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B. S. Rana , R. K. Khanna , S. K. Verma

Abstract

Carbon and nutrient budgets for two Central Himalayan Sal (Shorea robusta Gaertn.) forests (Sal old growth and new growth forests) are described. The total Carbon storage in Sal old growth forest (379 t Cha^-1) was greater than Sal new growth forest (242 t Cha^-1). However, net primary productivity values (9.3-10.11C ha^-1yr^-1) revealed almost similar potential of both forests. Of the total carbon uptake in ecosystem, the net accumulation accounted for 33%. Of the total nutrient storage in two forests, vegetation pool accounted for 53-54% N; 67.72%, P; 90-93% K; 18034% Ca; and 77-78% Na. The net primary productivity and nutrient uptake in Sal new growth forest were higher than that of old growth forest, irrespective of nutrient storage in biomass. The total nutrient uptake (kg ha^-1 yr^-1) by the vegetation was: 155-178N; 13-15P; 73-85K; 119-135 Ca; and 7-8 Na in two forests. Under relatively undisturbed condition, Central Himalayan Sal forests are efficient carbon sink and nutrient rich ecosystems.

Keywords

Shorea robusta , Carbon and Nutrient Cycling, Central Himalayan Sal Forests

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Ashwini Joshi Thosar ¹, Manoj Thosar ², R. K. Khanna ³

Affiliations
1 Department of Electrical Engg., Poornima University, Jaipur, IN
2 Department of Physics, Vivekananda Institute of Technology – East, VIT- campus, Jaipur, IN
3 Department of Physics, Vivekananda Global University, VIT- campus, Jaipur, IN

Abstract

The objective of this work is to reduce the front surface reflectivity of the GaAs solar cell by depositing AR-coating of appropriate thickness and refractive index material. We use MgO and ZnO film and optimize their thickness for minimum reflectivity. Results indicate that the reflectivity is reduced up to 4% for MgO film and 2% for ZnO film at solar spectrum wavelength range from 550 nm to 650 nm. The external efficiency of GaAs solar cell with AR-coating is increased by 31.53% and 33.09% for MgO and ZnO film respectively.

Keywords

AM1.5D Spectrum, Anti-reflection Coating, External Efficiency, Fresnel Reflection, Interference of Light

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