Quantum light-matter interactions in structured waveguides

We explore special features of quantum light-matter interactions inside structured waveguides due to their finite bandwidth, band edges, and non-trivial topological properties. We model the waveguides as either a tight-binding (TB) chain or a Su-Schrieffer-Heeger (SSH) chain. For unstructured waveguides with infinite bandwidth, the transmission and reflection amplitude of a side-coupled two-level emitter (2LE) are the same as the reflection and transmission amplitude of a direct-coupled 2LE. We show that this analogy breaks down for structured waveguides with finite bandwidth due to the appearance of Lamb shift only for the direct-coupled 2LE. We further predict a robust light-emitter coupling at zero collective decay width of a single giant 2LE (with two couplings at different points) near the band edges of the structured waveguides where topological features can be beneficial. Finally, we study single-photon dynamics in a heterojunction of a long TB and short SSH waveguide connected to a 2LE at the SSH end. We show the propagation of a photon from the excited emitter to the TB waveguide only when the SSH waveguide is in the topological phase. Thus, the heterojunction acts as a quantum switch or conditional propagation channel.Comment: 15 pages, 11 figure

The Role of Audio Visual Contents on the Economic Development of Bangladesh: A Systematic Review

Background: Information is defined as any written audio-visual contents that convey knowledge about a novel person, place, item, circumstance, or environment and communication is the act of transmitting a message to another person. To do so, a sender and a recipient are required as well as a medium, coherent message, and conversation. In this digital age, audio-visual digital contents are playing a significant role on the sustainable economic development of the world.Objectives: The aim of this current review article was to identify the role of audio visual contents on the economic development of Bangladesh.Methodology: An electronic literature search was conducted for the data databases of the study. The data of this study were retrieved from Scopus and Google scholar published from 2004 to 2022. The reference lists of all included studies and relevant systematic reviews were also evaluated to identify additional research. All searches were restricted to English-language and research on humans only. The PRISMA standards were followed to perform this systematic review.Results:Wider use of audio-visual contents can build-up technological knowledge, attitude and practice in cultivationamong the rural farmers. As a result, agricultural productivity is being improved. At the same time, Audio- visual digital contents are playing a potential role to promote teaching-learning process of Bangladesh and simultaneously which can strongly claim that audio-visual contents have a positive contribution to the promotion of GDP of Bangladesh economy.Conclusion:After reviewing the articles it was identified that there are certain role of audio visual contents in agricultural sector and increase knowledge, attitude and practice which has certain impact in other sector like health care, and education. Further project and study required to know the audio-visual concept in-depth contribution of the society. Keywords: Role, audio-visual contents, economic, development, Bangladesh. DOI: 10.7176/JESD/14-2-01 Publication date: January 31st 202

Study on localized thermal expansion gradient formation for acoustic wave generation in a novel thermoacoustic imaging modality

Thermoacoustics is the process of generation of sound by heat or vice versa. Volume generated thermoacoustic signals can be produced by thermal expansion induced volume contraction and rarefaction inside a target body. Thermoacoustic imaging uses this modality to obtain vivid insight into the internal structure of target body, both for non-destructive testing and biomedical imaging. Any penetrating pulsed radiation can be used for such purpose, including microwave where the modality is called thermoacoustics in general or by incident light waves where the same is termed as photoacoustics. The current thesis establishes the theoretical basis for a novel thermoacoustic imaging modality where pulsed ultrasound is used as the incident penetraing source. A formal forward transient theoretical eqution set is derived based on established transient acoustic propagation models and the problem is solved using a commercially available FEM software. The results are then compared with experimental results and considerable agreement has been observed

Telesupport Experiment for Agricultural Information Management in West Bengal, India

The article describes the experimentation of Change Initiatives, an Indian NGO of sub-regional scope, with the application of ICT in agricultural information management under the EU sponsored TeleSupport Project at Nadia district of West Bengal, India. During the project period an innovative mechanism of information management was experimented to facilitate two-way interaction between expert and client system with the involvement of local community. To sustain the two-way communication system two mobile and one fixed telecentre were established in the project area. The web resource created for sustaining the project hosted a large number of good practices, inspired numerous interactions among the stakeholders and facilitated diffusion of several agro-technologies. Large number of organizations and experts also joined the network. Within the project period, a considerable number of villagers including rural women and youth could be reached periodically with relevant agricultural information. Information related to crop management, livestock management, marketing etc. were professionally provided to the villagers. In spite of the initial success of the experimentation in terms of people’s participation and magnitude of information created and exchanged, the project could not achieve sustainability in the long run. Lack of e-readiness, lack of appropriate resource persons among the stakeholders, absence of any explicit incentive system within the organizational context, constraints of human resources and fund caused failure of the project. Despite of its failure it has been successful in empowering people, especially the Muslim women of the area. The information management system tried during the project may be tried in many rural communities of third world countries with necessary modifications

Telesupport Experiment for Agricultural Information Management in West Bengal, India

The article describes the experimentation of Change Initiatives, an Indian NGO of sub-regional scope, with the application of ICT in agricultural information management under the EUsponsored TeleSupport Project at Nadia district of West Bengal, India. During the piloting phase, an innovative mechanism of information management was experimented for facilitating a twoway interaction between expert and client system with the involvement of local community. To sustain this two-way communication system one fixed telecentre and two mobile telecentres were established in the project area. The web resources created for sustaining the project hosted a large number of good agricultural practices, inspired numerous interactions among the stakeholders and facilitated diffusion of several agro-technologies. Large number of organizations and experts also joined the network. Within the project period, a considerable number of villagers including rural women and youth could be reached regularly with relevant and need-based agricultural information. Information related to crop management, livestock management, marketing etc. were provided to the villagers timely. In spite of the initial success of the experimentation in terms of people’s participation and magnitude of information created and exchanged, the project could not achieve sustainability in the long run. Lack of e-readiness, lack of appropriate resource persons among the stakeholders, absence of any explicit incentive system within the organizational context, constraints of human resources and fund flow eluded the success of the project. Despite of its failure in achieving sustainability, the project has been successful in empowering local people, especially the Muslim women of the project area. The information management system experimented during the project may be tried in many rural communities of third world countries with necessary modifications

Hemodynamic wall shear stress profiles influence the magnitude and pattern of stenosis in a pig AV fistula

Venous stenosis is a significant problem in arteriovenous fistulae, likely due to anatomical configuration and wall shear stress profiles. To identify linkages between wall shear stress and the magnitude and pattern of vascular stenosis, we produced curved and straight fistulae in a pig model. A complete wall stress profile was calculated for the curved configuration and correlated with luminal stenosis. Computer modeling techniques were then used to derive a wall shear stress profile for the straight arteriovenous fistula. Differences in the wall shear stress profile of the curved and straight fistula were then related to histological findings. There was a marked inverse correlation between the magnitude of wall shear stress within different regions of the curved arteriovenous fistula and luminal stenosis in these same regions. There were also significantly greater differences in wall shear stress between the outer and inner walls of the straight as compared to curved arteriovenous fistula, which translated into a more eccentric histological pattern of intima-media thickening. Our results suggest a clear linkage between anatomical configuration, wall shear stress profiles, and the pattern of luminal stenosis and intima-media thickening in a pig model of arteriovenous fistula stenosis. These results suggest that fistula failure could be reduced by using computer modeling prior to surgical placement to alter the anatomical and, consequently, the wall shear stress profiles in an arteriovenous fistula

Enhancing the Efficiency of SnS Solar Cells bia Band-Offset Engineering with a Zinc Oxysulfide Buffer Layer

SnS is a promising earth-abundant material for photovoltaic applications. Heterojuction solar cells were made by vapor deposition of p-type tin(II) sulfide, SnS, and n-type zinc oxysulfide, Zn(O,S), using a device structure of soda-lime glass/Mo/SnS/Zn(O,S)/ZnO/ITO. A record efficiency was achieved for SnS-based thin-film solar cells by varying the oxygen-to-sulfur ratio in Zn(O,S). Increasing the sulfur content in Zn(O,S) raises the conduction band offset between Zn(O,S) and SnS to an optimum slightly positive value. A record SnS/Zn(O,S) solar cell with a S/Zn ratio of 0.37 exhibits short circuit current density $(J_{sc})$, open circuit voltage $(V_{oc})$, and fill factor (FF) of $19.4 mA/cm^{2}$, 0.244 V, and 42.97%, respectively, as well as an NREL-certified total-area power-conversion efficiency of 2.04% and an uncertified active-area efficiency of 2.46%.Chemistry and Chemical BiologyOther Research Uni