Ultra-high-Q optoelectronic oscillator based on bilaterally coupled loops

An optoelectronic oscillator (OEO) based on bilateral coupling between two individual optoelectronic loops is demonstrated. The resulting OEO has two modes of operation, in which the individual loops either oscillate or act as IIR filters. A Q-factor greater than 1010 at 5.8 GHz is observed

High-Q wavelength division multiplexed optoelectronic oscillator based on a cascaded multi-loop topology

A WDM optoelectronic oscillator (OEO) based on a cascaded optical multi-loop configuration and multiple photodiodes is proposed and demonstrated experimentally. By employing up to three lasers widely separated in wavelength along with two cascaded multi-loop fiber sections and two photodiodes, we demonstrate OEO topologies that scale up to six effective loops revealing an ultra-high quality factor in excess of 1010 and a phase noise performance down to −119 dBc/Hz at 10 kHz offset

Optoelectronic oscillator based on class AB photonic link

An optoelectronic oscillator topology based on a class AB analogue optical link is proposed. The motivation for this approach is based on the unique property of class AB links for mitigating both shot noise and relative intensity noise contributions. The class AB optoelectronic oscillator is compared with a conventional single loop optoelectronic oscillator

Mitigation of salinity stress by exogenous application of cytokinin in faba bean (Vicia faba L.)

Soil salinity limits agricultural land use and crop productivity, thereby a major threat to global food safety. Plants treated with several phytohormones including cytokinins were recently proved as a powerful tool to enhance plant’s adaptation against various abiotic stresses. The current study was designed to investigate the potential role of 6-benzyladenine (BA) to improve broad bean (Vicia faba L.) salinity tolerance. The salt-stressed broad bean plantlets were classified into two groups, one of which was sprayed with water and another was sprayed with 200 ppm of BA. Foliar applications of BA to salt-exposed plants promoted the growth performance which was evidenced by enhanced root-shoot fresh and dry biomass. Reduced proline was strongly connected to the enhanced soluble proteins and free amino acids contents, protecting plant osmotic potential following BA treatment in salt-stressed broad bean. BA balanced entire mineral homeostasis and improved mineral absorption and translocation from roots to shoots, shoots to seeds and roots to seeds in salt-stressed plants. Excessive salt accumulation increased malondialdehyde level in leaves creating oxidative stress and disrupting cell membrane whereas BA supplementation reduced lipid peroxidation and improved oxidative defence. BA spray to salinity-stressed plants also compensated oxidative damage by boosting antioxidants defence mechanisms, as increased the enzymatic activity of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase. Moreover, clustering heatmap and principal component analysis revealed that mineral imbalances, osmotic impairments and increased oxidative damage were the major contributors to salts toxicity, on the contrary, BA-augmented mineral homeostasis and higher antioxidant capacity were the reliable markers for creating salinity stress tolerance in broad bean. In conclusion, the exogenous application of BA alleviated the antagonistic effect of salinity and possessed broad bean to positively regulate the osmoprotectants, ion homeostasis, antioxidant activity and finally plant growth and yield, perhaps suggesting these easily-accessible and eco-friendly organic compounds could be powerful tools for the management of broad bean growth as well as the development of plant resiliency in saline prone soils

Toxicity assessment of groundwater quality in Bangladesh.

A study was conducted to assess long-term effect of ground water for irrigation at Chirirbandar upazila, 25 kilometers eastern from Dinajpur district in from February to April in 2006. All the waters were analyzed and classified into different categories for their suitability as irrigation, drinking and industrial usage. The chemical analyses were included pH, EC, TDS, Ca, Mg, Na, K, Fe, Cu, Mn, Zn, B, As, SO4, P, HCO3 and Cl. The SAR, SSP, RSC and HT were calculated for the research. The pH (6.55 to 7.75) showed slightly acidic to slightly alkaline. The TDS was rated as ‘fresh water’, EC and SAR were ‘medium’ (C2 ) class and ‘low alkali hazard’ (SI) class which jointly expressed as C3S1. The study was found that SSP was in ‘excellent’ category. Waters were free from RSC and belonged to ‘suitable’ category for irrigation. The waters were classified as ‘hard’ and ‘very hard’ based on hardness (HT). It was found that both Fe and Mn content of all samples were not having problem for industrial usage. Boron was identified as ‘suitable’ for drinking consumption and sulphate was ‘suitable’ for drinking and industrial usage. The relationship of pH vs. EC, pH vs. TDS, EC vs. TDS, EC vs. HT, TDS vs. HT, SAR vs. SSP, SAR vs. RSC, and SSP vs. RSC indicated significant positive correlation. Among the quality determining factors SSP and SAR were highly correlated where correlation coefficient was 0.964

Investigation into use of double-layer grid structures as frequency selective surfaces for buildings

A simple Double–Layer Grid plane wave filter structure is proposed that can provide multiple transmission bands for cellular phone frequencies but with a reflection band for WLAN signals. The approach offers ease of construction making it applicable to building applications. A parametric study using simulation supported by simple experimental data investigates the proposed, novel desig

Differential game model and coordination model for green supply chain based on green technology research and development

The purpose of this paper is to establish a green supply chain differential game model for green technology research and development based on a secondary green supply chain composed of a single manufacturer and a single retailer. It compares the differential game equilibrium solutions under centralized and decentralized decision-making. The green supply chain members are coordinated through the dynamic wholesale price mechanism, and numerical simulation is used as a methodology, to verify and explain the results. The study found that compared to decentralized decision-making, the level of green technology and the total profit of green channels are higher under centralized decision-making. When the coordination parameters are within a certain range, the dynamic wholesale price mechanism can coordinate the behavior of manufacturers and retailers. The result also discovers that under the dynamic wholesale price mechanism, with the increase of investment cost coefficient, or the increase of price sensitivity or the decrease of consumer's environmental awareness, the green technology level, product green degree, price, retailer's profit, and the total profit of green channel is decreased. In contrast, the wholesale price and manufacturer's profits are increased

W-band Radio-over-fiber Link Based on Self-oscillating Optical Frequency Comb Generator

A 94.8 GHz radio-over-fiber link was implemented with a self-oscillating frequency comb. An LTE Advanced OFDM FDD 64-QAM signal of 20 MHz bandwidth was transmitted over 1.3 m wireless distance with an EVM of 2.23%

Study of heterosis in Bangladeshi chilli (Capsicum annuum L.) landraces

Chilli is an important cash crop in Bangladesh but average yield is very low (0.89 t ha-1) and genetic potentiality of Bangladeshi chilli landraces for hybrid variety development has not been evaluated. The objective of this study was to find out heterotic behavior following Gardner and Eberhart model (1966) II. Six different homozygous divergent parents CCA 2, CCA 5, BARI Morich 1, CCA 11, CCA 15 and CCA 19 were used to estimate heterosis. A significant amount of heterosis was present in yield and yield contributing traits. Estimate of variety heterosis for yield per plant was significantly positive in CCA 5 and BARI Morich 1. In BARI Morich 1, the significant and positive variety heterosis for yield per plant was associated with significant and positive estimates of heterosis for number of fruits per plant and number of seeds per fruit, suggesting that these yield traits contributed to the final heterosis manifested through yield. Indigenous×exotic crosses showed significant amount of heterosis. It is possible to emphasize indigenous×exotic crosses for good fruit yield, particularly to be used as commercial hybrids. Hybrids of BARI Morich 1×CCA 19 and CCA 5×BARI Morich 1 showed better performance

Automating assessment and evaluation for a bachelor’s degree program

Outcome-based education (OBE) makes learning happen and measures automating assessment and evaluation system. The objective of the study is to assess student’s learning in International Finance course and report OBE and propose strategies for continual quality improvement (CQI). In this study, a widely accepted self-developed spreadsheet used to measure course learning outcomes (CLO) and program learning outcomes (PLO) of international finance in a bachelor’s degree program of fall 2021. The method of sampling technique is purposive and a sample of 27 students have been considered for the analysis. Using direct method on specific parameters (quiz, assignment, presentation, and exams), an overall CLO attainment has been measured and compared with a targeted key performance indicators (KPI) (70% is set). Findings reveal that the first three out of five CLO have met the standard KPI. However, a CQI has been proposed for further improvement of CLO. Also, future works proposed to instrument CQI processes, engage industry experts and external OBE experts from foreign universities. Program self-assessment is mandatory for quality assurance at university and also preparation for accreditation of the program needs self-assessment. Therefore, CLO is mandatory for assessment and evaluation urgently