Experimental investigation of various solid particle materials on the steady state gassolid fluidized bed system

The present study provides a comprehensive experimental work about fluidized bed gas-solid system characteristics by using different solid particles. Naphthalene, silica gel and sand (197 µm diameter) are utilized as a solid particles while air is used for fluidization. An experimental rig is build to test the various solid particles and to establish a good description of flow and heat transfer patterns for the fluidized bed gas-solid system. Based on the experimental tests, it is found that the solid particle type has a significant influence on the gas-solid flow dynamics. The experimental tests are performed for various fluidized bed velocities ( 0.8 , 1.2 and 1.6 m/sec ) and when the heat fluxes are varied as 80 , 120 and 160 W respectively. Experimental measurements are carried out under steady state situation. Depending on the experimental results , it can be concluded that sand solid particles are better than silica gel and naphthalene solid particles for heat transfer enhancement. Also, it can found for naphthalene , silica gel and sand solid particles that as the fluidized bed velocity and heat flux increase the temperature distribution along the fluidization column increases. Moreover, an empirical equation based on the experimental measurements which linking between Nusselt number (Nu) , Froude number (Fr) and Reynolds number (Re) is suggested. Comparisons with previously published works on gas-solid fluidized bed system are performed and good agreements between the results are observed

assessment of fetal oxygenation in grade III placental cacification

background

Chemical Composition, Antioxidant and Anti-bacterial Potential of Essential Oil of Medicinal plant Isodon rugosus

Isodon rugosus is a medicinally valuable herb containing a variety of important secondary metabolites and essential oil with important chemical constituents of pharmaceutical precursors. The active components of volatile oil of I. rugosus were analyzed using GC-MS. Anti-oxidant potential of the oil was assessed with 2, 2-diphenyl-1-picrylhydrazyl (DPPH). Anti-bacterial power of the essential oil accessed disc diffused method. A total of 19 constituents were quantified and identified with different concentrations in essential oil. Among which Caryophyllene oxide was 28.99 %. Limonene oxide cis was 26.52 %, (Z, E)-Farnesol was 17.34 %, followed by 1-erpinen-4-ol 3.33 %, o-Cymene 2.04 while the concentrations of rest of constituents were between 1.11 to 0.2 %. The investigation showed that the essential oil of I. rugosus possessed significant antibacterial and antioxidant potentia

Intussusception and COVID-19 in Children: A Systematic Review and Meta-Analysis

Background: Intussusception (ISN) post-COVID-19 infection in children is rare but can occur. SARS-CoV-2 may play a role in the pathogenesis of ISN and trigger immune activation and mesenteric adenitis, which predispose peristaltic activity to “telescope” a proximal bowel segment into the distal bowel lumen. Objectives: To estimate the prevalence of SARS-CoV-2 infection in ISN children and analyze the demographic parameters, clinical characteristics and treatment outcomes in ISN pediatric patients with COVID-19 illness. Methods: We performed this systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Studies reporting on the incidence of ISN post-SARS-CoV-2 infection in children, published from 1 December 2019 until 1 October 2022, in PROQUEST, MEDLINE, EMBASE, PUBMED, CINAHL, WILEY ONLINE LIBRARY, SCOPUS and NATURE, with a restriction to articles available in the English language, were included. Results: Of the 169 papers that were identified, 34 articles were included in the systematic review and meta-analysis (28 case report, 5 cohort and 1 case-series studies). Studies involving 64 ISN patients with confirmed COVID-19 (all patients were children) were analyzed. The overall pooled proportions of the ISN patients who had PCR-confirmed SARS-CoV-2 infection was 0.06% (95% CI 0.03 to 0.09, n = 1790, four studies, I2 0%, p = 0.64), while 0.07% (95% CI 0.03 to 0.12, n = 1552, three studies, I2 0%, p = 0.47) had success to ISN pneumatic, hydrostatic and surgical reduction treatment and 0.04% (95% CI 0.00 to 0.09, n = 923, two studies, I2 0%, p = 0.97) had failure to ISN pneumatic, hydrostatic and surgical reduction treatment. The median patient age ranged from 1 to 132 months across studies, and most of the patients were in the 1–12 month age group (n = 32, 50%), p = 0.001. The majority of the patients were male (n = 41, 64.1%, p = 0.000) and belonged to White (Caucasian) (n = 25, 39.1%), Hispanic (n = 13, 20.3%) and Asian (n = 5, 7.8%) ethnicity, p = 0.000. The reported ISN classifications by location were mostly ileocolic (n = 35, 54.7%), and few children experienced ileo-ileal ISN (n = 4, 6.2%), p = 0.001. The most common symptoms from ISN were vomiting (n = 36, 56.2%), abdominal pain (n = 29, 45.3%), red currant jelly stools (n = 25, 39.1%) and blood in stool (n = 15, 23.4%). Half of the patients never had any medical comorbidities (n = 32, 50%), p = 0.036. The approaches and treatments commonly used to manage ISN included surgical reduction of the ISN (n = 17, 26.6%), pneumatic reduction of the ISN (n = 13, 20.2%), antibiotics (n = 12, 18.7%), hydrostatic reduction of the ISN (n = 11, 17.2%), laparotomy (n = 10, 15.6%), intravenous fluids (n = 8, 12.5%) and surgical resection (n = 5, 7.8%), p = 0.051. ISN was recurrent in two cases only (n = 2, 3.1%). The patients experienced failure to pneumatic (n = 7, 10.9%), hydrostatic (n = 6, 9.4%) and surgical (n = 1, 1.5%) ISN treatment, p = 0.002. The odds ratios of death were significantly higher in patients with a female gender (OR 1.13, 95% CI 0.31–0.79, p = 0.045), Asian ethnicity (OR 0.38, 95% CI 0.28–0.48, p \u3c 0.001), failure to pneumatic or surgical ISN reduction treatment (OR 0.11, 95% CI 0.05–0.21, p = 0.036), admission to ICU (OR 0.71, 95% CI 0.83–1.18, p = 0.03), intubation and placement of mechanical ventilation (OR 0.68, 95% CI 0.51–1.41, p = 0.01) or suffering from ARDS (OR 0.88, 95% CI 0.93–1.88, p = 0.01) compared to those who survived. Conclusion: Children with SARS-CoV-2 infection are at low risk to develop ISN. A female gender, Asian ethnicity, failure to ISN reduction treatment (pneumatic or surgical), admission to ICU, mechanical ventilation and suffering from ARDS were significantly associated with death following ISN in pediatric COVID-19 patients