Anthraquinones- A probe to enhance the photovoltaic properties of DSSCs

Natural dye sensitized solar cells are a promising class of photovoltaic cells with the capacity of generating green energy at low production cost since no expensive equipment is required in their fabrication. Photovoltaics are a precious technology in the hasty world where energy prices are goes on increasing within seconds. Researchers are focusing to facilitate for producing eco-friendly, low cost and more efficient dye sensitized solar cells. In the present work we discuss the comparative photovoltaic studies of Lawsone, a natural dye from henna plant and Alizarin, a natural dye from the root of madder for fabricating the Dye sensitized solar cells (DSSCs). The absorption spectrum of Lawsone and Alizarin is found to be shifted to the longer wavelength region after the complex formation. As a result there is a significant increase in short circuit current density and conversion efficiency. This result compares with the standard dye i.e. N719 dye

Protean authentication scheme - a time-bound dynamic KeyGen authentication technique for IoT edge nodes in outdoor deployments

IoT edge/sensor nodes are exposed to large attack surface and could easily succumb to several well-known attacks in the wireless sensor network (WSN) domain. Authenticating edge nodes before they join a network especially after a sleep state is a critical step to maintain the overall trust of any given IoT Local Area Network (IoT LAN). The low resources and computational constraints of such IoT nodes make this a challenging and non-trivial problem. As many IoT deployments are in uncontrolled environments, IoT devices are often placed in the open so that physical access to them is inevitable. Due to easy physical access of the devices, common attacks including cloning of devices or stealing secret keys stored in an edge node are some of the most common attacks on IoT deployments. This paper focuses on developing an extremely lightweight authentication scheme for constrained end-devices that are part of a given IoT LAN. Authentication occurs between the end-device and the gateway which acts as an edge computing device. The proposed authentication scheme is put through both formal and informal security verification. Voltage drop, current, and power are measured to gauge the overall impact of the security scheme. All the three parameters were measured while configuring the edge node as an end-device or as a router. Our testing results show that the impact on the resources was minimal

A Remote Triggered Compound Parabolic Collector for Thermal Engineering Studies

Solar thermal energy systems are one of the most cost-effective renewable energy systems in use today. Engineering students study the design of these systems with the goal of learning how to design similar systems and perform research on improving the heating efficiency and overall operations. This paper elaborates on the design, construction, testing, and validation of a solar thermal system as a remote, open instrumentation lab, using two Compound Parabolic Collector (CPC) evacuated tube collectors with separate heating media. The lab allows for comparing heat transfer rates and collector efficiencies simultaneously for two fluids that have different thermal capacities. The heat patterns could be viewed using thermal cameras to analyze the CPC design. The unique feature of the system is its facility to control the lab remotely, as the setup is interfaced with instrumentation on a web server, thereby allowing students from geographically distant areas to access and perform experiments on the CPCs. A cumbersome lab with expensive hardware and outdoor requirements is thus made easy to perform and learn from via remote access. This remote methodology and hardware and IT architectures are especially pertinent and relevant in the blended and remote learning scenarios made common by the pandemic

Using Theme-based Narrative Construct of Images as Passwords: Implementation and Assessment of Remembered Sequences

Secret keys connecting users to the system is the heart of cryptographic systems. With the recent wars, several cryptographic systems that use alpha-numeric passwords have been known to be vulnerable to many attacks. Image based password systems were introduced to add more complexity and security. This paper employs human uniqueness of narrative skills on an image-based password system with focus on theme in the password generation process. To generate the secret password, a specially designed computer game was used. We used narrative constructs composed of cartoon image sequences to generate user-specific secret key. The durability of generated passwords and the authentication process while assessing the reconstruction process by a potential hacker was verified. Under imposed psychological duress, users failed retrieving the password sequence suggesting the reliability as an anti-coercive attack cybersecurity tool. A set of experiments were used to analyze user behavior behind the image-based password system. EEG measurements demonstrated increased activity of α rhythms in F3 and FC5 channel bins and augmented levels of β rhythms in F3 and O1 channels, suggesting users added personalization to authentication more than in alpha-numeric password-based logins

Effectiveness of Virtual Laboratory Teacher Training Workshops: A Kirkpatrick Model Analysis

Performing laboratory experiments is an integral and unavoidable part of STEM education. The teaching efficacy of laboratory experiments can be optimized by integrating ICT-based tools into the curriculum. As teachers are the key facilitators in practical lessons, it is imperative that they adopt the latest teaching technologies, such as virtual laboratories (VLs). To achieve optimal student learning outcomes, teachers ideally undergo adequate training programs that equip them with relevant knowledge and skills to utilize VLs. As myriad training workshops and self-learning tools are available to teachers, the efficacy of training programs needs to be precisely evaluated to determine their quality and design better programs for posterity. Kirkpatrick’s four-level model is suited to evaluate teaching training, as it takes into consideration holistic aspects of learning: learners’ reactions, learning outcomes, behavior, and results. In this study, we conducted and evaluated a VL teacher training program in Africa, applying Kirkpatrick’s model analysis. Our results indicate a significant improvement in participants’ perception and attitude toward VL after attending the training. Also, the training proved to be effective in improving the learning outcomes of the participants. We found a huge hike in the number of VL users in Africa after conducting the training program, indicating the overall success of the program. It met the needs of the teachers and equipped them with the necessary skills and knowledge to utilize VLs in their teaching practices. This study may assist future trainers to design successful teacher training programs in laboratory education

COVIDTAS COVID-19 Tracing App Scale—An Evaluation Framework

Mobile apps play an important role in COVID-19 tracing and tracking, with different countries taking different approaches. Our study focuses on 17 government owned COVID-19 Contact Tracing Apps (CTAs) and analyze them using a proposed COVIDTAS framework. User satisfaction is not directly related to the COVIDTAS score or the interaction between users and the app developers. To increase adoption of CTAs, government leadership must offer assurance to its citizens that their identify will be concealed and emphasize the benefits of CTAs as it relates to shared public health. While no country has topped the list on all three major factors (COVIDTAS Score, User Reviews, and User Ratings), the CTA from India seems to have above average performance on all three factors

Innovation Adoption and Diffusion of Virtual Laboratories

Educational technology such as Virtual laboratories (VLs) are being perceived as sustainable solutions to growing concerns related to laboratory skill training i.e. delivering quality laboratory education to a large number of students due to shortage of infrastructure and access especially in developing nations. With these VLs being an innovation for engineering education, the study of its diffusion in higher educational institutions is critical for gauging its impact. This study examines the five variables of Rogers Diffusion of Innovations theory in determining how VLs have changed or modified users through its adoption. The involvement of early adopters participating through a program called Nodal centers and their innovation decision stages are addressed. The study also analyzed the change agents as the nodal centers for diffusing the innovation in teaching and learning processes. Virtual laboratory adoption by users (n=43600) over 30 months was surveyed and factors of diffusion were reported. Similar scoring in assessment factors suggested relative advantage, technology acceptance, intention of use and relevance of trialability were pertinent in users' perception of VLs. Social hubs among higher education institutions promoted early adoption through better engagement of students.</p