DESIGN OF A FOUR STAGES VCO USING A NOVEL DELAY CIRCUIT FOR OPERATION IN DISTRIBUTED BAND FREQUENCIES

The manuscript proposes a novel architecture of a delay cell that is implemented in 4-stage VCO which has the ability to operate in two distributed frequency bands. The operating frequency is chosen based on the principle of carrier mobility and the transistor resistance. The VCO uses dual delay input techniques to improve the frequency of operation. The design is implemented in Cadence 90nm GPDK CMOS technology and simulated results show that it is capable of operating in dual frequency bands of 55 MHz to 606 MHz and 857 MHz to 1049 MHz. At normal temperature (270) power consumption of the circuit is found to be 151μW at 606 MHz and 157μW at 1049 MHz respectively and consumes an area of 171.42µm2. The design shows good tradeoff between the parameters-operating frequency, phase noise and power consumption

Genetic parameters and path analysis of yield and its components in okra at different sowing dates in the Gangetic plains of eastern India

There is continuing need to identify traits that can facilitate selection of productive progenies. For this, 18 genotypes of okra [Abelmoschus esculentus (L.) Moench] were evaluated for the extent of genetic variability, heritability, correlation and path analysis among various morphological, reproductive and nutritional  characters related to fruit yield over two growing seasons in the Gangetic plains of eastern India. Phenotypic co-efficient of variation (PCV) agreed closely with the genotypic co-efficient of variation (GCV) but the magnitude of PCV was higher than GCV for almost all the characters studied during both seasons which reflect the influence of environment on the expression of traits. High PCV and GCV values were shown by fruit yield per plant, numbers of fruit per plant and plant height at flowering during both seasons. The remaining traits  recorded moderate to low PCV and GCV estimates, indicating that selection for these characters will be less  effective. All characters studied exhibited moderate to high heritability. However, pooled genetic advance (GA) expressed as percentage of mean was high for fruit yield per plant, numbers of fruit per plant, plant height at  flowering and fruit weight. Characters showing moderate to high genetic gain also showed high heritability,  indicating that most genetic variations in these characters were due to additive gene effects. From the  correlation and path coefficient analyses, it revealed that the top priority should be given to selection based on numbers of fruit per plant and fruit weight for yield improvement and could be considered while formulating  selection indices in the improvement of okra.Key words: Okra, genetic variability, heritability, correlation, path analysis

Chitosan Nanoparticle: Synthesis, Characterization, and Use as Plant Health Materials

Chitosan is a naturally occurring biopolymer having multifaceted applications in agriculture, medicine, food industry, and cosmetics. The association of this natural biopolymer with nanotechnology can produce revolutionary effects in plant protection and agriculture. Nano-chitosan can be fabricated using various methods. However, the green synthesis approach has gained attention in recent years. The green engineered nanoparticles are economical, energetically feasible, and environmentally benign. The biosynthesized nano-chitosan has evolved as a potential plant protection agent. Chitosan nanoparticles possess antifungal, antibacterial, and antiviral properties, and are found to be effective against seed-borne and soil-borne pathogens. Nano-chitosan also behaves as an effector molecule and induces local and systemic defense responses in plants. The mode of action of nano-chitosan involves alterations in membrane permeability, replication, cytoplasmic alterations, induction of defense-related genes, and cell lysis. Furthermore, chitosan nanoparticles can be used for soil improvement and can reduce pest and pathogen attacks, thereby promoting the growth of plants. The authors outline the methods of synthesis and characterization of chitosan nanoparticles, their utilization in plant protection and growth promotion, along with the underlying mechanisms

Electromagnetically Induced Transparency (EIT) aided cooling of strontium atoms

The presence of ultra-narrow inter-combination spectroscopic lines in alkaline earth elements places them as promising candidates for optical atomic clocks, quantum computation, and for probing fundmental physics. Doppler cooling of these atoms is typically achieved through two subsequent stages: the initial cooling is on the 1s0-1p1 transition followed by cooling using the narrow-line 1s0-3p1 transition. However, due to significantly lower linewidth of the second stage cooling transition, efficient transfer of atoms into the second stage becomes technically challenging. The velocity distribution of the atoms after the first stage of cooling is too broad for atoms to be captured efficiently in the second stage cooling. As a result, the capture efficiency of atoms into the second stage Magneto-Optical Trap is low, even if the linewidth of the second stage cooling laser is artificially broadened.Comment: 7 pages, 3 figure