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Certain chemical and enzymes like sodium deoxycholate, sodium dodecyl sulphate and Triton X-100 have been used as biological detergents but are responsible for residual cytotoxicity in the decellularized extracellular matrix. The periosteum plays a key role in bone regeneration. We aimed to prepare decellularized caprine periosteum scaffold by exploring the decellularization property of Sapindus mukorossi fruit pericarp extract (SPE). We developed decellularization protocols to completely remove the periosteum cellular components and for good maintenance of the hierarchical multilayer structures and components of the extracellular matrix (ECM) with no cytotoxicity. Histological analysis of hematoxylin and eosin and Masson’s trichrome stained tissue samples decellularized by 5% SPE extract confirmed decellularization with preservation of extracellular matrix microarchitecture. DAPI stained decellularized tissues revealed complete removal of nuclear components, verified by DNA content measurement. It was concluded that 5% SPE is ideal for preparation of decellularized caprine periosteum scaffold and these scaffolds can be used for bone regeneration.

Plasma waves are observed in almost all the solar system objects. The planetary ionospheres are capable of sustaining plasma waves which are observed there and play an important role in the ionospheric dynamics. Venus does not possess a global magnetic field unlike Earth. The solar EUV radiation ionizes the neutrals and generates a plasma environment around Venus which can sustain plasma waves. Very few attempts are made to observe all plasma waves that can exist around Venus and that too with instruments having a limited dynamic range such as with Pioneer Venus Orbiter and Venus Express. However, there are some other plasma waves which can exist around Venus but are yet to be observed.

Plasma waves are observed around almost all the solar system objects – Sun, planets and their satellites, comets, interplanetary medium, etc. The plasma environment around a planet has sufficient p...

Plasma wave is one of the special features of any space plasma system. One such wave, namely Alfven wave, is a magnetic disturbance which during its propagation picks ions from the backgrou...

The Aditya-L1 is first Indian solar mission scheduled to be placed in a halo orbit around the first Lagrangian point (L1) of Sun-Earth system in the year 2018–19. The approved scientific payloads onboard Aditya-L1 spacecraft includes a Fluxgate Digital Magnetometer (FGM) to measure the local magnetic field which is necessary to supplement the outcome of other scientific experiments onboard. The in-situ vector magnetic field data at L1 is essential for better understanding of the data provided by the particle and plasma analysis experiments, onboard Aditya-L1 mission. Also, the dynamics of Coronal Mass Ejections (CMEs) can be better understood with the help of in-situ magnetic field data at the L1 point region. This data will also serve as crucial input for the short lead-time space weather forecasting models. The proposed FGM is a dual range magnetic sensor on a 6 m long boom mounted on the Sun viewing panel deck and configured to deploy along the negative roll direction of the spacecraft. Two sets of sensors (tri-axial each) are proposed to be mounted, one at the tip of boom (6 m from the spacecraft) and other, midway (3 m from the spacecraft). The main science objective of this experiment is to measure the magnitude and nature of the interplanetary magnetic field (IMF) locally and to study the disturbed magnetic conditions and extreme solar events by detecting the CME from Sun as a transient event. The proposed secondary science objectives are to study the impact of interplanetary structures and shock solar wind interaction on geo-space environment and to detect low frequency plasma waves emanating from the solar corona at L1 point. This will provide a better understanding on how the Sun affects interplanetary space. In this paper, we shall give the main scientific objectives of the magnetic field experiment and brief technical details of the FGM onboard Aditya-1 spacecraft.

The altitude profiles of argon-40 (Ar) in the Martian exosphere are reported using Mars Exospheric Neutral Composition Analyser aboard Indian Mars Orbiter Mission (MOM) from four orbits during December 2014 (Ls = 250°–257°), when MOM's periapsis altitude was the lowest. The upper limit of Ar number density corresponding to this period is ∼5 × 105 cm−3 (∼250 km), and the typical scale height is ∼16 km, corresponding to an exospheric temperature of ∼275 K. However, on two orbits, the scale height over this altitude region is found to increase significantly making the effective temperature >400 K. Neutral Gas and Ion Mass Spectrometer observations on the Mars Atmosphere and Volatile Evolution mission also indicate that the change in slope in Ar density occurs near the upper exosphere (around 230–260 km). These observations indicate significant suprathermal CO2 and Ar populations in the Martian exosphere. Significant wave-like perturbations are observed but only on certain days when suprathermal population is seen. Pickup ion-induced heating is discussed as the other viable source.

Plasma waves are observed in almost all the solar system objects such as planets, their satellites, comets and interplanetary medium. In planetary ionospheres, typical plasma density range is 103 – 106 cm-3 and plasma temperature about 0.1 eV which is capable of sustaining plasma waves. A number of planetary satellites such as Io, Europa, Ganymede and Callisto of Jupiter and Saturnian satellites such as Titan, Enceladus and Rhea, are found to have plasma waves in their ionospheres. Earth’s natural satellite Moon, which has a tenuous atmosphere and even a more tenuous surface bound ionosphere, also support plasma waves around it. It is important to study the plasma waves as these waves play significant role in the dynamics of a space plasma system by controlling the scattering and loss of energetic charged particles and also provide information on solar wind-planet interactions, the energy distribution in plasma, etc. This paper summarizes the plasma waves observed in and around the Moon so far in the form of a brief review.

Plasma waves have a universal presence in our solar system – planets, some of their satellites and interplanetary medium. The solar plasma environment of also supports the generation of plasma waves such as electron and ion cyclotron waves, the magnetosonic and Alfven waves which travels a long distance in heliosphere. The plasma environment around a comet is also capable of sustaining plasma waves, some of which are observed in comets Giacobini-Zinner, Halley, Grigg-Skjellerup and Borrelly. Some other comets such as Hyakutake and 67/PChuryumov-Gerasimenko are also supposed to sustain plasma waves but are yet to be observed. This paper presents a brief review on the plasma wave observations in cometary plasma environment carried out so far and some of the unresolved plasma wave issues in comets.

The Mars Exospheric Neutral Composition Analyser (MENCA) aboard the Indian Mars Orbiter Mission (MOM) is a quadrupole mass spectrometer which provides in situ measurement of the composition of the low-latitude Martian neutral exosphere. The altitude profiles of the three major constituents, i.e., amu 44 (CO2), amu 28 (N2 + CO), and amu 16 (O) in the Martian exosphere during evening (close to sunset terminator) hours are reported using MENCA observations from four orbits of MOM during late December 2014, when MOM's periapsis altitude was the lowest. The altitude range of the observation encompasses the diffusively separated region much above the well-mixed atmosphere. The transition from CO2 to O-dominated region is observed near 270 km. The mean exospheric temperature derived using these three mass numbers is 271 ± 5 K. These first observations corresponding to the Martian evening hours would help to provide constraints to the thermal escape models.

The near surface lunar plasma environment is modulated by important components like the photoelectron sheath, solar wind, lunar surface potential, etc. In situ measurements of lunar near surface plasma are not available as of now. Previous lunar missions which explored the near surface environment have arrived at estimates of lunar photo electron densities mainly from lunar sample returns. The Chandrayaan-2 lunar mission affords a unique opportunity to explore the near surface lunar plasma environment from the lunar lander platform. A Langmuir probe is developed indigenously for probing the tenuous lunar near surface plasma environment from the top deck of the lunar lander. The probe is designed to cater to a wide dynamic range of 10/cc to 10,000/cc. The probe behaviour is characterized in the ambient room conditions using a current source. The sensitivity of the probe to incoming ionized species is also characterized in a vacuum chamber. The Langmuir probe response is characterized such that the input current to the probe is correctly deciphered during the mission duration. The calibration of the present Langmuir probe is carried out using a standard calibrated Langmuir probe. The details of the theoretical simulations of the expected currents, the characterization and calibration activities are presented and discussed.

Fluxgate Magnetometers (FGM) are regularly sent onboard space missions to measure the local magnetic field magnitude. These magnetic field measurements are one of the methods used to study the plasma wave parameters. The plasma waves emanating from a plasma environment carries the history of their generation mechanism with them. Plasma waves can also provide information about various physical phenomena which take place locally in and around the Sun where the in-situ measurements are not possible due to extreme and hostile conditions. For solar plasma waves study, the first Lagrangian point (L1) is an excellent location as it is far off from the solar plasma environment as well as from Earth's magnetosphere. There are many spacecrafts sent at L1 point to study the scientific aspects of Sun. However only WIND and ACE were two missions which carried the magnetic field measurement instruments such as the FGM to measure the steady state magnetic field environment at L1 point. The FGMs onboard these two spacecrafts collects magnetic field data at very finite intervals to extract scientific information. Magnetic field data from FGM can be used to detect the solar plasma waves (primarily Alfven) at L1 point to estimate their wave properties.

We have carried out 2 week-long campaigns in Indian winter and summer to study VLF signals from the Indian navy transmitter (VTX) operating at 18.2 kHz. We have used more than a dozen of receivers scattered throughout the Indian sub-continent in each of these campaigns. To our knowledge, this is the largest campaign of its kind in this region. The propagation paths range from 500 km to almost 3,000 km covering an area of about 4 million sq km. We have presented the results of the amplitude variation of the diurnal signal at each of these receiving stations in winter and summer and compare them. We have clearly found the non-reciprocity of the east to west and west to east propagation. Our results generally agree with the signal shapes obtained using the long wave propagation capability code based on mode propagation through the Earth-ionosphere cavity.

We present the results of simulations of shadows cast by a zone plate telescope which may have one to four pairs of zone plates. From the shadows we reconstruct the images under various circumstances. We discuss physical basis of the resolution of the telescope and demonstrate this by our simulations. We allow the source to be at a finite distance (diverging beam) as well as at an infinite distance (parallel beam) and show that the resolution is worsened when the source is nearby. By reconstructing the zone plates in a way that both the zone plates subtend the same solid angles at the source, we obtain back high resolution even for sources at a finite distance. We present simulated results for the observation of the galactic center and show that the sources of varying intensities may be reconstructed with accuracy. Results of these simulations would be of immense use in interpreting the X-ray images from recently launched CORONAS-PHOTON satellite., Comment: 17 pages, 36 figures, Published in Experimental Astronomy

Combination of Fresnel Zone Plates (FZP) can make an excellent telescope for imaging in X-rays. We present here the results of our experiments with several pairs of tungsten made Fresnel Zone plates in presence of an X-ray source kept at a distance of about 45 feet. The quasi-parallel beam allowed us to study sources placed on the axis as well as off the axis of the telescope. We present theoretical study of the fringe patterns produced by the zone plates in presence of a quasi-parallel source. We compare the patterns obtained from experiments with those obtained by our Monte-Carlo simulations. The images are also reconstructed by deconvolution from both the patterns. We compare the performance of such a telescope with other X-ray imaging devices used in space-astronomy., 16 pages, 24 figures, published in Experimental Astronomy

Electron cyclotron resonance (ECR) plasma breakdown is studied in a small linear cylindrical system with four different gases — hydrogen, helium, argon and nitrogen. Microwave power in the experimental system is delivered by a magnetron at 2.45 ± 0.02 GHz in TE10 mode and launched radially to have extra-ordinary (X) wave in plasma. The axial magnetic field required for ECR in the system is such that the fundamental ECR surface (B = 875.0 G) resides at the geometrical centre of the plasma system. ECR breakdown parameters such as plasma delay time and plasma decay time from plasma density measurements are carried out at the centre using a Langmuir probe. The operating parameters such as working gas pressure (1 × 10−5−1× 10−2 mbar) and input microwave power (160–800 W) are varied and the corresponding effect on the breakdown parameters is studied. The experimental results obtained are presented in this paper.

Electron Cyclotron Resonance Heating (ECRH) system will play an important role in plasma formation, heating and current drive in the Superconducting Steady state Tokamak (SST-1). Commissioning activity of the machine has been initiated. Many of the sub-systems have been prepared for the first plasma discharge. A radial and a top port have been allotted for low field side (LFS) and high field side (HFS) launch of O and X- modes in the plasma. The system is based on a gyrotron source operating at a frequency of 82.6±0.1GHz (GLGD-82.6/0.2) and capable of delivering 0.2 MW / 1000s with 17% duty cycle. The transmission line consisting of ~15 meters length 63.5mm corrugated wave guide, DC break, wave guide switch, mitre bend, polariser, bellows that terminates with a vacuum barrier CVD window. A beam launching system used to steer the microwave beam in the plasma volume is connected between the end of the transmission line and the tokamak radial and top ports. A VME based real time data acquisition and control (DAC) system is used for monitoring, acquisition and control. Hard-wired interlock operates a rail-gap based crowbar system in less than 10µs under any fault condition. Burn patterns are recorded at various stages in the transmission line. The gyrotron is tested for ~200 kW / 1000s operation on a water dummy load. Transmission line is tested at various power levels for long pulse operation. The paper highlights the experimental results of successful commissioning of the system.

Electron Bernstein wave (EBW) generation via mode conversion is observed in a short cylindrical electron cyclotron resonance (ECR) plasma system. ECR plasma with input microwave power varying from 160 to 800 W is produced at an operating pressure of 10−3 mbar with hydrogen gas with a maximum plasma density of 3.1×1010 cm−3 at the center and plasma temperature of 10 eV. The axial magnetic field required for ECR in the system is produced by two identical magnetic coils arranged in the Helmholtz configuration. The fundamental ECR surface (B=875 G) is located at the geometrical center of the plasma system. Microwaves of 2.45±0.02 GHz from a magnetron in TE10 mode are launched radially to have extraordinary (X) wave in plasma. The EBW is observed to be generated at the upper hybrid resonance layer at a distance of 2 cm from the center towards the microwave source. The EBW is assumed to be generated through X-B mode conversion which is inferred by the observation of the parametric decay of the incident wave. The experimental results pertaining to the EBW detection and characterization are discussed in this paper.

Electron cyclotron resonance (ECR) plasma is produced and studied in a small cylindrical system. Microwave power is delivered by a CW magnetron at 2.45 GHz in TE10 mode and launched radially to have extraordinary (X) wave in plasma. The axial magnetic field required for ECR in the system is such that the first two ECR surfaces (B = 875.0 G andB = 437.5 G) reside in the system. ECR plasma is produced with hydrogen with typical plasma density ne as 3.2 × 1010 cm-3 and plasma temperature Te between 9 and 15 eV. Various cut-off and resonance positions are identified in the plasma system. ECR heating (ECRH) of the plasma is observed experimentally. This heating is because of the mode conversion of X-wave to electron Bernstein wave (EBW) at the upper hybrid resonance (UHR) layer. The power mode conversion efficiency is estimated to be 0.85 for this system. The experimental results are presented in this paper.

Nonlinear wave coupling phenomena in an electron cyclotron resonance (ECR) produced plasma are observed. Experiments are carried out in a small linear cylindrical system with hydrogen plasma. Microwave power in the system is delivered by a magnetron at 2.45 GHz in TE10 mode and is launched radially to have extraordinary (X) wave in plasma. The axial magnetic field configuration, required for ECR to occur in the system, is such that the first ECR surface (B=875 G) resides at the center of the system. Parametric decay spectrum of the launched electromagnetic wave is observed at the upper hybrid resonance (UHR) layer with the appearance of sidebands on the higher and lower side of the launched frequency. Experiments show that the appearance of parametric decay spectrum has a threshold on input microwave power. The decay spectrum is observed only at the UHR surface indicating strong spatial dependence. The parametric decay is also verified in argon and helium plasmas.

Ultrasoft x-ray emission in the energy range 10–100 eV is observed from a linear electron cyclotron resonance (ECR) plasma system. ECR plasma is produced in a short cylindrical stainless steel (SS) chamber with a central axial magnetic field of 875 G, generated by two coils placed axially to have the first two ECR surfaces inside the experimental chamber. Plasma is produced in a pressure range of 2 × 10−5 mbar with hydrogen. Also, plasma is produced with net microwave power varying from 160 to 800 W at 2.45 GHz frequency from a magnetron. The waveguide from the magnetron to the vacuum vessel supports rectangular TE10 mode and the electromagnetic wave propagation in plasma is in extraordinary (X) mode. The ultrasoft x-ray emission is observed with a vacuum photodiode. The results clearly indicate a decrease in x-ray emission on increasing the working pressure and an increase in emission with an increase in the input microwave power. The experiments also ensure that the presence of a metal target enhances the intensity of soft x-rays generated in the ECR plasma system.

Imaging in hard X-rays of any astrophysical source with high angular resolution is a challenging job. Shadow-casting technique is one of the most viable options for imaging in hard X-rays. We have used two different types of shadow-casters, namely, Coded Aperture Mask (CAM) and Fresnel Zone Plate (FZP) pair and two types of pixellated solid-state detectors, namely, CZT and CMOS in RT-2/CZT payload, the hard X-ray imaging instrument onboard the CORONAS-PHOTON satellite. In this paper, we present the results of simulations with different combinations of coders (CAM & FZP) and detectors that are employed in the RT-2/CZT payload. We discuss the possibility of detecting transient Solar flares with good angular resolution for various combinations. Simulated results are compared with laboratory experiments to verify the consistency of the designed configuration., 27 pages, 16 figures, Accepted for publication in Experimental Astronomy (in press)

To study electron cylotron resonance (ECR) breakdown and afterglow plasma in an experimental linear plasma system, a pulsed microwave source with rapid rise and fall of microwave power is desired. A pulsed microwave source with fast rise and fall capability for ECR breakdown experiments has been designed and tested for performance in the system. A tetrode, controlled by a modulator card, is used as a fast switch to initiate microwave power from a conventional magnetron operating at 2.45 GHz. The typical rise time of microwave power is approximately 3 micros and a fall time of approximately 10 micros. Using this scheme in a realistic pulsed microwave source at 800 W power, ECR breakdown of neutral gas is achieved and the plasma delay and fall time are observed from the plasma density measurements using a Langmuir probe. The design details of the fast rise pulsed microwave source are presented in this article with initial experimental results.

The Mars Exospheric Neutral Composition Analyser (MENCA) aboard the Indian Mars Orbiter Mission (MOM) is a quadrupole mass spectrometer-based experiment. Making use of the highly elliptical and low inclination (~150°) orbit of MOM, MENCA will conduct in situ measurements of the composition and radial distribution of the Martian neutral exosphere in the 1–300 amu mass range in the equatorial and low latitudes of Mars. The functionality of MENCA has been tested during the Earth-bound and heliocentric phases of MOM before its operation in the Martian orbit. This article describes the scientific objectives, instrument details, design and development, test and evaluation, and calibration of the MENCA instrument.

Electric probes, such as the Langmuir and capacitive probes, are designed and fabricated to characterize microwave-produced plasma. In microwave- or electron cyclotron resonance (ECR)-produced plasmas, the ordinary Langmuir probe shows errors in the measurement of plasma parameters due to the presence of a steady magnetic field. To eliminate these errors and the already existing sheath effects, some modifications have to be incorporated in the design of a Langmuir probe. Two such probes, a Langmuir probe for measuring plasma parameters such as density, temperature and floating potential and a capacitive probe for detecting plasma oscillations, are designed. The plasma parameters measured by the designed probe match well with the theoretically estimated values. The design details of the two probes and the plasma parameters obtained with these probes are presented in this paper.