Computational modeling of brittle impact erosion mechanisms

Materials are subjected to an erosion-corrosion environment in a wide range of applications today. Elevated temperatures promote the formation of oxide layers in jet engines. In fluidized bed boilers, the bed materials and piping of slurries and caustic materials cause erosion and corrosion. The process of erosion-corrosion may result in material loss and damage. Proper analytical modeling of the erosion-corrosion processes validated by experiments is needed to estimate the extent of damage in the material.;Empirical relations are available in the literature for predicting the amount of material loss due to erosion. These are obtained by conducting large number of experiments. But many restrictions apply in implementing these empirical relations. If the erosion process can be modeled analytically, in a very generic way, then they can be used to make a parametric study. The current work is focussed on developing a computational model for a metal-oxide system. A 3-D finite element model is developed using a commercial package and a transient dynamic analysis performed in order to predict the effects of erosion. Using suitable failure criteria, the amount of oxide lost in the metal-oxide system is predicted for various parameters like velocity, angle of attack, size of erodent, etc. The result of this study shows that volume loss for various angles of attack is that of typical brittle erosion. The volume loss has three different ranges with increase in velocity. And also two simultaneous adjacent impact results in volume loss as that of two isolated impacts

A Yoga Intervention for Stress Management of Young Athletes During Covid-19 Lockdown

This research aimed to check the effectiveness of a specially designed yogic package suitable for athletes who were in fear due to the covid-19 lockdown to test its effectiveness in bringing back their mental power. Yoga is not a new science. Centuries back, the importance of physical and psychological health and the impact of yoga has been explained in Thirumandiram by Yoga Maharishi Thirumoolar. Psychological resilience is necessary to enhance athletic performance and foster valuable life skills. Through positive adaptation to adversity and stressors in competitive performance, athletes can cultivate their ability to respond to negative stimuli, ultimately evolving personal growth effectively. For young athletes, the development of resilience is particularly crucial. Due to confinement and social isolation regulations, young athletes face distinct challenges in sport, including future fear, physical toughness, body image issues, emotional maturity, increased mental distress, and internalization of emotions during a covid lockdown. The aim of this research is to test if yoga could build resilience and discuss the implications and applications relevant to young athletes. 30 young athletes between 19 - 21 years accepted to participate in the research were accommodated. The pretest was conducted on the selected variables and selected subjects were assigned into two groups of 15 subjects each. The Experimental Group (YG) underwent yoga training and the control group (CG) did not undergo any specific training for 3 weeks (6 days a week for 2 sessions a day).  After 3 weeks of training, a post-test was conducted on resilience (self-determination, physical toughness and Emotion control & Maturity) for both groups. To find out if any significant difference exists between pre and post-training, a t-ratio was applied.  The result depicts that yoga is the best tool to work on resilience in such unprecedented tough times, securing current physical and mental health, enhancing sports performance, and helping young athletes stay navigated to life's goals

Impact of COVID Lockdown on Mental Health of Elite Athletes – A Status Study

Covid lockdown upset the whole globe to a stunning shock. Never in life had we ever faced such a crisis, complete lockdown, which all led to lonely untouchable deaths, sickness, isolation, quarantine finally ended up in disordered mental health. Though there is an increased awareness of health and using the need to stay fit, the lockdown restrictions don’t pay space for it. If this is the case for the typical athletes who dedicate their entire life, investing time, body, mind and soul into the athletic performance, have completely dislodged routines. A layman’s eyes may find a sportsman's life a fun-filled, excited, easy go. But it’s not the true colour. Ambitious and amateurish life in training has changed to a cloudy future feared min set. This study aimed to determine the mental health status of elite athletes during the covid lockdown. To cosnduct the study, data was collected through google form using Kessler Psychological Distress Scale (K-10). Out of the 374 athletes who responded, 218  athletes (58.29%) were in extreme stress almost all the time during the covid lockdown. Thus it is concluded that in this situation, coaches and sports psychologists have to create awareness about the lockdown, contact athletes and counsel them. Athletes are the pride of every nation and need to recover from psychological setbacks. So, it is. The need of the hour is to design the best training programme suitable and possible during lockdown to protect their skills and abilities. Even from these minds, our national athletes need to recover from psychological setbacks. So, we must find the best training method for them and protect their skills

Experimental Studies of Metal Oxide Suspended Nanofluids on the Enhancement of the Thermal Performance of Heat Pipes

Heat transmission by means of heat pipes is one of the fastest and most efficient thermal management technologies. The performance of typical thermal systems that use heat transfer fluid (HTF) can be improved by incorporating nanoparticles into the HTF (nanofluid). This work describes an experimental examination of metal oxide suspended nano-sized particles such as zinc oxide (ZnO) and copper oxide (CuO) in deionized water as the base fluid (DI water). The nanoparticle levels used for this investigation are 0%, 1%, 2% and 3% by weight. Experiments were carried out at all levels of nanofluids with heat pipe inclinations ranging from horizontal to vertical. The rheological measurements of the two nanofluids under a wide range of temperatures and shear rate were studied. The thermal performance of a heat pipe with water-based nanofluids is expected to improve more than that of a normal heat pipe. The thermal efficiency of a heat pipe using nanofluids was examined at various tilt angles. The results show that a heat pipe at a tilt angle of 60° generates superior effects. Temperature distribution along the length of the heat pipe under different power input conditions was presented using varied weight proportions of nanofluids (ZnO & CuO)

Intra sheath corticosteroid injection for De Quervain’s tenosynovitis

Background: De Quervain’s disease or stenosing tenosynovitis of the first dorsal compartment of the wrist is a common condition, which affects the Abductor pollicis longus and the extensor pollicis brevis tendons. There are characteristic signs and symptoms including a positive Finkelstein's test. Different options for treatment include conservative approaches like analgesics, splinting and physical therapy. If conservative options fail then steroid injection is considered.Methods: This is a retrospective study of single dose intra-sheath triamcinolone and lignocaine injection in 32 patients at our institute who were followed up for a period of 12 months.Results: In our study there were 25 females and 7 males with a mean age of 46.4±8.03 years. Right side was involved in 17 patients and left side in 15 patients. The pre procedure VAS score was 8.65±1.07. The follow up VAS scores at 1, 6 and 12 months respectively were 1.4±1.14, 0.84±1.06 and 1.03±1.26 respectively. 4 out of 32 patients had positive Finkelstein’s test at 1 year follow up. Common complications were pain at injection site, which was seen in 5/32 patients and depigmentation seen in 2/32 patients.Conclusions: Thus intra sheath triamcinolone injection is a safe and effective procedure for treatment of De Quervains disease

Unilateral percutaneous vertebroplasty for symptomatic osteoporotic vertebral compression fractures -evaluation of radiological and clinical outcomes

Background: Vertebral fractures are the most common type of osteoporotic fractures. These are developing into a significant health problem worldwide as about 30% of the patients above 50 years suffer from a fracture secondary to osteoporosis. Osteoporotic vertebral fractures may be treated with rest and analgesics. Some fractures may also require surgery. Percutaneous procedure like vertebroplasty and kyphoplasty done under local anaesthesia can reduce the pain and restore height of vertebral body without need for an open surgery. The aim of the study was to assess the clinical and radiological outcomes following unilateral percutaneous vertebroplasty under local anaesthesia.Methods: 21 patients who underwent unilateral vertebroplasty for symptomatic osteoporotic compression fracture between 2012 and 2015 were included in the study. Unilateral vertebroplasty using an 11-gauge trocar through transpedicular technique was performed under c-arm guidance. Patient was mobilized as soon as tolerated. Oswestry disability index and visual analogue scale were assessed pre-operatively, in the immediate post-op and at 1-year follow up.Results: There were 15 females and 6 males. The mean age was 70.04±6.07 years. The pre-op ODI score was 76.8±7.6. The pre-op VAS score was 7.66±0.71. The average time period from fracture to vertebroplasty is 4.19±3.19 days. The immediate post-operative VAS score was 5.76±0.8 and the ODI score was 62.85±7.17.  The VAS at final follow up was 1.23±1.19. ODI at final follow up was 9.04±3.19. There was a showed a significant improvement when preoperative, immediate post-operative ODI and VAS scores and final follow up (p<0.001).Conclusions: In our study unilateral percutaneous vertebroplasty has provided pain relief, early mobilization of the patient with less complication without the requirement of general anaesthesia

Standardization of Trichotillometer

INTRODUCTION : Hair is a defining characteristic of mammals. Hair originally evolved in the mammals as a protective coat. However, it has lost its functional value in humans except in the regions of the scalp where it is thick and coarse. Elsewhere in the body, it is fine and delicate. The human skin has approximately five million follicles of which only one hundred thousand are on the scalp. Hair loss is a common problem. That may affect both male and female in all age group. Hair disorders are difficult to treat, example-alopecia. Alopecia can be classified as scaring and non-scarring. The main cause of scaring alopecia are DLE, SLE, LP, for non-scarring alopecia are androgenetic alopecia, diffuse alopecia, alopecia areata. Among these androgenetic alopecia are most frequently occurring problem. Hair loss can be result from due to systemic and local condition. Diffuse hair loss can further be classified by the type of hair that are shed whether they are anagen or telogen. Diagnosis and treatment of these disorders are becoming increasingly important. A detailed history, complete physical examination and relevant lab investigation are indicated to come to the conclusion. Morphologically hair can be divided into four major categories; straight, spiral, helical, and wavy. The fetus is covered by soft, fine, highly pigmented hair called languo hair. The fine hair that covers most of the body of adult are termed vellus hair. Long, coarse, pigmented hair is called terminal hair. During ones life time a particular hair follicle may produce different type of hair. A hair follicle in the scalp may initially produce a lanugo hair, later a terminal hair and finally a vellus hair. There are different types of terminal hair. They are Anagen (growing hair) phase, catagen (involuting hair) phase, and telogen (resting hair) phase. There are various tests available to investigate the hair loss. They are hair pull test, hair pluck test (trichogram), phototrichogram, digital phototrichogram, unit area trichogram, hair diameter assessment and trichotillometer. Trichotillometer was first designed and constructed by C L Krumdieck in 1981, to measure the force in grams necessary to epilate individual hairs. Trichotillometer is not available commercially. We used Instron universal Tensile Strength Tester 6021 (Instron limited, U K) as trichotillometer. It is a very sensitive machine, used in textile department to test the tensile strength of fibers. Trichotillometer is used in various studies to measure the amount of force required to pluck the hair in protein energy malnutrition. AIMS AND OBJECTIVES : To measure the diameter of hair and to determine the force required to pluck the anagen and telogen hair. MATERIALS AND METHODS : The Study was carried out from Oct 2007 to March 2008 in the department of Dermatology, Venereology and Leprology, PSG Hospitals, Coimbatore in collaboration with SITRA (South Indian Textile Research Association). Ten healthy volunteers (5 males and 5 females) were selected and included in the study. The volunteers were subjected to test by using Instron Universal Tensile Strength Tester and the hair was plucked from four regions of the scalp (frontal, vertex, occipital and parietal) and the force required to pluck the hair was recorded. The plucked hair was examined under microscope to determine whether the hair was in anagen or telogen phases. The diameter of each hair was measured using image analyzer. Data were analyzed using SPSS PC (11.5version). Mean and standard deviation (SD) were calculated. Z test was done to test the statistical significance. Examination of hair was carried out at standard time (atleast 3 days) after the last washing of the hair. Inclusion criteria : Volunteer who was not on any medication. Not suffering from chronic disease. Exclusion criteria : Those who are on medications. Individuals with diffuse hair loss. Trichotillometry: Trichotillometer is a hand held spring dynamometer designed and constructed to specifically measure the force in grams necessary to epilate individual hair,21 this instrument is not commercially available, so we used Instron Universal Tensile Strength Tester. Which is very sensitive machine used in textile physics to determine the tensile characteristics of textile materials. Then the plucked hair was examined under microscope to determine whether the hair anagen or telogen phase. Hair diameter assessment : The plucked hair was mounted and marked at 1 cm above the hair root and examined using image analyzer with 200 X magnification (video camera module) and the hair diameter was calculated and recorded. RESULTS : 10 healthy volunteers, 5 males and 5 females were selected and subjected to the test. The hair was plucked from four regions of scalp (frontal, vertex, occipital and parietal) using Instron universal tensile strength tester and the plucked hair was examined under microscope to determine whether the hair was in anagen or telogen phase. Subsequently hair diameter was calculated by using image analyzer. Total number of volunteers – 10, Male volunteer – 05, Female volunteer – 05, Total number of hair examined- 400. The force required to pluck the each hair is shown in the master chart. CONCLUSION : This study was conducted to determine and compare the force required to pluck the anagen and the telogen hair. Trichogram is commonly done procedure to calculate the percentage and ratio of anagen hair and telogen hair. The hair can be differentiated by simple microscopic examination as discussed earlier. This procedure is time taking and does not give information regarding the force required to pluck the hair. The present study measures the force required to pluck the anagen hair and telogen hair. Trichotillometery can be used calculate or assess the force required to pluck the hair in individuals or in patients with alopecia. Trichotillometery can be subsequently done to find whether the treatment is effective in increasing the growth of hair, prolonging anagen phase and increasing the number of anagen hair. The equipment used was large and expensive. However a smaller and portable one is being fabricated for rapid use in outpatient department

Thoraco lumbar spinal tuberculosis-assessment of functional outcome following posterior decompression and posterior instrumentation

Background: Spinal tuberculosis is the most common form of extra pulmonary tuberculosis. Complications of untreated spinal tuberculosis include neurological deficit and gibbus deformity. Treatment of spinal TB can be surgical or conservative. Surgical treatment is the mainstay in spinal tuberculosis with neurological deficit. Various approaches to surgical management are anterior only, combined anterior & posterior and posterior only. Posterior only approach is less traumatic and more familiar to orthopaedicians.Methods: 23 patients diagnosed of spinal tuberculosis with neurological involvement who underwent single stage posterior decompression and posterior stabilization were analyzed with ASIA grading and VAS score..Results: The mean age of the study population was 48.86. There were 12 females and 11 males. The mean operative time and blood loss were 152.19 minutes and 265 ml. Increasing age correlated with blood loss and operating time. The mean follow up period was 36.21 months. There were significant differences in the ASIA and the VAS scores when pre-operative, immediate post-op and final follow up where compared.Conclusions: Single stage posterior decompression and instrumentation is a safe and effective procedure in the treatment of tuberculous spondylodiscitis with neurological deficit and a kyphotic angle <60o. The long-term results are better because of posterior instrumentation, which provide stability and the healing anteriorly following antituberculous treatment