Bio - molecules detection and their quantification with a high precision is essential in modern era of medical diagnostics. In this context, the memristor device which can change its resistance state is a promising technique to sense the bio - molecules. In this work, detection of the Bovine Serum Albumin (BSA) protein using resistive switching memristors based on TiO2 and TiO2 + graphene oxide (GO) is explored. The sensitivity of BSA detection is found to be 4 mg/mL. Both the devices show an excellent bipolar resistive switching with an on/off ratio of 73 and 100 respectively, which essentially demonstrates that the device with GO, distinguishes the resistance states with a high precision. The enhanced performance in the GO inserted device (~ 650 cycles) is attributed to the prevention of multi-dimensional and random growth of conductive paths.

With industrial escalation, the increase in air toxicity leads to air quality degradation. There is a necessity to monitor environmental pollutants to protect animals and human beings from toxic/hazardous gases. Some of the dangerous gases causing worry for humankind are NH3, H2S, CO2, CH4, and CO; inhaling them may lead to fatal diseases. H2S is a colorless, poisonous, and flammable gas that causes immense toxicity among these gases. Several research groups work on gas sensors to monitor toxic and hazardous gases. Among various gas sensors, chemiresistive sensors are the best choice for detecting gases in the air environment. The metal oxide semiconductors like ZnO, CuO, NiO, SnO2, etc., are suitable materials for synthesizing chemiresistive gas sensors as they have good conductivity with a wide range of operating temperatures. Apart from the choice of materials, the morphology of the nanostructures also influences the gas sensing performance. The nanofibers with a high surface area can capture more gas species, resulting in good gas sensing performance. Hence, the present review focuses on detecting H2S by nanofibers-based chemiresistive gas sensors. The H2S gas sensing characteristics were explored with various types of nanofibers. H2S gas is hazardous, and its sensing applications can be found in petroleum and crude oil refineries. The surroundings of sewages pipelines, underground drainages, and sewage water treatment plants have a high level of H2S gas contents. Therefore, it is necessary to monitor the H2S gas levels in these areas for the safety of the workers and surrounding residents. The review article consists of various sensors that could be integrated with an IoT-based gas leakage detection system that can lower the risk of accidents in the manufacturing industry, agricultural activities, and emissions from automobiles, septic, and sewage treatment. 

An application is developed with surface mounted lead zirconate titanate (PZT) patches for sensing damage in the form of a stress-induced crack in a concrete substrate. A localized crack is introduced in a controlled manner using a fracture test. Full-field displacements obtained using digital image correlation are used for crack penetration and crack width measurements. Electrical impedance (EI) measurements are obtained from the individual PZT patches, which are attached at different locations relative to the crack. Stress wave transmission measurements are performed using the PZT patches as actuator-receiver (AR) pairs. The EI measurements indicate that small, quantifiable changes in the mechanical impedance of the substrate are experienced by the PZT patch in the vicinity of the localized crack, which sensitively detect crack initiation. The stress wave-based measurements are very sensitive to the presence of physical discontinuity created by a localized crack in the stress wave path. A measure of stress wave attenuation, the attenuation factor is developed, to quantify the measured changes in the stress wave produced by the physical discontinuity in concrete upon unloading a stress-induced crack. The physical discontinuity due to a stress-induced crack opening on the order of 10 μm can be detected from the measured changes in the attenuation factor. The physical discontinuity in the concrete associated with a stress-induced crack opening on the order of 100 μm produces a complete attenuation of the stress wave of 120 kHz. The combined use of PZT patches in the EI and the AR modes can be used to detect local changes close to a PZT patch and it allows distributed sensing over the entire volume of a structural element.

The metal-oxide semiconductor-based gas sensor has enthralled many researchers worldwide over past few decades. These sensors offer many advantages such as good selectivity, high sensitivity, and reliable and rapid detection of numerous pollutants. Among the pollutants, CO gas is highly toxic, and CO gas concentration of 9ppm causes harmful effect on human health; thus, high sensitivity of CO gas detection is extremely significant. Herein, we present the room temperature detection of low concentration CO gas by utilizing cerium oxide microflowers anchored on graphene nanoplatelets (GNPs). The GNPs-CeO2 nanocomposite was synthesized using solvothermal method and followed by structural and morphological characterizations were performed using various analytical techniques. The chemiresistive gas sensor was fabricated with a nanocomposite solution drop-casted on cellulose paper as a substrate and silver paste as an electrode. The as-fabricated gas sensor explored for its applicability on CO gas detection with various concentrations and displayed good selectivity over NO2, SO2,NH3, and CO2. The gas sensing response of the device is due to large number of oxygen vacancies in the nanocomposite and the heterojunction between CeO2 and GNPs. The sensor offers a potential platform for metal oxide-based gas sensors operated at room-temperature and displayed good repeatability and stability. 

The nternet of Things (IoT) is a very fast-growing technology and the field of IoT is extending its wings in every one of the areas today. With the progression in computers like Arduino, Raspberry pi, the innovation is achieving the ground level with its application in farming and aquaculture. In this work, we have outlined and actualized monitoring of water quality of aquaculture utilizing Raspberry Pi, Arduino, various Sensors, Smartphone Camera and Android application. Water quality parameters used in this work are Temperature, pH, Electrical Conductivity and Colour. Sensor acquisition is conducted by Arduino and Raspberry Pi is used as data processing device as well as server. Photo acquisition is also performed by Raspberry Pi with the help of the smartphone camera to detect the colour of the water. Android phone is used as the terminal device. A user can monitor the water condition using an android app through Wi-Fi within Wi-Fi range and through the Internet from anywhere in the world. Some analysis is performed with the four parameter values to determine the overall approximate condition of the water and required action. Every feature in this checking gadget can work legitimately and easily. 

Water plays a significant role in the survival of humankind. A primary percentage of the rural population depends on water for agriculture, drinking, and survival. Water coming from rain and various sources getting contaminated because of the pollution and the effluents of factories near rural areas. Consuming this contaminated water causes problems and incurable diseases for humankind. Not only is the contamination caused due to pollution, but also some ponds, lakes, and rivers on which the rural depend contain harmful chemicals like fluoride and lead, causing fluorosis, which ultimately leads to bone deformation, various nanoparticles, and so on. From this, many lives have been in danger for a long time. Understanding the situation, filtration is known to play a crucial role in rural areas to get water for all its requirements 

Corn cob is an abundant agricultural waste around Hyderabad, rich in pentosans (~30 wt%) and cellulose (~40 wt%). United Andhra (4 MMT/year) is the second largest producer of corn, with the highest productivity (5.7 MT/hectare) in the country after Karnataka (4.4 MMT). Therefore, this proposal was focused on utilizing waste corn cobs to produce industrially relevant organic chemicals: furfural and 5-hydroxymethyl furfural (HMF). Suck kinds of technological initiatives will improve the economics of our country by creating job opportunities in rural areas. 

Antibiotic/antimicrobial resistance (AMR) is among the looming global health concerns. In 2014, estimates and actual data show that infections with AMR led to the loss of over 7 million lives every year, and that number has been predicted to rise to 10 million lives by 2050. To tackle the growing issue of AMR, antimicrobial stewardship strategies are being adopted in health systems all over the world, mainly in hospitals. These programs are not well established in this industry despite the importance of primary healthcare services in providing healthcare to communities, especially in rural and remote areas.