scholarly journals Understanding the Dependence of Nanoparticles Magnetothermal Properties on Their Size for Hyperthermia Applications: A Case Study for La-Sr Manganites

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1826
Author(s):  
Mylla C. Ferreira ◽  
Bruno Pimentel ◽  
Vivian Andrade ◽  
Vladimir Zverev ◽  
Radel R. Gimaev ◽  
...  
Keyword(s):  
Room Temperature ◽  
Blocking Temperature ◽  
Maximum Efficiency ◽  
Heating Process ◽  
Alternative Health ◽  
Heating Efficiency ◽  
Different Temperatures ◽  
Mean Size ◽  
The One

Magnetic oxides are promising materials for alternative health diagnoses and treatments. The aim of this work is to understand the dependence of the heating power with the nanoparticle (NP) mean size, for the manganite composition La0.75Sr0.25MnO3 (LSMO)—the one with maximum critical temperature for the whole La/Sr ratio of the series. We have prepared four different samples, each one annealed at different temperatures, in order to produce different mean NP sizes, ranging from 26 nm up to 106 nm. Magnetization measurements revealed a FC-ZFC irreversibility and from the coercive field as function of temperature we determined the blocking temperature. A phase diagram was delivered as a function of the NP mean size and, based on this, the heating mechanism understood. Small NPs (26 nm) is heated up within the paramagnetic range of temperature (T>Tc), and therefore provide low heating efficiency; while bigger NPs are heated up, from room temperature, within the magnetically blocked range of temperature (T<TB), and also provide a small heating efficiency. The main finding of this article is related with the heating process for NPs within the magnetically unblocked range of temperature (Tc>T>TB), for intermediate mean diameter size of 37 nm, with maximum efficiency of heat transfer.

High Temperature Properties of CoFe/CoNi and Fe/CoNi Biphase Microwires

2015 ◽  
Vol 233-234 ◽  
pp. 265-268 ◽  
Author(s):  
Irene Iglesias ◽  
Rhimou El Kammouni ◽  
Kseniay Chichay ◽  
Manuel Vazquez ◽  
Valeria Rodionova
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Amorphous Structure ◽  
Magnetic Behaviour ◽  
Heating Process ◽  
Saturation Magnetostriction ◽  
Magnetostriction Constant ◽  
Different Temperatures ◽  
Drawing Technique

The objective of this work has been to analyze the high-temperature behavior of magnetically single-and biphase microwires because of its interest from fundamental and applications viewpoints. Two alloy compositions with amorphous structure covered by glass have been prepared as magnetically single phase microwires by quenching & drawing technique: CoFe-based with near zero saturation magnetostriction constant and Fe-based with positive saturation magnetostriction constant. The same wires were used as the core for magnetically biphase microwires. Second CoNi phase was deposited by electroplating. Magnitudes as saturation magnetization and hysteresis parameters are determined in the temperature range from room temperature up to 1200 K. We proceed to a comparative analysis of their magnetic behaviour at different temperatures as well as after cooling down to room temperature. Information on the Curie temperature of different phases and on the influence of heating process on the magnetic properties is thus derived.

Influence of annealing temperature on optical, chemical and particle size properties of polyaniline nanomaterial

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Dhachanamoorthi N ◽  
Haripriya S
Keyword(s):  
Particle Size ◽  
Dominant Role ◽  
Oxidative Polymerization ◽  
Polymeric Materials ◽  
Electron Transition ◽  
Circuit Board ◽  
Heating Process ◽  
Particle Size Analyzer ◽  
Different Temperatures ◽  
Mean Size

Polyaniline is a representative conducting polymer because of its high electrical conductivity in doped state and it’s used in various fields of science and engineering because of its unique characteristics. Polymers are playing a dominant role in many areas such as material sciences, textile industries and chemical industries. Monomers of aniline are combined together to form a polymer of polyaniline by chemical oxidative polymerization method. The process of synthesis includes 1.5 M of aniline (C6H5N) as main reagent which causes chemical reaction, Sulfuric acid (H2SO4) as a dopant which alters its original electric and optical properties and Ammonium Peroxydisulfate (APS) as an oxidant which has the ability to oxidize and accept electrons. The synthesized nanoparticles are subjected to heating process at two different temperatures (200˚C and 400˚C). The prepared polymer material is characterized by UV-Visible Spectroscopy,Fourier Transform Infra-Red Spectroscopy, Particle Size Analyzer and antibacterial activity. The electron transition from ground state to excited state was revealed by UVVis Spectroscopy. Polymeric materials are identified using FTIR spectroscopy and it also exhibits the chemical bonds and structure of the sample. Particle Size Analyzer represents the mean size of the polyaniline sample. The overwhelming potential application of polyaniline includes manufacturing of circuit board, corrosion resistance, and fabrication of smart textiles.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

A CASE STUDY OF NL INFLUENCE IN UNIS FKIP ENGLISH DEPARTMENT STUDENTS' INTERLANGUAGE

2018 ◽  
Vol 18 (1) ◽  
pp. 46-54
Author(s):  
Irmala Sukendra ◽  
Agus Mulyana ◽  
Imam Sudarmaji
Keyword(s):  
Second Language ◽  
Second Language Acquisition ◽  
Native Speakers ◽  
Communicative Competence ◽  
Mother Tongue ◽  
Universal Grammar ◽  
Similar System ◽  
The One ◽  
L1 Acquisition

Regardless to the facts that English is being taught to Indonesian students starting from early age, many Indonesian thrive in learning English. They find it quite troublesome for some to acquire the language especially to the level of communicative competence. Although Krashen (1982:10) states that “language acquirers are not usually aware of the fact that they are acquiring language, but are only aware of the fact that they are using the language for communication”, second language acquisition has several obstacles for learners to face and yet the successfulness of mastering the language never surmounts to the one of the native speakers. Learners have never been able to acquire the language as any native speakers do. Mistakes are made and inter-language is unavoidable. McNeili in Ellis (1985, p. 44) mentions that “the mentalist views of L1 acquisition hypothesizes the process of acquisition consists of hypothesis-testing, by which means the grammar of the learner’s mother tongue is related to the principles of the ‘universal grammar’.” Thus this study intends to find out whether the students go through the phase of interlanguage in their attempt to acquire second language and whether their interlanguage forms similar system as postulated by linguists (Krashen).

Static and Dynamic Studies of Gasoline in View of its Octane Number and its Toxic Effect

2013 ◽  
Vol 12 (7) ◽  
pp. 451-459
Author(s):  
Ashraf Yehia El-Naggar ◽  
Mohamed A. Ebiad
Keyword(s):  
Toxic Effect ◽  
Aromatic Hydrocarbons ◽  
Octane Number ◽  
Liquid Fuel ◽  
Positive Impact ◽  
Hydrocarbon Composition ◽  
Different Temperatures ◽  
Different Seasons ◽  
The One ◽  
The Impact

Gasoline come primarily from petroleum cuts, it is the preferred liquid fuel in our lives. Two gasoline samples of octane numbers 91 and 95 from Saudi Arabia petrol stations were studied. This study was achieved at three different temperatures 20oC, 30oC and 50oC representing the change in temperatures of the different seasons of the year. Both the evaporated gases of light aromatic hydrocarbons (BTEX) of gasoline samples inside the tank were subjected to analyze qualitatively and quantitatively via capillary gas chromatography. The detailed hydrocarbon composition and the octane number of the studied gasoline samples were determined using detailed hydrocarbon analyzer. The idea of research is indicating the impact of light aromatic compounds in gasoline on the toxic effect of human and environment on the one hand, and on octane number of gasoline on the other hand. Although the value of octane number will be reduced but this will have a positive impact on the environment as a way to produce clean fuel.

Interrelationships between municipal spatial policy strategy and airport operation and development. Lodz Airport case study

2018 ◽  
Vol 59 (1) ◽  
pp. 65-79
Author(s):  
Katarzyna Nikorowicz-Zatorska
Keyword(s):  
Land Use ◽  
Urban Planning ◽  
Cultural Development ◽  
The Other ◽  
Local Authorities ◽  
Spatial Management ◽  
The One ◽  
Surrounding Areas

Abstract The present paper focuses on spatial management regulations in order to carry out investment in the field of airport facilities. The construction, upgrades, and maintenance of airports falls within the area of responsibility of local authorities. This task poses a great challenge in terms of organisation and finances. On the one hand, an active airport is a municipal landmark and drives local economic, social and cultural development, and on the other, the scale of investment often exceeds the capabilities of local authorities. The immediate environment of the airport determines its final use and prosperity. The objective of the paper is to review legislation that affects airports and the surrounding communities. The process of urban planning in Lodz and surrounding areas will be presented as a background to the problem of land use management in the vicinity of the airport. This paper seeks to address the following questions: if and how airports have affected urban planning in Lodz, does the land use around the airport prevent the development of Lodz Airport, and how has the situation changed over the time? It can be assumed that as a result of lack of experience, land resources and size of investments on one hand and legislative dissonance and peculiar practices on the other, aviation infrastructure in Lodz is designed to meet temporary needs and is characterised by achieving short-term goals. Cyclical problems are solved in an intermittent manner and involve all the municipal resources, so there’s little left to secure long-term investments.

A Series of Metal-Organic Frameworks for Selective CO2 Capture and Catalytic Oxidative Carboxylation of Olefins

2018 ◽  
Author(s):  
Huong T. D. Nguyen ◽  
Y B. N. Tran ◽  
Hung N. Nguyen ◽  
Tranh C. Nguyen ◽  
Felipe Gándara ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Adsorption ◽  
New Materials ◽  
One Pot ◽  
Acid Gas ◽  
Naphthalene Diimide ◽  
Styrene Carbonate ◽  
Metal Organic ◽  
Adsorption Of Co ◽  
The One

<p>Three novel lanthanide metal˗organic frameworks (Ln-MOFs), namely MOF-590, -591, and -592 were constructed from a naphthalene diimide tetracarboxylic acid. Gas adsorption measurements of MOF-591 and -592 revealed good adsorption of CO<sub>2</sub> (low pressure, at room temperature) and moderate CO<sub>2</sub> selectivity over N<sub>2</sub> and CH<sub>4</sub>. Accordingly, breakthrough measurements were performed on a representative MOF-592, in which the separation of CO<sub>2</sub> from binary mixture containing N<sub>2</sub> and CO<sub>2</sub> was demonstrated without any loss in performance over three consecutive cycles. Moreover, MOF-590, MOF-591, and MOF-592 exhibited catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO<sub>2</sub> under mild conditions (1 atm CO<sub>2</sub>, 80 °C, and solvent-free). Among the new materials, MOF-590 revealed a remarkable efficiency with exceptional conversion (96%), selectivity (95%), and yield (91%). </p><br>

De la gestión local a la gobernanza global: actores e interacciones multiniveles en la gestión del agua en la ciudad de México

2011 ◽  
Vol 1 (3) ◽  
pp. 34-66
Author(s):  
Joyce Valdovinos
Keyword(s):  
Private Sector ◽  
Water Governance ◽  
The State ◽  
Public Authorities ◽  
Service Contracts ◽  
Governance Model ◽  
Role Of The State ◽  
The One

The provision of water services has traditionally been considered a responsibility of the state. During the late 1980s, the private sector emerged as a key actor in the provision of public services. Mexico City was no exception to this trend and public authorities awarded service contracts to four private consortia in 1993. Through consideration of this case study, two main questions arise: First, why do public authorities establish partnerships with the private sector? Second, what are the implications of these partnerships for water governance? This article focuses, on the one hand, on the conceptual debate of water as a public and/or private good, while identifying new trends and strategies carried out by private operators. On the other hand, it analyzes the role of the state and its relationships with other actors through a governance model characterized by partnerships and multilevel networks.Spanish La provisión del servicio del agua ha sido tradicionalmente considerada como una responsabilidad del Estado. A finales de la década de 1980, el sector privado emerge como un actor clave en el suministro de servicios públicos. La ciudad de México no escapa a esta tendencia y en 1993 las autoridades públicas firman contratos de servicios con cuatro consorcios privados. A través de este estudio de caso, dos preguntas son planteadas: ¿Por qué las autoridades públicas establecen partenariados con el sector privado? ¿Cuáles son las implicaciones de dichos partenariados en la gobernanza del agua? Este artículo aborda por una parte, el debate conceptual del agua como bien público y/o privado, identificando nuevas tendencias y estrategias de los operadores privados. Por otra parte, se analizan el rol y las relaciones del Estado con otros actores a través de un modelo de gobernanza, definido en términos de partenariados y redes multi-niveles.French Les services de l'eau ont été traditionnellement considérés comme une responsabilité de l'État. À la fin des années 1980, le secteur privé est apparu comme un acteur clé dans la fourniture de certains services publics. La ville de Mexico n'a pas échappé à cette tendance et en 1993, les autorités publiques ont signé des contrats de services avec quatre consortiums privés. À travers cette étude de cas, nous nous interrogerons sur deux aspects : pourquoi les autorités publiques établissentelles des partenariats avec le secteur privé ? Quelles sont les implications de ces partenariats sur la gouvernance de l'eau ? Cet article s'intéresse, d'une part, au débat conceptuel sur l'eau en tant que bien public et/ou privé, en identifiant les tendances nouvelles et les stratégies menées par les opérateurs privés. D'autre part y sont analysés le rôle de l'État et ses relations avec d'autres acteurs à travers un modèle de gouvernance, défini en termes de partenariats, et des réseaux multi-niveaux.

Paranasal Sinus Mucocele Clinical, imagistic and biochemical aspects

2018 ◽  
Vol 69 (8) ◽  
Author(s):  
Doina Vesa ◽  
Cristian Martu ◽  
Razvan Leata ◽  
Ludmila Lozneanu ◽  
luminita Radulescu ◽  
...  
Keyword(s):  
Facial Asymmetry ◽  
Retrospective Case ◽  
Mri Scans ◽  
The One ◽  
Ethmoid Sinuses ◽  
Retrospective Case Study ◽  
Cellular Components ◽  
Ct And Mri

Paranasal mucoceles are a type of cysts that evolve slowly and are asymptomatic; this poses a difficulty in diagnosing the patient because the symptoms can go unnoticed. The mucocele evolves unpredictably. On the one hand, it can become infected turning into pyoceles and on the other hand, it can invade important regions such as the orbital, cranial or genian regions, creating facial asymmetry. This is a retrospective case study of 37 patients diagnosed with sinus mucoceles, followed up by clinical examination and paraclinical tests such as CT and MRI scans. The biochemical components of the liquid from within the mucocele were analyzed and the following criteria were recorded: NaCl-, Cl-, Na+ and cholesterine as well as cellular components such as mastocytes, macrophages, hematocytes and leucocytes. In all cases, the treatment option was surgery with favorable post-operative and follow-up evaluation. The mucoceles that appeared post-operatively (maxillary and ethmoid sinuses) evolved more rapidly than the mucoceles that were induced byan external injury. Longer follow-up of operated patients permitted a more timely diagnosis of recurrences.

A Study on the Rearrangement of Dialkyl 1-Aryl-1-hydroxymethylphosphonates to Benzyl Phosphates

2020 ◽  
Vol 24 (4) ◽  
pp. 465-471 ◽  
Author(s):  
Zita Rádai ◽  
Réka Szabó ◽  
Áron Szigetvári ◽  
Nóra Zsuzsa Kiss ◽  
Zoltán Mucsi ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Room Temperature ◽  
Phase Transfer ◽  
One Pot ◽  
Substrate Dependence ◽  
Triethylbenzylammonium Chloride ◽  
One Step ◽  
The Pudovik Reaction ◽  
The One ◽  
Solid Liquid

The phospha-Brook rearrangement of dialkyl 1-aryl-1-hydroxymethylphosphonates (HPs) to the corresponding benzyl phosphates (BPs) has been elaborated under solid-liquid phase transfer catalytic conditions. The best procedure involved the use of triethylbenzylammonium chloride as the catalyst and Cs2CO3 as the base in acetonitrile as the solvent at room temperature. The substrate dependence of the rearrangement has been studied, and the mechanism of the transformation under discussion was explored by quantum chemical calculations. The key intermediate is an oxaphosphirane. The one-pot version starting with the Pudovik reaction has also been developed. The conditions of this tandem transformation were the same, as those for the one-step HP→BP conversion.

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