Multiple myeloma presenting with a maxillary lesion as the first sign

Kiran Kumar Kotagudda Ramaiah,Vajendra Joshi,Shilpa Ravishankar Thayi,Pathalapate Sathyanarayana,Prashant Patil,Zaheer Ahmed 대한영상치의학회 2015 Imaging Science in Dentistry Vol.45 No.1

Multiple myeloma is a clonal neoplastic proliferation of terminally differentiated B-lymphocytes involving the skeletal system in a multifocal fashion. Its oral manifestations are less common in the maxilla than in the mandible due to the lower amount of hemopoietic bone marrow in the maxilla. We report the case of a 50-year-old man who presented with a mass in the left maxillary alveolar region with tooth mobility. The mass had become enlarged after the teeth were extracted 15 days previously. Radiographs demonstrated multiple punched-out radiolucent lesions in the skull and pelvic region. Computed tomography images showed a soft tissue density mass in the left maxilla, eroding the floor and walls of the maxillary sinus. Although several analytical techniques were used to characterize the lesion, it was finally confirmed as multiple myeloma through immunohistochemistry.

Three-dimensional finite element modeling of pulsed AC gas metal arc welding process

Kiran, D. V.,Cheon, J.,Arif, N.,Chung, H.,Na, S. J. Springer Science + Business Media 2016 INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TE Vol.86 No.5

<P>The behavior of the welding arc in the pulsed DC and AC gas metal arc welding processes was studied using real-time recorded current, voltage waveforms, and synchronized high-speed video at different electrode negative (EN) ratios for a constant wire feed rate. The regression equations were developed to predict the arc root dimensions as a function of welding current, voltage, time, and the EN ratio. A methodology was proposed to estimate the available energy rate distribution to the electrode and the base plate during the positive and negative cycles in pulsed AC gas metal arc welding (pulsed AC-GMAW) process. For an approximately equal peak positive current, the increase in the pulse time enhanced the molten electrode droplet diameter, arc plasma distribution, and the arc root dimensions. The fraction of the available arc energy rate supplied to the base plate was higher in positive pulse when compared to the negative pulse. A three-dimensional finite element modeling of pulsed DC-GMAW and pulsed AC-GMAW processes was performed to estimate the weld pool profile and temperature distribution in the weldment. The computed weld width, penetration, and the thermal cycles were in reasonable agreement with the corresponding experimental results. The peak temperature of the region in the weld pool near to the Gaussian distributed heat source experience fluctuations which were in synchronization with the current waveform. Increase in the EN ratio decreased the peak temperature while increased the cooling rate in the weldment. This reduced the bainite phase and enhanced the martensite phase in the weldment.</P>

Physics-based Interactive Virtual Grasping

Kiran Nasim,Young J. Kim 한국HCI학회 2016 한국HCI학회 학술대회 Vol.2016 No.1

In this paper, we propose an interactive virtual grasping system, enabling physically-realistic interaction between a user and virtual objects, using kinematic hand models whose motions are tracked and controlled in real-time by the user. Since hand tracking devices provide only one-way coupling between the user and kinematic hands resulting in penetrations and friction-less interaction, our method implements the contacts as Coulomb’s friction model and includes a dynamic proxy hand in the system which follows the kinematic virtual hand to provide a two-way control loop for the physics interactions. Our system, taking advantage of the graphics and physics engine of Unity3D, presently allows us to interact with 3D objects in the virtual space in real-time with no visible latency. Moreover, to visually assist the user’s grasping we render the hand model as transparent and provide visual markers at the contact locations. We demonstrate how the use of these tools helps us to perform real-time grasping tasks in complicated virtual environment.

A study on the quality of two-wire tandem submerged arc welds under iso-heat input conditions

Kiran, Degala Venkata,Cho, Dae-Won,Lee, Hee-Keun,Kang, Chung Yun,Na, Suck-Joo Springer-Verlag 2015 INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TE Vol.78 No.1

Arc behavior in two wire tandem submerged arc welding

Kiran, D.V.,Cho, D.W.,Song, W.H.,Na, S.J. Elsevier 2014 Journal of materials processing technology Vol.214 No.8

Pyknodysostosis: report of a rare case with review of literature

Kiran Kumar Kotagudda Ramaiah,Giju Baby George,Sheeba Padiyath,Rupak Sethuraman,Babu Cherian 대한영상치의학회 2011 Imaging Science in Dentistry Vol.41 No.4

Pyknodysostosis is a rare autosomal recessive disorder characterized by the post natal onset of short limbs, short stature, and generalized hyperostosis along with acro-osteolysis with sclerosis of the terminal phalanges, a feature that is considered essentially pathognomonic. Other features include persistence of fontanelles, delayed closure of sutures, wormian bones, absence of frontal sinuses, and obtuse mandibular gonial angle with relative mandibular prognathism. We report a case of 17-year-old girl who presented with a chief complaint of retention of deciduous teeth. General physical examination demonstrated short stature, frontal and parietal bossing, depressed nasal bridge,beaked nose, hypoplastic midface, wrinkled skin over the finger tips, and nail abnormalities. Radiographs showed multiple impacted permanent and supernumerary teeth, hypoplastic paranasal sinuses with acro-osteolysis of terminal phalanges, and open fontanelles, and sutures along with wormian bones in the lambdoidal region.

The ultrafast nonlinear optical response and multi-photon absorption of a new metal complex in the near-infrared spectral range

Kiran, A J,Lee, H W,Sampath Kumar, H C,Rudresha, B J,Bhat, B R,Yeom, D-I,Kim, K,Rotermund, F IOP Publishing 2010 Journal of optics Vol.12 No.3

<P>A new coordination compound, chloro(1,10-phenanthroline-<I>N</I>, <I>N</I><SUP>′</SUP>)(triphenylphosphine)copper(I) dichloromethane, incorporated in poly(methyl methacrylate) exhibits superior nonlinear optical properties in the near-infrared spectral region. Its nonlinear response time and third-order nonlinear optical susceptibility at 800 nm are ≤ 90 fs and 1.8 × 10<SUP> − 10</SUP> esu, respectively. Considerable nonlinear absorption is observed with this sample, near 800 and 1250 nm. The contribution of the excited states to the total nonlinear absorption process is discussed. The results reveal the potential of this newly designed compound for multi-photon absorption-based photonic applications.</P>

Fracture and Size Effect on Strength of Plain Concrete Disks under Biaxial Flexure Analyzed by Microplane Model M7

Kirane, Kedar,Baž,ant, Zdeně,k P.,Zi, Goangseup American Society of Civil Engineers 2014 Journal of engineering mechanics Vol.140 No.3

The biaxial tensile strength of concrete (and ceramics) can be easily tested by flexure of unreinforced circular disks. A recent experimental study demonstrated that, similar to plain concrete beams, the flexural strength of disks suffers from a significant size effect. However, the experiments did not suffice to determine the size effect type conclusively. The purpose of this study is to use three-dimensional stochastic finite-element analysis to determine the size effect type and shed more light on the fracture behavior. A finite-element code using the microplane constitutive Model M7 is verified and calibrated by fitting the previously measured load-deflections curves and fracture patterns of disks of thicknesses 30, 48, and 75 mm, similar in three dimensions, and on flexure tests on four-point loaded beams. It is found that the deformability of the supports and their lifting and sliding has a large effect on the simulations, especially on the fracture pattern, and the strength and Young's modulus of concrete must be treated as autocorrelated random fields. The calibrated model is then used to analyze the size effect over a much broader range of disk thicknesses ranging from 20 to 192 mm. The disks are shown to exhibit the typical energetic size effect of Type I, that is, the disks fail (under load control) as soon as the macrofracture initiates from the smooth bottom surface. The curve of nominal strength versus size has a positive curvature and its deterministic part terminates with a horizontal asymptote. The fact that material randomness had to be introduced to fit the fracture patterns confirms that the Type 1 size effect must terminate at very large sizes with a Weibull statistical asymptote, although the disks analyzed are not large enough to discern it.

Experimental Studies on Submerged Arc Welding Process

Kiran, Degala Ventaka,Na, Suck-Joo The Korean Welding and Joining Society 2014 대한용접·접합학회지 Vol.32 No.3

The efficient application of any welding process depends on the understanding of associated process parameters influence on the weld quality. The weld quality includes the weld bead dimensions, temperature distribution, metallurgical phases and the mechanical properties. A detailed review on the experimental and numerical approaches to understand the parametric influence of a single wire submerged arc welding (SAW) and multi-wire SAW processes on the final weld quality is reported in two parts. The first part deals with the experimental approaches which explain the parametric influence on the weld bead dimensions, metallurgical phases and the mechanical properties of the SAW weldment. Furthermore, the studies related to statistical modeling of the present welding process are also discussed. The second part deals with the numerical approaches which focus on the conduction based, and heat transfer and fluid flow analysis based studies in the present welding process. The present paper is the first part.

Arc interaction and molten pool behavior in the three wire submerged arc welding process

Kiran, Degala Venkata,Cho, Dae-Won,Song, Woo-Hyun,Na, Suck-Joo Elsevier 2015 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.87 No.-

<P><B>Abstract</B></P> <P>A three-dimensional numerical heat transfer and fluid flow model is developed to understand the temperature distribution and molten pool behavior in a three wire submerged arc welding process. The model solves the equations of the conservation of mass, momentum, and energy along with the volume of fluid method. The volume of fluid method is used to track the shape of the free surface. Further, a physical model is developed to estimate the arc center displacement. For a given welding condition, connecting the leading electrode with direct current electrode positive polarity, the middle and trailing electrodes with trapezoidal alternating current waveform displayed deeper weld pools when compared to the sine waveforms. Within the range of welding conditions considered in the present work, weld width is significantly influenced by the leading arc whereas the penetration by the middle and trailing arcs. The computed weld width and penetration are in fair agreement with the corresponding experimental results.</P>