Three-dimensional graphene nanosheet encrusted carbon micropillar arrays for electrochemical sensing

Integrating graphene onto three-dimensional (3D) microelectrodes is a plausible technique to significantly improve the sensitivity of electrochemical devices. However, the construction of graphene coated 3D microstructures has been a considerable challenge. In this paper, we present a simple methodology using electrostatic spray deposition (ESD) to conformally coat graphene onto 3D carbon micropillars that are fabricated by pyrolyzing finely patterned photoresist. During the ESD, changes in the critical parameters such as substrate temperature, deposition time, and nozzle to substrate distance have shown a significant effect on the morphology of the deposited graphene film. The amperometric response of graphene/carbon micropillar electrode arrays exhibited higher electrochemical activity, improved charge transfer and a linear response towards H(2)O(2) detection between 250 μM and 5.5 mM. The ESD technique, with the flexibility of integrating a wide variety of functional nanomaterials onto complex 3D microstructures, is attractive in the field of electrochemistry and biotechnology.     

Evaluation of the effects of engine parameters on performance and emissions of diesel engine operating with biodiesel blend

Diminishing resources, alarming pollution levels and escalating price associated with the application of diesel in compression ignition engine have forced scientific community throughout the world to conduct several experiments for the evaluation of biodiesel (BD) as a substitute for diesel. Due to difference in the physical and chemical properties of BD and diesel, the engine parameters such as compression ratio (CR), injection pressure (IP) and injection timing (IT) may not be optimum for BD, especially for higher blends. The present study is carried out with the aim to investigate the combined effect of CR, IP and IT on the performance and emission of a diesel engine widely used in agriculture sector in India, fuelled with B40 (40% BD and 60% diesel on a volume basis). Furthermore, this paper also aims to find the optimum engine parameters. A total of 27 sets of experiments were conducted for different combination of engine parameters and 162 sets of performance and emission data were recorded with varying load conditions. Adjustment of operating parameters was helpful to overcome the shortcoming of higher blend of BD (B40). The results demonstrated that higher CR (18:1) and IP (240 bar) along with advance IT (26° bTDC) is the best combination for a constant speed engine with brake power of 3.5 kW.     

Autoignition of ethanol in a rapid compression machine

Ethanol is a renewable source of energy and significant attention has been directed to the development of a validated chemical kinetic mechanism for this fuel. The experimental data for the autoignition of ethanol in the low temperature range at elevated pressures are meager. In order to provide experimental data sets for mechanism validation at such conditions, the autoignition of homogeneous ethanol/oxidizer mixtures has been investigated in a rapid compression machine. Experiments cover a range of pressures (10–50 bar), temperatures (825–985 K) and equivalence ratios of 0.3–1.0. Ignition delay data are deduced from the experimental pressure traces. Under current experimental conditions of elevated pressures and low temperatures, chemistry pertaining to hydroperoxyl radicals assumes importance. A chemical kinetic mechanism that can accurately predict the autoignition characteristics of ethanol at low temperatures and elevated pressures has been developed and this mechanism is compared with other models available in the literature.     

Package Coupling Measurement in Object-Oriented Software

The grouping of correlated classes into a package helps in better organization of modern object-oriented software. The quality of such packages needs to be measured so as to estimate their utilization. In this paper, new package coupling metrics are proposed, which also take into consideration the hierarchical structure of packages and direction of connections among package elements. The proposed measures have been validated theoretically as well as empirically using 18 packages taken from two open source software systems. The results obtained from this study show strong correlation between package coupling and understandability of the package which suggests that proposed metrics could be further used to represent other external software quality factors.     

Particle Swarm Optimization for Solving Sine-Gordan Equation

The term ‘optimization’ refers to the process of maximizing the beneficial attributes of a mathematical function or system while minimizing the unfavorable ones. The majority of real-world situations can be modelled as an optimization problem. The complex nature of models restricts traditional optimization techniques to obtain a global optimal solution and paves the path for global optimization methods. Particle Swarm Optimization is a potential global optimization technique that has been widely used to address problems in a variety of fields. The idea of this research is to use exponential basis functions and the particle swarm optimization technique to find a numerical solution for the Sine-Gordan equation, whose numerical solutions show the soliton form and has diverse applications. The implemented optimization technique is employed to determine the involved parameter in the basis functions, which was previously approximated as a random number in the work reported till now in the literature. The obtained results are comparable with the results obtained in the literature. The work is presented in the form of figures and tables and is found encouraging.     

Ecological interface design and emergent users: Designing for small-scale trucking ecology in India

Effective on-road safety requires proper maintenance of vehicles. In the trucking sector in India, there is a need for supporting predictive maintenance to decrease downtime and improve safety. Improving maintenance in this sector involves certain challenges. First, most trucks are owned by small-scale fleet owners (trucks < 5). Second, maintenance is often handled by small-scale mechanic workshops. The fault diagnosis is very often limited to recognition by the driver and later reassessed by the mechanic by relying on the feel or the sound of the vehicle. Third, a majority of stakeholders in this sector—drivers, mechanics, and owners—have low levels of education. Despite these challenges, with the increase in the rate of digitalization, in the future, it will be easier to monitor the health of the parts of a truck. In addition, there is a developing trend of mobile phone and internet penetration in India that has leapfrogged a majority of Indians into becoming “emergent users” of information technology. Therefore, this article shows that sociotechnical approaches such as ecological interface design can be used to develop mobile interfaces for supporting predictive maintenance through health and usage monitoring of trucks for small-scale fleet owners in India. To develop the interface, a field study was conducted at several sites in the state of Tamil Nadu, India. The insights were used to develop scenarios and the abstraction hierarchy, which were later used creatively to develop the interface design for emergent users.     

Implementation of Band Gap and Gate Oxide Engineering to Improve the Electrical Performance of SiGe/InAs Charged Plasma-Based Junctionless-TFET

Silicon - This paper reports on a charged plasma-based adjustable bandgap source/channel (So/Ch) interface using a new semiconductor compound (SiGe/ InAs) and bimaterial oxide (HfO2/SiO2)...     

Machine learning enabled integrated formulation and process design framework for a pharmaceutical 3D printing platform

The pharmaceutical manufacturing sector needs to rapidly evolve to absorb the next wave of disruptive industrial innovations—Industry 4.0. This involves incorporating technologies like artificial intelligence and 3D printing (3DP) to automate and personalize the drug production processes. This study aims to build a formulation and process design (FPD) framework for a pharmaceutical 3DP platform that recommends operating (formulation and process) conditions at which consistent drop printing can be obtained. The platform used in this study is a displacement-based drop-on-demand 3D printer that manufactures dosages by additively depositing the drug formulation as droplets on a substrate. The FPD framework is built in two parts: the first part involves building a machine learning model to simulate the forward problem—predicting printer operation for given operating conditions and the second part seeks to solve and experimentally validate the inverse problem—predicting operating conditions that can yield desired printer operation.     

Dry Sliding Wear Behavior of Tempered (T4 and T6) Hypereutectic Aluminum Alloy-Based Composites

Silicon - The present work describes the effect of tempering (T4 and T6) processes on the dry sliding wear properties of ilmenite reinforced aluminum alloy (LM30) composites, prepared through stir...     

Light-Regulated Pro-Angiogenic Engineered Living Materials

Regenerative medicine aims to restore damaged cells, tissues, and organs, for which growth factors are vital to stimulate regenerative cellular transformations. Major advances have been made in growth factor engineering and delivery like the development of robust peptidomimetics and controlled release matrices. However, their clinical applicability remains limited due to their poor stability in the body and need for careful regulation of their local concentration to avoid unwanted side-effects. In this study, a strategy to overcome these limitations is explored using engineered living materials (ELMs), which contain live microorganisms that can be programmed with stimuli-responsive functionalities. Specifically, the development of an ELM that releases a pro-angiogenic protein in a light-regulated manner is described. This is achieved by optogenetically engineering bacteria to synthesize and secrete a vascular endothelial growth factor peptidomimetic (QK) linked to a collagen-binding domain. The bacteria are securely encapsulated in bilayer hydrogel constructs that support bacterial functionality but prevent their escape from the ELM. In situ control over the release profiles of the pro-angiogenic protein using light is demonstrated. Finally, it is shown that the released protein is able to bind collagen and promote angiogenic network formation among vascular endothelial cells, indicating the regenerative potential of these ELMs.