Diffraction of light from a long rectangular phase slit.

The phenomenon of light diffraction from an opaque screen containing a long rectangular slit has a closed-form solution in the Fraunhofer regime, which is covered in the undergraduate physics curriculum and experimentally verified. Here, we examine the more general situation of a semi-transparent plane that contains a long rectangular slit. Our analysis reveals that the diffraction patterns differ significantly between two specific cases: diffraction from an opaque screen containing a slit, and diffraction from a transparent plane featuring a slit (phase slit or a phase strip). The calculations demonstrate that the diffraction pattern resulting from the phase slit comprises two distinct sets of fringes with different spatial frequencies, and the width (size) of the phase slit (or strip) can be determined by examining the lower-frequency fringes. To verify these calculations, we fabricated appropriate phase slits and phase strips and analyzed their diffraction patterns. Our experimental findings showed excellent agreement with the theoretical predictions.

Effect of Calebin-A on Critical Genes Related to NAFLD: A Protein-Protein Interaction Network and Molecular Docking Study.

Background: Calebin-A is a minor phytoconstituent of turmeric known for its activity against inflammation, oxidative stress, cancerous, and metabolic disorders like Non-alcoholic fatty liver disease(NAFLD). Based on bioinformatic tools. Subsequently, the details of the interaction of critical proteins with Calebin-A were investigated using the molecular docking technique. Methods: We first probed the intersection of genes/ proteins between NAFLD and Calebin-A through online databases. Besides, we performed an enrichment analysis using the ClueGO plugin to investigate signaling pathways and gene ontology. Next, we evaluate the possible interaction of Calebin-A with significant hub proteins involved in NAFLD through a molecular docking study. Results: We identified 87 intersection genes Calebin-A targets associated with NAFLD. PPI network analysis introduced 10 hub genes (TP53, TNF, STAT3, HSP90AA1, PTGS2, HDAC6, ABCB1, CCT2, NR1I2, and GUSB). In KEGG enrichment, most were associated with Sphingolipid, vascular endothelial growth factor A (VEGFA), C-type lectin receptor, and mitogen-activated protein kinase (MAPK) signaling pathways. The biological processes described in 87 intersection genes are mostly concerned with regulating the apoptotic process, cytokine production, and intracellular signal transduction. Molecular docking results also directed that Calebin-A had a high affinity to bind hub proteins linked to NAFLD. Conclusion: Here, we showed that Calebin-A, through its effect on several critical genes/ proteins and pathways, might repress the progression of NAFLD.

Porphyrin-based ligand interaction with G-quadruplex: Metal cation effects.

The G-quadruplex planar-ligand complex is used to detect heavy metal cations such as Ag+ , Cu2+ , Pb2+ , Hg2+ , organic molecules, nucleic acids, and proteins. The interaction of the three planar porphyrins (L1), 5,10,15,20-tetrakis (1-ethyl-1-λ4 -pyridine-4-yl) porphyrin (L2), and 5,10,15,20-tetrakis (1-methyl-1-λ4 -pyridine-4-yl) porphyrin (L3), coming from the porphyrin family, with G-quadruplex obtained from human DNA telomeres in the presence of lithium, sodium, potassium, rubidium, cesium, magnesium, and calcium ions was studied by molecular dynamics simulation. When G-quadruplex containing divalent ions of magnesium and calcium interacts with L1, L2, and L3 ligands, the hydrogen bonds of the lower G-quadruplex sheet are more affected by ligands and the distance between guanines in the lower tetrad increases. In the case of G-quadruplex interactions containing monovalent ions with ligands, the hydrogen bond between the sheets does not follow a specific trend. For example, in the presence of lithium ions, the upper and middle sheets are more affected by ligands, while they are less affected by ligands in the presence of sodium. The binding pocket and the binding energy of the three ligands to the G-quadruplex were also obtained in the various systems. The results show that ligands make the G-quadruplex more stable through the penetration between the sheets and the interaction with the loops. Among the ligands mentioned, the interaction level of the ligand L2 is greater than the others. Our calculations are consistent with the previous experimental observations so that it can help to understand the molecular mechanism of porphyrin interaction and its derivatives with the G-quadruplex.

Efferocytosis: a double-edged sword in microbial immunity.

Efferocytosis is characterized as the rapid and efficient process by which dying or dead cells are removed. This type of clearance is initiated via "find-me" signals, and then, carries on by "eat-me" and "don't-eat-me" ones. Efferocytosis has a critical role to play in tissue homeostasis and innate immunity. However, some evidence suggests it as a double-edged sword in microbial immunity. In other words, some pathogens have degraded efferocytosis by employing efferocytic mechanisms to bypass innate immune detection and promote infection, despite the function of this process for the control and clearance of pathogens. In this review, the efferocytosis mechanisms from the recognition of dying cells to phagocytic engulfment are initially presented, and then, its diverse roles in inflammation and immunity are highlighted. In this case, much focus is also laid on some bacterial, viral, and parasitic infections caused by Mycobacterium tuberculosis (M. tb), Mycobacterium marinum (M. marinum), Listeria monocytogenes (L. monocytogenes), Chlamydia pneumoniae (CP), Klebsiella pneumoniae (KP), Influenza A virus (IAV), human immunodeficiency virus (HIV), and Leishmania, respectively.

Bayesian inference of ancestral recombination graphs.

We present a novel algorithm, implemented in the software ARGinfer, for probabilistic inference of the Ancestral Recombination Graph under the Coalescent with Recombination. Our Markov Chain Monte Carlo algorithm takes advantage of the Succinct Tree Sequence data structure that has allowed great advances in simulation and point estimation, but not yet probabilistic inference. Unlike previous methods, which employ the Sequentially Markov Coalescent approximation, ARGinfer uses the Coalescent with Recombination, allowing more accurate inference of key evolutionary parameters. We show using simulations that ARGinfer can accurately estimate many properties of the evolutionary history of the sample, including the topology and branch lengths of the genealogical tree at each sequence site, and the times and locations of mutation and recombination events. ARGinfer approximates posterior probability distributions for these and other quantities, providing interpretable assessments of uncertainty that we show to be well calibrated. ARGinfer is currently limited to tens of DNA sequences of several hundreds of kilobases, but has scope for further computational improvements to increase its applicability.

On the Characteristics of Fatigue Fracture with Rapid Frequency Change.

The effect of sudden variations in working modes and fatigue behavior of CS 1018 is studied. A general model based on the framework of the fracture fatigue entropy (FFE) concept is developed to capture such changes. Fully reversed bending tests are performed on flat dog bone specimens with a series of variable frequency tests without turning the machine off to simulate fluctuating working conditions. The results are then post-processed and analyzed to assess how fatigue life changes when a component is subjected to sudden changes in multiple frequencies. It is demonstrated that regardless of the frequency changes, FFE remains constant and stays within a narrow band range, similar to that of a constant frequency.

The role of exosomal miRNA in nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) impacts more than one-third of the population and is linked with other metabolic diseases. The term encompasses a wide spectrum of diseases, from modest steatosis to nonalcoholic steatohepatitis, fibrosis and, ultimately, cirrhosis with the potential for development of hepatocellular carcinoma. Currently, available methods for diagnosing NAFLD are invasive or lack accuracy, and monitoring to determine response to therapeutic interventions is challenging. Exosomes are nano-scaled extracellular vesicles that are secreted by a variety of cells. They convey proteins, mRNA, miRNA, and other bioactive molecules between cells and are involved in an extensive range of biological processes, particularly cell-cell communication. Several reports suggest that exosomes mediate miRNAs and, thus, they have potential clinical utility for diagnosis, prognosis, and therapeutics in liver diseases. In view of the vital role of exosomal microRNA in disease, we here synthesized current knowledge about the biogenesis of exosomal miRNA and exosome-mediated microRNA transfer. We then discuss the potential of exosomal miRNA in diagnosis and therapeutics of NAFLD.

Effect of diabetes on efferocytosis process.

Diabetes is a complex of genetic, metabolic, and autoimmune disorders that are characterized by hyperglycemia. Elevated apoptotic cell count following defective clearance of dead cells that can cause chronic inflammation is a hallmark of the diabetic wound. Effective dead cell clearance is a prerequisite for rapid inflammation resolution and successful recovery. Efferocytosis is a multistep process in which phagocytes engulf the dead cells. Cell body elimination is of great significance in disease and homeostasis. Recent research has clarified that diabetic wounds have an enhanced load of the apoptotic cell, which is partly attributed to the dysfunction of macrophages in apoptotic clearance at the site of the diabetic wounds. In the current work, we highlight the pathways implicated in efferocytosis, from the diagnosis of apoptotic cells to the phagocytic swallowing and the homeostatic resolution, and explain the possible pathophysiological episodes occurring when the proceeding is abrogated. Also, we describe the last development in the management of inflammation in diabetes wound and future directions of surveillance.

Application of Fresnel diffraction from the edge of a transparent plate to measurement of glucose concentration.

We present a new method for measuring the solution concentration based on laser light diffraction from the edge of a glass plate immersed in the solution. It is shown experimentally that the visibility of diffraction fringes is varied periodically with solution concentration and the period is related to light wavelength and thickness of the glass plate. There are intervals of concentrations in which the visibility-concentration curve is very near to linear. By choosing a suitable glass plate, one can change the extent of measurable concentrations and the resolution of the method. Using a 1 mm thick glass plate, we obtained a resolution of7.67×10-6g/cc in the detection of glucose concentration. The presented method is accurate and much simpler than other methods for measuring the solution concentration.

Investigation of the Effects of Difluorinated Curcumin on Glycemic Indices in Streptozotocin-Induced Diabetic Rats.

BACKGROUND: Curcumin is an antioxidant agent that improves glycemia in animal models of diabetes. Clinically curcumin use is limited due to poor solubility, weak absorption, and low bioavailability; therefore, this study to investigate the effects of curcumin's analog, difluorinated curcumin (CDF), on fasting blood glucose (FBG), oral glucose tolerance test (OGTT), and insulin tolerance test (ITT), in streptozotocin (STZ)-induced diabetic rats was undertaken. METHODS: STZ-induced diabetes rats were randomly assigned to six groups (7 rats per group). They were treated daily by oral gavage with curcumin (200 and 100 mg/kg/day), CDF (200 and 100 mg/kg/day), and metformin (200 mg/kg/day) as a positive control group, for 4 weeks. Two diabetic control (DC) and normal control (NC) groups (non-diabetic rats) received normal saline and citrate buffer, respectively. FBG was measured at the beginning and end of the treatment (Day 0 and week 4) and OGTT and ITT were performed to determine glucose tolerance and insulin sensitivity. RESULTS: Cur100, CDF 100, and CDF200 significantly decreased FBG levels after 4 weeks oral administration by -34% (-150 mg/dL ± 70, p = 0.02), -36% (123 mg/dL ±67, p < 0.04), and - 40% (-189 mg/dL ± 91, p = 0.03), respectively. Glucose sensitivity by OGTT showed a significant improvement in glucose tolerance ability in all treated groups compared with DC group. ITT demonstrated that insulin response improved significantly in Cur100 and CDF 200 groups. CONCLUSION: Overall, CDF improved glucose tolerance and insulin sensitivity, while reducing FBG compared to curcumin, suggesting that curcumin analogs may have therapeutic utility in diabetes.

Investigation of the Effects of Trehalose on Glycemic Indices in Streptozotocin-Induced Diabetic Rats.

BACKGROUND AND AIM: Diabetes is a chronic metabolic disorder with considerable morbidity and mortality because of its associated complications that has become a challenging health problem worldwide. Trehalose (mycose) is a nonreducing disaccharide with a unique therapeutic potency without adverse effects, which has been found to improve glucose metabolism and homeostasis in different diabetes models. We hypothesized that trehalose can reduce blood glucose and improve insulin sensitivity. We have conducted this study to evaluate the effect of trehalose on glycemic indices in streptozotocin (STZ)-induced diabetic rats. METHOD: Fourteen diabetic rats were randomly assigned in two treatment groups (seven rats per group) that received trehalose at a dose of 1.5 g/kg/day via oral gavage and a dose of 45 mg/kg/day via intraperitoneal (i.p.) injection. Three control groups, including a positive control, diabetic control (DC), and nondiabetic rats as a normal control group (NC), received metformin (200 mg/kg/day), normal saline, and citrate buffer, respectively. The levels of fasting blood glucose (FBG) were measured at baseline (week 0) and after 4 weeks of treatment. Moreover, an oral glucose tolerance test (OGTT) was performed at the end of the study to determine glucose tolerance. RESULTS: The results showed that FBG levels were significantly decreased by -66% (-221 ± 65 mg/dL, p = 0.01), -40% (-114 ± 46 mg/dL, p = 0.02), and - 72% (-191 ± 68 mg/dL, p = 0.01) in trehalose-oral, trehalose-i.p., and metformin groups, respectively, after 4 weeks of administration. Evaluating the results of glucose tolerance test and analysis of corresponding areas under the glucose curve (AUCglucose) over 180 min indicated that glucose tolerance was significantly improved in the trehalose-i.p. group (p = 0.03) compared to DC group. CONCLUSION: Our findings suggested that trehalose administered via i.p. route might reduce FBG levels and improve glycemic control in STZ-induced diabetic rats.

Construction of a sensitive and specific lead biosensor using a genetically engineered bacterial system with a luciferase gene reporter controlled by pbr and cadA promoters.

BACKGROUND: A bacterial biosensor refers to genetically engineered bacteria that produce an assessable signal in the presence of a physical or chemical agent in the environment. METHODS: We have designed and evaluated a bacterial biosensor expressing a luciferase reporter gene controlled by pbr and cadA promoters in Cupriavidus metallidurans (previously termed Ralstonia metallidurans) containing the CH34 and pI258 plasmids of Staphylococcus aureus, respectively, and that can be used for the detection of heavy metals. In the present study, we have produced and evaluated biosensor plasmids designated pGL3-luc/pbr biosensor and pGL3-luc/cad biosensor, that were based on the expression of luc+ and under the control of the cad promoter and the cadC gene of S. aureus plasmid pI258 and pbr promoter and pbrR gene from plasmid pMOL30 of Cupriavidus metallidurans. RESULTS: We found that the pGL3-luc/pbr biosensor may be used to measure lead concentrations between 1-100 µM in the presence of other metals, including zinc, cadmium, tin and nickel. The latter metals did not result in any significant signal. The pGL3-luc/cad biosensor could detect lead concentrations between 10 nM to 10 µM. CONCLUSIONS: This biosensor was found to be specific for measuring lead ions in both environmental and biological samples.

Association between obesity categories with cardiovascular disease and its related risk factors in the MASHAD cohort study population.

BACKGROUND: Cardiovascular disease (CVD) is a significant cause of morbidity and mortality globally. Obesity is an important CVD risk factor and is increasing in prevalence. METHODS: In this study, 3829 men and 5720 women (35-65 years) were enrolled as part of the MASHAD cohort study. Four categories were identified according to body mass index and waist circumference that was defined by the World Health Organization. Logistic regression analysis was used to determine the adjusted odds ratio (OR) for the occurrence of CVD, and Cox regression model was used to evaluate the association of obesity with CVD incidence. RESULTS: We found that the higher risk groups defined by categories of adiposity were significantly related to a higher prevalence of a high serum total cholesterol (TC), and triglycerides (TG), and lower high-density lipoprotein cholesterol (HDL), and higher fasting blood glucose (FBG) in both genders and a higher low-density lipoprotein cholesterol (LDL) in women (P < .001). Additionally, a high percentage of participants with dyslipidemia, high LDL, high TC, and low HDL and a high percentage of participants with metabolic syndrome, diabetes, hypertension, and a high serum TG were observed across obesity categories (P < .001). Moreover, women with the very high degrees of obesity had a greater risk of CVD (HR: 1.91, 95% CI: 1.06-3.43, P = .03). CONCLUSION: Obesity strongly predicts several CVD risk factors. Following 6 years of follow-up, in individuals within increasing degrees of obesity, there was a corresponding significant increase in CVD events, rising to approximately a twofold higher risk of cardiovascular events in women compared with men.

Application of Fresnel diffraction to fabrication and characterization of glass phase steps.

In this paper we used Fresnel diffraction in order to study the effects of hydrofluoric acid concentration and temperature on glass etching rate. The technique is very simple and accurate, and nanoscale change of the glass thickness can be detected and measured during etching. Using measured etching rates we have fabricated several glass phase steps. The fabricated phase steps were characterized by Fresnel diffractometry and optical interferometry. Using this method one can fabricate and characterize low-cost phase shifters of appropriate accuracy in less than 1 h.

Prevalence of combined and noncombined dyslipidemia in an Iranian population.

BACKGROUND: Combination of dyslipidemic phenotypes, including elevated plasma levels of low-density lipoprotein cholesterol (LDL-C), elevated plasma triglycerides (TG), and decreased low-density lipoprotein cholesterol (HDL-C) concentrations, is important because of the association of individual phenotypes with increased risk of cardiovascular disease (CVD). We investigated the prevalence of combined dyslipidemias and their effects on CVD risk in an Iranian large population. METHOD: A total of 9847 individuals were recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorders (MASHAD) cohort study. Anthropometric parameters and biochemical indices were measured in all of the subjects. Different types of combined dyslipidemias including high TG + low HDL-C, high TG + low HDL-C + high LDL-C, low HDL-C + high LDL-C, high TG + high LDL-C, and finally high TG + high LDL-C + low HDL-C were considered. Ten-year CVD risk was calculated using the QRISK2 risk algorithm and adjustments were made as suggested by the Joint British Societies' (JBS2). Logistic regression analyses were performed to determine the association between different combined dyslipidemias and categorical QRISK. RESULTS: A total of 3952 males and 5895 females were included in this current study. Among the included subjects, 83.4% had one form of dyslipidemia, and 16.6% subjects were not dyslipidemic. The mean age was 48.88 ± 7.9 and 47.02 ± 8.54 years for dyslipidemic and nondyslipidemic groups, respectively. The results showed that the frequency of dyslipidemia was 98%, 87.1%, and 90% in subjects with metabolic syndrome, CVD, and diabetes, respectively. Our results suggested that around 15.7% of study population were at 10 years CVD risk (high ≥20) and it was higher in men than women (P < .001). Moreover, risk of CVD was higher in TG↑ & HDL↓ & LDL↑ group than other groups. CONCLUSION: Prevalence of dyslipidemia was 83.4% among Iranian adults. The results showed that individuals with increased plasma TG and LDL-C, and low HDL-C levels had the highest 10 years CVD risk compared to other combined dyslipidemic phenotypes.

Application of Fresnel diffraction from phase steps to measurement of etching rate of transparent materials.

Based on Fresnel diffraction from phase steps, we present an optical method for real-time monitoring and measurement of thickness during the wet etching of transparent materials. It is shown experimentally that during the etching process, the visibility of diffraction fringes varies periodically with time (thickness) and the rate the etching is measured. Using dilute etching solutions, we measured an average etching rate of 5.3 nm/s for glass.

Exploration of the Key Genes Involved in Non-alcoholic Fatty Liver Disease and Possible MicroRNA Therapeutic Targets.

Background: MicroRNAs (miRNAs) are promising therapeutic agents for non-alcoholic fatty liver disease (NAFLD). This study aimed to identify key genes/proteins involved in NAFLD pathogenesis and progression and to evaluate miRNAs influencing their expression. Methods: Gene expression profiles from datasets GSE151158, GSE163211, GSE135251, GSE167523, GSE46300, and online databases were analyzed to identify significant NAFLD-related genes. Then, protein-protein interaction networks and module analysis identified hub genes/proteins, which were validated using real-time PCR in oleic acid-treated HepG2 cells. Functional enrichment analysis evaluated signaling pathways and biological processes. Gene-miRNA interaction networks identified miRNAs targeting critical NAFLD genes. Results: The most critical overexpressed hub genes/proteins included: TNF, VEGFA, TLR4, CYP2E1, ACE, SCD, FASN, SREBF2, and TGFB1 based on PPI network analysis, of which TNF, TLR4, SCD, FASN, SREBF2, and TGFB1 were up-regulated in oleic acid-treated HepG2 cells. Functional enrichment analysis for biological processes highlighted programmed necrotic cell death, lipid metabolic process response to reactive oxygen species, and inflammation. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, the highest adjusted P-value signaling pathways encompassed AGE-RAGE in diabetic complications, TNF, and HIF-1 signaling pathways. In gene-miRNA network analysis, miR-16 and miR-124 were highlighted as the miRNAs exerting the most influence on important NAFLD-related genes. Conclusion: In silico analyses identified NAFLD therapeutic targets and miRNA candidates to guide further experimental investigation.

Identification and analysis of the molecular targets of statins in colorectal cancer.

Colorectal cancer (CRC) is the third most common cancer in the world. According to several types of research, statins may impact the development and treatment of CRC. This work aimed to use bioinformatics to discover the relationship between statin targets and differentially expressed genes (DEGs) in CRC patients and determine the possible molecular effect of statins on CRC suppression. We used CRC datasets from the GEO database to select CRC-related DEGs. DGIdb and STITCH databases were used to identify gene targets of subtypes of statin. Further, we identified the statin target of CRC DEGs hub genes by using a Venn diagram of CRC DEGs and statin targets. Funrich and enrichr databases were carried out for the KEGG pathway and gene ontology (GO) enrichment analysis, respectively. GSE74604 and GSE10950 were used to identify CRC DEGs. After analyzing datasets,1370 genes were identified as CRC DEGs, and 345 targets were found for statins. We found that 35 genes are CRC DEGs statin targets. We found that statin targets in CRC were enriched in the receptor and metallopeptidase activity for molecular function, cytoplasm and plasma membrane for cellular component, signal transduction, and cell communication for biological process genes were substantially enriched based on FunRich enrichment. Analysis of the KEGG pathways revealed that the overexpressed DEGs were enriched in the IL-17, PPAR, and Toll-like receptor signaling pathways. Finally, CCNB1, DNMT1, AURKB, RAC1, PPARGC1A, CDKN1A, CAV1, IL1B, and HSPD1 were identified as hub CRC DEGs statin targets. The genetic and molecular aspects of our findings reveal that statins might have a therapeutic effect on CRC.

Analysis of the therapeutic potential of miR-124 and miR-16 in non-alcoholic fatty liver disease.

BACKGROUNDS: Non-alcoholic fatty liver disease (NAFLD) is a common condition affecting >25 % of the population worldwide. This disorder ranges in severity from simple steatosis (fat accumulation) to severe steatohepatitis (inflammation), fibrosis and, at its end-stage, liver cancer. A number of studies have identified overexpression of several key genes that are critical in the initiation and progression of NAFLD. MiRNAs are potential therapeutic agents that can regulate several genes simultaneously. Therefore, we transfected cell lines with two key miRNAs involved in targeting NAFLD-related genes. METHODS: The suppression effects of the investigated miRNAs (miR-124 and miR-16) and genes (TNF, TLR4, SCD, FASN, SREBF2, and TGFß-1) from our previous study were investigated by real-time PCR in Huh7 and HepG2 cells treated with oleic acid. Oil red O staining and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay were utilized to assess cell lipid accumulation and cytotoxic effects of the miRNAs, respectively. The pro-oxidant-antioxidant balance (PAB) assay was undertaken for miR-16 and miR-124 after cell transfection. RESULTS: Following transfection of miRNAs into HepG2, oil red O staining showed miR-124 and miR-16 reduced oleic acid-induced lipid accumulation by 35.2 % and 28.6 % respectively (p < 0.05). In Huh7, miR-124 and miR-16 reduced accumulation by 23.5 % and 31.3 % respectively (p < 0.05) but without impacting anti-oxidant activity. Real-time PCR in HepG2 revealed miR-124 decreased expression of TNF by 0.13-fold, TLR4 by 0.12-fold and SREBF2 by 0.127-fold (p < 0.05). miR-16 decreased TLR4 by 0.66-fold and FASN by 0.3-fold (p < 0.05). In Huh7, miR-124 decreased TNF by 0.12-fold and FASN by 0.09-fold (p < 0.05). miR-16 decreased SCD by 0.28-fold and FASN by 0.64-fold (p < 0.05). MTT assays showed, in HepG2, viability was decreased 24.7 % by miR-124 and decreased 33 % by miR-16 at 72 h (p < 0.05). In Huh7, miR-124 decreased viability 42 % at 48 h and 29.33 % at 72 h (p < 0.05), while miR-16 decreased viability by 32.3 % (p < 0.05). CONCLUSION: These results demonstrate the ability of miR-124 and miR-16 to significantly reduce lipid accumulation and expression of key pathogenic genes associated with NAFLD through direct targeting. Though this requires further in vivo investigation.

An experimental study on a cylindrical-conical cavity receiver for the parabolic dish collector.

Solar thermal energy is a promising solution to the environmental and energy demands issues which the world is faced with them. Among all the solar thermal collectors and solar towers used in this field, parabolic dish collectors are one of the preferable options for researchers due to their high working temperature range and high thermal performance. It has been proved that cavity receivers in solar dish collectors are the best way to achieve the best thermal performance. The main concern in the cavity receivers is their thermal efficiency enhancement by employing different geometries. The hybrid geometry of cylindrical-conical can be used to achieve the high pressure drop and low thermal efficiency of conventional cylindrical and conical cavity receivers, respectively. Furthermore, using proper insulation for the cavity receiver helps to performance enhancement of the dish collector. Ceramic fiber insulation can be suitable for this purpose due to its good thermal properties and fewer environmental issues. Hence, in this study, the objective of efficiency enhancement of parabolic dish collector is followed by utilizing a cylindrical-conical cavity receiver equipped with the fiber ceramic insulation. The results show that ceramic fiber is better insulation than the common mineral wool insulation and can enhance thermal performance by 5.03% on average. In addition, the maximum, average, and minimum thermal efficiencies of the cylindrical-conical cavity receiver by using the ceramic fiber insulation and water as the working fluid were obtained up to 38.77%, 35.19%, and 32.66%, respectively.