Effect of Secondary Structure and Side Chain Length of Hydrophobic Amino Acid Residues on the Antimicrobial Activity and Toxicity of 14-Residue-Long de novo AMPs

Herein we report the efficacy and toxicity of three de novo designed cationic antimicrobial peptides (AMPs) LL-14, VV-14 and ββ-14, where side chains of the hydrophobic amino acids were reduced gradually. The AMPs showed broad-spectrum antimicrobial activity against three pathogens from the ESKAPE group and two fungal strains. This study showed that side chains which are either too long or too short increase toxicity and lower antimicrobial activity, respectively. VV-14 was found to be non-cytotoxic and highly potent under physiological salt concentrations against several pathogens, especially Salmonella typhi TY2. These AMPs acted via membrane deformation, depolarization, and lysis. The activity of the AMPs is related to their ability to take on amphipathic helical conformations in the presence of microbial membrane mimics. Among AMPs with the same charge, hydrophobic interactions between the side chains of the residues with cell membrane lipids determine their antimicrobial potency and cytotoxicity. Strikingly, an optimum hydrophobic interaction is the crux of generating highly potent non-cytotoxic AMPs.     

Electroosmotic flow of a fractional second-grade fluid with interfacial slip and heat transfer in the microchannel when exposed to a magnetic field

We investigated the time-dependent viscoelastic fluid flow through a parallel-plate microchannel under the influence of a transversely applied magnetic field and an axially imposed electric field. We performed the analysis by employing the Poisson-Boltzmann equation under the Debye-Huckel approximation. The generalized second-grade fluid model with a fractional-order time derivative is used to observe the non-Newtonian and fractional behavior rates of deformation employing the Riemann-Liouville fractional operator. We considered the asymmetric zeta potentials and different slip effects at the walls to study the flow behavior near the vicinity of the channel. We obtained an analytical solution in terms of Mittag-Leffler function, applying Fourier and Laplace transformations. We imposed the heat transfer phenomena with the dissipation of energy and Joule heating effects on the model. The governing equations were also solved numerically by employing an implicit finite difference scheme. The numerical solution was compared with the analytical results, considering the influence of the pertinent parameters involved in the problem. The study delineates that the flow rate decreases with a rise in the fractional-order parameter, while the opposite trend is observed with the electroosmotic parameter. Due to the application of sufficient strength of the magnetic field and the Joule heating effects, the temperature increases within the channel.     

Performance Evaluation of Best Feature Subsets for Crop Yield Prediction Using Machine Learning Algorithms

The rapid innovations and liberalized market economy in agriculture demand accuracy in Crop Yield Prediction (CYP). In accurate prediction, machine learning (ML) algorithms and the selected features play a major role. The performance of any ML algorithm may improve with the utilization of a distinct set of features in the same training dataset. This research work evaluates the most needed features for accurate CYP. The ML algorithms, namely, Artificial Neural Network, Support Vector Regression, K-Nearest Neighbour and Random Forest (RF) are proposed for better accuracy. Agricultural dataset consists of 745 instances; 70% of data are randomly selected and are used to train the model and 30% are used for testing the model to assess the predictive ability. The results show that the RF algorithm reaches the highest accuracy by means of its error analysis values for all the distinct feature subsets using the same training agricultural data.     

Polypyrrole as the interlayer for thin-film poly(piperazine-amide) composite membranes: Separation behavior of salts and pesticides

The preparative membrane process is a dynamic one and intertwined with the separation arena. As for the progression of technology in membranes, our direction is to prepare polypyrrole interlayer-based thin-film composite (TFC) membrane. Polypyrrole shows its attachment ability with polysulfone membranes. The coverings of pores with the polypyrrole entity result in better flux in terms of TFC membranes compared to TFC membranes on polysulfone (Memb-I). The membranes are characterized by FTIR-ATR, contact angle, zeta potential, SEM, AFM. Polypyrrole interlayer-based membrane (Memb-II) show better flux though it sacrifices salt separation ability compared to Memb-I. Memb-II shows a better separation of pesticides (diuron and isoproturon) compared to Memb-I. Memb-II provides isoproturon's separation ability (89.52% rejection, 54.9 LMH), whereas, for diuron, it is 78.82%, 53.46 LMH. The antimicrobial property is seen for interlayer polypyrrole-based TFC membranes.     

Overall efficiency enhancement and cost optimization of semitransparent photovoltaic thermal air collector

A semitransparent photovoltaic‐thermal (PV/T) air collector can produce electricity and heat simultaneously. To maximize the thermal and overall efficiency of the semitransparent PV/T air collector, its availability should be maximum; this can be determined through a Markov analysis. In this paper, a Markov model is developed to select an optimized number of semitransparent PV modules in service with five states and two states by considering two parameters, namely failure rate ( λ ) and repair rate (µ). Three artificial neural network (ANN) models are developed to obtain the minimum cost, minimum temperature, and maximum thermal efficiency of the semitransparent PV/T air collector by setting its type appropriately and optimizing the number of photovoltaic modules and cost. An attempt is also made to achieve maximum thermal and overall efficiency for the semitransparent PV/T air collector by using ANN after obtaining its minimum temperature and available solar radiation.     

Heat recovery schemes in the UK

It would seem that many industrial companies in the UK, even though their profit margins are being squeezed, still have money to burn, literally. Although fuel prices have escalated quite sharply over the past two decades, the cost of energy is not yet high enough to force companies to implement conservation measures as a matter of course. Energy managers have been appointed throughout the country, but they have mostly proved ineffective. Gopal Srinivasan urges UK industry to consider heat recovery projects.     

The potential for the SCC of titanium alloys under repository-relevant environments for U.S. nuclear waste

Stress corrosion cracking (SCC) is one of the most common corrosion-related causes of premature failure of metal structural components. This paper presents an assessment of the performance of titanium alloys (titanium grade 7 for the drip shield and grade 29 for the structural support), which may be subjected to SCC under proposed U.S. nuclear waste repository environments. The threshold stresses for SCC initiation, SCC crack propagation rates, and the threshold stress intensity factors for titanium grades 7, 28, and 29 are discussed.     

A transmission electron microscopy study of WC-10Co cemented carbides with modified hard and binder phases

The alloy design of WC-10Co cemented carbide, modified with addition of a hard carbide phase, TiC, and with Ni and Mo in the binder phase, has been highlighted by the authors in a number of publications. The present article deals with the fine microstructural features of various phases in such cemented carbides. WC grains in all the investigated cemented carbide compositions appear to develop straight facets during sintering because of their anisotropic nature. In contrast, the TiC phase is characterized by its rounded shape. Dislocations are present in both WC and TiC grains, being of lesser density in the latter. The binder phase is always associated with stacking faults. The nature of the hard phase/binder interfaces has been found to be dependent on the binder phase chemistry. The observed changes in microstructures and mechanical properties have been correlated with the wettability and solubility of the hard phases in the binder melt, and with the different strengthening mechanisms in the binder phase.