Clinical Impact of Patient’s Head Position in Supraclavicular Irradiation of the Whole Breast Radiotherapy

Anbumani Surega,G. Reddy Lohith,V Priyadarshini,P Sasikala,S. Bilimagga Ramesh 한국의학물리학회 2023 의학물리 Vol.34 No.1

Patients with breast cancer can be positioned with their head turned to the contra lateral side or with their head straight during the radiation therapy treatment set-up. In our hospital, patients with locally advanced breast cancer who were receiving radiation therapy have experienced swallowing difficulty after 2 weeks of irradiation. In this pilot study, the impact of head position on reducing dysphagia occurrence was dosimetrically evaluated. Patients were divided into two groups viz., HT (head turned to the contra lateral side of the breast) and HS (head straight) with 10 members in each. Treatment planning was performed, and the dosimetric parameters such as Dmin, Dmax, Dmean, V5, V10, V20, V30, V40, and V50 of both groups were extracted from the dose volume histogram (DVH) of esophagus. The target coverage in the supraclavicular fossa (SCF) region was analyzed using D95 and D98; moreover, the dose heterogeneity was assessed with D2 from the DVHs. The average values of the dose volume parameters were 27.6%, 58.6%, 35.4%, 19%, 13.8%, 14.1%, 11.8%, 8.4%, and 8.1% higher in the HT group compared with those in the HS group. Furthermore, for the SCF, the mean values of D98, D95, and D2 were 42.4, 47.5, and 54 Gy, respectively, in the HS group and 38.9, 45.35, and 55.5 Gy, respectively, in the HT group. This pilot study attempts to give a solution for the poor quality of life of patients after breast radiotherapy due to dysphagia. The findings confirm that the head position could play a significant role in alleviating esophageal toxicity without compromising tumor control.

Principal Component Analysis and Molecular Characterization of Reniform Nematode Populations in Alabama

Nyaku, Seloame T.,Kantety, Ramesh V.,Cebert, Ernst,Lawrence, Kathy S.,Honger, Joseph O.,Sharma, Govind C. The Korean Society of Plant Pathology 2016 Plant Pathology Journal Vol.32 No.2

U.S. cotton production is suffering from the yield loss caused by the reniform nematode (RN), Rotylenchulus reniformis. Management of this devastating pest is of utmost importance because, no upland cotton cultivar exhibits adequate resistance to RN. Nine populations of RN from distinct regions in Alabama and one population from Mississippi were studied and thirteen morphometric features were measured on 20 male and 20 female nematodes from each population. Highly correlated variables (positive) in female and male RN morphometric parameters were observed for body length (L) and distance of vulva from the lip region (V) (r = 0.7) and tail length (TL) and c' (r = 0.8), respectively. The first and second principal components for the female and male populations showed distinct clustering into three groups. These results show pattern of sub-groups within the RN populations in Alabama. A one-way ANOVA on female and male RN populations showed significant differences ($p{\leq}0.05$) among the variables. Multiple sequence alignment (MSA) of 18S rRNA sequences (421) showed lengths of 653 bp. Sites within the aligned sequences were conserved (53%), parsimony-informative (17%), singletons (28%), and indels (2%), respectively. Neighbor-Joining analysis showed intra and inter-nematodal variations within the populations as clone sequences from different nematodes irrespective of the sex of nematode isolate clustered together. Morphologically, the three groups (I, II and III) could not be distinctly associated with the molecular data from the 18S rRNA sequences. The three groups may be identified as being non-geographically contiguous.

Effect of Surface Condition on the Torsional Fatigue Behaviour of 20MnCr5 Steel

S. Ramesh,S. Natarajan,V. J. Sivakumar 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.9

Torsional fatigue behaviour of steel is influenced by various significant factors on the surface of steel such as the stress state,the metallurgical conditions and the surface roughness etc. This research presents the results of the studies conducted on thetorsional fatigue life of steel for different surface stresses, conditions and microstructures. Based on the results, inferenceswere derived out of the factors and conditions which are instrumental in increasing the fatigue performance. This researchis done with the purpose of increasing the fatigue performance of power train shafts processed through vacuum carburizingfollowed by second tempering. The fatigue tests were conducted using a bi-directional torsional cyclic loading in a MTSmake torque testing machine. Various researches has been conducted in this paper to find out the impact of surface roughness,second tempering, inter granular oxidation and carbon case depth on the transmission shafts. The existence of surfaceretained austenite has not yielded a notable enhancement in fatigue performance in the power train shaft whereas existenceof martensite with minimum fraction of retained austenite enhanced the fatigue performance significantly from 12,000 to35,000 cycles on ± 3100 N m torque load.

Structural and Magnetic Characterizations of Ni—Zn—Co Ferrite Nanoparticles Synthesized by Sol—Gel Autocombustion Method

Ramesh, S.,Dhanalakshmi, B.,Sekhar, B. Chandra,Rao, P. S. V. Subba,Rao, B. Parvatheeswara,Kim, CheolGi American Scientific Publishers 2016 Journal of Nanoscience and Nanotechnology Vol.16 No.10

<P>Cobalt substituted Ni-Zn ferrite nanoparticles with the formula, Ni0.4Zn0.6-xCoxFe2O4, where x varies from 0.00 to 0.25 in steps of 0.05, were prepared by sol-gel autocombustion method and analyzed for their structural and magnetic properties. The synthesized nanoparticles were subjected to X-ray analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, thermal analysis and magnetic measurements. The X-ray patterns confirm cubic spinel structures with the crystallite sizes in the range from 31.72 nm to 36.87 nm. The particle sizes estimated using electron micrographs are in good agreement with the crystallite sizes obtained from the X-ray data. Infrared data confirms the spinel structure by showing Fe-A-O and Fe-B-O stretching vibrations while the thermal data hints at a slight weight gain due to oxidation. The obtained magnetic data suggests a marginal increase in saturation magnetization with the Co substitution at x = 0.10 and 0.25. The results are analyzed in terms of the compositional and structural modifications, and it was found that the variation of magnetic moment was governed by a corresponding change in the oxygen positional parameter in these materials.</P>

Detection of Defects on Steel Surface for using Image Segmentation Techniques

S. M. Ramesh,B. Gomathy,T.V.P.Sundararajan 보안공학연구지원센터 2014 International Journal of Signal Processing, Image Vol.7 No.5

An online surface inspection system m of hot rolled strips is introduced. This system is designed t o detect such main Surface defects on hot rolled strips as scar, scratches, pits, water drops Cracks. Cross hatchings, and so on. Multiple CCD area scan cameras are adopted to capture images of strip surface simultaneously, and all the images are processed by parallel computation system Real-time, which is supported by fast image process techniques and parallel computation techniques, in order to snap main defect regions on the surface of strips. At last, the defects will be classified to several types. The application of the system to practical production line shows that it can detect main defects of hot rolled strips more effectively than traditional method, and it is easily to be maintained.

Principal Component Analysis and Molecular Characterization of Reniform Nematode Populations in Alabama

Seloame T. Nyaku,Ramesh V. Kantety,Ernst Cebert,Kathy S. Lawrence,Joseph O. Honger,Govind C. Sharma 한국식물병리학회 2016 Plant Pathology Journal Vol.32 No.2

U.S. cotton production is suffering from the yield losscaused by the reniform nematode (RN), Rotylenchulusreniformis. Management of this devastating pest is ofutmost importance because, no upland cotton cultivarexhibits adequate resistance to RN. Nine populationsof RN from distinct regions in Alabama and onepopulation from Mississippi were studied and thirteenmorphometric features were measured on 20 male and20 female nematodes from each population. Highly correlatedvariables (positive) in female and male RN morphometricparameters were observed for body length(L) and distance of vulva from the lip region (V) (r = 0.7)and tail length (TL) and c’ (r = 0.8), respectively. Thefirst and second principal components for the femaleand male populations showed distinct clustering intothree groups. These results show pattern of sub-groupswithin the RN populations in Alabama. A one-wayANOVA on female and male RN populations showedsignificant differences (p ≤ 0.05) among the variables.Multiple sequence alignment (MSA) of 18S rRNA sequences(421) showed lengths of 653 bp. Sites within thealigned sequences were conserved (53%), parsimonyinformative(17%), singletons (28%), and indels (2%),respectively. Neighbor-Joining analysis showed intraand inter-nematodal variations within the populationsas clone sequences from different nematodes irrespectiveof the sex of nematode isolate clustered together. Morphologically, the three groups (I, II and III) couldnot be distinctly associated with the molecular datafrom the 18S rRNA sequences. The three groups maybe identified as being non-geographically contiguous.

Contact analysis of spherical ball and a deformable flat model with the effect of tangent modulus

V.C. Sathish Gandhi,S. Ramesh,R. Kumaravelan,M. Thanmanaselvi 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.44 No.1

The paper is on contact analysis of a spherical ball with a deformable flat, considering the effect of tangent modulus on the contact parameters of a non-adhesive frictionless elastic-plastic contact. The contact analysis of this model has been carried out using analysis software Ansys and Abaqus. The contact parameters such as area of contact between two consecutive steps, volume of bulged material are evaluated from the formulated equations. The effect of the tangent modulus is considered for determining these parameters. The tangent modulus are accounted between 0.1E and 0.5E of materials E/Y value greater than 500 and less than 1750. Result shows that upto an optimal tangent modulus values the elastic core push up to the free surface in the flat. The simulation is also carried out in Abaqus and result provide evidence for the volume of bulged material in the contact region move up and flow into the free surface of the flat from the contact edge between the ball and flat. The strain energy of the whole model is varied between 20 to 40 percentage of the stipulated time for analysis.

Mean pressure prediction for the case of 3D unsteady turbulent flow past isolated prismatic cylinder

V. Ramesh,S. Vengadesan,J.L. Narasimhan 한국풍공학회 2006 Wind and Structures, An International Journal (WAS Vol.9 No.5

Unsteady 3D Reynolds Averaged Navier-Stokes (URANS) solver is used to simulate the turbulent flow past an isolated prismatic cylinder at Re = 37,400. The aspect ratio of height to base width of the body is 5. The turbulence closure is achieved through a non-linear k - e model. The applicability of this model to predict unsteady forces associated with this flow is examined. The study shows that the present URANS solver with standard wall functions predicts all the major unsteady phenomena showing closer agreement with experiment. This investigation concludes that URANS simulations with the non-linear k - e model as a turbulence closure provides a promising alternative to LES with view to study flows having complex features.

Mean pressure prediction for the case of 3D unsteady turbulent flow past isolated prismatic cylinder

Ramesh, V.,Vengadesan, S.,Narasimhan, J.L. Techno-Press 2006 Wind and Structures, An International Journal (WAS Vol.9 No.5

Unsteady 3D Reynolds Averaged Navier-Stokes (URANS) solver is used to simulate the turbulent flow past an isolated prismatic cylinder at Re=37,400. The aspect ratio of height to base width of the body is 5. The turbulence closure is achieved through a non-linear $k-{\varepsilon}$ model. The applicability of this model to predict unsteady forces associated with this flow is examined. The study shows that the present URANS solver with standard wall functions predicts all the major unsteady phenomena showing closer agreement with experiment. This investigation concludes that URANS simulations with the non-linear $k-{\varepsilon}$ model as a turbulence closure provides a promising alternative to LES with view to study flows having complex features.

Analysis of material dependency in an elastic - plastic contact models using contact mechanics approach

V.C. Sathish Gandhi,R. Kumaravelan,S. Ramesh,K. Sriram 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5

The study aims on the effect of material dependency in elastic- plastic contact models by contact analysis of sphere and flat contact model and wheel rail contact model by considering the material propertieswithout friction. The various materials are selected for the analysis based on Young‟s modulus and yield strength ratio (E/Y). The simulation software „ANSYS‟ is employed for this study. The sphere and flat contact model is considered as a flattening model, the stress and strain for different materials are estimated. The simulation of wheel-rail contact model is also performed and the results are compared with the flattening model. The comparative study has also been extended for finding out the mean contact pressurefor different materials the E/Y values between 150 and 660. The results show that the elastic-plastic contact analysis for materials up to E/Y=296.6 is depend on the nature of material properties and also for this material the mean contact pressure to yield strength reaches 2.65.