A New Heat Transfer Coefficient Correlation for Condensing Flows of Pure Refrigerants and Refrigerant Mixtures within Horizontal Microfin Tubes

A new correlation is presented to predict the heat transfer coefficients (HTCs) of pure refrigerants and refrigerant mixtures undergoing convective condensation within horizontal microfin tubes. Preliminary results are reported here for a 318–point experimental database put together from 8 sources. The data includes CO2, R134a, R22, R407C, and R410A, 3.6–9.0 mm fin root diameter tubes, 14.3°C to 47.0°C saturation temperatures, vapor qualities from 4% to 99%, reduced pressures from 0.25 to 0.98, and heat and mass fluxes ranging from 2.9 to 39.9 kW/m2 and 98.5 to 800 kg/s.m2 respectively. Sixty unique dimensionless parameters pertinent to convective condensation in microfin tubes were first selected. Multi-variable regression analysis was then applied to identify the most significant variables influencing the condensing Nusselt number. The new correlation was evaluated and compared with two extant correlations (Yu and Koyama (1998 and 2008). Overall evaluation for the entire database shows that the new correlation is significantly better than these extant correlations. For this overall assessment, the new correlation predicts 82.6% of the data within ±30% error bands, with a mean absolute deviation (MAD) of 18.8%. For the 127 CO2 points and the remaining 191 points for halogenated refrigerants, the new correlation predicts 85.4% and 80.6% of the data respectively within ±30% error bands, with a MAD of 17.8% and 19.4% respectively. In comparison, the Yu and Koyama (1998) and (2008) correlations give the following performance respectively for the same database: (a) entire database: 45.4% and 25.7% of the data within ±30% error bands, and a MAD of 66.9% and 56.6%, (b) CO2: 18.1% and 15.0% of the data within ±30% error bands, and a MAD of 79.1% and 59.5%, (c) halogenated refrigerants: 66.0% and 33.0% of the data within ±30% error bands, and a MAD of 24.1% and 54.7%. The database will be expanded to include more refrigerants and operating conditions/tube geometries of practical interest. The performance of additional extant correlations such as those of Kedzierski and Goncalves (1999), Cavallini et al. (1995), and Cavallini et al. (2009) for the extended database will also be explored. The distribution of the entire database and the performance of the new correlation will be examined relative to refrigerant, and for various bins of fin root diameter, Dr, mass flux, G, all-liquid Reynolds number, Real, reduced pressure, PR, saturation temperature, Tsat, heat flux q, and vapor quality, x. Based on the bin analysis, parameter ranges in which one of the extant correlations gives better predictions than the new correlation will also be identified. Based on this analysis, overall recommendations for using the correlation most effectively will be provided

Evaluation of antidiabetic activity of fruit of Coriandrum sativum. Linn methanolic extract in Streptozocin induced diabetic wistar Albino rats

Background: Diabetes prevalence is estimated to increase annually. Numerous people use traditional medicine, such as India also considered as the diabetic capital in the world. Diabetes is a metabolic disorder characterized by disturbances in lipid, carbohydrate and protein metabolism. The present study to evaluate the antidiabetic potential of coriandrum sativum. linn fruits methanolic extract in streptozocin induced diabetic wistar albino rats model.Methods: Diabetes induction in wistar albino rats by administration of streptozocin (50mg/kg, i.p.) in citrate buffer. 30 wistar albino rats were divided into 5 groups (A, B, C, D, E). Group A: served as normal control, whereas Group B: diabetic control, Group C, D methanolic coriandrum sativum Linn. fruits extract (CSFME) at a dose of 100, 200mg/kg orally, Group E was given standard drug Glibenclamide (0.5mg/kg) orally. All groups are administered for the period of 14 consecutive days and blood sugar levels was measured at regular intervals up to end of the study.Results: This present research study confirms that the test drug compound CSFME has sustained oral hypoglycaemic activity and statistically significant (p ≤0.05) and which is comparable with standard drug Glibenclamide.Conclusions: This research study confirms that the CSFME has antidiabetic activity against streptozocin induced wistar diabetic albino rats. It could be a novel antidiabetic agent and also a dietary adjunct in the type 2 diabetes management and its complication. Further studies are necessary required to confirm the antidiabetic activity of individual phytochemical compounds of Coriandrum sativum

The genotypes and virulence attributes of C. albicans isolates from oral leukoplakia

There is a debate as to whether some types of oral leucoplakias (OL) are caused by Candida species, and whether they contribute to the malignant transformation, associated with a minority of such lesions. As no detailed population analysis of yeast isolates from OL is available, we evaluated the virulence attributes, and genotypes of 35 C. albicans from OL, and compared their genotypes with 18 oral isolates from healthy individuals. The virulence traits evaluated were esterase, phospholipase, proteinase, haemolysin and coagulase production, and phenotypic switching activity, and yeast adherence and biofilm formation. DNA from OL and control yeasts were evaluated for A, B or C genotype status. Phospholipase, proteinase, and coagulase activity and biofilm formation was observed in 80%, 66%, 97 % and 77 % of the isolates, respectively. Phenotypic switching was detected in 8.6%, while heamolytic, and esterase activity and adherence were noted in all isolates. The genotype A was predominant amongst both the OL and control groups. Due to the small sample size of our study a larger investigation to define the role of candidal virulent attributes in the pathogenicity of OL is warranted, and the current data should serve as a basis until then

SRI LANKA OXYGEN READINESS AND STRATEGIES ADAPTED FOR COVID-19 PATIENTS’ MANAGEMENT

Background: Shortly after the Covid-19 oxygen crisis in India, the Sri Lanka Ministry of Health started investigating and analyzing gaps in oxygen production, supplies and demands. Aims: This study aimed to evaluate the preparedness in Covid-19 cases management and recommend strategies to prevent oxygen crisis in healthcare facilities. Methods: This study used information on oxygen source redundancy and delivery methods to assess whether a healthcare facility is prepared to provide the necessary oxygen demand for patients in need and to estimate the number of patients that can be treated with the currently available oxygen supplies. The predicted oxygen supplies and demands were assessed with a panel of experts using qualitative and quantitative methods. Data were collected using the Health Information Update System. Results: Sri Lanka had 39,529 designated hospital beds including Intensive Care Unit and High Dependency Unit beds for Covid-19 patients. Even though an average number of patients were reaching 30,000, the actual oxygen demands were around 1,200 which were easily manageable with the current capacity of 80 tons per day. Conclusions: Sri Lanka has made progress to increase access to oxygen by using novel methods to procure and increase oxygen availability, storing, and carrying capacity

All India Co-ordinated Research Project on Biological Control of Crop Pests

Not AvailableSurveys were undertaken to document the fauna of insects, spiders and entomopathogenic nematodesacross India despite the travel restrictions due to COVID-19. The expeditions undertaken yielded several species of natural enemies viz.,Chalcididae (66.32%), Eulophidae (19.94%), Pteromalidae (4.14%) and Encyrtidae (3.37%) of Hymenoptera and 14 species of trichogrammatids representing 7 genera. The predominant genera of hymenopteran insect parasitoids were identified as Dirhinus Dalman (30.47%) followed by Brachymeria Westwood (27.73%), Hockeria Walker (22.27%) and Antrocephalus Kirby (18.75%). Revisionary studies of the braconid parasitoid, Apanteles sp. ater-group including subgroup eublemmae of the genus (Hymenoptera: Braconidae) of the Oriental region was carried out with an illustrated key, in which a total of 97 species were recorded and illustrated. Three species of tachinid flies, Peribaea orbata on larva of Spodoptera litura, Halidaia luteicornis on larva of Parnara sp., Sturmiopsis inferens on larva of Sesamia inferens and Carcelia sp. from the larvae of Helicoverpa armigera (Noctuidae) were identified and described. The spider fauna of rice ecosystem was documented, where six species of long jawed orb weaver, Tetragnatha species have been described of which T. keyserlingi was the predominant species across the surveyed locations in Tamil Nadu. The species, Tetragnathanitens collected from Tamil Nadu and Telangana was the first report from India. The spitting spider, Scytodes fusca Walckenaer of family Scyotidae was redescribed with documentation of variations in the vulval pattern of the female and theory about the introduction of this Pantropical species to India.Not Availabl

Liver-Specific Expression of Transcriptionally Active SREBP-1c Is Associated with Fatty Liver and Increased Visceral Fat Mass

The pathogenesis of fatty liver is not understood in detail, but lipid overflow as well as de novo lipogenesis (DNL) seem to be the key points of hepatocyte accumulation of lipids. One key transcription factor in DNL is sterol regulatory element-binding protein (SREBP)-1c. We generated mice with liver-specific over-expression of mature human SREBP-1c under control of the albumin promoter and a liver-specific enhancer (alb-SREBP-1c) to analyze systemic perturbations caused by this distinct alteration. SREBP-1c targets specific genes and causes key enzymes in DNL and lipid metabolism to be up-regulated. The alb-SREBP-1c mice developed hepatic lipid accumulation featuring a fatty liver by the age of 24 weeks under normocaloric nutrition. On a molecular level, clinical parameters and lipid-profiles varied according to the fatty liver phenotype. The desaturation index was increased compared to wild type mice. In liver, fatty acids (FA) were increased by 50% (p<0.01) and lipid composition was shifted to mono unsaturated FA, whereas lipid profile in adipose tissue or serum was not altered. Serum analyses revealed a ∼2-fold (p<0.01) increase in triglycerides and free fatty acids, and a ∼3-fold (p<0.01) increase in insulin levels, indicating insulin resistance; however, no significant cytokine profile alterations have been determined. Interestingly and unexpectedly, mice also developed adipositas with considerably increased visceral adipose tissue, although calorie intake was not different compared to control mice. In conclusion, the alb-SREBP-1c mouse model allowed the elucidation of the systemic impact of SREBP-1c as a central regulator of lipid metabolism in vivo and also demonstrated that the liver is a more active player in metabolic diseases such as visceral obesity and insulin resistance

Automatic Valve Operation for Bunkering

Bunkering means refueling of the ships including the fuel filling and distributing the fuel which is being supplied to the shipboard tank. Bunkering is the most difficult procedure of operation on a ship which may lead to several accident and lead to spill of HFO into the sea. Bunkering on a ship can be of fuel oil, sludge, diesel oil, cargo etc. Bunkering of. fuel oil or diesel oil requires most care and alternate to prevent the different kind and type of accidents and oil spill. Current scenario of bunkering system is done manually. This process takes more man power and requires continuous sounding of the tank at particular time interval. So, it is necessary to find out an alternate solution which gives continuous sounding of the bunker tank automatically all the time. The proposed project aims to overcome above problems. A model is fabricated with two tanks, a submersible pump, solenoid valve, microcontroller which controls the operation of valve for bunkering operation and sensors to sense the level of the tanks such that the valves open and close at preset time. The prototype was tested based on time taken in filling a tank and the response of the sensor with respect to time was identified. It is found that the time taken for bunkering is reduced

Evaluation of antidiabetic activity of fruit of Coriandrum sativum. Linn methanolic extract in Streptozocin induced diabetic wistar Albino rats

Background: Diabetes prevalence is estimated to increase annually. Numerous people use traditional medicine, such as India also considered as the diabetic capital in the world. Diabetes is a metabolic disorder characterized by disturbances in lipid, carbohydrate and protein metabolism. The present study to evaluate the antidiabetic potential of coriandrum sativum. linn fruits methanolic extract in streptozocin induced diabetic wistar albino rats model.Methods: Diabetes induction in wistar albino rats by administration of streptozocin (50mg/kg, i.p.) in citrate buffer. 30 wistar albino rats were divided into 5 groups (A, B, C, D, E). Group A: served as normal control, whereas Group B: diabetic control, Group C, D methanolic coriandrum sativum Linn. fruits extract (CSFME) at a dose of 100, 200mg/kg orally, Group E was given standard drug Glibenclamide (0.5mg/kg) orally. All groups are administered for the period of 14 consecutive days and blood sugar levels was measured at regular intervals up to end of the study.Results: This present research study confirms that the test drug compound CSFME has sustained oral hypoglycaemic activity and statistically significant (p ≤0.05) and which is comparable with standard drug Glibenclamide.Conclusions: This research study confirms that the CSFME has antidiabetic activity against streptozocin induced wistar diabetic albino rats. It could be a novel antidiabetic agent and also a dietary adjunct in the type 2 diabetes management and its complication. Further studies are necessary required to confirm the antidiabetic activity of individual phytochemical compounds of Coriandrum sativum