Role of ethylene diurea (EDU) in assessing impact of ozone on Vigna radiata L. plants in a suburban area of Allahabad (India)

A field study was conducted to evaluate the suitability of ethylene diurea (N-[2-(2-oxo-1-imidazolidinyl)ethyl]-N'-phenylurea; EDU) in assessing the impact of O3 on mung bean plants (Vigna radiata L. var. Malviya Jyoti) grown in suburban area of Allahabad city situated in a dry tropical region of India. EDU is a synthetic chemical having anti-ozonant property. Mean monthly O3 concentration varied between 64 and 69 microg m(-3) during the experimental period. In comparison to EDU-treated plants, non-EDU-treated plants showed significant reductions in plant growth and yield under ambient conditions. Significant favourable effects of EDU-application were observed with respect to photosynthetic pigments, soluble protein, ascorbic acid and phenol contents. EDU-treated plants maintained higher levels of pigments, protein and ascorbic acid in foliage as compared to non-EDU-treated ones. The study clearly demonstrated that EDU alleviates the unfavourable effects of O3 on mung bean plants, and therefore can be used as a tool to assess the growth and yield losses in areas having higher O3 concentrations.     

Experimental investigation of open core downdraft biomass gasifier for food processing industry

This paper deals with field related experience of a low temperature industrial heat application through biomass gasification. The gasification system is essentially consists of an open top down draft reactor lined with ceramic. The experiment reveals that 6.5 kg of liquefy petroleum gas (LPG) is fully replaced by 38 kg of sized wood on hourly basis. The maximum temperature attained was 367°C in 130 min at 100.7 Nm³ h⁻¹ gas flow rate. This system has resulted a saving of about 19.5 tons of LPG over 3,000 h of operation, implying a saving of about 33 tons of CO₂ emission, thus a promising candidate for clean development mechanism. Fuel economic analysis of gasifier system showed that the saving was about 13,850 US$ for 3,000 h of baking operation.     

Potential of surplus biomass gasifier based power generation: A case study of an Indian state Rajasthan

Facing the finiteness of fossil fuels and its associated environmental problems, new prospects to cover energy demand are urgently required. Energy from surplus biomass can support an essential contribution to a sustainable energy generation. This paper deals with a case study of surplus biomass available in the Indian state Rajasthan. About 1275 MW electrical power is possible to generate through biomass gasifier based power generation plant through surplus biomass available in Rajasthan. About 1656 tonnes of CO₂ can be saved annually by installation of 1 MW biomass gasifier based power plant. The techno economic parameter like net present worth, cost benefit ratio and pay back period are also carried out for this route of power generation and these are about 1.18 million US$, 1.42 and 8 years and 2 months respectively.     

Amelioration of Indian urban air pollution phytotoxicity in Beta vulgaris L. by modifying NPK nutrients

Air pollution levels are increasing at an alarming rate in many developing countries, including India and causing a potential threat to crop production. Field experiments were conducted to examine the impact of urban air pollutants on biomass (yield) and some physiological and biochemical parameters of palak (Beta vulgaris L. var. All Green) that grew from germination to maturity at seven periurban sites of Allahabad city having different concentrations of air pollutants under different levels of nutrients. The 6h daily mean NO2, SO2 and O3 concentrations varied from 2.5 to 42.5, 10.6 to 65 and 3.5 to 30.8 microg m(-3), respectively at different locations. Levels of air pollution showed significant negative correlations with photosynthetic pigments, protein, ascorbic acid and starch contents and catalase activity of palak leaves. A significant negative correlation was found for total biomass with SO2 (r=-0.92), NO2 (r=-0.85) and O3 (r=-0.91) concentrations. The increased fertilizer application (N, P and K) over the recommended dose resulted in a positive response by reducing losses in photosynthetic pigments and total biomass. This study proved that ambient air pollution of Allahabad city is influencing negatively to the growth and yield of palak plants.     

Seasonal variations in different physico-chemical parameters of the effluents of Century Pulp and Paper Mill, Lal Kuan, Uttarakhand

The present study was undertaken with the objective to study the characteristics of the effluent of Century Pulp and Paper Mill, Lalkuan (Uttarakhand) in different seasons. The variations in the physicochemical characteristics were observed and monitored up to 12 months at three different sites. Mean values of temperature, pH, chlorides and total phenols of the effluent were found below, whereas colour, BOD5, COD and lignin concentrations were above the minimum national standards (MINAS).     

Seasonal variations in abundance of nitrifying bacteria in fish pond ecosystem

Seasonal changes in abundance of nitrifiers (ammonia-oxidizing and nitrite-oxidizing bacteria) in surface and bottom water of freshwater ponds were examined with respect to temperature, DO, pH as well as concentration of ammonia and nitrite. The most probable number (MPN) of ammonia-oxidizers in different ponds varied from 1297 +/- 3.6 to 1673.23 +/- 0.36 ml(-1) in bottom and 720.5 +/- 8.1 to 955.3 +/- 10.8 ml(-1) in surface water during the rainy season while the MPN ranged from 1074 +/- 1.07 to 1372.17 +/- 4.6 ml(-1) in bottom and 515 +/- 10.1 to 678 +/- 11.8 ml(-1) in surface water in winter. However, the MPN were greatly reduced in summer and ranged from 435.05 +/- 15.7 to 547.54 +/- 2.12 ml(-1) in bottom and 218.7 +/- 7.3 to 368.4 +/- 9.32 ml(-1) in surface water. Similar seasonal trends were also observed in MPN of nitrite-oxidizers. Among all the physico-chemical parameters, abundance of nitrifiers was more positively correlated with ammonia and nitrite concentration in all the seasons. The abundance of nitrifiers in surface and bottom water was highest in rainy season followed by winter and modest in summer. The potential nitrification activities and oxidation rates were shown to be linear and activity of ammonia-oxidizing and nitrite-oxidizing bacteria was highest during rainy season.     

Evaluation of carrying capacity with particular reference to firewood and fodder resources in Central Himalaya: a case study of Baliya catchment

SUMMARY

The dwindling forests of the Central Himalaya are suffering from serious losses, threatening the subsistence population of the region. This study analyses the rate of consumption of fodder and firewood in a Central Himalayan catchment and estimates the carrying capacity of the catchment for these resources. Estimates indicate that the carrying capacity of the natural ecosystems and agroecosystems, in terms of availability of fodder and fuelwood resources, has already been exceeded.     

Preliminary Report on Radon Concentration in Drinking Water and Indoor Air in Kenya

A screening survey has been carried out to determine activity concentrations of radon (²²²Rn) in drinking water and indoor air in various locations in Kenya. The concentration of ²²²Rn in water was measured using a liquid scintillation counter (LSC). Three different passive integrating devices were used in the measurements of ²²²Rn in air. In the short-term measurements, radon is absorbed in activated charcoal and the analyses were carried out using either LSC or gamma ray spectrometry. The long-term measurements were carried out using solid-state nuclear track detectors (SSNTD). The mean and maximum values of ²²²Rn concentrations in water are 37 and 410 Bq L^–1 and 100 and 1160 Bq m^–3, respectively, in air. The highest values were obtained from groundwater sources and in the basements of buildings. When these values are compared with the internationally recommended reference levels, there are indications of existence of radon problems in some of the water sources and the dwellings tested in this survey.     

Crosslinking of Polyvinyl Alcohol (PVA) and Effect of Crosslinker Shape (Aliphatic and Aromatic) Thereof

In the presented work, the effect of crosslinker geometry on the properties of PVA is reported. The aliphatic (suberic) and aromatic (terephthalic) dicarboxylic acids are used as crosslinker molecules. On the basis of tensile test and thermal properties, it is observed that crosslinking of PVA by suberic acid is more effective than terephthalic acid. The maximum strength measured in crosslinked samples is 32.5 MPa for suberic acid crosslinked PVA which is higher than that of neat PVA (22.6 MPa). Swelling study shows that 8 h crosslinked terephthalic acid (35% w/w) samples have a minimum of 5.4% of water uptake compared to neat PVA, which dissolves readily in water. DTGA shows that the decomposition temperature of crosslinked PVA is 345?°C while neat PVA has a decomposition temperature of 315?°C. FTIR spectroscopy confirms the formation of crosslink ester bond in crosslinked PVA. The crosslinked samples kept for bio-degradation show maximum degradation in terephthalic acid (15% w/w) crosslinked PVA.