scholarly journals Effect of a Circular Ring on the Side Force of a Cone-Cylinder Body

2020 ◽  
Author(s):  
Shashank Gaurav ◽  
Sudip Das ◽  
Priyank Kumar
Keyword(s):  
Angle Of Attack ◽  
Circular Ring ◽  
Diameter Ratio ◽  
The Body ◽  
Base Diameter ◽  
Initial Portion ◽  
Side Force ◽  
Nose Shape ◽  
Almost All ◽  
Local Diameter

This paper aims to investigate the side force on a cone-cylinder geometry at different angles of attack (α) by adopting experiments and computations. The cone-cylinder configuration had a length to diameter ratio (L/D) of 10, and a base diameter (D) of 25 mm. The nose shape had a fineness ratio of approximately 3. Results indicated that the side force increases with the increasing of the angle of attack. A circular ring was used to reduce the side force at different angles of attack. Using a smaller height ring (2% of local diameter) in the initial portion of the body did not reduce the side force significantly at lower angles of attack. However, a ring with larger height (5% of local diameter) placed at 2.5 times the diameter of the body from the tip reduced the side force at almost all the angles of attack.

Effect of ring size on the side force over ogive-cylinder body at subsonic speed

2016 ◽  
Vol 120 (1231) ◽  
pp. 1487-1506 ◽  
Author(s):  
P. Kumar ◽  
J.K. Prasad
Keyword(s):  
Rectangular Cross Section ◽  
Substantial Reduction ◽  
Circular Ring ◽  
The Body ◽  
Leeward Side ◽  
Axial Distance ◽  
Base Diameter ◽  
Freestream Velocity ◽  
Side Force ◽  
Lift And Drag

ABSTRACTExperiments and computations have been made to obtain the details of the flow field over a slender body at high angles of attack at a freestream velocity of 17 m/s corresponding to a Reynolds number of 2.9×104based on the base diameter. Experiments indicated that the existence of side force at higher angles of attack is mainly due to the presence of asymmetric vortices in the leeward side. A rectangular cross-section circular ring placed at an axial distance of 3.5 times the base diameter reduced the side force at all the angles of attack. Investigations were made to obtain the effect of the height of the ring at an angle-of-attack of 50° where the side force experienced is relatively large. A ring placed at a distance of 3.5 times the base diameter alters the initial vortices and hence helps in substantial reduction of the side force. Studies with rings of different heights indicate that a ring having a height of 3% of the local diameter reduced the side force at almost all the angles of attack for the present flow conditions and provided the least disturbance to the lift and drag of the body.

Side force over slender body with rings at different location at subsonic speed

2016 ◽  
Vol 231 (8) ◽  
pp. 1478-1491 ◽  
Author(s):  
P Kumar ◽  
JK Prasad
Keyword(s):  
The Body ◽  
Slender Body ◽  
Flow Conditions ◽  
Base Diameter ◽  
Initial Portion ◽  
Side Force ◽  
Model Base ◽  
Axial Location ◽  
Subsonic Speed ◽  
Asymmetric Vortices

Investigations have been made adopting experiments and computations on an ogive-nosed slender body at different angles of attack and Reynolds number of 29,000 based on the model base diameter diameter. The results indicated an increase in the side force at large angles of attack, which is mainly due to the presence of asymmetric vortices in the leeward of the body. The inclusion of a rectangular cross-sectioned ring in the initial portion of the body reduced the side force at higher angles of attack. However, significant side force was experienced at lower angles of attack (30° < α < 40°). Use of a ring of 3% height was found to be suitable for reducing the side force at a higher angle of attack. From the results obtained it was observed that a ring if placed at a different axial location alters the flow field and changes the side force at higher angles of attack. Further studies indicated that placing of rings pair at an axial location of 3.5 and 4.5 times the base diameter reduced the side force to a very low value at all the angles of attack for the present shape of body and flow conditions.

scholarly journals Rolling Moment of Slender Body at High Incidence for Air to Air Missile Rocket Applications

2020 ◽  
Vol 70 (1) ◽  
pp. 18-22
Author(s):  
Priyank Kumar
Keyword(s):  
Diameter Ratio ◽  
The Body ◽  
Slender Body ◽  
Control Technique ◽  
Angle Of Incidence ◽  
Rolling Moment ◽  
Side Force ◽  
High Incidence ◽  
Nose Shape ◽  
Length To Diameter Ratio

Measurements of moments were carried out on a slender body having a pointed forebody at lower velocities. The slender body had an ogive nose shape and an overall length to diameter ratio of 16. The angle of incidence was varied from low to moderate angles of attack in the pitch plane. The main objective of the present investigation was to measure the rolling moments on the slender body with and without the control technique. The side force was reduced using a rectangular cross-sectioned ringplaced suitably on the body, however, the slender body was found to experience rolling moments which may be catastrophic.

Digestibility of nutrients and milk productivity of cows when using the concentrate mixture with the inclusion of rapeseed presscake

2020 ◽  
pp. 48-53
Author(s):  
L. Yarmots ◽  
G. Yarmots ◽  
A. Belenkaya
Keyword(s):  
Protein Digestibility ◽  
High Energy ◽  
Negative Influence ◽  
The Body ◽  
Milk Productivity ◽  
Lactating Cows ◽  
Low Protein ◽  
Concentrate Mixture ◽  
Almost All ◽  
Experimental Group

For ruminants, especially high-yielding animals in addition to the complete supply of animals with protein, its digestibility in the rumen is important. With low protein digestibility in the rumen, the released ammonia will be more effectively used by the rumen microflora, and the undigestible protein in the subsequent sections of the digestive tract can serve as a source of amino acids for the body. The use of concentrate mixtures with the inclusion of local, affordable and cheaper grain feeds, in particular a high-energy and protein ingredient- rapeseed presscake makes it possible to increase the milk productivity of cows throughout lactation. These presscakes are well balanced in their amino acid composition and belong to feeds whose protein has a low degree of digestibility in the rumen. The purpose of the researches was to study the digestibility of nutrients and milk productivity of cows when using the concentrate mixture with the inclusion of rapeseed presscake. In the scientific and economic experiment has been carried out on lactating cows, where the cows of the experimental group in the concentrate mixture of peas has been replaced with rapeseed presscake the digestibility of nutrients in the ration, energy metabolism and milk productivity have been studied. Studies have shown that almost all the nutrients were significantly better digested by the animals of the experimental group. Energy in milk was more allocated by cows of the experimental group by 6,29 MJ. From cows of the experimental group for 100 and 305 days of lactation has been obtained more milk by 6,27 and 7,06 %, respectively, than from control herdmates. The biochemical parameters of blood were within the limits of the physiological norm in animals of both groups. Thus, the replacement of peas with rapeseed presscake in the concentrate mixture did not have a negative influence on the metabolic processes and helped to increase the milk productivity of cows.

Blood, joy and tears: menarche narratives of undergraduate females in a selected in Nigeria Private University

2017 ◽  
Vol 31 (4) ◽  
Author(s):  
Adenike Adegbayi
Keyword(s):  
Adolescent Health ◽  
Qualitative Methodology ◽  
Private University ◽  
The Body ◽  
Female Adolescent ◽  
Menstrual Period ◽  
Future Health ◽  
Female Relative ◽  
Undergraduate Females ◽  
Almost All

Abstract The aim of the study is to add to the body of knowledge on less researched aspects of female adolescent health in Nigeria. It specifically explored the menarche or first period narratives of 136 young women, focusing on the contents of the discussion that ensued with whom they told when they first got their period using qualitative methodology. It also explores sources of premenstrual information and how the menstrual period is managed. The sample consisted of 136 undergraduate females in Redeemer’s University, Ede, Nigeria. Almost all of the respondents (95%) received information about menstruation from mothers, female relatives and school lessons prior to menarche. The majority of the respondents first told either their mother or a female relative when they first got their period and viewed menarche as a crisis. Two salient themes emerged from the contents of the narratives; celebration and advice. The advice theme was further explored and three advice patterns were identified: being a woman, hygiene and changed dynamics in relationships with males. Data from the present study suggests that only certain aspects of the menstruation discourse have evolved. All respondents reported using sanitary towels during their menstrual period with the majority experiencing cramps regularly and (61%) using pharmalogical agents for remedy. It is envisaged that findings from the study will be useful in future health intervention programmes and research on female adolescent health in Nigeria and elsewhere.

Demonstration of the relationship between MSD and online learning during the COVID-19 pandemic

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kochu Therisa Karingada ◽  
Michael Sony
Keyword(s):  
Online Learning ◽  
Undergraduate Students ◽  
Online Survey ◽  
Cross Sectional Study ◽  
The Body ◽  
Body Parts ◽  
Cross Sectional ◽  
Content Type ◽  
The Right ◽  
Almost All

PurposeThe COVID-19 pandemic lockdown has caught many educational institutions by surprise and warranted an abrupt migration from offline to online learning. This has resulted in an education change, without any time for due consideration, as regards its impact on musculoskeletal disorders (MSD) on students. The purpose of this study is to investigate MSD related to online learning during the COVID-19 pandemic lockdown.Design/methodology/approachA cross-sectional study was conducted on undergraduate students in India. In total, 261 students participated in this online survey.FindingsThe study finds that around 80% of students have reported some symptom in the head, neck and eyes since they started online learning. In total, 58% have reported MSD symptom in the right shoulder and 56% in the right hand fingers. Besides, more than 40 % of students experienced some MSD symptoms, in almost all the body parts studied, due to online learning. Correlation analysis is conducted between time spent on online learning per day and MSD symptoms.Originality/valueThis is the first study conducted on MSD and online learning during COVID-19 pandemic.

Strakes Effects on Asymmetric Flow Over a Blunt-Nosed Slender Body at a High Angle of Attack

2018 ◽  
Vol 141 (6) ◽  
Author(s):  
Qihang Yuan ◽  
Yankui Wang ◽  
Zhongyang Qi
Keyword(s):  
Angle Of Attack ◽  
Slender Body ◽  
Axial Position ◽  
High Angle ◽  
Asymmetric Flow ◽  
High Angle Of Attack ◽  
Side Force ◽  
Asymmetric Vortices ◽  
High Angles Of Attack ◽  
Blunt Nose

In general speaking, the missiles execute flight at high angles of attack in order to enhance their maneuverability. However, the inevitable side-force, which is caused by the asymmetric flow over these kinds of traditional slender body configurations with blunt nose at a high attack angle, induces the yawing or rolling deviation and the missiles will lose their predicted trajectory consequently. This study examines and diminishes the side-force induced by the inevitable asymmetric flow around this traditional slender body configuration with blunt nose at a high angle of attack (AoA = 50 deg). On one hand, the flow over a fixed blunt-nosed slender body model with strakes mounted at an axial position of x/D = 1.6–2.7 is investigated experimentally at α = 50 deg (D is the diameter of the model). On the other hand, the wingspan of the strakes is varied to investigate its effect on the leeward flow over the model. The Reynolds number is set at ReD = 1.54 × 105 based on D and incoming upstream velocity. The results verify that the formation of asymmetric vortices is hindered by the existence of strakes, and the strake-induced vortices develop symmetrically and contribute to the reduction in side-force of the model. In addition, the increase in strake wingspan reduces asymmetric characteristics of the vortex around the model and causes a significant decrease in side-force in each section measured. The strake with the 0.1D wingspan can reduce the sectional side-force to 25% of that in the condition without strakes.

scholarly journals Total body irradiation induced mouse small intestine senescence as a late effect

2019 ◽  
Vol 60 (4) ◽  
pp. 442-450 ◽  
Author(s):  
Yu Zhao ◽  
Junling Zhang ◽  
Xiaodan Han ◽  
Saijun Fan
Keyword(s):  
Small Intestine ◽  
Total Body Irradiation ◽  
Profile Analysis ◽  
Bacterial Flora ◽  
Body Weight Loss ◽  
Underlying Mechanism ◽  
The Body ◽  
Mouse Small Intestine ◽  
Total Body ◽  
Almost All

Abstract Radiation can induce senescence in many organs and tissues; however, it is still unclear how radiation stimulates senescence in mouse small intestine. In this study, we use the bone marrow transplantation mouse model to explore the late effects of total body irradiation on small intestine. Our results showed that almost all of the body hairs of the irradiated mice were white (which is an indication of aging) 10 months after the exposure to radiation. Furthermore, compared with the age-matched control mice, there were more SA-β-galactosidase (SA-β-gal)–positive cells and an upregulation of p16 and p21 in 8 Gy–irradiated mice intestinal crypts, indicating that radiation induced senescence in the small intestine. Intestinal bacterial flora profile analysis showed that the diversity of the intestinal bacterial flora decreased in irradiated mice; in addition it showed that the principal components of the irradiated and control mice differed: there was increased abundance of Bacteroidia and a decreased abundance of Clostridia in irradiated mice. To explore the underlying mechanism, an RNA-sequence was executed; the results suggested that pancreatic secretion, and the digestion and absorption of proteins, carbohydrates, fats and vitamins were damaged in irradiated mice, which may be responsible for the body weight loss observed in irradiated mice. In summary, our study suggested that total body irradiation may induce senescence in the small intestine and damage the health status of the irradiated mice.

scholarly journals THE BIOLOGICAL SIGNIFICANCE OF SELENIUM AND ITS PLACE IN RNA VIRAL DISEASES

2020 ◽  
Vol 21 (4) ◽  
pp. 21-31
Author(s):  
T.M. Guseynov ◽  
◽  
R.T. Guliyeva ◽  
F.R. Yakhyayeva ◽  
◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Immune Response ◽  
Viral Infections ◽  
Biological Significance ◽  
The Body ◽  
Viral Diseases ◽  
Essential Trace Element ◽  
Regulatory Processes ◽  
P Protein ◽  
Almost All

ABSTRACT. Selenium as an essential trace element takes part in the regulation of many vital processes. This is realized with the help of over 25 selenoproteins that affect oxidative stress, immune response, hormonal metabolism, cognitive function, etc. Recently (in the next 30 - 40 years), there have been reports of the effect on viral infections, which have now become widespread. It turned out that almost all RNA viruses are selenium-dependent objects, that is, their genome contains the codes of the most important selenium containing proteins, including such as glutathione peroxidase, thioredoxinreductase, selenium-P protein, etc. Their synthesis during the development of a viral infection at the expense of the host leads to a weakening of the synthesis of the body's own intracellular selenium proteins, which contributes to the development of oxidative stress and a failure of the immune response. And this leads to the devastation of the selenium depot of the body, intended for the synthesis of its selenium proteins, which participate in vital regulatory processes. This circumstance determines, to replenish the body's resources with selenium, the expediency of using selenium-containing pharmacopoeia preparations as adjuvant in the treatment of RNA viral infections.

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