Ashish Mishra - Academia.edu (original) (raw)

Papers by Ashish Mishra

Research paper thumbnail of Effect of Process Parameters on Melt Pool Characteristics and Solidification Process During Laser Powder Bed Fusion of AlSi10Mg Alloy

Lasers in Manufacturing and Materials Processing, Jan 5, 2024

Research paper thumbnail of Effect of Different Powder Bed Thermal Conductivity Models on the Melt Pool Characteristics and Solidification Parameters during Laser Powder Bed Fusion of Ti6Al4V

Transactions of the Indian Institute of Metals, Dec 7, 2023

Research paper thumbnail of Detecting border intrusion using wireless sensor network and artificial neural network

2010 6th IEEE International Conference on Distributed Computing in Sensor Systems Workshops (DCOSSW), 2010

Abstract— Monitoring movement across national borders is a challenging problem due to several eco... more Abstract— Monitoring movement across national borders is a challenging problem due to several economic and technical issues. Due to the vast size, remoteness and other geographical confines of border regions, technical solutions are necessary to complement the limitations of ...

Research paper thumbnail of Non linear stability analysis of parallel channels with natural circulation

Nuclear Engineering and Design, 2016

Abstract Linear stability analysis of two-phase flow in natural circulation loop is quite extensi... more Abstract Linear stability analysis of two-phase flow in natural circulation loop is quite extensively studied by many researchers in past few years. It can be noted that linear stability analysis is limited to the small perturbations only. It is pointed out that such systems typically undergo Hopf bifurcation. If the Hopf bifurcation is subcritical, then for relatively large perturbation, the system has unstable limit cycles in the (linearly) stable region in the parameter space. Hence, linear stability analysis capturing only infinitesimally small perturbations is not sufficient. In this paper, bifurcation analysis is carried out to capture the non-linear instability of the dynamical system and both subcritical and supercritical bifurcations are observed. The regions in the parameter space for which subcritical and supercritical bifurcations exist are identified. These regions are verified by numerical simulation of the time-dependent, nonlinear ODEs for the selected points in the operating parameter space using MATLAB ODE solver.

Research paper thumbnail of Two Phase Flow Stability Analysis of Multiple Horizontal Uniformaly Heated Channel

Lecture Notes in Mechanical Engineering, 2016

ABSTRACT Two-phase flow in multiple horizontal heated channels has wide applications in heat exch... more ABSTRACT Two-phase flow in multiple horizontal heated channels has wide applications in heat exchangers, solar heating systems, nuclear systems etc. The theoretical study of two-phase flow instability analysis for parallel multiple channels are carried out by Zhang et al., 2009. This was done for vertical channels and they used nodal methods to carry out stability analysis. Similar analysis was done by Lee et al. 1999 & 2005, for multiple vertical, parallel boiling channels with forced flows. Following the Zhang et al. 2009 and Lee et al. 1999 & 2005, the stability analysis of multiple horizontal channels with uniform heat flux has been carried out. The system is mathematically represented by non-linear PDEs for mass, momentum and energy in single as well as two-phase region. Coupling equation is being used under the assumption that pressure drop in each channel is same and total mass flow rate is equal to sum of individual mass flow rate. The homogeneous equilibrium model is assumed to be valid in the two phase region. Stability boundary is obtained in terms of phase change number (Npch) and Sub-cooling Number (Nsb) and can be validated by comparing it with result obtained by Matcont under same parametric values. Numerical simulations of the time-dependent, nonlinear ODEs are carried out for selected points in the operating parameter space to obtain the actual damped and growing oscillations in the channel inlet flow velocity which confirms the stability region across the stability map.

Research paper thumbnail of Design of VCO for Microwave Frequency Band

Ijca Proceedings on Recent Advances in Wireless Communication and Artificial Intelligence, Sep 29, 2014

Research paper thumbnail of A Density Fit Model for Stability Analysis of Heated Channel

In the present work an analytical model is developed to describe density wave oscillation (DWO) i... more In the present work an analytical model is developed to describe density wave oscillation (DWO) in uniformly heated coolant channels. The analysis is done by assuming the flow channel to be composed of two discrete regimes, single phase and two-phase kept separated by a well-defined time varying boiling boundary. The density variation of subcooled coolant in the single phase is considered whereas the incompressible flow assumption still remains valid. The stability characteristics of the system are demonstrated by various kinds of stability boundaries plotted in parameter planes of inlet-subcooling number, phase-change number and external pressure drop. A comparison between existing model and the present model is done to which describes the effect of density variation in various stability boundaries. It is observed that unlike to the earlier existing models where the single phase density remains invariant, the stability boundaries show a better shift towards exact solutions.

Research paper thumbnail of Utilization of and barriers to public sector tuberculosis services in India

The National medical journal of India

Tuberculosis control in India still faces many challenges related to the provision of services un... more Tuberculosis control in India still faces many challenges related to the provision of services under the Directly Observed Treatment, Short-course (DOTS) strategy. We assessed the utilization of and barriers to the Revised National Tuberculosis Control Programme (RNTCP) services based on DOTS in 4 states of India, and recommend actions to optimize utilization of the RNTCP services. Two districts each in 4 states with more than 50% of the population covered under the RNTCP in 2002, representing diverse levels of general health indicators, were selected. Sex-disaggregated data on patients who reported to the RNTCP facilities for the diagnosis and treatment of tuberculosis in 2002 were reviewed from the laboratory and tuberculosis registers to assess the utilization of these services. Data on barriers to utilization of the RNTCP services were collected through interviews of 4310 patients with tuberculosis who were 16 years of age or older. A total of 83,099 patients had reported for th...

Research paper thumbnail of Impact of lighting on poultry reproduction and recent advances

CABI Reviews, 2014

Different wavelengths of visible light spectrum influence the reproductive system of domestic avi... more Different wavelengths of visible light spectrum influence the reproductive system of domestic avian species. Light perceived by the retina is involved in growth and behaviour whereas light perceived by the hypothalamus is involved in reproduction through photosensitive cells in the brain (extra-retinal photoreceptors) and it varies with intensity of different wavelengths of light. Red spectrum of light with 675 nm of wavelengths is more gonadostimulatory than shorter wavelengths of 450-475 nm of light. Recent studies indicate that the hypothalamic opsins are involved in avian photoreception. Non-mammalian vertebrates detect light by deep brain photoreceptors that lie outside the retina and pineal gland to regulate seasonal cycle of reproduction. It was reported that opsin is a deep-brain photoreceptive molecule in the avian brain that regulate seasonal reproduction in birds. Lighting recommendations should be based on local environmental conditions, house type, light requirements fo...

Research paper thumbnail of Using Wireless Sensor Networks and Artificial Neural Networks for Implementing a Border Intrusion Detection System

International Conference on Wireless Networks, 2010

Research paper thumbnail of Substrate effect on phonon confinement in TiO2 nanoparticles for thermal sensing application

Applied Physics Letters, 2014

The great potential of anatase TiO2 nanoparticles (NPs) for high temperature applications is limi... more The great potential of anatase TiO2 nanoparticles (NPs) for high temperature applications is limited by the agglomeration, grain growth, and phase transformation into rutile. In this regard, we have decorated TiO2 NPs over the surface of Santa Barbara Amorphous-15 (SBA15) and studied the substrate effect on the thermal stability of anatase TiO2 NPs in terms of the grain growth and the phase transformation. Here, we reported the ultrafast grain growth of anatase TiO2 NPs in TiO2-SBA15 nanocomposite in response to short time thermal exposure and the resulting phonon confinement effect for high temperature thermal sensing application.

Research paper thumbnail of Analytical Performances Evaluation of Compact Heat Exchanger Using Nano-fluids

International Journal of Scientific Research, 2012

ABSTRACT Researches in heat transfer have been carried out over the previous several decades, lea... more ABSTRACT Researches in heat transfer have been carried out over the previous several decades, leading to the develop-ment of the currently used heat transfer enhancement techniques. Water and ethylene glycol as conventional coolants have been widely used in a compact heat exchanger for many years. These heat transfer fluids offer low thermal conductivity. With the advancement of nanotechnology, the new generation of heat transfer fluids called, “nanofluids ” have been developed and researchers found that these fluids offer higher thermal conductivity compared to that of conventional coolants. This study is focused on the application of mixture of water (80%) and ethylene glycol (20%) based nanofluids (Cu, Sic, Al2O3, and TiO2) are presented in this article. Use of nanofluid as coolant in compact heat exchanger improves the effectiveness, cooling capacity with the reduction in pumping power. Effects of various operating parameters such as air inlet temperature, coolant inlet temperature, air and coolant mass flow rates, effectiveness, pumping power and exergy analysis are studied as well. SiC-80 % H2O-20 % EG (base fluid) yields best performance in compact heat exchanger having louvered fin geometry followed by Al2O3-base fluid, TiO2-base fluid and Cu-base fluid. The maximum cooling improvement for SiC is 18.36%, whereas that for Al2O3 is 17.39%, for TiO2 is 17.05 % and for Cu is 13.41% as coolants and enhancement in second law efficiency for SiC is highest (21.89%) followed by Al2O3 (21.53%), TiO2 (21.3%), Cu (18.97%) nanofluids compare to base fluid as a coolant alone. Present study reveals that the nanofluids may effectively use as coolant

Research paper thumbnail of A comparative study of endophytic and epiphytic fungal association with leaf of Eucalyptus citriodora Hook., and their antimicrobial activity

World Journal of Microbiology and Biotechnology, 2010

Research paper thumbnail of Assessment of diversity, distribution and antibacterial activity of endophytic fungi isolated from a medicinal plant Adenocalymma alliaceum Miers

Research paper thumbnail of Wave propagation in a one-dimensional photonic crystal with metamaterial

Solid State Communications, 2009

Research paper thumbnail of Tunable and omnidirectional filters based on one-dimensional photonic crystals composed of single-negative materials

Journal of the Optical Society of America B, 2011

Received January 6, 2011; revised February 21, 2011; accepted March 3, 2011; posted April 11, 201... more Received January 6, 2011; revised February 21, 2011; accepted March 3, 2011; posted April 11, 2011 (Doc. ID 140714); published May 18, 2011 Tunable and omnidirectional filters have been demonstrated theoretically, using one-dimensional photonic crys-tals composed of ...

Research paper thumbnail of Anticancer compounds derived from fungal endophytes: their importance and future challenges

Natural Product Reports, 2011

Research paper thumbnail of Season and Tissue Type Affect Fungal Endophyte Communities of the Indian Medicinal Plant Tinospora cordifolia More Strongly than Geographic Location

Research paper thumbnail of Ultrahigh arsenic sorption using iron oxide-graphene nanocomposite supercapacitor assembly

Journal of Applied Physics, 2012

In response to the increasing water demand, electro-sorption method has shown promise in context ... more In response to the increasing water demand, electro-sorption method has shown promise in context of high removal efficiency of metals with less energy consumption. Here, we report for the first time ultrahigh sorption capacity of iron oxide-graphene (Fe3O4-HEG) nanocomposite supercapacitor assembly for both inorganic arsenic species (arsenate and arsenite). Graphene has been synthesized by hydrogen induced exfoliation of graphitic oxide and decorated with iron oxide (Fe3O4) nanocrystals by chemical route. Electrochemical sorption behavior of nanocomposite electrodes for arsenic has been examined by cyclic voltammetry and kinetic studies. Adsorption isotherm models have been tested to calculate the maximum adsorption capacities (using Langmuir isotherm) for arsenate and arsenite and found to be nearly 172.1 and 180.3 mg/g, respectively, using supercapacitor assembly. These values are higher than other adsorbents for arsenic.

Research paper thumbnail of Expression Profile of Connexin 43 and Poly A Polymerase Genes in Buffalo(Bubalus bubalis)Oocytes and Developing Embryos Producedin vitro

Journal of Applied Animal Research, 2010

ABSTRACT Mishra, A., Sharma, G.T. and Kumar, G.S. 2010. Expression profile of connexin 43 and pol... more ABSTRACT Mishra, A., Sharma, G.T. and Kumar, G.S. 2010. Expression profile of connexin 43 and poly A polymerase genes in buffalo (Bubalus bubalis) oocytes and developing embryos produced in vitro. J. Appl. Anim. Res., 38: 29–32.To find out the expression pattern of Connexin 43 (Cx43) a gap junction protein and Poly A polymerase (PAP) necessary for synthesis of poly (A) tail in mRNA, genes in buffalo (Bubalus bubalis) oocytes and developing embryos produced in vitro, pools of immatured oocytes (n=200), in vitro matured oocytes (n=200), embryos of 2–4 cell (n=83), 8–16 cell (n=80), morula (n=77) and blastocyst (n=40) were collected in vitro from slaughter house ovaries for mRNA isolation. RT-PCR was carried out by using mRNA as the template and PCR was carried out by using cDNA as template for amplification of 425 bp Cx43 and 252 bp PAP. Cx43 was expressed in all except blastocysts stage, whereas, PAP was expressed in all. It is concluded that expression pattern of Cx43 and PAP in oocytes and developing embryos can be used as a marker of developmental potential for embryos derived from oocytes.

Research paper thumbnail of Effect of Process Parameters on Melt Pool Characteristics and Solidification Process During Laser Powder Bed Fusion of AlSi10Mg Alloy

Lasers in Manufacturing and Materials Processing, Jan 5, 2024

Research paper thumbnail of Effect of Different Powder Bed Thermal Conductivity Models on the Melt Pool Characteristics and Solidification Parameters during Laser Powder Bed Fusion of Ti6Al4V

Transactions of the Indian Institute of Metals, Dec 7, 2023

Research paper thumbnail of Detecting border intrusion using wireless sensor network and artificial neural network

2010 6th IEEE International Conference on Distributed Computing in Sensor Systems Workshops (DCOSSW), 2010

Abstract— Monitoring movement across national borders is a challenging problem due to several eco... more Abstract— Monitoring movement across national borders is a challenging problem due to several economic and technical issues. Due to the vast size, remoteness and other geographical confines of border regions, technical solutions are necessary to complement the limitations of ...

Research paper thumbnail of Non linear stability analysis of parallel channels with natural circulation

Nuclear Engineering and Design, 2016

Abstract Linear stability analysis of two-phase flow in natural circulation loop is quite extensi... more Abstract Linear stability analysis of two-phase flow in natural circulation loop is quite extensively studied by many researchers in past few years. It can be noted that linear stability analysis is limited to the small perturbations only. It is pointed out that such systems typically undergo Hopf bifurcation. If the Hopf bifurcation is subcritical, then for relatively large perturbation, the system has unstable limit cycles in the (linearly) stable region in the parameter space. Hence, linear stability analysis capturing only infinitesimally small perturbations is not sufficient. In this paper, bifurcation analysis is carried out to capture the non-linear instability of the dynamical system and both subcritical and supercritical bifurcations are observed. The regions in the parameter space for which subcritical and supercritical bifurcations exist are identified. These regions are verified by numerical simulation of the time-dependent, nonlinear ODEs for the selected points in the operating parameter space using MATLAB ODE solver.

Research paper thumbnail of Two Phase Flow Stability Analysis of Multiple Horizontal Uniformaly Heated Channel

Lecture Notes in Mechanical Engineering, 2016

ABSTRACT Two-phase flow in multiple horizontal heated channels has wide applications in heat exch... more ABSTRACT Two-phase flow in multiple horizontal heated channels has wide applications in heat exchangers, solar heating systems, nuclear systems etc. The theoretical study of two-phase flow instability analysis for parallel multiple channels are carried out by Zhang et al., 2009. This was done for vertical channels and they used nodal methods to carry out stability analysis. Similar analysis was done by Lee et al. 1999 & 2005, for multiple vertical, parallel boiling channels with forced flows. Following the Zhang et al. 2009 and Lee et al. 1999 & 2005, the stability analysis of multiple horizontal channels with uniform heat flux has been carried out. The system is mathematically represented by non-linear PDEs for mass, momentum and energy in single as well as two-phase region. Coupling equation is being used under the assumption that pressure drop in each channel is same and total mass flow rate is equal to sum of individual mass flow rate. The homogeneous equilibrium model is assumed to be valid in the two phase region. Stability boundary is obtained in terms of phase change number (Npch) and Sub-cooling Number (Nsb) and can be validated by comparing it with result obtained by Matcont under same parametric values. Numerical simulations of the time-dependent, nonlinear ODEs are carried out for selected points in the operating parameter space to obtain the actual damped and growing oscillations in the channel inlet flow velocity which confirms the stability region across the stability map.

Research paper thumbnail of Design of VCO for Microwave Frequency Band

Ijca Proceedings on Recent Advances in Wireless Communication and Artificial Intelligence, Sep 29, 2014

Research paper thumbnail of A Density Fit Model for Stability Analysis of Heated Channel

In the present work an analytical model is developed to describe density wave oscillation (DWO) i... more In the present work an analytical model is developed to describe density wave oscillation (DWO) in uniformly heated coolant channels. The analysis is done by assuming the flow channel to be composed of two discrete regimes, single phase and two-phase kept separated by a well-defined time varying boiling boundary. The density variation of subcooled coolant in the single phase is considered whereas the incompressible flow assumption still remains valid. The stability characteristics of the system are demonstrated by various kinds of stability boundaries plotted in parameter planes of inlet-subcooling number, phase-change number and external pressure drop. A comparison between existing model and the present model is done to which describes the effect of density variation in various stability boundaries. It is observed that unlike to the earlier existing models where the single phase density remains invariant, the stability boundaries show a better shift towards exact solutions.

Research paper thumbnail of Utilization of and barriers to public sector tuberculosis services in India

The National medical journal of India

Tuberculosis control in India still faces many challenges related to the provision of services un... more Tuberculosis control in India still faces many challenges related to the provision of services under the Directly Observed Treatment, Short-course (DOTS) strategy. We assessed the utilization of and barriers to the Revised National Tuberculosis Control Programme (RNTCP) services based on DOTS in 4 states of India, and recommend actions to optimize utilization of the RNTCP services. Two districts each in 4 states with more than 50% of the population covered under the RNTCP in 2002, representing diverse levels of general health indicators, were selected. Sex-disaggregated data on patients who reported to the RNTCP facilities for the diagnosis and treatment of tuberculosis in 2002 were reviewed from the laboratory and tuberculosis registers to assess the utilization of these services. Data on barriers to utilization of the RNTCP services were collected through interviews of 4310 patients with tuberculosis who were 16 years of age or older. A total of 83,099 patients had reported for th...

Research paper thumbnail of Impact of lighting on poultry reproduction and recent advances

CABI Reviews, 2014

Different wavelengths of visible light spectrum influence the reproductive system of domestic avi... more Different wavelengths of visible light spectrum influence the reproductive system of domestic avian species. Light perceived by the retina is involved in growth and behaviour whereas light perceived by the hypothalamus is involved in reproduction through photosensitive cells in the brain (extra-retinal photoreceptors) and it varies with intensity of different wavelengths of light. Red spectrum of light with 675 nm of wavelengths is more gonadostimulatory than shorter wavelengths of 450-475 nm of light. Recent studies indicate that the hypothalamic opsins are involved in avian photoreception. Non-mammalian vertebrates detect light by deep brain photoreceptors that lie outside the retina and pineal gland to regulate seasonal cycle of reproduction. It was reported that opsin is a deep-brain photoreceptive molecule in the avian brain that regulate seasonal reproduction in birds. Lighting recommendations should be based on local environmental conditions, house type, light requirements fo...

Research paper thumbnail of Using Wireless Sensor Networks and Artificial Neural Networks for Implementing a Border Intrusion Detection System

International Conference on Wireless Networks, 2010

Research paper thumbnail of Substrate effect on phonon confinement in TiO2 nanoparticles for thermal sensing application

Applied Physics Letters, 2014

The great potential of anatase TiO2 nanoparticles (NPs) for high temperature applications is limi... more The great potential of anatase TiO2 nanoparticles (NPs) for high temperature applications is limited by the agglomeration, grain growth, and phase transformation into rutile. In this regard, we have decorated TiO2 NPs over the surface of Santa Barbara Amorphous-15 (SBA15) and studied the substrate effect on the thermal stability of anatase TiO2 NPs in terms of the grain growth and the phase transformation. Here, we reported the ultrafast grain growth of anatase TiO2 NPs in TiO2-SBA15 nanocomposite in response to short time thermal exposure and the resulting phonon confinement effect for high temperature thermal sensing application.

Research paper thumbnail of Analytical Performances Evaluation of Compact Heat Exchanger Using Nano-fluids

International Journal of Scientific Research, 2012

ABSTRACT Researches in heat transfer have been carried out over the previous several decades, lea... more ABSTRACT Researches in heat transfer have been carried out over the previous several decades, leading to the develop-ment of the currently used heat transfer enhancement techniques. Water and ethylene glycol as conventional coolants have been widely used in a compact heat exchanger for many years. These heat transfer fluids offer low thermal conductivity. With the advancement of nanotechnology, the new generation of heat transfer fluids called, “nanofluids ” have been developed and researchers found that these fluids offer higher thermal conductivity compared to that of conventional coolants. This study is focused on the application of mixture of water (80%) and ethylene glycol (20%) based nanofluids (Cu, Sic, Al2O3, and TiO2) are presented in this article. Use of nanofluid as coolant in compact heat exchanger improves the effectiveness, cooling capacity with the reduction in pumping power. Effects of various operating parameters such as air inlet temperature, coolant inlet temperature, air and coolant mass flow rates, effectiveness, pumping power and exergy analysis are studied as well. SiC-80 % H2O-20 % EG (base fluid) yields best performance in compact heat exchanger having louvered fin geometry followed by Al2O3-base fluid, TiO2-base fluid and Cu-base fluid. The maximum cooling improvement for SiC is 18.36%, whereas that for Al2O3 is 17.39%, for TiO2 is 17.05 % and for Cu is 13.41% as coolants and enhancement in second law efficiency for SiC is highest (21.89%) followed by Al2O3 (21.53%), TiO2 (21.3%), Cu (18.97%) nanofluids compare to base fluid as a coolant alone. Present study reveals that the nanofluids may effectively use as coolant

Research paper thumbnail of A comparative study of endophytic and epiphytic fungal association with leaf of Eucalyptus citriodora Hook., and their antimicrobial activity

World Journal of Microbiology and Biotechnology, 2010

Research paper thumbnail of Assessment of diversity, distribution and antibacterial activity of endophytic fungi isolated from a medicinal plant Adenocalymma alliaceum Miers

Research paper thumbnail of Wave propagation in a one-dimensional photonic crystal with metamaterial

Solid State Communications, 2009

Research paper thumbnail of Tunable and omnidirectional filters based on one-dimensional photonic crystals composed of single-negative materials

Journal of the Optical Society of America B, 2011

Received January 6, 2011; revised February 21, 2011; accepted March 3, 2011; posted April 11, 201... more Received January 6, 2011; revised February 21, 2011; accepted March 3, 2011; posted April 11, 2011 (Doc. ID 140714); published May 18, 2011 Tunable and omnidirectional filters have been demonstrated theoretically, using one-dimensional photonic crys-tals composed of ...

Research paper thumbnail of Anticancer compounds derived from fungal endophytes: their importance and future challenges

Natural Product Reports, 2011

Research paper thumbnail of Season and Tissue Type Affect Fungal Endophyte Communities of the Indian Medicinal Plant Tinospora cordifolia More Strongly than Geographic Location

Research paper thumbnail of Ultrahigh arsenic sorption using iron oxide-graphene nanocomposite supercapacitor assembly

Journal of Applied Physics, 2012

In response to the increasing water demand, electro-sorption method has shown promise in context ... more In response to the increasing water demand, electro-sorption method has shown promise in context of high removal efficiency of metals with less energy consumption. Here, we report for the first time ultrahigh sorption capacity of iron oxide-graphene (Fe3O4-HEG) nanocomposite supercapacitor assembly for both inorganic arsenic species (arsenate and arsenite). Graphene has been synthesized by hydrogen induced exfoliation of graphitic oxide and decorated with iron oxide (Fe3O4) nanocrystals by chemical route. Electrochemical sorption behavior of nanocomposite electrodes for arsenic has been examined by cyclic voltammetry and kinetic studies. Adsorption isotherm models have been tested to calculate the maximum adsorption capacities (using Langmuir isotherm) for arsenate and arsenite and found to be nearly 172.1 and 180.3 mg/g, respectively, using supercapacitor assembly. These values are higher than other adsorbents for arsenic.

Research paper thumbnail of Expression Profile of Connexin 43 and Poly A Polymerase Genes in Buffalo(Bubalus bubalis)Oocytes and Developing Embryos Producedin vitro

Journal of Applied Animal Research, 2010

ABSTRACT Mishra, A., Sharma, G.T. and Kumar, G.S. 2010. Expression profile of connexin 43 and pol... more ABSTRACT Mishra, A., Sharma, G.T. and Kumar, G.S. 2010. Expression profile of connexin 43 and poly A polymerase genes in buffalo (Bubalus bubalis) oocytes and developing embryos produced in vitro. J. Appl. Anim. Res., 38: 29–32.To find out the expression pattern of Connexin 43 (Cx43) a gap junction protein and Poly A polymerase (PAP) necessary for synthesis of poly (A) tail in mRNA, genes in buffalo (Bubalus bubalis) oocytes and developing embryos produced in vitro, pools of immatured oocytes (n=200), in vitro matured oocytes (n=200), embryos of 2–4 cell (n=83), 8–16 cell (n=80), morula (n=77) and blastocyst (n=40) were collected in vitro from slaughter house ovaries for mRNA isolation. RT-PCR was carried out by using mRNA as the template and PCR was carried out by using cDNA as template for amplification of 425 bp Cx43 and 252 bp PAP. Cx43 was expressed in all except blastocysts stage, whereas, PAP was expressed in all. It is concluded that expression pattern of Cx43 and PAP in oocytes and developing embryos can be used as a marker of developmental potential for embryos derived from oocytes.