7-May-2020: JNCASR scientists fabricate energy-efficient photodetector for security application
Scientists from Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), an autonomous institute under the Department of Science and Technology, have fabricated an economical and energy-efficient wafer-scale photodetector (thin slice-based) using gold – silicon interface, for security applications. It could help detect weak scattered light as an indication of unwanted activity.
Photodetectors are the heart of any optoelectronic circuit that can detect elect and are employed for a wide variety of applications ranging from controlling automatic lighting in supermarkets to detecting radiation from outer galaxy as well as security-related applications. However, the material cost and the intricate fabrication processes involved in realizing high-performance detectors make them unaffordable for day to day applications.
The invention by JNCASR scientists, which was published in the journal Applied Electronic Materials of American Chemical Society, provides a simple and cost-effective solution-based fabrication method for high-performance photodetector.
The scientists have fabricated gold (Au)– silicon (n-Si) interface, which showed high sensitivity towards light demonstrating the photodetection action. The Au–Si interface was brought about by galvanic deposition, a technique for electroplating of metals, wherein water-based solutions (electrolytes) are used, which contain the metals to be deposited as ions. In addition, a nanostructured Au film also was deposited on top of p-type silicide (having an excess of positive charges), which acts as a charge collector.
Being a solution-based technique, the method is highly economical and enabled large-area fabrication without compromising the detector response. The process is quick, taking only minutes to fabricate a detector of any arbitrary area. The metal nanostructures enhanced the performance of the fabricated detector through trapping the incoming light. This photodetector displayed long-term environmental stability.
The detector exhibits a rapid response of 40 microseconds and can detect low light intensities. The device covers a broad spectral range from Ultraviolet to Infrared. Besides, it shows excellent uniformity throughout the entire active area with less than 5% variation in response. Notably, the detector operates in self-powered mode, which means the device does not require external power for its operation, thus making it energy efficient. With a commonly available protective coating, excellent environmental stability is shown for the device under the harsh conditions for several days. The scientists also demonstrated the photodetector’s utility as a prototype imaging system, lux and power meter, and also as a tool for security applications.
Prototype security system: In the prototype, inside the model house, a fabricated detector was mounted beside a high-value commercial detector for comparison and connected to same external circuit to trigger warning lights (blue lights in the image) and security buzzer. The door is opened to allow only weak scattered light as a sign of unwanted activity. With such low level of lighting, not detectable by the human eye, the fabricated detector was activated, turning on the buzzer and the lights.
23-Apr-2020: IIFPT, research and educational institution under MoFPI, supports the battle against COVID-19 by manufacturing and supplying nutrient-rich foods to Covid-19 patients
Indian Institute of Food Processing Technology ( IIFPT), a pioneer Research and Educational Institution under the Ministry of Food Processing Industries(MoFPI), is supporting India’s fight against Covid-19. Union FPI Minister Smt. Harsimrat Kaur Badal appreciated the initiative taken by IIFPT to manufacture nutrient rich foods for COVID-19 patients at a time when the need for healthy and immunity boosting foods is indispensable.
The Indian Institute of Food Processing Technology (IIFPT) has been manufacturing such nutrient-rich foods for COVID-19 patients under medical examination and those who recently recovered from the pandemic after treatment at Thanjavur Medical College, Tamil Nadu.
The IIFPT has been supporting the efforts of the District Administration, Thanjavur and Thanjavur Medical College (TMC) in combating COVID-19. Director. Dr. C. Anandharamakrishnan said that focusing on nutrition to improve immunity in wake of Covid-19, scientists from the IIFPT have come up with novel food product formulations that have been packed with a range of indigenous foods. Breads, cookies, rusks and millet pops are being prepared on a daily basis at IIFPT’s HACCP and ISO Certified Food Processing Business Incubation Center (FPBIC) and are being supplied to the Medical College and Hospital. The initiative kicked off on 21st April, 2020 in the presence of the District Collector and the Dean, TMC. All products are being prepared and packed carefully by IIFPT staff.
Bread loaves are being enriched with dried moringa leaves, groundnut powder and whey protein to make up to around 9.8% protein and 8.1% fibre, apart from natural immunity-boosters like garlic, turmeric, ginger, pepper, and other spices. Cookies have around 14.16% protein and 8.71% fibre, apart from the benefits of spice extracts. With around 12.85% protein and 10.61% fibre, the rusks were equally good in terms of organoleptic attributes. Importantly, no synthetic additives are being added to these products and they are sent to the hospital soon after manufacturing (packaging and labelling).
In addition, IIFPT also houses a FSSAI referral laboratory and the Department of Food Safety and Quality Testing is preparing hand sanitizers for the District Police Department and other officers who are involved in various duties during this period. These hand sanitizers are being formulated as per WHO protocols.
About IIFPT: The IIFPT is a national level academic and research Institution under the Ministry of Food Processing Industries, Govt. of India. Through its main campus at Thanjavur, Tamil Nadu and liaison offices at Bathinda, Punjab and Guwahati, Assam, the IIFPT offers various services in areas of food processing, value addition, food quality and safety, and business incubation.
20-Apr-2020: New model to predict ionospheric electron density can help communication
Researchers from Indian Institute of Geomagnetism (IIG), Navi Mumbai, an autonomous institute of the Department of Science & Technology, Govt. of India, have developed a global model to predict the ionospheric electron density with larger data coverage—a crucial need for communication and navigation.
Dr. V. Sai Gowtam, with his research supervisor Dr. S. Tulasiram from IIG, has developed a new Artificial Neural Networks based global Ionospheric Model (ANNIM) using long-term ionospheric observations to predict the ionospheric electron density and the peak parameters.
ANNs replicate the processes in the human brain (or biological neurons) to solve problems such as pattern recognition, classification, clustering, generalization, linear and nonlinear data fitting, and time series prediction, and very few attempts have been made to model the global ionosphere variability using ANNs.
Tracking the variability of the Ionosphere is important for communication and navigation. The ionospheric variability is greatly influenced by both solar originated processes and the neutral atmosphere origin, therefore, difficult to model. Scientists have tried to model the ionosphere using theoretical and empirical techniques; however, the accurate prediction of electron density is still a challenging task.
In recent years, the Artificial Neural Networks (ANNs) are showing potential to handle more complex and non-linear problems. Keeping these aspects in mind, a novel machine learning approach was implemented by the IIG team in the ionospheric model development using global ionospheric observations.
The researchers developed a neural network-based global ionospheric model by using an extensive database consisting of nearly two decades of global Digisonde (an instrument that measures real-time on-site electron density of the ionosphere by sending the radiofrequency pulses), Global Navigation Satellite System (GNSS) radio occultation and topside sounders observations. These datasets were processed with various quality control measures to eliminate spurious data points (outliers) and prepared for the training. Day number, Universal Time, latitude, longitude, F10.7 index (responsible for Photo-ionization), Kp (represents the disturbed space weather conditions), magnetic declination, inclination, dip latitude, zonal and meridional neutral winds were taken as inputs in the study. The target (output) of ANNs is the electron density as a function of altitude for any given location and time. The data was trained with the ANNs using high-performance computer at IIG to develop the ANNIM.
The ANNIM predictions done by the IIG team matched with the incoherent scatter radar and the satellite in situ electron density observations. Further, the ANNIM successfully reproduced large scale anomalies of the ionosphere. The ANNIM also captured the general morphological features of the ionosphere during the disturbed space weather periods, such as geomagnetic storms which occurs when the magnetic cloud originated from Sun (known as Coronal Mass Ejection (CME)) interacts with the Earth’s magnetosphere
The model developed by IIG researchers may be utilized as a reference model in the ionospheric predictions and has potential applications in calculating the Global Navigation Satellite System (GNSS) positioning errors.