Self-standing piezoelectric nanogenerator fabrics from ZnO-doped PVDF nanofiber yarns

Today a wide variety of wearable electronics are in our daily lives and their uses are increasing. The development of portable, flexible, lightweight, cost-effective, and stable devices that produce sustainable energy with renewable approaches in the field of wearable electronics, as in every field, is one of the important issues of today. According to their volume and weight, the use of nanofibers with high surface area in energy-generating devices may bring them advantages such as lightness and higher energy density. Therefore, in recent years, researchers have focused on the development of nanofiber-based nanogenerators that produce energy using mechanical energy in a sustainable and renewable way. In this paper, self-standing piezoelectric nanogenerator (PENG) fabrics were obtained by developing flexible composite poly(vinylidene fluoride) (PVDF) nanofiber yarns doped with zinc oxide (ZnO) nanoparticles at different rates to provide higher power output. It has been characterized from electromechanical, structural, and morphological aspects. The most successful self-standing PENG fabric obtained (at 5% ZnO loading) doubled the energy output of the fabric made from pure PVDF nanofiber yarn and provided a peak total power of 81 μW and a power density of 30 μW/cm². The present results open up the field for the development of PVDF/ZnO-based nanomats and their use in sensors and actuators in the healthcare and engineering industries.     

Development of microencapsulated grape juice powders using black ‘Isabel’ grape peel pectin and application in jelly formulation with enhanced in vitro bioaccessibility of anthocyanins

In this study, pigmented pectin (grape pectin, GP) was extracted from the peels of black Isabel grapes. This highly methoxylated GP was composed mainly of galacturonic acid, arabinose, and other neutral monosaccharides. Its red color was ascribed to the anthocyanin content, and the main contribution was from malvidin-3-O-glucoside. To improve the yield and color properties of spray-dried Isabel grape juice powders, maltodextrin (MD) was substituted with this colored GP. When 25% of MD was substituted with GP, the powder yield increased from 46.0% to 60.4%, but it decreased to 21% when the substitution was 40%. GP inclusion increased the encapsulation efficiency of total anthocyanin in powders from 55.70% to 88.66%. When this spray-dried grape juice powder containing GP was utilized in a jelly recipe (4%–10%), a higher level of inclusion yielded stronger and more brittle jellies. When the jellies containing varying amounts of GP were subjected to in vitro digestion, the formulation with a higher amount of GP yielded a higher recovery of anthocyanins. In addition to being utilized as a carrier agent for spray-drying applications, this pigmented GP can also be tailored for a variety of applications, such as the development of pH-sensitive edible films and functional beverage formulations.     

Thermal properties of socks made from reclaimed fibre

In this study, thermal properties of the socks made from the blend of reclaimed cotton fibre and virgin polyester fibre are investigated in comparison with those of similar socks made from virgin cotton fibre, together with the influence of incorporated elastane. Statistical results reveal that elastane addition and fibre type significantly affect all of the thermal properties of the socks. Elastane addition leads to increase in the thermal conductivity, thermal resistance and thermal absorptivity values and decrease in the water vapour permeability values. The reclaimed fibre socks exhibit lower thermal conductivity and thermal absorptivity and higher thermal resistance than the cotton socks. The water vapour permeability results of the reclaimed fibre socks with no elastane are higher than those of the cotton socks with no elastane. The difference between the water vapour permeability of the reclaimed socks with elastane and the cotton socks with elastane is found to be statistically insignificant.     

A SNP-based PCR–RFLP capillary electrophoresis analysis for the identification of the varietal origin of olive oils

Authenticity and traceability of high quality monovarietal extra virgin olive oils is a major concern for markets and consumers. Although analytical chemistry techniques are widely used to satisfy these needs recently developed DNA-based methods can serve as complementary approaches. A SNP database comprising 10 Greek olive varieties was constructed and five SNPs, residing in restriction sites, were selected for the development of a PCR–RFLP capillary electrophoresis method to discriminate these varieties using leaf DNA as template. An identification key was constructed indicating that five SNPs were adequate to discriminate nine out of the 10 varieties. As a proof of principle the assay was applied on DNA extracted from five of their corresponding monovarietal olive oils. Three SNPs were able to identify the varietal origin of these olive oils confirming the validity of this approach.     

Prediction of wheat quality parameters using near-infrared spectroscopy and artificial neural networks

In wheat and flour processing, the quality control needs quick analytical tools for predicting physical, rheological, and chemical properties. In this study, near infrared reflectance (NIR) spectroscopy combined with artificial neural network (ANN) was used to predict the flour quality parameters that are protein content, moisture content, Zeleny sedimentation, water absorption, dough development time, dough stability time, degree of dough softening, tenacity (P), extensibility (L), P/G, strength, and baking test (loaf volume and loaf weight). A total of 79 flour samples of different wheat varieties grown in different regions of Turkey were chemically analyzed, and the results of both NIR spectrum (400–2,498 nm) and chemical analysis were used to train/test the network by applying various ANN architectures. Prediction of protein, P, P/G, moisture content, Zeleny sedimentation, and water absorption in particular gave a very good accuracy with coefficient of determination (R ²) of 0.952, 0.948, 0.933, 0.920, 0.917, and 0.832, respectively. The results indicate that NIR combined with the ANN can successfully be used to predict the quality parameters of wheat flour.     

Polythiophene/SiO2 nanocomposites prepared in the presence of surfactants and their application to glucose biosensing

Conducting polythiophene/SiO₂ (PT/SiO₂) nanocomposites were prepared in the presence of three different surfactants (anionic, cationic and non-ionic) via chemical oxidative polymerization in an anhydrous medium to create an enzyme-immobilized polymeric amperometric biosensor. An anionic surfactant, sodium dodecylbenzenesulfonate (DBSNa), a cationic surfactant, tetradecyltrimethylammonium bromide (TTAB), and a non-ionic surfactant, poly(ethylene oxide) (20) sorbitan monolaurate (Tween 20), were used as additives. The properties of the nanocomposites were investigated, as a function of surfactant type and the amount of PT contained, by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The SEM results reveal that all PT/SiO₂ samples form nanometer-dimensioned globular structures. The highest conductivity obtained was 2.7 × 10⁻² S cm⁻¹ for a PT/SiO₂-Tween 20 nanocomposite. Thermogravimetric analysis (TGA) shows that the residue decreases with increasing amount of PT. Glucose oxidase (GOX) was immobilized by crosslinking to the conducting PT/SiO₂ composites and was used for amperometric detection of glucose.     

Cost-effective synthesis of polyricinoleate: Investigation of coating characteristics,in vitro degradation,and antibacterial activity

Ricinoleic acid (RA) is a component of various bio-based copolymers. However, high-molecular weight polyricinoleate homopolymers are not widely investigated due to high cost of commercial monomer and catalysts. In this work, we present low-cost approach for the synthesis of high-molecular-weight polyricinoleate by preparing large amount of pure monomer and use of lipozyme TL IM as catalyst. First, polymerization conditions were optimized and comparative studies of medium-molecular-weight polyricinoleate (PRA-M) of M_w = 30 000 gmol⁻¹ and high-molecular-weight polyricinoleate (PRA-H) of M_w = 72 000 gmol⁻¹ were conducted. Polyricinoleates were characterized by common spectroscopic, chromatographic, and thermal methods. Solvent casting of polyricinoleates resulted in thin and continuous coating with perfectly smooth surface under SEM observation. AFM analysis of PRA films showed that surface roughness decreased with increasing molecular weight of polyricinoleate (roughness PRA-M = 68.39 nm and PRA-H = 57.36 nm). Degradation studies under in vitro conditions showed that both PRA-M and PRA-H showed good stability with only ~2% of mass loss after 6 months, possibly due to its hydrophobic nature and relatively high-molecular weight. In contrast to RA, PRA-M and PRA-H do not have significant antibacterial effect on Staphylococcus aureus and Escherichia coli. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48172.     

Statistical Analysis and Multimodal Classification on Noisy Eye Tracker and Application Log Data of Children with Autism and ADHD

Emotion recognition behavior and performance may vary between people with major neurodevelopmental disorders such as Autism Spectrum Disorder (ASD), Attention Deficit Hyperactivity Disorder (ADHD) and control groups. It is crucial to identify these differences for early diagnosis and individual treatment purposes. This study represents a methodology by using statistical data analysis and machine learning to provide help to psychiatrists and therapists on the diagnosis and individualized treatment of participants with ASD and ADHD. In this paper we propose an emotion recognition experiment environment and collect eye tracker fixation data together with the application log data (APL). In order to detect the diagnosis of the participant we used classification algorithms with the Tomek links noise removing method. The highest classification accuracy results were reported as 86.36% for ASD vs. Control, 81.82% for ADHD vs. Control and 70.83% for ASD vs. ADHD. This study provides evidence that fixation and APL data have distinguishing features for the diagnosis of ASD and ADHD.     

Biofilm formation by Staphylococcus aureus strains and their control by selected phytochemicals

Biofilm formation by 30 Staphylococcus aureus dairy isolates and their control by phytochemicals were investigated. The majority of strains were biofilm positive by phenotypic analysis. The nuc and icaA genes were present in 30 and 27 strains, respectively. In addition, 13 strains were positive for all nuc, clfA, fnbA and icaA genes. The antimicrobial and antibiofilm activities of citral, cinnamaldehyde, eugenol, farnesol, limonene and terpinen‐4‐ol were also evaluated for seven strains. It was shown that the use of farnesol, cinnamaldehyde or terpinen‐4‐ol at a concentration of 2 mg/mL could be at least 80% effective on S. aureus strains and their biofilms.