Explore the vast range of titles available.

BackgroundLung infections are among the most consequential manifestations of cystic fibrosis (CF) and are associated with reduced lung function and shortened survival. Drugs called CF transmembrane conductance regulator (CFTR) modulators improve activity of dysfunctional CFTR channels, which is the physiological defect causing CF. However, it is unclear how improved CFTR activity affects CF lung infections.MethodsWe performed a prospective, multicenter, observational study to measure the effect of the newest and most effective CFTR modulator, elexacaftor/tezacaftor/ivacaftor (ETI), on CF lung infections. We studied sputum from 236 people with CF during their first 6 months of ETI using bacterial cultures, PCR, and sequencing.ResultsMean sputum densities of Staphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Achromobacter spp., and Burkholderia spp. decreased by 2-3 log10 CFU/mL after 1 month of ETI. However, most participants remained culture positive for the pathogens cultured from their sputum before starting ETI. In those becoming culture negative after ETI, the pathogens present before treatment were often still detectable by PCR months after sputum converted to culture negative. Sequence-based analyses confirmed large reductions in CF pathogen genera, but other bacteria detected in sputum were largely unchanged. ETI treatment increased average sputum bacterial diversity and produced consistent shifts in sputum bacterial composition. However, these changes were caused by ETI-mediated decreases in CF pathogen abundance rather than changes in other bacteria.ConclusionsTreatment with the most effective CFTR modulator currently available produced large and rapid reductions in traditional CF pathogens in sputum, but most participants remain infected with the pathogens present before modulator treatment.Trial RegistrationClinicalTrials.gov NCT04038047.FundingThe Cystic Fibrosis Foundation and the NIH.

This paper reviews different ways to manage energy in Hybrid Electric Vehicles (HEVs) for smart cities by looking at three separate studies. Initially, it explores a structured approach to solving energy management issues in HEVs, comparing three known methods and highlighting one that can be used in real-time. Next, it discusses a creative use of Petri Nets (PNs) for managing energy, either on its own or with the Global Positioning System (GPS). This part points out the benefits of using GPS to manage energy better during different driving conditions. Lastly, the paper talks about the need to improve energy management in a specific type of HEV to address current environmental and energy challenges. It mentions the use of a Genetic Algorithm (GA) to improve energy management strategies, aiming to extend the life of the vehicle’s fuel cell and improve energy efficiency. Through these discussions, this review aims to provide a clear understanding of how energy management in HEVs can be improved in smart city settings.

The synchronization between the grid and inverter is crucial for power sharing. By reconnecting the inverter to the electrical grid, it becomes possible to provide power in grid-off mode. Inverter-interfaced distributed generators (DGs) rely on control methods to drive the power devices in the inverter. A three-phase inverter produces output in terms of voltage, frequency, and phase, which can be matched with the electrical output using control methods. These control methods determine the pulse width modulation (PWM) pulses for driving the inverter. Simulations of the proposed systems with a grid-connected inverter are expressed through a MATLAB SIMULINK Model. Various algorithms generate different PWM pulses for the inverter. The differences between these algorithms are summarized in the results. Finally, the simulation results are analyzed across the load, total harmonic distortion (THD), error in grid voltage, and inverter voltage.

The use of multi‐walled carbon nanotubes (MWCNT) as reinforcing material for thermoplastic polymer matrices, polymethyl methacrylate (PMMA), and polystyrene (PS) has been studied. MWCNT were synthesized by chemical vapor deposition (CVD) technique using ferrocene‐toluene mixture. As‐prepared nanotubes were ultrasonically dispersed in toluene and subsequently dispersed in PMMA and PS. Thin polymer composite films were fabricated by solvent casting. The effect of nanotube content on the electrical and mechanical properties of the nanocomposites was investigated. An improvement in electrical conductivity from insulating to conducting with increasing MWCNT content was observed. The carbon nanotube network showed a classical percolating network behavior with a low percolation threshold. Electromagnetic interference (EMI) shielding effectiveness value of about 18 dB was obtained in the frequency range 8.0–12 GHz (X‐band), for a 10 vol% CNT loading. An improved composite fabrication process using casting followed by compression molding and use of functionalized MWCNT resulted in increased composites strength. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Solar energy is a primary source on earth and photovoltaic (PV) cells are using to produce electricity through solar energy. Due to nonlinear behavior of power vs voltage curves of PV system, a maximum power point tracking (MPPT) circuits must be employed to harvest maximum energy. Among many MPPT techniques, a Perturbed and Observed (P&O) algorithm is one of the best methods. Generally partial shading conditions (PSCs) are commonly appearing on the PV systems. Under these PSCs, the P-V curve exhibits multiple peaks where one can be a global maximum and other are local maximum points. The global maximum location needs to be identifying to harvest more energy during PSCs. Hence, modified grey wolf optimization method is integrated with P&O algorithm to make a hybrid control method of a boost converter to operate PV system at its best utilization point. Hardware – in the – Loop (HIL) is designed with the help of two OPAL-RT modules to present various results under different operating conditions.

Despite the much touted mechanical properties of carbon nanotubes, composites reinforced with nanotubes have failed to achieve mechanical properties which rival those present in conventional fiber reinforced polymer composites. This article describes an attempt to bridge this gap. Multi‐walled carbon nanotubes (MWCNT) were synthesized using a chemical vapor deposition method and were dispersed in phenolic resin by both the wet and dry dispersion techniques before molding into composite bars (50 × 5 × 3 mm3). Although no improvement in the mechanical properties of the MWCNT/phenolic composites was observed over the neat resin value when wet mixing dispersion was employed, an improvement of nearly 158% (160 MPa as compared with 62 MPa for neat resin) was achieved in 5 vol% MWCNT containing phenolic resin prepared by the dry mixing. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers

During Diwali festival, extensive burning of crackers and fireworks is made. Weeklong intensive observational campaign for aerosol study was carried out at a representative urban location in the eastern Indo-Gangetic Plain (IGP), Varanasi (25.3°N, 83.0°E), from October 29 to November 04, 2005 (Diwali on November 01, 2005), to investigate behavioral change of aerosol properties and radiative forcing between firework affected and nonaffected periods. Results show a substantial increase (~27%) in aerosol optical depth, aerosol absorption coefficients, and aerosol scattering coefficients during affected period as compared to non-affected periods. Magnitudes of radiative forcing at top of atmosphere during affected and non-affected periods are found to be +10 ± 1 and +12 ± 1 Wm−2, respectively, which are −31 ± 7 and −17 ± 5 Wm−2, respectively, at surface. It suggests an additional cooling of ~20% at top of atmosphere, ~45% cooling at surface, and additional atmospheric heating of 0.23 Kday−1 during fireworks affected period, which is ~30% higher than the non-affected period average.

Multiwalled carbon nanotubes‐polymethyl methacrylate composites (MWCNT‐PMMA) were prepared by an in situ polymerization method. The effect of nanotube content and their surface functionalization on the mechanical properties of the resulting nanocomposites was investigated. The use of only 1.8 wt% functionalized tubes improved flexural modulus by about 43% and flexural strength by about 60%. In situ polymerization using functionalized tubes improved interfacial bonding strength due to a chemical interaction between carbon nanotubes and the growing PMMA, which resulted in improved load transfer mechanism. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

Due to our modern standard of living, the demand of electrical energy is growing rapidly. To meet this exigency, the conventional metal wires have become obsolete to meet highly efficient electrical energy supply demands. The suitable alternative to metal wires must exhibit good electrical and thermal conductivity, low mass density, negligible skin effects and non-corrosive properties. The axially aligned carbon nanotubes (CNT) assemblies, the CNT fibers, are among the most promising materials to meet these requirements. The CNT fibers hold great potential for highly fuel-efficient electric vehicles and low-power nanochips in ever-advancing computer hardware where conventional wires have no future. This article provides an overview of the conducting nature of CNT fibers. First, CNTs as futuristic conducting material will be elucidated briefly, followed by synthesis techniques of CNT fiber. Specific attention is devoted to the direct spinning technique (FC-CVD) as the fiber produced by this method has quite high electrical conductivity (EC) and of limitless length. Then, the effect of various parameters (during synthesis like carrier gas or feedstock flow rate and after synthesis like doping of metallic nanomaterials, coating of polymers or interaction with the acidic environment) on its EC is discussed. This study would pave the way for the bright future of CNT fiber to be used as electrical wiring by concentrating on current challenges confronting this field.

The study attempts to re-validate Venkatesh’s model of acceptance and use of digital technology on school teachers. 197 school teachers participated in the study on the Qualtrics survey platform. The study used Smart PLS-SEM (Partial-Least Squares-Structural Equation Model) to re-validate the Venkatesh’s model. Teachers adopted digital technology for online teaching, leading to continued behavioural usage intention. Facilitating conditions and perceived cost emerged as strong predictors in promoting behavioural intention to use digital technology. The research showed that teachers would continue using technology in future irrespective of the situation. Social influence was less effective in predicting behavioural intention; habit, on the other hand, had no direct link to the use behaviour as expected; and perceived cost had a direct linkage to the use behaviour, showing that teachers acknowledged the affordable cost of digital tools for teaching. Based on path coefficients, the study confirmed the significant effects of latent constructs on behavioural intention (BI).