Sung In Kim, Hamidur Rahman and Ibrahim Hassan
One of the most critical gas turbine engine components, the rotor blade tip and casing, is exposed to high thermal load. It becomes a significant design challenge to protect the…
Abstract
Purpose
One of the most critical gas turbine engine components, the rotor blade tip and casing, is exposed to high thermal load. It becomes a significant design challenge to protect the turbine materials from this severe situation. The purpose of this paper is to study numerically the effect of turbine inlet temperature on the tip leakage flow structure and heat transfer.
Design/methodology/approach
In this paper, the effect of turbine inlet temperature on the tip leakage flow structure and heat transfer has been studied numerically. Uniform low (LTIT: 444 K) and high (HTIT: 800 K) turbine inlet temperature, as well as non‐uniform inlet temperature have been considered.
Findings
The results showed the higher turbine inlet temperature yields the higher velocity and temperature variations in the leakage flow aerodynamics and heat transfer. For a given turbine geometry and on‐design operating conditions, the turbine power output can be increased by 1.33 times, when the turbine inlet temperature increases 1.80 times. Whereas the averaged heat fluxes on the casing and the blade tip become 2.71 and 2.82 times larger, respectively. Therefore, about 2.8 times larger cooling capacity is required to keep the same turbine material temperature. Furthermore, the maximum heat flux on the blade tip of high turbine inlet temperature case reaches up to 3.348 times larger than that of LTIT case. The effect of the interaction of stator and rotor on heat transfer features is also explored using unsteady simulations. The non‐uniform turbine inlet temperature enhances the heat flux fluctuation on the blade tip and casing.
Originality/value
The increase of turbine inlet temperature is usually proposed to achieve the higher turbine efficiency and the higher turbine power output. However, it has not been reported how much the heat transfer into the blade tip and casing increases with the increased turbine inlet temperature. This paper investigates the heat transfer distributions on the rotor blade tip and casing, associated with the tip leakage flow under high and low turbine inlet temperatures, as well as non‐uniform temperature distribution.
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This study aims to assess the association of dietary inflammatory index (DII), consumption of functional food and some antioxidants with COVID-19 vaccine side effects in Iranian…
Abstract
Purpose
This study aims to assess the association of dietary inflammatory index (DII), consumption of functional food and some antioxidants with COVID-19 vaccine side effects in Iranian adults.
Design/methodology/approach
This was a case–control study conducted among the 1,067 Iranian adults who were invited to participate through WhatsApp software. The dietary intake was assessed using the food frequency questionnaire.
Findings
There was a significant difference (p = 0.04) in vitamin D consumption between healthy people and persons with a vaccine side effect. Vitamin E intake in healthy participants was significantly (p = 0.04) more than case group. There was a significant difference in the consumption of zinc (p = 0.01), selenium (p = 0.02) and vitamin C (p = 0.02), between persons without vaccine side effects and the case group. Consumption of onion (82.5 ± 9.5 g/day vs 32.2 ± 6.3; p = 0.0001), garlic (6 ± 0.3 g/day vs 0.2 ± 0.08; p = 0.0001) and oat (2.2 ± 0.05 g/day vs 0.5 ± 0.01; p = 0.001) in the control group was significantly more than persons with vaccine side effects. With the increase in each unit in the score of the DII, the risk of COVID-19 vaccine side effect incidence increased 1.7 times (OR = 1.7; 95% CI: 1.3–1.8).
Originality/value
To the best of the authors’ knowledge, this study is the first that investigated the association between functional food intake and side effects of the COVID-19 vaccine.
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Hawal Lateef Fateh, Negin Kamari, Ayad M. Ali, Jalal Moludi and Shahab Rezayaeian
The nutritional and anthropometric status can be essential in determining their immune response to vaccines. The purpose of this paper was to investigate the association between…
Abstract
Purpose
The nutritional and anthropometric status can be essential in determining their immune response to vaccines. The purpose of this paper was to investigate the association between diet quality and anthropometric indices with the side effects of the Pfizer-BioNTech COVID-19 vaccine and the SARS-CoV-2 immunoglobulin G titer among Kurdish adults.
Design/methodology/approach
This cross-sectional survey-based study was conducted between December 2021 and February 2022. This paper included data on 115 adults, 20–89 years old, from the Kurdistan region. Dietary information was collected using a short food frequency questionnaire, and diet quality was assessed using a plant-based healthy diet score. A blood test was performed to measure the SARS-CoV-2 immunoglobin G (IgG) titer after the vaccination's first and second doses.
Findings
Overweight and obese subjects reported more local pain, myalgia, headache, local bruising and local reactions after receiving the first dose of the vaccine (p = 0.04). People on a less healthy diet reported more local pain, myalgia and headache (p = 0.04) and more local bruising and reactions (p = 0.01) after receiving the second dose of the vaccine. On the other hand, the authors observed that those with healthy dietary habits had more IgG titer after the first and second doses of vaccination than those with less healthy dietary habits (p = 0.001).
Originality/value
The results showed that participants with a healthy diet and normal weight status had fewer side effects of the Pfizer-BioNTech COVID-19 vaccine than obese people and those with a less healthy diet.