Synthesis and biological activities of some 3,5-diaryl-N-hydroxy-tetrahydro-1,4-thiazine-1,1-dioxides

Some new 3,5-diaryl-N-hydroxy-tetrahydro-1,4-thiazine-1,1-dioxides (6a-i) have been synthesized by reacting thiazine (4) with dimethyldioxirane (5) and tested for their antibacterial and acute toxicity studies. The synthesized compounds were characterized by elemental analysis, IR and NMR spectral data

Identification of Medicinal Plants in Homam: a religious practice

In India, Homam is an important religious practice. The consecrated fire is the central element of the ritual homa. It is offered in many hindu temples in early morning before dawn. Apart from the temples, many hindus offer this practice during their home ceremonies also. The most beneficial factor of these homas, is that smoke not only purifies the atmosphere but also helps us to get rid of many diseases. In this paper, the local and scientific name, plant parts used in the Homam were identified and presented. Different plant parts like leaf, aerial root, fruit, seed, bark, root, flower, wood, tuber, rhizome and pericarp of fruits have been used in the practice. Some highly useful medicinal plants listed are Justicia adhatoda, Withania somnifera, Phyllanthus emblica, Tinospora cordifolia, Andrographis paniculata, Strychnos nux-vomica, Pongamia pinnata, Ficus benghalensis, Chrysopogon zizanioides and Curcuma aromatica.

HET acid based oligoesters – TGA/FTIR studies

One of the important reactive halogenated dicarboxylic acids used in the synthesis of flame retardant unsaturated polyester resins is 1,4,5,6,7,7-hexachlorobicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid (HET acid). In the present investigation four different oligoesters are synthesized using HET acid as the diacid component and 1,2-ethane diol, 1,2-propane diol, 1,3-propane diol and 1,4-butane diol as the aliphatic diols. Melt condensation technique in vacuum is used for the synthesis of the oligoesters. The number average molecular weights of the oligoesters are determined using end group analysis. The degree of polymerization is estimated to be 3–5. The structural characterization is done using FTIR and NMR (1H and 13C) techniques. In the present investigation, TGA-FTIR studies for the different oligoesters are carried out in nitrogen atmosphere. The materials are heated from ambient to 600 °C at a heating rate of 20 °C/min. The main volatile products identified are CO, HCl, H2O, CO2, hexachlorocyclopentadiene and HET acid/anhydride. The evolution profile of these materials with respect to the structure of the oligoesters is discussed in detail and presented. The importance of β-hydrogens in the diol component and the plausible mechanism for the flame retardant behavior of these oligoesters are presented

Thermal Degradation Studies on PMMA–HET Acid Based Oligoesters Blends

Imparting thermal stability to polymethyl methacrylate (PMMA) without affecting its optical clarity is attempted by incorporating HET acid based oligoesters. Pure PMMA and PMMA containing five and 20 wt% of four different oligoesters are separately prepared using bulk polymerization. The thermal properties of the materials studied using DSC, TG, TG–FTIR and Pyr–GC–MS are presented. The main volatile degradation products identified are CO, HCl, CO2, H2O, hexachlorocyclopentadiene, hexachloroendomethylene tetrahydrophthalic acid/anhydride and methyl methacrylate. A detailed mechanism for the influence of the degradation products of HET acid based oligoesters on the thermal degradation of PMMA is also presented

Some endemic medicinal plants of Andamans with antimicrobial potential

The present study was aimed to determine the antimicrobial activity of some endemic plant species used in folkloric medicine by the inhabitants of Andaman Islands, India. The ethanol extracts prepared from the leaves of four plants viz; Alstonia kurzii, Tabernaemontana crispa, Mangifera andamanica and Vitex diversifolia were assessed for antibacterial activity against clinically isolated human pathogenic bacteria and antifungal activity against some phytopathogenic fungi. The ethanol extracts showed more inhibition towards Gram positive than Gram negative bacteria and the bacterial strains showed more susceptibility than the fungal strains tested. Among the plants, Vitex diversifolia exhibited the highest antibacterial activity and Mangifera andamanica showed the highest antifungal activity

Effects of scaling on high subsonic cavity flow oscillations and control

The effects of scaling on cavity oscillations and control have been studied by measuring the unsteady pressure on the floor of three cavities of different scales. The cavities have a length-to-depth ratio of 5 and a length-to-width ratio of 2, and the corresponding linear dimensions are in the ratio0.5∶1∶2. The experiments were conducted with clean cavities and cavities fitted with leading-edge sawtooth spoilers so as to study the influence of scaling on clean cavities as well as the effectiveness of the passive control method on different sized cavities. The results showed significant variation of certain spectral characteristics of the clean cavities. The control effectiveness of the spoilers also showed variations with a change in scale of the model. It is recommended that, before implementing a passive control device for practical applications, the device should be tested in the possible range of cavity length-to-boundary-layer-thickness ratio (L/δ) that can be experienced in actual flight

Diabetes Mellitus: Can Stem Cells be the Answer?

This review aims to enlighten the readers regarding the past, present and future of stem cells in the treatment of Diabetes. Diabetes is one of the leading causes of morbidity and mortality, affecting more than 415 million people worldwide. It is estimated that one in ten adults will have diabetes by 2030. Diabetes is mainly due to reduction in β-cell mass which are responsible for insulin production. Exogenous administration of insulin is having good impact on restoring glucose homeostasis, but it does not entirely control the minute-to-minute fluctuations in systemic blood glucose. Recently cellular-based therapies have been established for exogenous insulin administration by modern pump technology. One of the most interesting therapies involves substitution of insulin producing islet cells by transplantation. But lack of donor material and lifelong immunosuppression made the technique unfeasible. These restrictions have led to exploration of other sources of β-cells, one of the prospects being the stem cells. Several types of stem cells have been used to make pancreatic β-cells, including human embryonic stem cells / induced pluripotent stem cells, pancreatic stem / progenitor cells, and non-pancreatic stem cells. There is also evidence of adult β-cells regeneration through β-cell replication and cellular reprogramming. Functional restoration of existing β-cells, transplantation of stem cells or stem cell-derived β-like cells might provide new opportunities for treatment. In conclusion it can be said that the research is still wide open to arrive at the efficient reprogramming of various types of stem cells to destine them towards functional β-cells

Design and performance of subirrigation system in maize (Zea mays) in Kumulur farm, Trichy district, Tamil Nadu, India

Subirrigation system can furnish water to plants. The upward flux and the discharge rate must satisfy the plant’s lifesaving irrigation needs during summer. The experiment was laid out in  A-block of Eastern farm, Agricultural Engineering College and Research Institute, Kumulur, Trichy, Tamil Nadu. Subirrigation system spacing was arrived using Moody's equation calculated as 10 m. The experiment was laid out in spilt plot design with three replications. Four drain spacing levels (7.5, 10, 12.5 and 15 m) were the main plot treatments and two levels of depth and diameter of drain pipes (75 cm, 60 cm & 75 mm, 63 mm) were the sub plot treatments. The highest volumetric water content was recorded in 7.5 m spacing + 45 cm soil depth + lower reach (S1T3T1). Capillary rise on water table management system under subirrigation mode was fixed as 33.5 cm and the average deep percolation loss was obtained in 0.3 cm/d at development stage of crop period. The highest maize yield (4.30 t/ha) was obtained in 7.5 m spacing + 60 cm drain depth + 75 mm diameter (S1D3). The highest water use efficiency of (0.86 kg/m3) was recorded in 7.5 m spacing + 60 cm drain depth + 75 mm drain diameter (S1D3). This subirrigation system could furnish water to plants due to upward flux and the same system also functioned efficiently under drainage modes and removed the waterlogging during wet periods.       

Experimental investigation of abrasive waterjet machining of Nickel based superalloys (Inconel 625)

This work explores abrasive waterjet machining (AWJM) process to improve the machining capabilities of conventional water jet machine by adding abrasive particles to the water jet. The addition of abrasive particles can turn the water jet into a modern machining tool for all materials. The experimental data of cutting parameters for hard-to-machine metal Inconel 625 is obtained. Inconel 625 is machined using an abrasive water jet and the effect of water pressure, abrasive flow rate, stand-off distance, surface quality has been studied and the response parameters are investigated. Experiments were conducted, based on Taguchi's L18 orthogonal array and the process parameters were optimized using Grey relational analysis. Further, the morphological study is made using scanning electron microscope (SEM) on the samples that were machined at optimized parameters. It is observed from the experiment that Stand-off distance is the most influencing parameter among the input parameters

Performance of water table management system for alleviating sodic soil reclamation at Kumulur farm, Trichy District, Tamil Nadu

Waterlogging and sodicity is common problem in many irrigation canal command areas. The water table management system is the next level of improving water management in irrigated agriculture. In the present study, the water table management system was designed to work effectively in the monsoon season as a controlled drainage system and sub-irrigation system during summer. The field evaluation of drain water quality analysis was carried out from the water table management system installed at A-block of Eastern Farm, Agricultural Engineering College and Research Institute, Kumulur farm, Trichy, Tamil Nadu during 2015-2016. The experiment was laid out in a split plot design with three replications. Four levels of drain spacing of drain pipes (7.5, 10, 12.5 and 15m) were the main plot treatment and two levels of depth and diameter of drain pipes (75 cm, 60 cm & 75 mm, 63 mm) were the sub plot treatments. The results showed that the recommended quality of press mud 2 t ha-1 was a help to reduce the Exchangeable sodium percentage (ESP) level of 33 to 28 percent when compared to other ameliorants. It was concluded that solubilization should be removed by providing drainage and brought to ESP level of less than 16 percent and 15 m drain spacing to adapt to reduce the ESP level below the critical.