Resilience of aerobic sludge biomass under chlorpyrifos stress and its recovery potential.

Non-agricultural sources of pesticides in urban areas are responsible for their presence in domestic wastewater. Therefore, pesticides are typically found in sewage treatment plants in developed and developing countries as micro-pollutant. The presence of pesticides in the wastewater can impart stress on the aerobic sludge biomass and disrupt the functioning of the plant. However, there exists a knowledge gap regarding the resilience of aerobic sludge biomass towards stress due to the presence of pesticides in the wastewater. This study investigated the impact of chlorpyrifos (CPS) - a widely used pesticide, on sludge biomass and explored its recovery capability when CPS is discontinued in the influent. Four duplicate reactors were operated with different CPS concentrations ranging from 50 to 200 mg/L. Chemical oxygen demand (COD) removal for reactors has ranged within 18-73 % at the steady state of the stressed phase, whereas COD removal for the control reactor was 91 %. CPS stress slightly inhibited filamentous biomass growth. Biomass activity and cell viability have decreased significantly, whereas biochemical contents have varied slightly under CPS stress. The activities of the enzymes dehydrogenase and urease were significantly inhibited when compared to catalase and protease. Amplified ribosomal DNA restriction analysis reflected changes in the microbial community. The discontinuation of CPS has allowed aerobic sludge biomass to recover in its organic degradation capability (COD removal of more than 88 % at steady-state conditions of recovery phase operation), biomass growth, and cell viability. In addition, enzyme activities have retrieved to their original levels, and 78-93 % similarity of microbial community structure has been displayed between CPS-exposed and control reactor biomasses. Overall, the present study has indicated the orderly changes in the quality of aerobic sludge biomass under CPS stress through physico-chemical and biological characteristics. The study also has highlighted the self-recovery of sludge biomass characteristics stressed with different concentrations of CPS.

Echocardiographic and Angiographic Assessment of Right Ventricular Function and Right Coronary Artery Stenosis in Acute Inferior Wall Myocardial Infarction.

BACKGROUND: Cardiovascular diseases (CVDs) are a global concern. CVD remains a primary cause of death despite reduced coronary heart disease death rates. Acute coronary syndrome (ACS) involves myocardial infarction (MI) and unstable angina, sharing mechanisms such as plaque instability. Our study assesses the right ventricular (RV) function's predictive value in acute inferior wall MI (IWMI) to identify high-risk patients with an elevated likelihood of experiencing severe cardiac complications, hemodynamic instability, or a higher mortality risk following an acute IWMI. METHODOLOGY: The research was conducted in the Department of Cardiology at the Rajendra Institute of Medical Sciences (RIMS), Ranchi, from July 2021 to June 2022, following the necessary ethical approval. A cohort of 140 patients with IWMI, carefully chosen according to rigorous criteria, clearly understood the study's objectives before providing informed consent. The evaluations were conducted in the following order: clinical assessments, followed by blood testing, then echocardiography, and finally, coronary angiography. Furthermore, the study examined risk factors and utilized statistical methods to elucidate the associations between qualities and results. RESULTS: The study included 140 participants, with 61% being male and 39% female. Among the participants, 14% were aged 30-45, 50% were aged 46-60, and 30% were over 60. Age shows significant proportions in different categories. Diabetes, dyslipidemia, hypertension, and smoking/tobacco addiction did not differ among stenosis groups. Proximal right coronary artery (RCA) stenosis patients had elevated jugular venous pressure (JVP). The echocardiograms were performed within 48 hours of post-percutaneous coronary intervention, and significant differences between groups were observed. Participants with proximal stenosis had lower tricuspid annular plane systolic excursion (TAPSE) and right ventricular fractional area change (RVFAC), which showed compromised RV systolic function. Proximal stenosis patients had reduced systolic motion velocity (Sm), indicating impaired myocardial contraction. Echocardiographic parameters such as early diastolic velocity (Em), atrial contraction velocity (Am), Em/Am ratio (a marker of diastolic function), isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT), and ejection time (ET) between groups were different, indicating distinct cardiac functions. Proximal stenosis increased the myocardial performance index (MPI), indicating cardiac impairment. The left ventricular ejection fraction (LVEF) was comparable in the two stenosis groups, indicating similar left ventricular performance. CONCLUSION:  Echocardiography showed significant RV function differences in acute inferior wall ST-segment elevation myocardial infarction (STEMI) patients with proximal and distal RCA lesions. RV dysfunction is linked to right ventricle myocardial infarction (RVMI), and echocardiographic markers can provide valuable insights. Results emphasize that acute inferior wall STEMI is diagnosed by electrocardiogram (ECG) criteria, particularly ST-segment elevation. However, these markers emphasize the importance of RV assessment in RCA involvement assessment. These findings suggest that RV function can help diagnose acute inferior wall STEMI RCA involvement. In acute inferior STEMIs, RV function echocardiography is essential for RCA lesion location.

Behavior of higher-order MDD on energy ratios at the interface of thermoelastic and piezothermoelastic mediums.

This paper investigates the intricate energy distribution patterns emerging at an orthotropic piezothermoelastic half-space interface by considering the influence of a higher-order three-phase lags heat conduction law, accompanied by memory-dependent derivatives (referred to as HPS) within the underlying thermoelastic half-space (referred to as TS). This study explores the amplitude and energy ratios of reflected and transmitted waves. These waves span various incident types, including longitudinal, thermal, and transversal, as they propagate through the TS and interact at the interface. Upon encountering the interface, an intriguing dynamic unfolds: three waves experience reflection within the TS medium, while four waves undergo transmission into the HPS medium. A graphical representation effectively illustrates the impact of higher-order time differential parameters and memory to offer comprehensive insights. This visual representation reveals the nuanced fluctuations of energy ratios with the incidence angle. The model astutely captures diverse scenarios, showcasing its ability to interpret complex interface dynamics.

A Case of Inflammatory Pseudotumour Masquerading as Hepatocellular Carcinoma.

Inflammatory pseudotumors (IPTs) of the liver can mimic malignant lesions. As the name implies, they are usually associated with an inflammatory process and usually regress with the treatment of the underlying pathology. We report a case of a 67-year-old female who presented with right upper quadrant pain, deranged liver enzymes, elevated tumor markers [alpha-fetoprotein (AFP) and CA 19-9], and a large liver mass on imaging, suspected to be hepatocellular carcinoma (HCC). She was eventually diagnosed with IPT complicating the liver inflammation due to autoimmune hepatitis (AIH). She responded well to treatment with steroids and immunosuppressive therapy.

Investigation of memory influences on bio-heat responses of skin tissue due to various thermal conditions.

Advancement of new technologies such as laser, focused ultrasound, microwave and radio frequency for thermal therapy of skin tissue has increased numerous challenging situations in medical treatment. In this article, a new meticulous bio-heat transfer model based on memory-dependent derivative with dual-phase-lag has been developed under different thermal conditions such as thermal shock and harmonic-type heating. Laplace transform method is acquired to perceive the analytical consequences. Quantitative results are evaluated for displacement, strain and temperature along with stress distributions in time domain by adopting the technique of inverse Laplace transform. Impacts of the constituents of memory-dependent derivatives-kernel functions along with time-delay parameter are analysed on the studied fields (temperature, displacement, strain and stress) for both thermal conditions separately using computational results. It has been found that the insertion of the memory effect proves itself a unified model, and therefore, this model can better predict temperature field data for thermal treatment processes.

Application of triangular duct in solar-assisted air-heating system with surface roughness: a numerical investigation.

The device called solar air heater (SAH) is used to collect and transfer solar-thermal energy to air that can further be used for space heating, drying, etc. The conventional air heater (solar-assisted) has poor performance, and with this work, an attempt has been made to improve its performance by providing surface roughness over the heated surface. The roughness employed over the surface has an elliptical cavity, and its distribution over the heated surface is defined with the three parameters (dimensionless): relative flow-wise distance (ranging from 6 to 14), relative cavity depth (ranging from 0.016 to 0.038), and relative crosswise distance (ranging from 6 to 14). A CFD code has been developed and validated with experimentation to do the parametric study for understanding the effect of the proposed surface roughness on the performance of the air heater. It is concluded that the proposed surface roughness promotes the local turbulence, flow separation, and strong vortices in the flow field resulting in comparatively higher thermal performance in the proposed air heater. But this higher thermal performance is achieved at the expense of higher-pressure loss in the passage. A substantial change in heat augmentation by 2.57 times (with 2.3 times higher pressure loss) which results in 1.75 times higher thermo-hydraulic performance has been noticed over conventional designs at a relative flow-wise distance of 10, relative cavity depth 0.038, and relative crosswise distance of 10.

Lithium co-administration with rutin improves post-stroke neurological outcomes via suppressing Gsk-3ß activity in a rat model.

Cerebral ischemic stroke is one of the leading causes of adult disability worldwide. Reperfusion is the only therapeutic option with a lot of side effects. In the current study, we investigated the efficacy of rutin and lithium co-treatment in improving post-stroke neurological outcomes in a transient global cerebral ischemia-reperfusion injury rat model. Middle-aged male rats were subjected to transient global cerebral ischemia-reperfusion. NORT and Y-maze were used to assess the cognitive processes. Lipid peroxidation, protein carbonylation, and nitric oxide assays were performed to study oxidative stress. The excitotoxicity index was calculated by HPLC. Real time-PCR and western blotting were performed to study gene and protein expressions. The co-administration of rutin and lithium improved the overall survival, recognition memory, spatial working memory, and neurological score following cerebral ischemia-reperfusion in rats. Further, a marked decrease in malonaldehyde, protein carbonyls, and nitric oxide levels was observed following combined treatment. The mRNA expression of antioxidant (Hmox1 and Nqo1) and pro-inflammatory (Il2, Il6, and Il1ß) markers were significantly attenuated in the rutin and lithium co-administrated group. The treatment inhibited the Gsk-3ß and maintained a normal pool of the downstream ß-catenin and Nrf2 proteins. The results revealed that co-administration of rutin and lithium had a neuroprotective potential, suggesting it to be a viable treatment to overcome post-stroke deaths and neurological complications.

Buckwheat tartary regulates the Gsk-3ß/ß-catenin pathway to prevent neurobehavioral impairments in a rat model of surgical menopause.

Menopause is a natural aging process characterized by decreased levels of sex hormones in females. Deprivation of estrogen following menopause results in alterations of dendritic arborization of the neuron that leads to neurobehavioral complications. Hormone replacement therapy is in practice to manage postmenopausal conditions but is associated with a lot of adverse effects. In the present study, the efficacy of buckwheat tartary (Fagopyrum tataricum) whole seed extract was investigated against the neurobehavioral complication in middle-aged ovariectomized rats, which mimic the clinical postmenopausal condition. Hydroalcoholic extraction (80% ethanol) was done, and quantification of major marker compounds in the extract was performed using HPLC. Oral treatment of the extract following the critical window period rescued the reconsolidation process of spatial and recognition memory, as well as depression-like behavior. Gene expression analysis disclosed elevated oxidative stress and neuroinflammation that largely disturb the integrity of the blood-brain barrier in ovariectomized rats. Gfap and Pparγ expression also showed reactive astrogliosis in the rats subjected to ovariectomy. The extract treatment reverted the elevated oxidative stress, neuroinflammation and expression of the studied genes. Furthermore, protein expression analysis revealed that Gsk-3ß was activated differentially in the brain, as suggested by ß-catenin protein expression, which was normalized following the treatment with extract and rescued the altered neurobehavioral process. The results of the current study concluded that Fagopyrum tataricum seed extract is better option to overcome the neurobehavioral complications associated with the menopause.

Enhance photoluminescence properties of Ca-Eu:Y2O3@SiO2 core-shell nanomaterial for the advanced forensic and LEDs applications.

The divalent (Ca2+)-doped Eu:Y2O3@SiO2 core-shell luminescent nanophosphors have been synthesised by a cost-effective combustion technique. Various characterizations were carried out to confirm the successful formation of the core-shell structure. The TEM micrograph reveals the thickness of the SiO2 coating over Ca-Eu:Y2O3 as ∼25 nm. The optimal value of silica coating over the phosphor has been obtained as 10 vol%(TEOS) of SiO2, with this value increasing fluorescence intensity by 34 %. Phosphor exhibits CIE coordinates as x = 0.425, y = 0.569 and a CCT value as ∼2115 K with color purity and the respective CRI of 80 % and 98 %, respectively, which make the core-shell nanophosphor suitable for warm LEDs, and other optoelectronic applications. Further, the core-shell nanophosphor has been investigated for the visualisation of latent finger prints and as security ink. The findings point towards the prospective future application of nanophosphor materials for anti-counterfeiting purposes and latent finger prints for forensic purposes.

The utility of non-invasive tests to assess advanced fibrosis in Asian subjects with chronic hepatitis B and concomitant hepatic steatosis.

BACKGROUND: Chronic hepatitis B (CHB) is endemic to Asia and is a leading cause of liver-related morbidity. The prevalence of concomitant CHB and hepatic steatosis (HS) is increasing in Asia. Non-invasive tests (NITs) including FIB-4, NFS and APRI assess fibrosis in populations with a single aetiology, but not in subjects with concomitant CHB and HS. AIM: To explore the accuracy of NITs in predicting advanced fibrosis in patients with concomitant CHB and HS. METHODOLOGY: This multicentre study of CHB patients who underwent liver biopsy explored clinical characteristics of these subjects, stratified by presence of HS. Fibrosis scores from NITs were compared against histological fibrosis stage in CHB subjects with and without HS. RESULTS: 2262 subjects were enrolled, 74.5% were males, and the mean age was 39.5 years ±11.8 SD. 984 (44.4%) had HS, 824 (36.4%) had advanced fibrosis. In the CHB group, the AUROC for advanced fibrosis were 0.65 (95% CI 0.62-0.69) for FIB-4 and 0.63 (95% CI 0.60-0.66) for APRI. The specificities were 0.94 for FIB-4 greater than 3.25 and 0.81 for APRI greater than 1.5. In the CHBHS group, the AUROC for advanced fibrosis were 0.67 (95% CI 0.63-0.71) for FIB-4, 0.60 (95% CI 0.56-0.64) for APRI and 0.65 (95% CI 0.61-0.69) for NFS. The specificities were 0.95 for FIB-4 greater than 3.25, 0.88 for APRI greater than 1.5 and 0.99 for NFS greater than 0.675. CONCLUSION: The performance of NITs to exclude advanced fibrosis did not differ greatly regardless of HS. FIB-4 and NFS have the best negative predictive values of 0.80 and 0.78, respectively, to exclude advanced fibrosis in CHBHS subjects.

Designing Excess Electron Compounds by Substituting Alkali Metals to a Small and Versatile Tetracyclic Framework: A Theoretical Perspective.

Organic compound-based nonlinear optical (NLO) materials have sparked a lot of attention due to their multitude of applications and shorter optical response times than those of inorganic NLO materials. In the present investigation, we designed exo-exo-tetracyclo[6.2.1.13,6.02,7]dodecane (TCD) derivatives, which were obtained by replacing H atoms of methylene bridge carbon with alkali metals (Li, Na, and K). It was observed that upon the substitution of alkali metals at bridging CH2 carbon, absorption within the visible region occurred. Moving from 1 to 7 derivatives, the maximum absorption wavelength of the complexes exhibited a red shift. The designed molecules showed a high degree of intramolecular charge transfer (ICT) and excess electrons in nature, which were responsible for rapid optical response time and significant large molecular (hyper)polarizability. Calculated trends also inferred that the crucial transition energy decreased in order that also played a key role in the higher nonlinear optical response. Furthermore, to examine the effect of the structure/property relationship on the nonlinear optical properties of these investigated compounds (1-7), we calculated the density of state (DOS), transition density matrix (TDM), and frontier molecular orbitals (FMOs). The largest first static hyperpolarizability (ßtot) of TCD derivative 7 was 72059 au, which was 43 times greater than that of the prototype p-nitroaniline (ßtot = 1675 au).

Virtual monitoring for stable chronic hepatitis B patients does not reduce adherence to medications: A randomised controlled study.

INTRODUCTION: Chronic hepatitis B (CHB) remains common in endemic regions, causing significant healthcare burden. Patients with CHB may need to be adherent to nucleoside analogue (NA) for a long period of time to prevent complications. This study aims to investigate the safety, efficacy and patient experience of a virtual monitoring clinic (VMC) in monitoring stable patients taking NA for CHB. METHODS: Patients on NA and regular follow-up were randomised to either VMC alternating with doctors' clinic visit or to a control group in which they continued standard follow-up by doctors. Therapy adherence was measured by medication possession ratio (MPR) for NA therapy, incidence of virological breakthrough and hepatocellular carcinoma (HCC) development at two years of follow-up. Patient acceptance was measured on a Likert scale of 1-10. RESULTS: A total 192 patients completed follow-up: 94 and 98 patients in the VMC and control groups, respectively. Mean age was 60.6 ± 10.8 years, with 95.3% Chinese ethnicity and 64.1% males. Age, gender, race, educational, employment and financial status were similar in both groups. Upon study completion, the majority of patients - 76 (80.9%) in VMC group and 74 (75.5%) in control group - had MPR ≥0.8; 88.8% were satisfied and rated VMC better than a traditional follow-up clinic with doctors only. More than 85% of patients rated ≥8/10 on the Likert scale for VMC, and preferred VMC over traditional clinic visits. Clinical outcomes observed were HCC development in one (1.1%) in the VMC group and four (4.1%) in the control group (p = 0.369). Two (2.1%) and one (1.0%) virological breakthroughs were observed in the VMC and control groups, respectively (p = 0.615). No incidence of HCC or abnormal blood tests were missed in the VMC arm. DISCUSSION: VMC is a viable and safe clinical model for monitoring stable CHB patients on NA therapy without compromising patients' adherence to medications and is preferred by patients.

Chemo-kindling in adult zebrafish alters spatial cognition but not social novelty recognition.

In the past decades, zebrafish have gathered immense attention and importance in the field of neurological sciences. In the case of epilepsy, zebrafish have appeared as a promising acute animal model for the screening and identification of potential antiepileptic molecules. However, the necessity for establishing competent chronic models of epilepsy in zebrafish is apparent. In this regard, recently we developed a chemo-kindling zebrafish model with a better clinical resemblance. In the present study, an attempt to examine the effect of pentylenetetrazole (PTZ)-induced kindling on the cognitive functions of zebrafish was made. In brief, adult zebrafish were repetitively given a sub-effective concentration of PTZ, till the onset of clonic-tonic seizures, entitled as kindled. Thereafter, T-maze test and social recognition memory test were conducted to evaluate spatial memory and social novelty recognition memory of the fish. At the end, both the groups were sacrificed and the brains were isolated to estimate neurotransmitter and gene expression levels. It was observed that PTZ kindling induced spatial cognition deficits and lower social exploration in zebrafish. However, it didn't change the novelty recognition memory of kindled zebrafish. The results of genes and neurotransmitters estimations in the brain also supported the behavioural findings. The results concluded that PTZ kindling alters spatial cognitive functions in adult zebrafish without affecting the social novelty recognition memory.

Steatosis, HBV-related HCC, cirrhosis, and HBsAg seroclearance: A systematic review and meta-analysis.

BACKGROUND AND AIMS: NAFLD and chronic hepatitis B (CHB) infection are common etiologies of HCC. The impact of hepatic steatosis on HCC in CHB, as well as its relationship with the development of cirrhosis, fibrosis, and HBsAg seroclearance, remains controversial. APPROACH AND RESULTS: Data from observational studies were collected through PubMed, EMBASE, and the Cochrane Library from inception to February 1, 2022. Outcomes of interest included the association of hepatic steatosis with HCC, cirrhosis, advanced fibrosis, and HBsAg seroclearance, expressed in terms of pooled ORs. Additional subgroup and sensitivity analyses were performed to validate the robustness of findings. A total of 34 studies with 68,268 patients with CHB were included. Hepatic steatosis was associated with higher odds of HCC (OR, 1.59; 95% CI, 1.12-2.26; I2  = 72.5%), with the association remaining consistent in Asia (OR, 1.56; 95% CI, 1.08-2.25), studies with a median follow-up duration of ≥5 years (OR, 2.82; 95% CI, 1.57-5.08), exclusion of alcohol use (OR, 1.71; 95% CI, 1.01-2.91), and biopsy-proven steatosis (OR, 2.86; 95% CI, 1.61-5.06), although no significant association was noted among nucleos(t)ide analogue-treated patients (OR, 1.05; 95% CI, 0.62-1.77). Steatosis was associated with the development of cirrhosis (OR, 1.52; 95% CI, 1.07-2.16; I2  = 0%) and HBsAg seroclearance (OR, 2.22; 95% CI, 1.58-3.10; I2  = 49.0%). CONCLUSIONS: Hepatic steatosis was associated with an increased risk of HCC and cirrhosis among patients with CHB but with a higher chance of achieving a functional cure, highlighting the importance of identifying concomitant steatosis in CHB.

A novel design for solar collector used for water heating application having nanofluid as working medium: CFD modeling and simulation.

A solar collector is a simple and cheap device that converts solar radiation into valuable heat energy. The thermal performance of the solar collectors can be enhanced significantly with the suspension of nanoparticles in the base fluid. A novel design for a solar-assisted water heater (SWH) is proposed in the current study, and the effect of nanofluid has been investigated on the thermal efficiency of the SWH. The use of nanofluid is one of the prominent methods in comparison to other techniques for improving the performance of solar collectors. Therefore, the base working fluid, i.e., water is mixed with the alumina nanoparticles of average particle size of 30 nm, and they are assumed to be spherical. The flow and thermal characteristics of nanofluid through the solar water heater are simulated numerically with the help of the Eulerian-Eulerian two-phase model using the finite volume method (FVM). The commercial package ANSYS Fluent, is used for modeling the problem under transient conditions with a pressure-based solver. In comparison to a conventional flat plate collector, the proposed solar water heater consists of a corrugated absorber-plate and the effect of the radius of curvature has been investigated on the heat transfer and collector efficiency. With the proposed design, the heat transfer area available with the riser tubes increases remarkably and it leads to a 43% and 14% increase in heat transfer augmentation and collector efficiency, in comparison to the conventional solar water heater.

Designing of gigantic first-order hyperpolarizability molecules via joining the promising organic fragments: a DFT study.

A suitable substitution of carbazole with a π-spacer group like cyanoethynylethene offers exciting future opportunities in terms of smart nonlinear optical material. In the quest of better organic nonlinear optical material, we have designed a series of derivatives based on carbazole and cyanoethynylethene fragment combinations in a unique fashion by employing the density functional (DFT) methods. The calculated time-dependent density functional theory (TD-DFT) calculations infer that the gigantic first static hyperpolarizability (ßtot) values are due to a lower energy gap and higher transition dipole moment for the crucial electronic transition. Furthermore, to see the in-depth execution for enhanced second-order nonlinear optics and the structure property relationship on nonlinear optics (NLO) behavior, we have performed frontier molecular orbitals (FMO), density of state (DOS), and transition density matrix (TDM). Furthermore, CAM-B3LYP functional-based calculated results infer that the designed molecule 10 show the first static hyperpolarizability is 923.93 × 10-30 esu which is 69 times larger than that of p-nitroaniline.

Prevalence of familial hypercholesterolemia in patients with confirmed premature coronary artery disease in Ranchi, Jharkhand.

BACKGROUND: Familial hypercholesterolemia (FH) is an under-diagnosed autosomal co-dominant genetic disorder characterized by very high plasma levels of low-density lipoprotein cholesterol (LDL-C), premature coronary artery disease (CAD) with arcus cornealis, and xanthomas. Among patients with CAD, the frequency of FH is significantly higher than that of the general population, but little data are available in India in this regard. This study aimed to assess the prevalence of FH in patients with premature coronary artery disease for the first time in the Jharkhand population. RESULTS: The study was conducted on 200 premature CAD patients at RIMS hospital, Ranchi, from January 2020 to June 2021 with CAG-confirmed acute coronary syndrome. The study, without taking the aid of genetic profiling of the patients and using the Dutch Lipid Clinic Network Criteria, revealed quite a high (23.5%) prevalence of potential FH in patients with premature CAD apart from the conventional risk factors. Mean LDL-C levels among patients with definite, probable, possible, and no FH were recorded as 250.39, 184.32, 136.11, and 108.09 mg/dl, respectively. Arcus cornealis was seen in 55.31% of patients with potential FH, 90% in definite FH, and 44.40% with probable FH. Patients with potential FH were more likely to be younger (age < 40 years) males, having a history of CAD and a family history of premature CAD as compared to patients without FH. CONCLUSIONS: There was no previous report of large studies on FH or its epidemiology and its natural history from India. The present study is the first one to show a high prevalence of potential FH in premature CAD (about 23.5%). This preliminary study revealed that the prevalence of FH in patients with premature CAD who came to the tertiary care hospital of Ranchi, Jharkhand, was high, apart from the conventional risk factors.

Computational analysis on solar air heater with combination of alternate dimple protrusions and intrusions on absorber plate with one rounded corner triangular duct.

This study focuses on improving heat transfer by converting one of the corners of the duct to a rounded structure. To study the effect of dimpled shaped protrusions and intrusions on the rounded corner triangular duct with a constant radius of curvature by varying relative streamwise distance (z/e) with a constant transverse distance x'/e = 10,14 and 18. Steady-state, turbulent flow heat transfer under thermal boundary conditions is to be analyzed by varying different Reynolds numbers (5600 to 21000). The duct with dimple-shaped protrusions and intrusions is compared with a simple triangular duct. Optimization of relative horizontal distance (z'/e) by keeping constant protrusion to protrusion distance as z/e = 28 and relative transverse distance as x/e = 10, 14, and 18. It was noted that there was a significant loss in friction and a rise in heat transfer. The relationship between friction factor and Nusselt number was formulated using operating and roughness parameters, using the data collected from the numerical investigation. The friction factor increases significantly with roughness elements, and it is maximum for x'/e = 20 at a low Reynolds number. Nusselt number increases with roughness elements, and it is maximum for x'/e = 14 for all Reynolds numbers and all the models. Enhancement of Nusselt number is due to increase of local heat transfer because of local vortex neat heat transfer zone. The maximum outlet temperature is obtained at a low Reynolds number. The maximum temperature of the heated surface is obtained for Rc = 0.67 h and the minimum for Rc = 0.33 h.