512 research outputs found
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
On the Feasibility of Carbon Nanotube Windings for Electrical Machines — Case Study for a Coreless Axial Flux Motor
The latest developments in carbon nanotube (CNT) wires and yarns attract great interest for potential application to electromagnetic devices, such as electrical machines and transformers. The CNT material properties are largely different from copper and aluminum in terms of electrical conductivity, mass density, and thermal transfer, creating a new design paradigm for which the traditional rules and device topologies no longer apply. This paper proposes a brushless permanent magnet multidisc axial flux construction with coreless stator and special windings and minimal rotor back iron, as a suitable topology for CNT winding application. Specific analytical closed-form sizing equations, as a function of winding electric conductivity, machine dimensions, and operating speed/frequency, are derived and employed in a systematic comparative study over a range of kW power ratings and speeds between 1,000 and 10,000 rpm. The numerical study is complemented by 3D and 2D electromagnetic FEA. The results show that the designs with CNT windings may have substantially higher specific power per mass, particularly at high rotational speeds and/or supply frequency, where the combined effect of DC and AC conduction losses in the windings is significant
Coreless Multidisc Axial Flux PM Machine with Carbon Nanotube Windings
Coreless axial flux permanent magnet (AFPM) machines are attracting increasing attention due to their compact structure and high torque density. The torque to weight ratio can be further enhanced by the use of alternate conductor materials, such as carbon nanotube (CNT), or aluminum windings in place of the copper material coils. This paper proposes a coreless AFPM synchronous motor with CNT windings. Analytical equations are developed to allow a systematic comparison of machine designs with different conductor materials. The performance of machine designs with different coil materials, namely, copper, aluminum, and CNT, is evaluated and compared. The calculations are also backed by 3-D finite-element analysis
The idealPosition System: Sebagai Solusi Pendukung Keputusan untuk Menentukan Pemain Bola yang Ideal Berdasarkan Posisi Pemain
In North Maluku, especially in Ternate, many football schools have been opened to train and find potential Indonesian National players. One of them has contributed to producing Indonesian National player candidates, namely Sekolah Sepak Bola (SSB) Tunas Gamalama. The problems that occur at this time at SSB Tunas Gamalama, managers and coaches are difficult to determine the ideal player to fill each position. Oftentimes, SSB Tunas Gamalama students choose a position according to their idol football players, and also because of the popularity of these positions. The tendency of SSB Tunas Gamalama students to be like this results in an imbalance of potential players in certain position. During this time the coach takes a long time and is often subjective in selecting players at every position available. In this research, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method was used as a method of decision support. This article aims to build a Decision Support System (DSS) in determining the ideal football player based on the player's position (The idealPosition System) using the TOPSIS method. This research produces DSS which can be used to determine the ideal soccer player based on the player's position
Development of instrumental analytical approaches based on the principles of biosensorics for control of quality of milk and milk products
High emission rate of sulfuric acid from Bezymianny volcano, Kamchatka
High concentrations of primary sulfuric acid (H2SO4) in fumarolic gases and high emission rate of sulfuric acid aerosol in the plume were measured at Bezymianny volcano, an active dome-growing andesitic volcano in central Kamchatka. Using direct sampling, filter pack sampling, and differential optical absorption spectroscopy measurements, we estimated an average emission of H2SO4 at 243 ± 75 t/d in addition to an average SO2 emission of 212 ± 65 t/d. The fumarolic gases of Bezymianny correspond to arc gases released by several magma bodies at different stages of degassing and contain 25-92% of entrained air. H2SO4 accounts for 6-87 mol% of the total sulfur content, 42.8 mol% on average, and SO2 is the rest. The high H2SO4 in Bezymianny fumaroles can be explained by catalytic oxidation of SO2 inside the volcanic dome. Because sulfate aerosol is impossible to measure remotely, the total sulfur content in a plume containing significant H2SO4 may be seriously underestimated
Radiofrequency Volumetric Thermal Ablation of Fibroids and Laparoscopic Myomectomy: Long-Term Follow-up From a Randomized Trial
Unlocking full and fast conversion in photocatalytic carbon dioxide reduction for applications in radio-carbonylation
Harvesting sunlight to drive carbon dioxide (CO2) valorisation represents an ideal concept to support a sustainable and carbon-neutral economy. While the photochemical reduction of CO2 to carbon monoxide (CO) has emerged as a hot research topic, the full CO2-to-CO conversion remains an often-overlooked criterion that prevents a productive and direct valorisation of CO into high-value-added chemicals. Herein, we report a photocatalytic process that unlocks full and fast CO2-to-CO conversion (<10 min) and its straightforward valorisation into human health related field of radiochemistry with carbon isotopes. Guided by reaction-model-based kinetic simulations to rationalize reaction optimisations, this manifold opens new opportunities for the direct access to 11C- and 14C-labeled pharmaceuticals from their primary isotopic sources [11C]CO2 and [14C]CO2
Analiza efectului clinic al aplicării unguentului „Argidină” efectuat în Centrul Republican de leziuni termice
Catedra Ortopedie - Traumatologie şi Сhirurgie în Campanie
a USMF "Nicolae Testemitanu”The analysis of obtained clinical results after application of ”Argidina” salve demonstrates its high efficacy in treatment of superficial and profound burns of reduced surfaces. The ”Argidina” salve diminishes the colonies of infection, the bandage is atraumatic, creates optimum conditions of wound regeneration in case of burns of II-IIIAB grade, of sectors of donor wounds
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