. Kiran; Srinivasa Rao, S.
Renewable & sustainable energy reviews,
09/2017, Letnik:
77
Journal Article
Recenzirano
Nanofluids have found crucial presence in heat transfer applications with their promising characteristics that can be controlled as per requirements. Nanofluids possess unique characteristics that ...have attracted many researchers over the past two decades to design new thermal systems for different engineering applications. Mono nanofluids, prepared with a single kind of nanoparticles, possess certain specific benefits owing to the properties of the suspended nanoparticle. However to further improve the characteristics of nanofluids, that could possess a number of favourable characteristics, researchers developed a new generation heat transfer fluid called hybrid nanofluid. Hybrid nanofluids are prepared either by dispersing dissimilar nanoparticles as individual constituents or by dispersing nanocomposite particles in the base fluid. Hybrid nanofluids may possess better thermal network and rheological properties due to synergistic effect. Researchers, to adjudge the advantages, disadvantages and their suitability for diversified applications, are extensively investigating the behavior and properties of these hybrid nanofluids. This review summarizes the contemporary investigations on synthesis, thermo-physical properties, heat transfer characteristics, hydrodynamic behavior and fluid flow characteristics reported by researchers on different hybrid nanofluids. This review also outlines the applications and challenges associated with hybrid nanofluid and makes some suggestions for future scope of research in this area.
•Synthesis methods of hybrid nanocomposites are presented.•Correlations for thermophysical properties of mono nanofluids and hybrid nanofluids are thoroughly discussed.•Heat transfer and rheological characteristics of various hybrid nanofluids are intensively and comprehensively analyzed.•Applications and challenges of hybrid nanofluids are explored.
Biosensors are analytical devices having high sensitivity, portability, small sample requirement and ease of use for qualitative and quantitative monitoring of various analytes of human importance. ...Arsenic (As), owing to its widespread presence in nature and high toxicity to living creatures, requires frequent determination in water, soil, agricultural and food samples. The present review is an effort to highlight the various advancements made so far in the development of arsenic biosensors based either on recombinant whole cells or on certain arsenic-binding oligonucleotides or proteins. The role of futuristic approaches like surface plasmon resonance (SPR) and aptamer technology has also been discussed. The biomethods employed and their general mechanisms, advantages and limitations in relevance to arsenic biosensors developed so far are intended to be discussed in this review.
•The present review provides an extensive and up-to-date findings on arsenic biosensors, with an emphasis on their arsenic sensing mechanism.•The arsenic biosensors has been divided into whole-cell and cell-free biosensors and further sub-divided on the basis of their biological components employed.•The detection limits, response time and limitations of the arsenic biosensors reported so far have been compiled.•Comprehensive coverage of arsenic biosensor using nanotechnology based sensing approaches and techniques including SPR.
In contrast to apoptosis and autophagy, necrotic cell death was considered to be a random, passive cell death without definable mediators. However, this dogma has been challenged by recent ...developments suggesting that necrotic cell death can also be a regulated process. Regulated necrosis includes multiple cell death modalities such as necroptosis, parthanatos, ferroptosis, pyroptosis, and mitochondrial permeability transition pore (MPTP)-mediated necrosis. Several distinctive executive molecules, particularly residing on the mitochondrial inner and outer membrane, amalgamating to form the MPTP have been defined. The c-subunit of the F1F0ATP synthase on the inner membrane and Bax/Bak on the outer membrane are considered to be the long sought components that form the MPTP. Opening of the MPTP results in loss of mitochondrial inner membrane potential, disruption of ATP production, increased ROS production, organelle swelling, mitochondrial dysfunction and consequent necrosis. Cyclophilin D, along with adenine nucleotide translocator and the phosphate carrier are considered to be important regulators involved in the opening of MPTP. Increased production of ROS can further trigger other necrotic pathways mediated through molecules such as PARP1, leading to irreversible cell damage. This review examines the roles of PARP1 and cyclophilin D in necrotic cell death. The hierarchical role of p53 in regulation and integration of key components of signaling pathway to elicit MPTP-mediated necrosis and ferroptosis is explored. In the context of recent insights, the indistinct role of necroptosis signaling in tubular necrosis after ischemic kidney injury is scrutinized. We conclude by discussing the participation of p53, PARP1 and cyclophilin D and their overlapping pathways to elicit MPTP-mediated necrosis and ferroptosis in acute kidney injury.
Control of lipid droplet (LD) nucleation and copy number are critical, yet poorly understood, processes. We use model peptides that shift from the endoplasmic reticulum (ER) to LDs in response to ...fatty acids to characterize the initial steps of LD formation occurring in lipid-starved cells. Initially, arriving lipids are rapidly packed in LDs that are resistant to starvation (pre-LDs). Pre-LDs are restricted ER microdomains with a stable core of neutral lipids. Subsequently, a first round of "emerging" LDs is nucleated, providing additional lipid storage capacity. Finally, in proportion to lipid concentration, new rounds of LDs progressively assemble. Confocal microscopy and electron tomography suggest that emerging LDs are nucleated in a limited number of ER microdomains after a synchronized stepwise process of protein gathering, lipid packaging, and recognition by Plin3 and Plin2. A comparative analysis demonstrates that the acyl-CoA synthetase 3 is recruited early to the assembly sites, where it is required for efficient LD nucleation and lipid storage.
Lipid droplets (LDs) are intracellular organelles that provide fatty acids (FAs) to cellular processes including synthesis of membranes and production of metabolic energy. While known to move ...bidirectionally along microtubules (MTs), the role of LD motion and whether it facilitates interaction with other organelles are unclear. Here we show that during nutrient starvation, LDs and mitochondria relocate on detyrosinated MT from the cell centre to adopt a dispersed distribution. In the cell periphery, LD-mitochondria interactions increase and LDs efficiently supply FAs for mitochondrial beta-oxidation. This cellular adaptation requires the activation of the energy sensor AMPK, which in response to starvation simultaneously increases LD motion, reorganizes the network of detyrosinated MTs and activates mitochondria. In conclusion, we describe the existence of a specialized cellular network connecting the cellular energetic status and MT dynamics to coordinate the functioning of LDs and mitochondria during nutrient scarcity.
The involvement of cell death in acute kidney injury (AKI) is linked to multiple factors including energy depletion, electrolyte imbalance, reactive oxygen species, inflammation, mitochondrial ...dysfunction, and activation of several cell death pathway components. Since our review in 2003, discussing the relative contributions of apoptosis and necrosis, several other forms of cell death have been identified and are shown to contribute to AKI. Currently, these various forms of cell death can be fundamentally divided into accidental cell death and regulated or programmed cell death based on functional aspects. Several death initiator and effector molecules switch molecules that may act as signaling components triggering either death or protective mechanisms or alternate cell death pathways have been identified as part of the machinery. Intriguingly, several of these cell death pathways share components and signaling pathways suggesting complementary or compensatory functions. Thus, defining the cross talk between distinct cell death pathways and identifying the unique molecular effectors for each type of cell death may be required to develop novel strategies to prevent cell death. Furthermore, depending on the multiple forms of cell death simultaneously induced in different AKI settings, strategies for combination therapies that block multiple cell death pathways need to be developed to completely prevent injury, cell death, and renal function. This review highlights the various cell death pathways, cross talk, and interactions between different cell death modalities in AKI.
Signals that drive interstitial fibrogenesis after renal ischemia reperfusion injury remain undefined. Sympathetic activation manifests even in the early clinical stages of chronic kidney disease and ...is directly related to disease severity. A role for renal nerves in renal interstitial fibrogenesis in the setting of ischemia reperfusion injury has not been studied. In male 129S1/SvImJ mice, ischemia reperfusion injury induced tubulointerstitial fibrosis as indicated by collagen deposition and profibrotic protein expression 4 to 16 days after the injury. Leukocyte influx, proinflammatory protein expression, oxidative stress, apoptosis, and cell cycle arrest at G2/M phase were enhanced after ischemia reperfusion injury. Renal denervation at the time of injury or up to 1 day post injury improved histology, decreased proinflammatory/profibrotic responses and apoptosis, and prevented G2/M cell cycle arrest in the kidney. Treatment with afferent nerve-derived calcitonin gene-related peptide (CGRP) or efferent nerve-derived norepinephrine in denervated and ischemia reperfusion injury-induced kidneys mimicked innervation, restored inflammation and fibrosis, induced G2/M arrest, and enhanced TGF-β1 activation. Blocking norepinephrine or CGRP function using respective receptor blockers prevented these effects. Consistent with the in vivo study, treatment with either norepinephrine or CGRP induced G2/M cell cycle arrest in HK-2 proximal tubule cells, whereas antagonists against their respective receptors prevented G2/M arrest. Thus, renal nerve stimulation is a primary mechanism and renal nerve-derived factors drive epithelial cell cycle arrest and the inflammatory cascade causing interstitial fibrogenesis after ischemia reperfusion injury.
On 4th December 2020, a sudden outbreak, with neurological symptoms like seizures, loss of consciousness etc., was reported in a town from south India. By 3rd day about 400 people were involved. A ...multi disciplinary team from our institute visited the site to investigate the outbreak. Based on the case history and clinical examination of the patients, the team suspected a probable diagnosis of an acute pesticide, heavy metal and/or mycotoxin exposure for which, biological samples (blood, urine) were collected from those who reported the symptoms as well as from a few who did not report symptoms (controls). To identify the source, water and food samples were collected. The samples were subjected to ICP-MS for heavy metal analysis, LC-MS/MS for pesticide analysis, microbiological analysis and ELISA-Kit method for aflatoxins if any. Clinical and dietary details were collected from a total of 112 participants, of which, 103 cases (77 active cases at Hospital and 26 recovered cases from community) and 9 were controls. A total of 109 biological samples, 36 water samples and food samples were collected. The mean age of the study participants was 29.2 years. Among cases, Seizures were seen in 84%, loss of consciousness in 66%, mental confusion in 35%, pinpoint pupil in 11%. Triazophos (organophosphate) pesticide was present in 74% of Blood samples and its metabolites were present in 98% of the urine samples collected from the cases. All the ten heavy metals investigated including lead, mercury and nickel were found to be within permissible limits except for a few samples. No presence of mycotoxins was observed in Food samples. Water samples which included Head pump and reservoir were free from pesticides; however, all water samples from households of cases had triazophos pesticide with a mean concentration of 1.00 ug/L. Thus, it was concluded that, the probable cause of outbreak was Triazophos (Organophosphate) pesticide contamination in water at the Household level. Regular surveillance for the presence of residual pesticides in soil, water and food with heightened vigour is recommended to prevent future outbreaks.
This paper introduces a novel hybrid formulation of a peridynamics-based machine learning model for thermal diffusion analysis in one-dimensional and two-dimensional problems with evolving ...discontinuities. The hybrid model employs a multivariate linear regression approach to establish the relationship between the temperature values of material points, their neighboring points, and the applied external heat flux. The thermal modal analysis method uses the finite element method to generate training and testing data. An efficient numerical procedure is also developed to couple the peridynamics model and the peridynamics-based machine learning model. The model is analyzed under multiple configurations of micro-thermal conductivity functions for one-dimensional thermal bar problems, under both steady-state and transient loading conditions, to identify the configuration that exhibits superior convergence behavior towards the local solution. Furthermore, benchmark problems demonstrate the high accuracy of the formulated hybrid model, including the analysis of thermal plates with discontinuities, such as a plate with a hole, a plate with a pre-existing insulated crack, and plate with a bi-material interface with stationary and evolving discontinuances. The hybrid model effectively captures intricate discontinuities and boundaries while being computationally efficient, indicating its potential for thermal diffusion analysis in one- and two-dimensional problems with stationary and evolving discontinuities.
•The peridynamics-based machine learning model is proposed for diffusion problems.•An efficient scheme is proposed to couple peridynamics and machine learning models.•Machine learning data is generated using modal analysis for different thermal conditions.•The efficiency and robustness of the model is demonstrated through numerical examples.•The model is straightforward to extend to diffusion problems associated with pitting corrosion.
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