A note on inverses of power series

AbstractWe show the recurrence formula for coefficients of an inverse of a power series of two variables. This problem arises from geodesy

Antioxidative, sensory and volatile profiles of cookies enriched with freeze-dried Japanese quince (Chaenomeles japonica) fruits

The study aimed at assessing effects of freeze-dried Japanese quince fruit (FJQF; 0–9%) added to cookies to improve their antioxidant attributes during storage, sensory and volatile characteristics and acceptability by consumers. Cookies containing FJQF had 2-3.5-fold higher radical scavenging activity and exhibited less secondary lipid oxidation products compared with the control cookies. Enriched cookies had higher contents of volatile hexanal, heptanal, octanal, 2-heptenal, (E) than control cookies. Acetic acid dominated in the volatile profile of enriched cookies (ranging 7.05–23.37%), hence intensities of acidic and citrus aroma were scored high. Cookies stored for 16-weeks showed increased amounts of hydrocarbons as compared with fresh cookies and new hydrocarbons were also generated, which were not detected in fresh cookies. The consumer panel indicated a higher preference for cookies containing 1.0 and 1.5% FJQF than those containing 6.0 and 9.0%

Elucidation of role of graphene in catalytic designs for electroreduction of oxygen

Graphene is, in principle, a promising material for consideration as component (support, active site) of electrocatalytic materials, particularly with respect to reduction of oxygen, an electrode reaction of importance to low-temperature fuel cell technology. Different concepts of utilization, including nanostructuring, doping, admixing, preconditioning, modification or functionalization of various graphene-based systems for catalytic electroreduction of oxygen are elucidated, as well as important strategies to enhance the systems' overall activity and stability are discussed

Arteriovenous fistula of superficial temporal vessels

We present a case of patient with a rare vessel pathology — arteriovenous fistula (AVF) of superficial temporal artery and vein. The 56-year-old man was admitted to the Department of Neurology because of a headache in the right temporal region with concomitant buzzing sound in his right ear. The pain was present mainly in the evenings and was stronger when touching the temporal region. He denied having any head injury in the last few years. There were no signs of central nervous system involvement in the neurological examination. Within the right temporal area a subcutaneous mass with redness of the surrounding skin and with palpable and audible pulsatile thrill was observed. In computed tomography (CT) of the head no abnormalities were found. In duplex-Doppler ultrasound examination of carotid arteries the systolic blood velocity in the right external carotid artery was over two times higher than in the left one. Its flow profile was turbulent and low-resistant. In CT angiography (CTA) an AVF between superficial temporal artery and vein was revealed — it was located at the level of the right zygomatic arch. In both CTA and magnetic resonance angiography, no abnormal connections between extra- and intracranial vessels were found. The patient underwent surgery with good result — all the symptoms disappeared. AVFs of vessels of the scalp are rare and their aetiology is mainly traumatic or iatrogenic. By describing this case we wanted to draw attention to less frequent causes of headache

Evaluation of Reduced-Graphene-Oxide Aligned with WO3-Nanorods as Support for Pt Nanoparticles during Oxygen Electroreduction in Acid Medium

Hybrid supports composed of chemically-reduced graphene-oxide-aligned with tungsten oxide nanowires are considered here as active carriers for dispersed platinum with an ultimate goal of producing improved catalysts for electroreduction of oxygen in acid medium. Here WO3 nanostructures are expected to be attached mainly to the edges of graphene thus making the hybrid structure not only highly porous but also capable of preventing graphene stacking and creating numerous sites for the deposition of Pt nanoparticles. Comparison has been made to the analogous systems utilizing neither reduced graphene oxide nor tungsten oxide component. By over-coating the reduced-graphene-oxide support with WO3 nanorods, the electrocatalytic activity of the system toward the reduction of oxygen in acid medium has been enhanced even at the low Pt loading of 30 microg cm-2. The RRDE data are consistent with decreased formation of hydrogen peroxide in the presence of WO3. Among important issues are such features of the oxide as porosity, large population of hydroxyl groups, high Broensted acidity, as well as fast electron transfers coupled to unimpeded proton displacements. The conclusions are supported with mechanistic and kinetic studies involving double-potential-step chronocoulometry as an alternative diagnostic tool to rotating ring-disk voltammetry.Comment: arXiv admin note: text overlap with arXiv:1805.0315