On the identification of Ti-Ta-Nb-oxides in “wiikites” from Karelia

Purpose. With respect to the nature of Ti-Ta-Nb-oxides, which are included in the mineral associations that have historically gone by the now outdated name of “wiikites”, there is no unanimity of opinion. The main difficulty in identifying them is associated with the complexity of their chemical composition, their metamict structure and the substantial changes in their initial mineral form due to the effects of natural weathering. The aim of this work is the development of methodology to identify Ti-Ta-Nb-oxides corresponding to the mineral formulas AB2O6 and A2B2O7. Methods. The methodology developed in the work includes two experimental approaches: 1) electron probe microanalysis of phases revealed through use of the SEM-BSE method. Based on the resulting data, a hypothesis about the nature of the Ti-Ta-Nb-oxides in a number of wiikite samples is proposed. 2) XRD analysis of those phases that are formed in the course of thermal annealing of samples from 200 to 1000°C. Based on the resulting data here, the previous hypotheses are either accepted or rejected for each sample. Findings. Using this methodology, three “wiikite” samples were analyzed (the experimental codes were Wk-2, Wk-3 and Wk-7). The Ti-Ta-Nb-oxides in two of these wiikites (Wk-2 and Wk-3) were preliminarily determined to be hydroxyyttropyrochlore and hydroxycalciobetafite, respectively. In the third sample (Wk-7), the Ti-Ta-Nb-oxide was classified as polycrase. The results of XRD phase analysis of the annealed samples were compatible with the primary hypotheses that hydroxycalciobetafite and polycrase were the initial minerals in “wiikites” 3 and 7, respectively. Originality. The paper considers the issue of the chemical conditions necessary for the recovery of the original Ti-Ta-Nb-oxide during recrystallization of the metamict structures. This is a problem that has not been substantively addressed in the literature. Also for the first time experimentally proved the existence of the polycrase in “wiikites”. Practical implications. Completed work expands our knowledge of the mineral composition of the granitic pegmatites of the Baltic shield and the possibility of their use both for research purposes and for needs of national economy.Мета. Розробка методології ідентифікації Ti-Ta-Nb-оксидів складного хімічного складу з метаміктною структурою, що відповідають мінеральним формулами АВ2О6 та А2В2О7. Методика. Для розробки методології ідентифікації у роботі використано два експериментальних підходи: 1) рентген-спектральний мікроаналіз фаз, виявлених методом скануючої електронної мікроскопії зразків у назад відображених електронах. На основі отриманих результатів висунута гіпотеза щодо природи Ti-Ta-Nb-оксидів. 2) рентген-дифракційний аналіз фаз, що утворюються в процесі термічного відпалу зразків від 200 до 1000°С. На основі отриманих результатів для кожного зразка первинна гіпотеза приймалася або відкидалася. Результати. З використанням даної методики були вивчені три зразки “віікітів” (шифри зразків: Wk-2, Wk-3 і Wk-7). Наявність Ti-Ta-Nb-оксидів попередньо визначено e двох зразках (Wk-2 і Wk-3) відповідно, як гідроксііттропірохлор та гідроксікальціобетафіт. У третьому зразку (Wk-7) Ti-Ta-Nb діагностований як полікраз. Результати рентген-дифракційного аналізу відпалених зразків підтвердили гіпотези про те, що початковими мінералами у Wk-3 і Wk-7 були гідроксікальціобетафіт і полікраз відповідно. Наукова новизна. Визначено хімічні умови, необхідні для утворення початкового Тi-Ta-Nb під час рекристалізації метаміктної структури, що раніше не розглядалось у відповідній тематичній науковій літературі. Вперше експериментально виявлено присутність у “віікітах” полікраза. Практична значимість. Отримані результати розширюють й доповнюють знання щодо мінерального складу гранітних пегматитів Балтійського щита та надають можливість їх використання в дослідницьких цілях і потребах народного господарства.Цель. Разработка методологии идентификации Ti-Ta-Nb-оксидов сложного химического состава с метамиктной структурой, соответствующих минеральным формулам АВ2О6 и А2В2О7. Методика. Для разработки методологии идентификации в работе использовано два экспериментальных подхода: 1) рентген-спектральный микроанализ фаз, выявленных методом сканирующей электронной микроскопии образцов в обратно отраженных электронах. На основе полученных результатов выдвинута гипотеза о природе Ti-Ta-Nb-оксидов. 2) рентген-дифракционный анализ фаз, образующихся в процессе термического отжига образцов от 200 до 1000°С. На основе полученных результатов для каждого образца первоначальная гипотеза принималась или отвергалась. Результаты. С использованием данной методики были изучены три образца “виикитов” (шифры образцов: Wk-2, Wk-3 и Wk-7). Наличие Ti-Ta-Nb-оксидов предварительно определено в двух образцах (Wk-2 и Wk-3) соответственно, как гидроксииттропирохлор и гидроксикальциобетафит. В третьем образце (Wk-7) Ti-Ta-Nb диагностирован как поликраз. Результаты рентген-дифракционного анализа отожженных образцов подтвердили гипотезы о том, что первоначальными минералами в Wk-3 и Wk-7 были гидроксикальциобетафит и поликраз соответственно. Научная новизна. Определены химические условия, необходимые для образования первоначального Тi-Ta-Nb во время рекристаллизации метамиктной структуры, что ранее не рассматривалось в соответствующих тематических научных литературе. Впервые экспериментально выявлено присутствие в “виикитах” поликраза. Практическая значимость. Полученные результаты расширяют и дополняют знания о минеральном составе гранитных пегматитов Балтийского щита и дают возможности их использования в исследовательских целях и нуждах народного хозяйства.The study was conducted using equipment of the Center of X-ray Diffraction Studies and the Center for Microscopy and Microanalysis of the Research Park at Saint Petersburg State University, as well as the analytical laboratory of OJSC MMC Norilsk Nickel in Saint Petersburg

Peritoneal Potassium and pH Measurement in Early Diagnosis of Acute Mesenteric Ischemia in Rats

Background: In contemporary practice, acute mesenteric ischemia (AMI) remains a serious cause of morbidity and mortality in abdominal emergencies. Objectives: We report the measurement of peritoneal fluid potassium and pH on a small series of rats that developed extensive AMI following the surgical ligation of superior mesenteric vessels and compare the results with control groups. Materials and Methods: A total of 32 rats were used in our study. They were divided into four groups with eight rats in each one and received following treatments: group I (G-I), 60-minute controls; group II (G-II), 120-minute controls; group III (G-III), 60-minute cases; and group IV (G-IV), 120-minute cases. In case groups, the small bowel mesenteric root was double-ligated and an arrow single-lumen central venous catheter was passed through the skin to the peritoneum. In control groups, the catheter was placed without any intervention. Postoperatively, peritoneal lavage was performed at 60 (G-I, G-III) and 120 minutes (G-II, G-IV). Results: The mean peritoneal potassium values were 1.3 ± 0.3, 1.97 ± 1.06, 2.14 ± 0.89, and 3.28 ± 0.66 mmol/L in G-I, G-II, G-III, and G-IV, respectively. There were significant differences between G-III and G-IV (P = 0.002), between G-I and G-III (P = 0.024), and between G-II and G-IV (P = 0.001). The mean values of peritoneal fluid pH were 7.1 ± 0.26, 6.82 ± 0.22, 6.66 ± 0.16, and 6.78 ± 0.04 in G-I, G-II, G-III, and G-IV, respectively, which indicated significant differences between G-I and G-III (P = 0.001) and between G-II and G-IV (P = 0.018). There was a significant correlation between peritoneal fluid potassium and intestine ischemic grade (F = 4.77, P = 0.048) Conclusions: Our findings show that for early detection of bowel ischemia, an evaluation of intraperitoneal potassium and pH was useful and with prolongation of ischemia, potassium changes were more significant

Pediatric Elbow Fractures in a Major Trauma Center in Iran

Background: Elbow fractures are one of the most common traumatic fractures in the pediatric population. Since severe complications may occur, appropriate diagnosis and treatment are imperative when dealing with this type of fracture. Objectives: The aim of this study was to evaluate the epidemiology of elbow fracture in children admitted in Alzahra hospital, Isfahan, IR Iran over a one year period. Patients and Methods: During a one year period, a prospective study was conducted on 300 patients under the age of 16 who had sustained elbow fractures. Data included age, gender, mechanism of trauma, type of elbow fractures, complications, and outcomes. Results: The mean age of the patients was 8.1 ± 2.31 years old. Boys were injured 2.6 times more often than the girls. Falling was the major cause of pediatric elbow fractures (86%). Supra condylar were the most common type of fracture. There was a significant association between gender and type of injury (P < 0.01). Conclusions: Supracondylar fracture is the most common fracture type resulting from 4 - 8 year old boys’ falls. Our findings indicate the critical nature of appropriate treatment in order to prevent severe complications

Novel silver-doped NiTiO3: auto-combustion synthesis, characterization and photovoltaic measurements

Novel silver-doped nickel titanate nanoparticles (Ag-NiTiO3) were successfully prepared via a sol-gel method in the presence of stearyl alcohol as the capping agent and solvent. The formation of pure crystallized nickel titanate and silver-doped nickel titanate was occurred when the precursor was heat-treated at 700 °C in air for 150 and 60 min, respectively. The structural, morphological, and optical properties of obtained products were characterized by techniques such as X-ray diffraction (XRD), Fourier transforminfrared (FT-IR) spectroscopy, Energy dispersive X-ray microanalysis (EDX), ultraviolet-visible (UV-vis), and scanning electron microscopy (SEM). The magnetic property of the prepared Ag-NiTiO3 nanoparticles was also investigated with vibrating sample magnetometer (VSM). To fabricate a FTO/TiO2/Ag-NiTiO3/Pt-FTO solar cell, Ag-NiTiO3 film was directly deposited on top of the TiO2 prepared by electrophoresis deposition method. Furthermore, solar cell result indicates that an inexpensive solar cell could be developed by the synthesized Ag-NiTiO3 nanoparticles.Keywords: Ag-NiTiO3, sol-gel method, semiconductor, photovoltaic, dopin

A Comparison Between Foley and Nelatone Urinary Catheters in Causing Urinary Tract Infection in Animal Models

Background: Urinary catheterization is one of the main measures used to treat and care for hospitalized patients. Several complications have been attributed to the presence of latex with routine Foley catheters. Therefore, some studies have recommended that Nelatone catheters be substituted for the ordinary Foley catheters to prevent these complications. Objectives: This study aimed to compare the rates of urinary tract infection (UTI) in rabbits catheterized either with Foley or with Nelatone catheters. Materials and Methods: A randomized controlled trial was conducted on 60 rabbits that were randomly assigned to three groups of twenty. The first group was catheterized using Nelatone catheter; the second group was catheterized using Foley catheter and the third group was studied without performing any catheterization. After seven days, urine samples were collected using suprapubic aspiration and were sent to the laboratory for culture. Descriptive statistics were calculated. Moreover, chi-square and Fisher’s exact tests were used for data analysis. Results: At the end of the study, four 4 cases in the Nelatone group and 12 cases in the Foley group presented with UTI (P = 0.01). No positive urine cultures were found in the control group. Conclusions: The Nelatone catheters, compared with the Foley ones, had a lower risk of UTI in the long term use. Verifying this claim by further studies can have an important role in reducing UTIs in patients using urinary catheters

A comparative study of proximate composition of Artemia urmiana enriched with different sources and levels of HUFA

The nutritional quality of commercially available Artemia strains is relatively poor in Eicosapentaenoic acid (EPA), Arachidonic acid (ARA) and especially Docosahexaenoic acid (DHA). Hence, it is essential and common practice to enrich this live prey with emulsions of special oils. One commercial ICES30/4 (Belgium), Linseed oil as a vegetable oil, Cod liver oil and Sturgeon ovary oil as two animal oils with EPA amounts in these oils were 6.29, 0.03, 11.39, 7.55 and the DHA amounts were 20.90, 0.00, 7.64, 2.76 respectively with three concentrations (100, 200 and 300ppm) during two enrichment periods (12 and 24h) were tested in order to improve the HUFA content, the DHA/EPA ratio and ARA content of Artemia urmiana nauplii. The results showed that Artemia enriched with different levels of vegetable oil and enrichment periods was poor in relation to either HUFA content or DHA/EPA ratio but the fish oils and emulsion resulted in HUFA incorporation. Sturgeon ovary oil caused the poorest DHA/EPA ratio enrichment (0.40 in 300ppm-24h) but the commercial emulsion (ICES30/4) was found as the best for DHA/EPA ratio enrichment (1.20 in 300 ppm- 24h). Cod liver oil (0.53 in 100ppm-24h) can be a good internal source substitute for improving the DHA/EPA ratio enrichment compared to ICES30/4 due to price and availability. As a result, HUFA content was increased with enrichment level 200ppm during 24h. Also, all oil sources improved lipid and protein percentages in A. urmiana nauplii

Using online image processing technique for measurement the browning in banana during drying (a new and automatic method)

Determination and controlling of quality parameters can be useful for ordering and marketing of fruits. &nbsp;Color is the first and the most important parameter in the visual appearance of fruits, specifically in banana. &nbsp;The aim of this study is to use image-processing technique (online operation) to measure and analyze the color change of banana slices during thin layer drying. &nbsp;Using online-image-processing technique resulted in designing a machine vision system to control the color change of products automatically. &nbsp;The results show a linear relation with high correlation coefficient for L*, a* and b* (0.967, 0.962 and 0.991 respectively) between the data of the image-processing technique and the hold-hand colorimeter. &nbsp;In this study, parameters of chroma, hue and browning index were determined to describe the kinetics of color change in banana slices. &nbsp;The change of chroma was not significant, but hue was decreased and browning index was increased during drying time. &nbsp;In addition, the experimental data of the L* and ∆E was fitted using zero and first order models with high correlation coefficient (0.80-0.97). &nbsp; Keywords: image processing, machine vision, online, banan

Evaluation of the Safe Ischemic Time of Clamping During Intermittent Pringles Maneuver in Rabbits

Background: The liver is the most commonly injured organ in blunt abdominal trauma. Although major hepatic bleeding may be partially controlled with portal triade clamping (the Pringle’s maneuver), continuous prolonged clamping results in liver ischemia. Objectives: The purpose of this study was to determine the safe time of Pringle maneuver based on pathologic changes of liver in rabbit models. Materials and Methods: In an experimental study, 20 New-Zealand white rabbits were selected. In laparotomy, a blunt dissector was passed through the foramen of Winslow and the hepato-duodenal ligament encircled with an umbilical tape. En masse Pringle maneuver was performed using atraumatic flexible clamps. Rabbits were divided into four groups based on Pringle maneuver time (30 minutes, 45 minutes, 60 minutes, and 75 minutes). A hepatic biopsy was performed at the beginning of operation. The degree of tissue injury was evaluated using blood markers. Results: There were five rabbits in each group. At the end of 60 minutes ischemia, only minor alterations were observed in pathological specimens. At the end of 75 minutes, hepatocyte damage and necrosis were observed. The serum levels of alanine aminotransferase (Group A: P = 0.02; Group B: P = 0.01; Group C: P = 0.0002; Group D: P = 0.01) and Aspartate aminotransferase (Group A: P = 0.03; Group B: P = 0.002; Group C: P = 0.0004; Group D: P = 0.0003) were significantly increased post-operatively. The maximum level was in the first day after operation. Conclusions: Continuous portal triade clamping (the Pringle maneuver) during liver ischemia (30 and 45 minutes) in rabbits resulted in no ischemic change. Increasing time of clamping to 30 minutes was safe in intermittent Pringle maneuver

Effect of substrate grain size on structural and corrosion properties of electrodeposited nickel layer protected with self-assembled film of stearic acid

In the present study, the impact of copper substrate grain size on the structure of the succeeding electrodeposited nickel film and its consequent corrosion resistance in 3.5% NaCl medium were evaluated before and after functionalization with stearic acid. Nickel layers were electrodeposited on two different copper sheets with average grain size of 12 and 25 \u3bcm, followed by deposition of stearic acid film through self-assembly. X-ray diffraction analysis of the electrodeposited nickel films revealed that the deposition of nickel film on the Cu substrate with small (12 \u3bcm) and large (25 \u3bcm) grains is predominantly governed by growth in the (220) and (111) planes, respectively. Both electrodeposited films initially exhibited a hydrophilic nature, with water-contact angles of 56\ub0 and <10\ub0, respectively. After functionalization with stearic acid, superhydrophobic films with contact angles of ~150\ub0 were obtained on both samples. In a 3.5% NaCl medium, the corrosion resistance of the nickel layer electrodeposited on the copper substrate with 25 \u3bcm grains was three times greater than that deposited on the copper substrate with 12 \u3bcm grains. After functionalization, the corrosion resistance of both films was greatly improved in both short and long immersion times in 3.5% NaCl medium

Insights into galvanic corrosion behavior of Ti-Cu dissimilar joint: Effect of microstructure and volta potential

The effect of microstructure on corrosion behavior of a solid-state explosion welded Ti-Cu bimetal is investigated by means of alternating current-direct current (AC-DC) electrochemical measurements, optical microscopy, scanning electron microscopy, and scanning Kelvin probe force microscopy (SKPFM). The results indicate that the titanium regions in the welding interface, local melted zone (LMZ), and LMZ-Cu interface are potential sites for initiation of corrosion attacks. SKPFM mapping clearly shows that before exposure of the sample to a 3.5% NaCl corrosive solution and at the beginning of the exposure, the Cu side of the bimetal has a higher Volta potential in comparison to that of the Ti region, and thus acts as a cathode. Electrochemical measurements also confirm that titanium acts as an anode and copper as a cathode, in the first moments of immersion, in accordance with macroscopic observations and SKPFM results. However, by growing a passive layer of titanium oxide and titanium hydroxide on the Ti side after about 1 h exposure to the corrosive medium, the titanium side becomes nobler and the polarity arrangement in the galvanic couple reverses