Sustainable Carrot Production Technologies: The Interactive Effects of Soil Moisture and Nitrogen Fertilization on the Yield and Recovery of Slicer Carrots

Rajasekaran R. Lada,Azure Adams 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

New methodology for light weight solutions to improve BIW structural performance using bulk head optimization

Rajasekaran Mohan,, Hariram Venkatesan,Subramanian Mahadevan 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.8

Body-in-white (BIW) is the Car body with welded sheet metal parts painted in white. Automobile companies were trying to optimize mass and improve performance with optimal mass addition. In many automotive industries many BIW designs due to aggressive mass optimization, there is a need to have smart solutions to improve BIW structure performance with very little mass increase. In this paper, a new technique of identifying the optimized internal reinforcements in the BIW at conceptual BIW design phase using Deign of experiments and Multi-objective optimization has been investigated. The paper focus on the Bending and torsion stiffness load cases to evaluate the BIW performance. Bulk head designs were designed at the major joints like A-pillar, B-pillar, C-pillar and rocker and their optimal locations to improve stiffness with minimum mass increase were identified using Design of experiments and multi objective techniques. The research shows that the optimized Bulk head design locations using the DOE technique has improved the overall BIW stiffness performance by 3.9% with 1.2% of mass addition in the BIW.

Buckling of fully and partially embedded non-prismatic columns using differential quadrature and differential transformation methods

Rajasekaran, S. Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.2

Numerical solution to buckling analysis of beams and columns are obtained by the method of differential quadrature (DQ) and harmonic differential quadrature (HDQ) for various support conditions considering the variation of flexural rigidity. The solution technique is applied to find the buckling load of fully or partially embedded columns such as piles. A simple semi- inverse method of DQ or HDQ is proposed for determining the flexural rigidities at various sections of non-prismatic column ( pile) partially and fully embedded given the buckling load, buckled shape and sub-grade reaction of the soil. The obtained results are compared with the existing solutions available from other numerical methods and analytical results. In addition, this paper also uses a recently developed technique, known as the differential transformation (DT) to determine the critical buckling load of fully or partially supported heavy prismatic piles as well as fully supported non-prismatic piles. In solving the problem, governing differential equation is converted to algebraic equations using differential transformation methods (DT) which must be solved together with applied boundary conditions. The symbolic programming package, Mathematica is ideally suitable to solve such recursive equations by considering fairly large number of terms.

Proteomic Signature of Nucleus Pulposus in Fetal Intervertebral Disc

Rajasekaran Shanmuganathan,Soundararajan Dilip Chand Raja,Tangavel Chitraa,K.S. Sri Vijay Anand,Nayagam Sharon Miracle,Matchado Monica Steffi,Muthurajan Raveendran,Shetty Ajoy Prasad,Kanna Rishi Muges 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.4

Study Design: Profiling proteins expressed in the nucleus pulposus of fetal intervertebral disc (IVD).Purpose: To evaluate the molecular complexity of fetal IVDs not exposed to mechanical, traumatic, inflammatory, or infective insults to generate improved knowledge on disc homeostasis.Overview of Literature: Low back pain is the most common musculoskeletal disorder, causing a significant reduction in the quality of life, and degenerative disc disorders mainly contribute to the increasing socioeconomic burden. Despite extensive research, the causative pathomechanisms behind degenerative disc disorders are poorly understood. Precise molecular studies on the intricate biological processes involved in maintaining normal disc homeostasis are needed.Methods: IVDs of nine fetal specimens obtained from medical abortions were used to dissect out the annulus fibrosus and nucleus pulposus under sterile operating conditions. Dissected tissues were transferred to sterile Cryovials and snap frozen in liquid nitrogen before transporting to the research laboratory for protein extraction and further liquid chromatography tandem mass spectrometry (LC-MS/ MS) analysis. Collected data were further analyzed using Gene Functional Classification Tool in DAVID and STRING databases.Results: A total of 1,316 proteins were identified through LC-MS/MS analysis of nine fetal IVD tissues. Approximately 247 proteins present in at least four fetal discs were subjected to further bioinformatic analysis. The following 10 clusters of proteins were identified: collagens, ribosomal proteins, small leucine-rich proteins, matrilin and thrombospondin, annexins, protein disulfide isomerase family proteins and peroxiredoxins, tubulins, histones, hemoglobin, and prolyl 4-hydroxylase family proteins.Conclusions: This study provides fundamental information on the proteome networks involved in the growth and development of healthy fetal discs in humans. Systematic cataloging of proteins involved in various structural and regulatory processes has been performed. Proteins expressed most abundantly (collagen type XIV alpha 1 chain, biglycan, matrilin 1, and thrombospondin 1) in their respective clusters also elucidate the possibility of utilizing these proteins for potential regenerative therapies.

Motion-Preserving Navigated Primary Internal Fixation of Unstable C1 Fractures

Rajasekaran Shanmuganathan,Soundararajan Dilip Chand Raja,Shetty Ajoy Prasad,Kanna Rishi Mugesh 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.4

Study Design: Prospective observational study.Purpose: To assess the safety, efficacy, and benefits of computed tomography (CT)-guided C1 fracture fixation.Overview of Literature: The surgical management of unstable C1 injuries by occipitocervical and atlantoaxial (AA) fusion compromises motion and function. Monosegmental C1 osteosynthesis negates these drawbacks and provides excellent functional outcomes.Methods: The patients were positioned in a prone position, and cranial traction was applied using Mayfield tongs to restore the C0–C2 height and obtain a reduction in the displaced fracture fragments. An intraoperative, CT-based navigation system was used to enable the optimal placement of C1 screws. A transverse rod was then placed connecting the two screws, and controlled compression was applied across the fixation. The patients were prospectively evaluated in terms of their clinical, functional, and radiological outcomes, with a minimal follow-up of 2 years.Results: A total of 10 screws were placed in five patients, with a mean follow-up of 40.8 months. The mean duration of surgery was 77±13.96 minutes, and the average blood loss was 84.4±8.04 mL. The mean combined lateral mass dislocation at presentation was 14.6±1.34 mm and following surgery, it was 5.2±1.64 mm, with a correction of 9.4±2.3 mm (<i>p</i> <0.001). The follow-up CT showed excellent placement of screws and sound healing. There were no complications and instances of AA instability. The clinical range of movement at 2 years in degrees was as follows: rotation to the right (73.6°±9.09°), rotation to the left (71.6°±5.59°), flexion (35.4°±4.5°), extension (43.8°±8.19°), and lateral bending on the right (28.4°±10.45°) and left (24.8°±11.77°). Significant improvement was observed in the functional Neck Disability Index from 78±4.4 to 1.6±1.6. All patients returned to their occupation within 3 months.Conclusions: Successful C1 reduction and fixation allows a motion-preserving option in unstable atlas fractures. CT navigation permits accurate and adequate monosegmental fixation with excellent clinical and radiological outcomes, and all patients in this study returned to their preoperative functional status.

Solution method for the classical beam theory using differential quadrature

Rajasekaran, S.,Gimena, L.,Gonzaga, P.,Gimena, F.N. Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.33 No.6

In this paper, a unified solution method is presented for the classical beam theory. In Strength of Materials approach, the geometry, material properties and load system are known and related with the unknowns of forces, moments, slopes and deformations by applying a classical differential analysis in addition to equilibrium, constitutive, and kinematic laws. All these relations are expressed in a unified formulation for the classical beam theory. In the special case of simple beams, a system of four linear ordinary differential equations of first order represents the general mechanical behaviour of a straight beam. These equations are solved using the numerical differential quadrature method (DQM). The application of DQM has the advantages of mathematical consistency and conceptual simplicity. The numerical procedure is simple and gives clear understanding. This systematic way of obtaining influence line, bending moment, shear force diagrams and deformed shape for the beams with geometric and load discontinuities has been discussed in this paper. Buckling loads and natural frequencies of any beam prismatic or non-prismatic with any type of support conditions can be evaluated with ease.

Mechanical properties of thin-walled composite beams of generic open and closed sections

Rajasekaran, S. Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.5

A general analytical model for thin-walled composite beams with an arbitrary open/(or/and) closed cross section and arbitrary laminate stacking sequence i.e., symmetric, anti-symmetric as well as un-symmetric with respect to the mid plane of the laminate, is developed in the first paper. All the mechanical properties, mechanical centre of gravity and mechanical shear centre of the cross section are defined in the function of the geometry and the material properties of the section. A program "fungen" and "clprop" are developed in Fortran to compute all the mechanical properties and tested for various isotropic sections first and compared with the available results. The locations of mechanical centre of gravity and mechanical shear centre are given with respect to the fibre angle variation in composite beams. Variations of bending and torsional stiffness are shown to vary with respect to the fibre angle orientations.

New mass optimization technique to achieve low mass BIW designs using optimal material layout methodology on the frontal vehicle crash

Rajasekaran Mohan,, Hariram Venkatesan,Subramanian Mahadevan 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.12

BIW is the car body made of sheet metals welded together. Numerous researches were performed across the world to optimize and save mass on the car body design. This paper describes the new methodology which can be used to reduce mass of the BIW in a full frontal rigid wall impact crash model. The new methodology of identifying materials for the BIW components has been presented. Frontal crash load case has been considered for the research. Since Frontal impact is an evaluation to predict only the frontal performance, parts in the front impact load path like dash, A-pillar, reinforcements and hinge pillar region has been considered as the design space for the material layout optimization. List of materials have been provided as a variable for a list of parts in the BIW and DOE sampling were generated. Response for the DOE designs results have been extracted to study the sensitivity of the parts for the frontal load case and design performance was analysed. Subsequent multi-objective optimization have been performed based on the DOE results, to achieve an optimal material selection for each of the parts in the design space. Further performance improving techniques considering the sensitivity chart have been explored and optimal design with low mass and improved frontal crash performance have been achieved and presented. The use of this methodology on a full vehicle crash model has achieved 15.4 % mass saving with the performance better than the baseline design.

Optimizing Photosynthetically Active Radiation and Moisture Regimes Can Enhance Water Use Efficiency in Carrots

Rajasekaran R. Lada,Arumugam Thiagarajan,Robert Gordon,Tessma Astatkie,Azure Adams 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Ambiol ®, a Derivative of 5-hydroxybenzimidazole, Seed Pre-Conditioning Acclimates Tomato Seedlings to Drought

Rajasekaran R. Lada,Mason T. MacDonald,Jeff Hoyle,Robin A. Robinson 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-