Effect of seed layer on the performance of ZnO nanorods-based photoanodes for dye-sensitized solar cells

In this paper, zinc oxide nanorods (ZnONRs) were synthesized by chemical bath deposition (CBD) method at 90 °C by using zinc nitrate hexahydrate and hexamethylenetetramine as precursors. In a first stage, the ZnO NRs were grown on un-seeded and pre-seeded fluorine-doped tin oxide (FTO) glass substrates by direct CBD method to study the effect of the ZnO seed layer on the NRs structural, morphological and optical properties. The X-ray diffraction (XRD) analysis performed on the preseeded NRs revealed a pure ZnO hexagonal wurtzite crystalline phase, while the Field Emission Scanning Electron Microscopy (FESEM) unveiled that the pre-seeded NRs exhibit a smaller diameter, higher density, higher aspect ratio and improved orientation along the c-axiswith respect to the un-seeded NRs. In a second stage, the powder obtained by aging, centrifuging and drying the precipitates formed during the CBD growth was analyzed by XRD to assess its crystal structure and phase purity and subsequently coated on un-seeded and pre-seeded FTO glass substrates by doctor blade technique. The ZnO NRs based seeded and non-seeded films fabricated by the two methods were finally used as photoanodes in dye-sensitized solar cells (DSSCs). Interestingly, the employment of pre-seeded ZnO NRs films deposited by doctor blade technique in comparison to the counterpart electrodes synthesized by direct CBD growth has led to a noticeable increase in the DSSC photoconversion efficiency from 0.35 to 1.86%. On the other hand, the inclusion of the seed layer has effectively improved the fill factor of the DSSC I-V curves for both the photoanode deposition techniques

Investigating the Sequential Deposition Route for Mixed Cation Mixed Halide Wide Bandgap Perovskite Absorber Layer

Wide bandgap (Eg) perovskite solar cells (PSCs) are emerging as the preferred choice for top cells in a tandem architecture with crystalline silicon solar cells. Among the wide bandgap perovskites, a mixed cation mixed halide composition containing CsyFA1-yPbI3-xBrx is a popular choice because the presence of bromine widens the bandgap and addition of cesium stabilizes the crystal structure. These perovskite layers are commonly fabricated using one-step spin coating technique; however, sequential spin coating followed by dip coating has been successful in offering better control over the crystallization process for low bandgap absorber layers. In this paper, the fabrication of a Cs0.2FA0.8PbI3-xBrx perovskite absorber layer using the sequential deposition route is reported. The concentration of bromine was varied in the range 0 <= x <= 1 and optical, structural, and morphological properties of the films were studied. As the concentration was increased, the perovskite showed better crystallinity and the presence of large grains with high surface roughness, indicating the formation of the CsPbBr3 phase. Optically, the perovskite films exhibited higher absorbance in the ultraviolet (UV) range between 300 and 500 nm, hence up to x = 0.3 they can be profitably employed as a wide bandgap photon absorber layer in solar cell applications

Counter electrode materials based on carbon nanotubes for dye-sensitized solar cells

Efficiency, stability, and cost-effectiveness are the prime challenges in research of materials for solar cells. Technologically as well as scientifically, attention gained by dye-sensitized solar cells (DSSCs) stems from their low material and fabrication costs as well as high efficiency projections. The aim of this study is to explore the carbon nanotubes (CNTs) based counter electrode (CE) materials for DSSCs and to reconnoiter the suitable alternative materials in place of noble metals such as Platinum (Pt), and Gold (Au).. Various classes of CE materials based on CNTs including pure single walled, double walled, and multiwalled CNTs, doped CNTs and their hybrid composites with various polymers, and transition metal compounds are discussed comprehensively in light of the research work started since the inspection of DSSCs and CNTs.The properties associated with such materials, including surface morphology, structural determination, thermal stability, and electrochemical activity, are also thoroughly analyzed and compared. This work provides a thorough insight into the possibility of exploiting CNTs as alternative CE materials. In addition to the above, this study also includes the working and brief overview of materials for other components of DSSCs such as photoanode, electrolyte, and sensitizer.

Modeling of the dye loading time influence on the electrical impedance of a dye-sensitized solar cell

A hemisquaraine dye molecule (CT1) was used as TiO2 sensitizer. The influence of the dye-adsorption time on the electrical impedance of a CT1-based dye-sensitized solar cell (DSC) was analyzed. Differently from what we observed with commercial Ru dye-based DSC, a non-monotonic effect of the impregnation time on the impedance has been found and the dye loading time is much reduced, a desirable outcome in economic grounds. This feature is analyzed in terms of the dye molecules tendency to aggregate close to the TiO2/electrolyte interface. A physical model that fits well the experimental data is proposed, which also takes into account a correction related to the difference between the illuminated area of the cell and the total area available in the electrical measurements

Postdischarge 24/7 hotline service for neurology and neurosurgery patients and 1-year impact on readmission rates, unplanned emergency department visits, and patient satisfaction

Objective: Telephone triage is a system in which trained nurses use standardized protocols to evaluate symptoms over the phone and determine the appropriate course of action.Materials and methods: We implemented a protocol for systematic follow up phone calls and telephonic triage to families of neurology and neurosurgery patients after discharge, primarily to improve care transition and to assess its impact on the ratio of visits in the emergency department, readmissions, and overall satisfaction of patients and families. The intervention comprised the implementation of nurse led telephone triage and postdischarge follow up phone calls. After implementing hotline services in mind and brain service line, a retrospective cohort study was conducted to evaluate the impact of hotline services on patient readmissions, emergency department visits, and overall satisfaction rate. We collected data of readmission rate and emergency visits of discharge patients in three periods a prehotline period, immediate posthotline period, and late posthotline period to make comparison. Patients discharged home from the neurology and neurosurgery services from January 2017 to September 2019 were provided with hotline number to call in case of any issue or query. These patients also received postdischarge follow up calls from hotline nurses. We initiated the hotline in October 2017.Results: On analysis, we found a 25% decline in readmission rate in the immediate period of hotline followed by a further decline to 37.2% in the late period as compared to the prehotline period. Among discharge patients visiting the emergency department, we found a decline of 18.5% in the immediate posthotline period which further declined to 77.7% in the later phase as compared to the prehotline period.Conclusion: A standardized telephone system and pathway can be an effective way to improve nurse-patient communication which can further improve health outcomes for many patients

Case series and literature review of multiple nodular sarcoidosis.

Background: Nodular lung disease is a rare presentation of sarcoidosis. Radiologically it can present as multiple pulmonary masses or solitary lung nodule. Case presentation: We report three cases of nodular sarcoidosis in young females of Asian origin who had initially presented with dry cough and worsening dyspnea non-responsive to initially administered antibiotics. Pulmonary nodules were discovered upon radiographic imaging in all three cases which raised concern for the possibility of neoplastic processes. Subsequent biopsies revealed granulomatous inflammation indicative of sarcoidosis. All cases responded very well to systemic corticosteroids. Conclusion: Sarcoidosis may present as nodular infiltrates which alerts the treating physician to other neoplastic and infectious diseases of the lungs. Appropriate workup may reveal the true nature of this disease and hence, simplify treatmen

N-(2-Hy­droxy-1,1-dimethyl­eth­yl)­benzene­sulfonamide

In the title mol­ecule, C10H15NO3S, the S atom is bonded in a distorted tetra­hedral geometry. In the crystal structure, inter­molecular N—H⋯O, O—H⋯O and weak C—H⋯O hydrogen bonds connect the mol­ecules to form a two-dimensional network parallel to (100). The 2-methyl­propan-1-ol group is disordered over two orientations with occupancies of 0.570 (3) and 0.430 (3)

Phosphate and zinc transport and signalling in plants: toward a better understanding of their homeostasis interaction

Zn and Pi are essential elements for plant growth. Current understanding of the regulation of their homeostasis interaction and signalling cross-talk is presente

Usability Evaluation of Online Educational Applications in COVID-19

COVID-19 is a pandemic faced by almost every country in the world, this has resulted in health crisis. Due to COVID-19, all the countries around the world have decided to close all educational institutes to prevent this pandemic. Educational institutes have taken every possible measure to minimize the impact of the closure of schools and introduce the concept of an online education system which is not only a massive shock for parents but it also affects the children's learning process and social life. The educational applications (Apps) are very important, because they offer more opportunities for development and growth to society. In this pandemic situation, educational Apps like Zoom, HEC LMS, Google Classroom, and Skype, etc. are the need of the hour when everything goes online. In this paper, the usability features of online educational Apps are thoroughly discussed including the effectiveness and usability for students. Using the results obtained from the survey, this paper observes the student's perspective of usefulness of online educational Apps in student’s learning process of different age groups. It also analyzes the easiness for students to understand, interact and use these Apps

A Concurrence Study on Interoperability Issues in IoT and Decision Making Based Model on Data and Services being used during Inter-Operability

The Internet-of-Things (IoT) has become an important topic among researchers owing to its potential to change the way we live and use smart devices. In recent years, many research work found in the world are interrelated and convey via the existing web structure which makes a worldwide system called IoT. This study focused on the significant improvement of answers for a wider scope of gadgets and the Internet of Things IoT stages in recent years. In any case, each arrangement gives its very own IoT framework, gadgets, APIs, and information configurations promoting interoperability issues. These issues are the outcome of numerous basic issues, difficulty to create IoT application uncovering cross-stage, and additionally cross-space, trouble in connecting non-interoperable IoT gadgets to various IoT stages, what's more, eventually averts the development of IoT innovation at an enormous scale. To authorize consistent data sharing between various IoT vendors, endeavors by a few academia, industrial, and institutional groups have accelerated to support IoT interoperability. This paper plays out a far-reaching study on the cutting-edge answers for encouraging interoperability between various IoT stages. Likewise, the key difficulties in this theme are introduced