Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

&nbsp;

IIT Palakkad

The present study describes the effect of thermally assisted machining (TAM) parameters on the cutting force, tool wear and surface integrity characteristics (surface roughness, surface topography, and microhardness) of Inconel 718. An inexpensive flame heating technique using oxy-acetylene flame is used to heat the workpiece material. The TAM parameters such as cutting speed, feed rate, depth of cut, and workpiece temperature were selected as process parameters over cutting force, tool wear and surface integrity characteristics.The experimental results reveal that the cutting forces and surface roughness decrease with increases in cutting speed and workpiece temperature, while the workpiece temperature increases as tool wear decreases. The tool wear mechanisms observed were abrasive, adhesive, diffusion and notch wear. The XRD results of thermally assisted machining reveal that neither phase change nor broadening of the peaks were observed at different machining conditions. © 2017, Springer Science+Business Media Dordrecht.

World University root node

Department of Mechanical Engineering

Silicon

Influence of Thermally Assisted Machining Parameters on the Machinability of Inconel 718 Superalloy

A reusable electrochemical sensor ensembling carbon nanotubes and a conducting polymer together is fabricated for the detection of an important anti-cancer drug, dacarbazine (DTIC). A thin film of a conducting polymer, poly(2-amino-1,3,4-thiadiazole) (poly-ATD), is formed on the carbon nanotube paste electrode (CNPE) by employing a potentiodynamic polymerization technique. The fabricated sensor surface has been characterized by FTIR spectroscopy and scanning electron microscopy (SEM) for the structural and chemical properties of the electrode system. The electrochemical capability of the fabricated poly-ATD/CNPE composite electrode for the detection of DTIC is examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopic analysis (EIS), and the poly-ATD/CNPE electrode is found to be efficient for electrocatalytic oxidation of DTIC. Optimization and evaluation of the sensor system are examined by differential pulse voltammetry (DPV). A linear relationship of DTIC concentration over the peak current of DPVs is exhibited over a wide concentration range of 0.05–24.0 μM with a low detection limit (3σ/b) of 35 nM. Steady state current–time analysis experiments under hydrodynamic conditions exhibited a low detection limit of 20 nM, and the analysis time is as low as 10 s. Practical utility of the fabricated poly-ATD/CNPE biosensor for the detection of DTIC directly from artificial urine and pharmaceutical formulations has been demonstrated with very good recovery limits. [Figure not available: see fulltext.] © 2017, Springer Science+Business Media New York.

Department of Chemistry

Electrocatalysis

Conducting Polymer-Layered Carbon Nanotube as Sensor Interface for Electrochemical Detection of Dacarbazine In-Vitro

The influence of growth substrate temperature on the development of CuAlNi shape memory alloy (SMA) over Kapton Polyimide sheet and its effect on tuning the thermomechanical behavior has been investigated. The SMA bi-morph was synthesized at varying substrate temperatures ranging from 100 °C–200 °C. Two-way shape memory effect could be demonstrated by the bi-morps without any post-processing and training, due to pre-straining of the flexible substrates. The deposited SMA film was responsible for the forward displacement and the return was achieved because of flexible kapton polyimide substrate. To investigate the life cycle behavior of the as developed SMA bi-morph, an in-house life cycle setup was developed with Joule heating as the actuation source. The cyclic behavior was investigated for 500 cycles, at three varying voltages of 2 V, 2.5 V and 3 V with an actuation frequency of 0.5 Hz. The film deposited with growth substrate temperature of 100 °C and 200 °C showed a maximum displacement of 0.6 mm and 0.9 mm, whereas samples prepared with substrate heating at 150 °C showed a maximum displacement of 2.6 mm with actuation voltage of 3 V. To probe the influence of substrate temperature in tuning the thermomechanical behavior, an analysis on the structural, morphological and thermal properties of the bi-morphs has been investigated in detail.

Journal of Alloys and Compounds

Parametric investigations to enhance the thermomechanical properties of CuAlNi shape memory alloy Bi-morph

In this paper, we study the variation of natural frequencies for thin walled circular cylindrical shells subject to external radial load (uniform and hydrostatic pressure). The study has been performed for four different types of boundary conditions viz. pinned-pinned, pinned-free, clamped-free and one end is pinned and other end axially constrained. Towards this, we have used approximate shape functions and Galerkin projections of the PDEs governing the shell motion, linearized about a steady state solution due to the applied mean radial pressure. Our results have very good agreement with the experimental and theoretical results available in literature. They have also been verified against finite element analysis (FEA) using ABAQUS. We have found that with increasing magnitude of inward radial load, the natural frequency decreases, however, the circumferential wavenumber corresponding to the lowest natural frequency increases. For outward radial load the opposite happens. Furthermore, the circumferential wavenumbers corresponding to lowest natural frequency and first buckling mode are different for short cylinders with the difference decreasing with increasing length of the cylinder. We have also found an interesting result for the beam mode vibration of cylindrical shells. For short cylinders, the natural frequency of the beam mode increases (decreases) with internal (external) pressure, which is consistent with other circumferential modes. Subsequently, we obtain a critical length at which the applied radial pressure has no effect on the natural frequency. For cylinders longer than the critical length, the effect of the radial load is opposite of that observed for the short cylinders, and this is contrary to the behavior of the other circumferential modes. As a result, buckling of the beam mode happens for an outward radial (internal) pressure. © 2017 Elsevier Ltd

International Journal of Mechanical Sciences

Effect of radial loads on the natural frequencies of thin-walled circular cylindrical shells

A class domination coloring (also called as cd-coloring) of a graph is a proper coloring such that for every color class, there is a vertex that dominates it. The minimum number of colors required for a cd-coloring of the graph G, denoted by χcd(G), is called the class domination chromatic number (cd-chromatic number) of G. In this work, we consider two problems associated with the cd-coloring of a graph in the context of exact exponential-time algorithms and parameterized complexity. (1) Given a graph G on n vertices, find its cd-chromatic number. (2) Given a graph G and integers k and q, can we delete at most k vertices such that the cd-chromatic number of the resulting graph is at most q? For the first problem, we give an exact algorithm with running time O(2nn4 log n). Also, we show that the problem is FPT with respect to the number of colors q as the parameter on chordal graphs. On graphs of girth at least 5, we show that the problem also admits a kernel with O(q3) vertices. For the second (deletion) problem, we show NP-hardness for each q ≥ 2. Further, on split graphs, we show that the problem is NP-hard if q is a part of the input and FPT with respect to k and q. As recognizing graphs with cd-chromatic number at most q is NP-hard in general for q ≥ 4, the deletion problem is unlikely to be FPT when parameterized by the size of deletion set on general graphs. We show fixed parameter tractability for q ∈ {2, 3} using the known algorithms for finding a vertex cover and an odd cycle transversal as subroutines. © Springer International Publishing AG 2017.

Department of Computer Science and Engineering

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Parameterized and exact algorithms for class domination coloring

Selective Catalytic Reduction (SCR) using Urea-Water Solution (UWS) as an ammonia precursor is considered as one of the best choices to meet the current stringent emission norms for reduction of NOx in diesel engines. UWS sprayed in the engine exhaust line forms ammonia, and this ammonia reduces NOx into nitrogen. The NOx reduction efficiency depends on the mixing and evaporation behavior of the UWS spray in the hot exhaust gas. Spray characteristics decide the evaporation rate and hence the NOx reduction efficiency. The spray structure is closely related to the breakup point and breakup mode of the jet. Hence, in this study, breakup length and breakup mode were investigated by injecting UWS (32.5 \% by weight) through a nozzle in a hot air cross flow. A CCD camera and pulsed Nd:Yag laser were used for capturing the images. Experiments were conducted with varying nozzle size (150, 250 and 400 micron), injection pressure (0.5 to 3 bar), temperature (32 degrees C,150 degrees C and 200 degrees C) and air flow rate. The effect of operating parameters (nozzle size, injection pressure, air temperature and velocity) in terms of dimensionless numbers (Weber number and momentum flux ratio) on jet breakup mode and jet breakup length was studied. It was observed that the breakup length for UWS was close to that of water. The jet breakup length increases with momentum flux ratio since a jet having a higher momentum is able to penetrate a larger distance in the cross flow. Increasing the air temperature increases the velocity of the cross flow and hence reduces the breakup length. A correlation for jet breakup length was developed. The effect of inclusion of Weber number in the breakup length correlation, in addition to the momentum flux ratio, was studied. Visual observation shows that droplet sizes obtained from the plain orifice injector without preheating is large. Preheating the UWS before injection is recommended to reduce the droplet size.

Breakup Length of Urea Water Solution Jet in a Hot Cross Flow

Intravenous immunoglobulin (IVIG), a pooled normal IgG formulation prepared from thousands of healthy donors’ plasma, is extensively used for the immunotherapy of autoimmune and inflammatory disorders. Recent reports demonstrate that IVIG exerts anti-inflammatory actions by stimulating the activation and expansion of regulatory T (Treg) cells by multiple mechanisms via antigen-presenting cells (APCs). © 2017 Elsevier Ltd

Biological Sciences and Engineering

Fulltext

Trends in Immunology

Circulating Normal IgG as Stimulator of Regulatory T Cells: Lessons from Intravenous Immunoglobulin

Adjuvants are substances that boost the protective immune response to vaccine antigens. The majority of known adjuvants have been identified through the use of empirical approaches. Our aim was to identify novel adjuvants with well-defined cellular and molecular mechanisms by combining a knowledge of immunoregulatory mechanisms with an in silico approach. CD4 + CD25 + FoxP3 + regulatory T cells (Tregs) inhibit the protective immune responses to vaccines by suppressing the activation of antigen presenting cells such as dendritic cells (DCs). In this chapter, we describe the identification and functional validation of small molecule antagonists to CCR4, a chemokine receptor expressed on Tregs. The CCR4 binds the chemokines CCL22 and CCL17 that are produced in large amounts by activated innate cells including DCs. In silico identified small molecule CCR4 antagonists inhibited the migration of Tregs both in vitro and in vivo and when combined with vaccine antigens, significantly enhanced protective immune responses in experimental models. © Springer Science+Business Media New York 2017.

Methods in Molecular Biology

In silico adjuvant design and validation

CD4+CD25+FoxP3+ regulatory T cells (Tregs) are key players for maintaining immune tolerance and for reducing the inflammation-mediated tissue damage following infection. However, Tregs also suppress protective immune responses to pathogens (including virus, bacteria, parasites, and fungi) and vaccines and enhance pathogen persistence by inhibiting the activation and functions of both innate and adaptive immune cells such as dendritic cells, macrophages, and T and B lymphocytes and by promoting immunosuppressive environment. Therefore, equilibrium in the Treg number and function is important to ensure pathogen clearance and protection from infection-associated immunopathologies. Recent advances in understanding of Treg influence on the outcome of infection opened new avenues to target them. Various small molecules, pharmacological inhibitors, monoclonal antibodies that target Tregs provided proof of concept in experimental models. The field also benefits from advances in other subjects, particularly oncology and autoimmunity, where Treg-targeted therapies are exploited in the clinic to a greater extent. The future research should aim at translating this preclinical success to human application. © 2017 John Wiley & Sons Ltd