Synthesis and characterisation of nanocrystalline ZrN PVD coatings on AISI 430 stainless steel

The nanocrystalline films of zirconium nitride have been synthesized using ion-plasma vacuum-arc deposition technique in combination with high-frequency discharge (RF) on AISI 430 stainless steel at 150oC. Structure examinations X-ray fluorescent analysis (XRF), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) with microanalysis (EDS), and transmission electron microscopy (TEM), nanoidentation method – were performed to study phase and chemical composition, surface morphology, microstructure and nanohardness of coatings. The developed technology provided low-temperature coatings synthesis, minimized discharge breakdown decreasing formation of macroparticles (MPs) and allowed to deposit ZrN coatings with hardness variation 26.6…31.5 GPa. It was revealed that ZrN single-phase coatings of cubic modification with finecrystalline grains of 20 nm in size were formed

Poplar Forests of the Charysh, Biya and Katun Rivers, Altai Territory, Russia

На основе классификации растительности методом Браун-Бланке охарактеризованы тополевые (Populus laurifolia, Populus nigra) леса Чарыша, Бии и Катуни, распространенные в местах выхода этих рек с Алтайских гор на Предалтайскую равнину. Топольники среднего Чарыша, известные как ассоциация Populetum laurifolio-nigrae Taran (1997)2015, обследованы у сел Трусово (51°42'30'' с. ш., 82°29'10'' в. д.) и Озерки (51°48'07'' с. ш., 82°24'18'' в. д.), топольники нижней Бии (асс. Viburno opuli-Populetum laurifoliae Taran 1997) – у с. Стан-Бехтемир (52°36'40'' с. ш., 85°39'00'' в. д.), топольники нижней Катуни (субассоциация Equiseto hyemalis-Populetum nigrae violetosum irinae Taran 1997) – у с. Талица (52°23'36'' с. ш., 85°40'30'' в. д.). Детально охарактеризованы видовой состав, фитоценотическая структура и условия произрастания этих лесов. Дан обзор литературы по лесам c доминированием Populus laurifolia. Тополевые (Populus laurifolia, P. nigra) леса горных притоков Оби образуют союз Populion laurifolio-nigrae Taran 2015 (Salicetalia purpureae Moor 1958, Salicetea purpureae Moor 1958). Ареал союза – горные и предгорные отрезки речных пойм, пересекающих северный и западный макросклоны Алтайских гор, а также верхнее течение р. ТомиOn a base of Braun-Blanquet vegetation classification, natural poplar (Populus laurifolia, Populus nigra) forests of the Charysh, Biya and Katun Rivers are defined. The forests are located in areas where the rivers exit from the Altai Mountains to Prealtai plain. The middle Charysh poplar forests known as association Populetum laurifolio-nigrae Taran (1997)2015 were studied near Trusovo (51°42'30'' N, 82°29'10'' E) and Ozerki (51°48'07'' N, 82°24'18'' E) villages, the lower Biya ones (ass. Viburno opuli-Populetum laurifoliae Taran 1997) were studied near Stan-Bekhtemir village (52°36'40'' N, 85°39'00'' E), the lower Katun ones (subass. Equiseto hyemalis-Populetum nigrae violetosum irinae Taran 1997) were studied near Talitsa village (52°23'36'' N, 85°40'30'' E). The forests species composition, phytocenotic structure, and habitat conditions are detailed defined. The review of the literature about forests dominated by Populus laurifolia is given. Poplar (Populus laurifolia, P. nigra) forests of the Ob River mountain tributaries form alliance Populion laurifolio-nigrae Taran 2015 (Salicetalia purpureae Moor 1958, Salicetea purpureae Moor 1958). The alliance areal envelopes mountain and piedmont reaches of river floodplains located on the north and west macroslopes of the Altai Mountains and also the Tom River upper cours

Anti-corrosion ceramic coatings on the surface of Nd-Fe-B repelling magnets

The results of vacuum-arc deposition of thin ZrO₂coatings to protect the surface of Nd-Fe-B permanent magnets used as repelling devices in orthodontics are presented. The structure, phase composition and mechanical properties of zirconium dioxide films have been investigated by means of SEM, XRD, EDX, XRF and nanoindentation method. It was revealed the formation of polycrystalline ZrO₂ films of monoclinic modification with average grain size 25 nm. The influence of the ZrO₂ coating in terms of its barrier properties for corrosion in quasi-physiological 0.9 NaCl solution has been studied. Electrochemical measurements indicated good barrier properties of the coating on specimens in the physiological solution environment

Simultaneous Determination of Nitrite and Nitrate in Milk Samples by Ion Chromatography Method and Estimation of Dietary Intake

The presence of nitrate and nitrite in foods may be considered hazardous after ingestion in the gastrointestinal tract due to their reaction with naturally occurred secondary amines to form potentially carcinogenic nitrosamines. Due to this fact, a new method was developed in this study for the simultaneous determination of nitrite and nitrate in milk samples using by ion chromatography. Proposed mobile phase composed of sodium hydrogen carbonate and sodium carbonate (1.0 and 3.2 mmol/L) with a flow rate of 0.7 ml/min. The average recoveries for nitrate and nitrite were higher than 86 and 88, respectively. The limit of detection for nitrate and nitrite were 0.24 and 0.09 mg/L, respectively. The results of 102 real milk samples showed nitrate was found in all of the samples (100) with a mean of 34 ± 11 mg/L, while nitrite was found in none of the samples. The mean intake of nitrate in all age groups was lower than World Health Organization guideline. The present assessment concludes that the maximum contaminant level was equal to 82.8 mg/L nitrate. This method was fast, sensitive and accurate and is capable of being an alternative method in food control laboratories for investigation of nitrite and nitrate content. This is the first study of the determination and survey of nitrite and nitrate and exposure assessment of the Iranian population to nitrite and nitrate level in milk, which was widely used in infants and adolescents as one of the basic food components. Copyright © Taylor & Francis Group, LLC

Geochemistry of H2- and CH4-enriched hydrothermal fluids of Socorro Island, Revillagigedo Archipelago, Mexico. Evidence for serpentinization and abiogenic methane

Socorro Island is the exposed part of an approx. 4000-m-high volcanic edifice rising from the oceanic floor to approx. 1000 m asl at the northern part of the Mathematician Ridge, Western Pacific. The volcano is active, with the most recent basaltic eruption in 1993. Moderate fumarolic activity and diffuse degassing with a total CO2 flux of approx. 20 total day)1 are concentrated in the summit region of the volcano composed of a group of rhy- olite domes. Low-temperature, boiling point, fumaroles discharge gas with high H2 (up to 20 mol% in dry gas) and CH4 (up to 4 mol%). Both carbon and He isotopic ratios and abundances correspond to those in MORB flu- ids (d13CCO2 )5&; 3He ⁄ 4He = 7.6 Ra, CO2 ⁄ 3He = (2–3) · 109, where Ra is the atmospheric ratio 3He ⁄ 4He of 1.4 · 10)6. Light hydrocarbons (CH4, C2H6, C3H8, and C4H10) are characterized by a high C1 ⁄C2+ ratio of approx. 1000. Methane is enriched in 13C (d13CCH4 from )15 to )20&) and 2H (d2H from )80 to )120&), and hydrocarbons show an inverse isotopic trend in both d13C and d2H (ethane is isotopically lighter than methane). These isotopic and concentration features of light hydrocarbons are similar to those recently discovered in fluids from ultramafic-hosted spreading ridge vents and may be related to the serpentinization processes: H2 generation and reduction of CO2 to CH4 within high-temperature zone of volcano-seawater hydrothermal system hosted in basaltic and ultramafic rocks beneath a volcano edifice. The thermodynamic analysis of this unusual composition of the Socorro fluids and the assessment of endmember compositions are complicated by the near-surface cool- ing, condensation and mixing with meteoric water

Modified Pectoralis Major Tendon Transfer for Reanimation of Elbow Flexion as a Salvage Procedure in Complete Brachial Plexus Injury: A Case Report

Traumatic brachial plexus injuries rarely recover spontaneously and if the window period for neurotisation has elapsed, the only option for restoration of function lies in a salvage procedure. Many such salvage procedures have been described in the literature with variable functional results. We report the case of a 16-year-old boy who presented after unsuccessful treatment for a complete brachial plexus injury; we performed a pectoralis major tendon transfer to attain elbow flexion. Postoperatively, the elbow was splinted with flexion at 100°. After 4 weeks of immobilization the splint was removed and the patient could actively flex his elbow from 30° to 100°

Метилювання положення 8 піридинової частини молекули N-(бензил)-2-гідрокси-4-оксо-4Н-піридо[1,2-a]піримідин-3-карбоксамідів як спроба посилення їх аналгетичних властивостей

The chemical modification of the pyridine moiety of the molecule – displacement of the methyl group in position 8 of pyrido[1,2-a]pyrimidine nucleus has been considered as one of the possible versions to optimize the biological properties of N-(benzyl)-2-hydroxy-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxamides. The synthesis of the research targets was carried out by the reaction of the corresponding benzylamines and ethyl 2-hydroxy-8-methyl-4-oxo-4H-pyrido[1,2-a] pyrimidine-3-carboxylate, in its turn obtained by condensation of 2-amino-4-methylpyridine (i.e. the product with the methyl group in the intentionally required position) and triethyl methanetricarboxylate. The structure of the compounds obtained has been confirmed by the data of elemental analysis and NMR 1H spectroscopy, and in the case of optically active 1-phenylethylamides additionally by polarimetry. The study of the analgesic properties of all N-(benzyl)-2-hydroxy-8-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxamides was performed on the standard experimental “acetic acid writhing” model. At the same time, it has been found that our modification is accompanied with the increased biological activity of exclusively para-substituted derivatives. For profound research 4-fluorobenzylamide exceeding Piroxicam and Nabumetone by the level of the specific effect has been recommended as a potential new analgesic.В качестве одного из возможных вариантов оптимизации биологических свойств N-(бензил)-2-гидрокси-4-оксо-4Н-пиридо[1,2-a]пиримидин-3-карбоксамидов рассмотрена химическая модификация пиридиновой части их молекулы – перемещение метильной группы в положение 8 пиридо[1,2-a]пиримидинового ядра. Синтез целевых объектов исследования осуществлен реакцией соответствующих бензиламинов с этил-2-гидрокси-8-метил-4-оксо-4Н-пиридо[1,2-a]пиримидин-3-карбоксилатом, в свою очередь, полученным конденсацией 2-амино-4-метилпиридина (т. е. продукта с метильной группой в заведомо требуемом положении) с триэтилметантрикарбоксилатом. Строение синтезированных веществ подтверждено данными элементного анализа и спектроскопии 1Н ЯМР, а в случае оптически активных 1-фенилэтиламидов дополнительно еще и поляриметрически. Изучение анальгетических свойств всех N-(бензил)-2-гидрокси-8-метил-4-оксо-4Н-пиридо[1,2-a]пиримидин-3-карбоксамидов проведено на стандартной экспериментальной модели уксуснокислых корчей. При этом найдено, что предпринятая нами модификация сопровождается усилением биологической активности исключительно паразамещенных производных. Для углубленных испытаний в качестве нового потенциального анальгетика рекомендован 4-фторбензиламид, превосходящий по уровню специфического эффекта Пироксикам и Набуметон.Як один з можливих варіантів оптимізації біологічних властивостей N-(бензил)-2-гідрокси-4-оксо-4Н-піридо[1,2-a]піримідин-3-карбоксамідів розглянуто хімічну модифікацію піридинової частини їх молекули – переміщення метильної групи у положення 8 піридо[1,2-a]піримідинового ядра. Синтез цільових об’єктів дослідження здійснено реакцією відповідних бензиламінів з етил-2-гідрокси-8-метил-4-оксо-4Н-піридо[1,2-a]піримідин-3-карбоксилатом, у свою чергу, одержаним конденсацією 2-аміно-4-метилпіридину (тобто продукту з метильною групою в завідомо необхідному положенні) з триетилметантрикарбоксилатом. Будову синтезованих речовин підтверджено даними елементного аналізу та спектроскопії 1Н ЯМР, а у випадку оптично активних 1-фенілетиламідів додатково ще й поляриметрично. Вивчення аналгетичних властивостей усіх N-(бензил)-2-гідрокси-8-метил-4-оксо-4Н-піридо[1,2-a]піримідин-3-карбоксамідів проведено на стандартній експериментальній моделі оцтовокислих корчів. При цьому знайдено, що здійснена нами модифікація супроводжується посиленням біологічної активності виключно паразаміщених похідних. Для поглиблених випробовувань як новий потенційний аналгетик рекомен

RF-Magnetron sputtering of silicon carbide and silicon nitride films for solar cells

RF-magnetron nonreactive sputtering method from solid-phase target in argon atmosphere was used for obtaining thin silicon carbide and silicon nitride films, that are used for constructing solar cells based on substrates of single crystal silicon of p-typ