scholarly journals Granitoids of the Ergelyakh Intrusion-Related Gold–Bismuth Deposit (Kular-Nera Slate Belt, Northeast Russia): Petrology, Physicochemical Parameters of Formation, and Ore Potential

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 297 ◽  
Author(s):  
Albert I. Zaitsev ◽  
Valery Yu. Fridovsky ◽  
Maxim V. Kudrin
Keyword(s):  
Physicochemical Parameters ◽  
Chemical Compositions ◽  
Northeast Russia ◽  
Reducing Conditions ◽  
Long Time ◽  
Minor Intrusion ◽  
Significant Temperature ◽  
Arc Setting ◽  
Two Stages ◽  
Ore Potential

This paper describes features of petrographic and chemical compositions and isotopic dating of the Ergelyakh and Sokh plutons, located within the Kular-Nera slate belt, Verkhoyansk-Kolyma folded region (VKFR), Northeast Russia. Intrusion of the massifs took place approximately 145–150 million years ago. Different isotopic systems on the whole rock samples and mineral separates record at least two stages of later tectono-magmatic activity 130–120 and 110–100 million years ago. Granitoid magmas for the Ergelyakh and Sokh plutons were formed at high temperatures (950–1060 °C) within the amphibolitic lower crust of an island arc setting. The ages of crustal protoliths for granitoids of the Ergelyakh intrusion-related gold–bismuth deposit, calculated on Rb–Sr and Sm–Nd two-stage models, are 1109–1383 and 1199–1322 million years, respectively. Formation of the Ergelyakh and Sokh plutons took place within a significant temperature interval (<450 to 901 °C) and, with regard to the superposition of later events, lasted for a long time. During the cooling process of granitoid melts, at the time of biotite crystallization in both massifs, a significant increase of oxygen fugacity was registered. The ore potential of granitoids of both massifs seems to be similar, but due to some differences in the physicochemical parameters of their formation (redox conditions), it was partially realized only within the Ergelyakh massif with the generation of several minor intrusion-related gold–bismuth deposits. Granitoid melts of the Ergelyakh massif were formed in relatively heterogeneous and oxidizing conditions (∆Ni–NiO = +3.26 to –3.60). Granitoid melts for the Sokh massif (∆Ni–NiO = –2.88 to –9.27) were formed in reducing conditions.

OS CAMINHOS DAS ÁGUAS NO MUNICÍPIO DE CARIRÉ, CEARÁ, BRASIL

2019 ◽  
Vol 21 (2) ◽  
pp. 564-580
Author(s):  
Eloiza Rocha Queiroz ◽  
José Falcão Sobrinho
Keyword(s):  
Water Resources ◽  
Potable Water ◽  
Field Trips ◽  
Central Theme ◽  
Northeast Region ◽  
Brazilian Semiarid ◽  
Long Time ◽  
Short Rains ◽  
Two Stages

A região Nordeste do Brasil vem sendo alvo de medidas do Estado a mais de um século, na tentativa de solucionar o problema da falta de água em época de secas. O Estado do Ceará, por sua vez, apresenta boa parte de seu território inserido no semiárido brasileiro, uma região caracterizada pelo clima seco, com poucas chuvas e elevada evapotranspiração. A problemática da água existe há bastante tempo, principalmente o acesso em quantidade e qualidade suficientes para atender a população. O presente trabalho tem como tema central a questão dos recursos hídricos, com enfoque no abastecimento humano do município de Cariré, localizado na região noroeste do Ceará. Nosso objetivo consiste em apresentar um panorama de como atualmente a população carireense tem acesso à água potável. A metodologia adotada constitui-se em duas etapas: na primeira, realizamos levantamento de material bibliográfico e a segunda diz respeito a parte prática realizada em saídas a campo. Segundo a ONU, a água é um bem comum e que deve ser de acesso a todos, é um direito humano. Nesta perspectiva, o gerenciamento adequado dos recursos hídricos é essencial para a manutenção da qualidade de vida. Palavras-chave: Recursos Hídricos; Abastecimento Humano; Cariré-Ce. ABSTRACTThe pnortheast region from Brazil has been subject of measures for more than a century in attempts to solve the problems lack of water in dry season. The state of Ceará has a good part of its territorial inserted in Brazilian semiarid, a region characterized by dry climate, short rains and high evapotranspiration. The water issue has existed for a long time, mainly in a sufficient access of quantity and quality to serve the population. Then, this article has as a central theme the water resources focusing on water supply of the Cariré localized at Northeast region from Ceará. Therefore the purpose of the paper is to present a study about how the Carire’s population has had access to potable water currently. The methodology adopted to this research consists of two stages: Firstly it was carried out a survey of bibliographical material and secondly it concerned the practical part carried out in the field trips. In accordance to United nations, water is a commom good and it has to be available to everyone, it is a human rights. In that sense, the proper management of water resources is essential to keep the quality of life.Key-words: Human supply; Water resources; Cariré – Ce. RÉSUMÉLa région du nord-est du Brésil est la cible de mesures prises par l’État depuis plus d’un siècle pour tenter de résoudre le problème de la pénurie d’eau en saison sèche. L’État du Ceará, en revanche, présente une bonne partie de son territoire inséré dans le semi-aride brésilien, région caractérisée par un climat sec, avec peu de pluies et une forte évapotranspiration. Le problème de l'eau existe depuis longtemps, principalement l'accès en quantité et qualité suffisantes pour satisfaire la population. Le travail actuel a pour thème central la question des ressources en eau, en mettant l'accent sur l'approvisionnement humain de la municipalité de Cariré, située dans la région nord-ouest du Ceará. Notre objectif est de présenter un aperçu de la façon dont la population carioca a actuellement accès à l’eau potable. La méthodologie adoptée comporte deux étapes: dans le premier, nous procédons à une enquête sur le matériel bibliographique et le second à la partie pratique réalisée lors des visites sur le terrain. Selon l'ONU, l'eau est un bien commun et doit être accessible à tous, c'est un droit humain. Dans cette perspective, la gestion adéquate des ressources en eau est essentielle au maintien de la qualité de la vie.Mots-clés: Ressources en eau; Approvisionnement humain; Cariré-Ce.

scholarly journals Stress Relaxation Properties and Microscopic Deformation Structure in Bending of the C7025 and C7035 Alloy

2018 ◽  
Author(s):  
Xiangpeng Xiao ◽  
Hai Xu ◽  
Jian Huang ◽  
Junfeng Wang ◽  
Jianbo Zhang
Keyword(s):  
Stress Relaxation ◽  
Structural Changes ◽  
Relaxation Curve ◽  
Relaxation Properties ◽  
Limit Value ◽  
The Matrix ◽  
Long Time ◽  
Microscopic Deformation ◽  
Cantilever Bending ◽  
Two Stages

Stress relaxation tests in cantilever bending were performed on the C7025 and C7035 alloys at 298K and 393K，respectively. The effect of stress-relief treatments on stress relaxation properties was investigated. The structural changes associated with the stress relaxation process were examined using transmission electron microscope. The stress relaxation curve fits well to empirical formula &sigma;*=[Kˊln(t+&alpha;0)+C]-n for stress relaxation. The curves can be split into two stages. The stress relax quickly in the first stage, slows down in the second stage, and tends to be a certain limit value after a long time. The curve and microstructure reveals that the C7035 alloy has a lower rate of stress relaxation and a higher anti-stress relaxation capacity than the C7025. The first reason is that the movement of vacancies required by spinodal decomposition is inhibited, and the quantity of cobalt -containing vacancies decreases dramatically in the C7035 alloy. The other reason is that the precipitated phases became uniformly diffused in the C7035 alloy. The precipitate phase uniformly distributes in the grain boundaries and the matrix, during the relaxed condition, and thus the dislocations moving is blocked by the precipitates.

scholarly journals How do diamonds grow in metal melt together with silicate minerals? An experimental study of diamond morphology

2020 ◽  
Vol 32 (1) ◽  
pp. 41-55
Author(s):  
Aleksei Chepurov ◽  
Valery Sonin ◽  
Jean-Marie Dereppe ◽  
Egor Zhimulev ◽  
Anatoly Chepurov
Keyword(s):  
Natural Diamond ◽  
Diamond Growth ◽  
Chemical Compositions ◽  
Silicate Minerals ◽  
Metal Melt ◽  
Origin And Evolution ◽  
Metal Melts ◽  
Reducing Conditions ◽  
Diamond Crystallization ◽  
The Stability

Abstract. The origin and evolution of metal melts in the Earth's mantle and their role in the formation of diamond are the subject of active discussion. It is widely accepted that portions of metal melts in the form of pockets can be a suitable medium for diamond growth. This raises questions about the role of silicate minerals that form the walls of these pockets and are present in the volume of the metal melt during the growth of diamonds. The aim of the present work was to study the crystallization of diamond in a complex heterogeneous system: metal-melt–basalt–carbon. The experiments were performed using a multianvil high-pressure apparatus of split-sphere type (BARS) at a pressure of 5.5 GPa and a temperature of 1500 ∘C. The results demonstrated crystallization of diamond in metal melt together with garnet and clinopyroxene, whose chemical compositions are similar to those of eclogitic inclusions in natural diamond. We show that the presence of silicates in the crystallization medium does not reduce the chemical ability of metal melts to catalyze the conversion of graphite into diamond, and, morphologically, diamond crystallizes mainly in the form of a cuboctahedron. When the content of the silicate material in the system exceeds 5 wt %, diamond forms parallel-growth aggregates, but 15 wt % of silicate phases block the crystallization chamber, preventing the penetration of metallic melt into them, thus interrupting the growth of diamond. We infer that the studied mechanism of diamond crystallization can occur at lower-mantle conditions but could also have taken place in the ancient continental mantle of the Earth, under reducing conditions that allowed the stability of Fe–Ni melts.

scholarly journals Chemical Compositions of the Essential Oil Extracted from the Seeds of Garcina Kola, and Its Biological Activities

2021 ◽  
Vol 14 (2) ◽  
pp. 607-621
Author(s):  
Olagoke Zacchaeus Olatunde ◽  
Danian Tian ◽  
Jianping Yong ◽  
Canzhong Lu
Keyword(s):  
Essential Oil ◽  
Biological Activities ◽  
Chemical Compositions ◽  
Anticancer Activities ◽  
Potent Inhibition ◽  
Icp Ms ◽  
Hela Cell Lines ◽  
Long Time ◽  
Human Breast Carcinoma Cells

The essential oil was obtained from the seeds of Garcina kola and its compositions were investigated by GC-MS and ICP-MS, respectively. 74 organic compounds and 9 trace elements beneficial to human health were confirmed in this oil. Then, the in vitro antioxidant and anticancer activities were evaluated accordingly. The results showed that this essential oil exhibited stronger antioxidant activity against DPPH⸱ with the scavenging rate of 94.19% at 0.2 mg/mL, as well as potent inhibition against gastric cancer, lung cancer(A549) and Hela cell lines with the inhibitions of 96.397%±0.929, 98.005%±0.513 and 94.77±2.09 respectively at 8.3 mg/mL. While it exhibited moderate inhibition against the human breast carcinoma cells (MCF-7) with the inhibition of 59.257%±4.544 at 8.3mg/mL. In consideration of Garcina kola being consumed in Nigeria for a long time, this essential oil obtained from the Garcina kola can be used in the field of food, cosmetic or drugs.

The Microstructure of Quasicrystalline Al-Cu-Fe Alloys Doped with Tungsten

2013 ◽  
Vol 203-204 ◽  
pp. 372-375 ◽  
Author(s):  
Wojciech Gurdziel ◽  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz
Keyword(s):  
Electron Microscope ◽  
Induction Furnace ◽  
Alloy Composition ◽  
Solidification Process ◽  
Icosahedral Phase ◽  
Chemical Compositions ◽  
X Ray ◽  
Fe Alloys ◽  
Two Stages ◽  
Scanning Electron

The microstructure of Al65Cu20Fe14 (numbers indicate at.%) alloy doped with 1 at.% of W was studied. The selected alloy composition should allow to obtain the quasicrystalline icosahedral phase after solidification process. The bulk samples were obtained in two stages. At first, the synthesis of alloy through premelting of component elements in induction furnace and then, the directional solidification by the Bridgman method were performed. The morphology of selected areas of the samples were studied using Scanning Electron Microscope equipped with energy dispersive X-ray spectroscope, which was used to examine chemical compositions of each analysed areas. Additionally the X-ray powder diffraction was used to identify the phases present in the alloys. It was stated that the filaments of tungsten were present in the alloys. The filaments have thickness ranged from 0.01 to 2.5 μm. As a result of investigation, the arrangement of filaments in the material was determined.

Effect of refining process on physicochemical parameters, chemical compositions and in vitro antioxidant activities of rice bran oil

LWT ◽  
2019 ◽  
Vol 109 ◽  
pp. 26-32 ◽  
Author(s):  
Ruijie Liu ◽  
Ruru Liu ◽  
Longkai Shi ◽  
Zhiyan Zhang ◽  
Tao Zhang ◽  
...  
Keyword(s):  
Rice Bran ◽  
Physicochemical Parameters ◽  
Antioxidant Activities ◽  
Rice Bran Oil ◽  
Refining Process ◽  
Chemical Compositions

scholarly journals Au‐Ag‐S‐Se‐Cl‐Br Mineralization at the Corrida Deposit (Russia) and Physicochemical Conditions of Ore Formation

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 144
Author(s):  
Elena E. Kolova ◽  
Nataly E. Savva ◽  
Tatiana V. Zhuravkova ◽  
Anton N. Glukhov ◽  
Galina A. Palyanova
Keyword(s):  
Chemical Compositions ◽  
Chukchi Peninsula ◽  
Medium Temperature ◽  
Ore Formation ◽  
X Ray ◽  
Epithermal Deposits ◽  
Low Salt ◽  
Temperature Environment ◽  
Two Stages ◽  
Host Rocks

The mineral and chemical compositions of ores from the Corrida epithermal Au-Ag deposit (Chukchi Peninsula, Russia) were studied using the optical and scanning electron microscopy with X-ray energy-dispersion microanalysis. The deposit was formed at the time close to the period when the basic volume of acid magmas had been emplaced within the Okhotsk–Chukotka belt (84 to 80 Ma). The Au–Ag mineralization is distinguished with Au-Ag sulphides and selenides (uytenbogaardtite-fischesserite solid solution, Se-acanthite, S-naumannite) and Ag halides of the chlorargyrite-embolite-bromargyrite series. The ores were formed in two stages. Using microthermometric methods, it has been established that the ore-bearing quartz was formed in the medium-temperature environment (340–160 °C) with the participation of low-salt (3.55 to 0.18 wt.% NaCl eq.) hydrotherms, mostly of the NaCl composition with magnesium, iron and low-density СО2. According to our results of thermodynamic modeling at temperatures from 300 to 25 °C and data on mineral metasomatic alterations of the host rocks, the Au-Ag-S-Se-Cl-Br mineralization was formed at decreasing temperature and fugacity of sulphur (logƒS2 from −6 to −27), selenium (logƒSe2 from −14 to −35), and oxygen (logƒО2 from −36 to −62), with near-neutral solutions replaced by acid solutions. Analysis of the obtained data shows that the Corrida refers to the group of the LS-type epithermal deposits. This deposit is a new example of epithermal deposits with significant quantities of Au–Ag chalcogenides (acanthite, uytenbogaardtite, fischesserite, naumannite and others).

scholarly journals Photodynamic Therapy for the Treatment and Diagnosis of Cancer–A Review of the Current Clinical Status

2021 ◽  
Vol 9 ◽  
Author(s):  
Gurcan Gunaydin ◽  
M. Emre Gedik ◽  
Seylan Ayan
Keyword(s):  
Photodynamic Therapy ◽  
Side Effects ◽  
Clinical Status ◽  
Treatment Method ◽  
Clinical Applications ◽  
Response To Treatment ◽  
Photodynamic Diagnosis ◽  
Light Illumination ◽  
Long Time ◽  
Two Stages

Photodynamic therapy (PDT) has been used as an anti-tumor treatment method for a long time and photosensitizers (PS) can be used in various types of tumors. Originally, light is an effective tool that has been used in the treatment of diseases for ages. The effects of combination of specific dyes with light illumination was demonstrated at the beginning of 20th century and novel PDT approaches have been developed ever since. Main strategies of current studies are to reduce off-target effects and improve pharmacokinetic properties. Given the high interest and vast literature about the topic, approval of PDT as the first drug/device combination by the FDA should come as no surprise. PDT consists of two stages of treatment, combining light energy with a PS in order to destruct tumor cells after activation by light. In general, PDT has fewer side effects and toxicity than chemotherapy and/or radiotherapy. In addition to the purpose of treatment, several types of PSs can be used for diagnostic purposes for tumors. Such approaches are called photodynamic diagnosis (PDD). In this Review, we provide a general overview of the clinical applications of PDT in cancer, including the diagnostic and therapeutic approaches. Assessment of PDT therapeutic efficacy in the clinic will be discussed, since identifying predictors to determine the response to treatment is crucial. In addition, examples of PDT in various types of tumors will be discussed. Furthermore, combination of PDT with other therapy modalities such as chemotherapy, radiotherapy, surgery and immunotherapy will be emphasized, since such approaches seem to be promising in terms of enhancing effectiveness against tumor. The combination of PDT with other treatments may yield better results than by single treatments. Moreover, the utilization of lower doses in a combination therapy setting may cause less side effects and better results than single therapy. A better understanding of the effectiveness of PDT in a combination setting in the clinic as well as the optimization of such complex multimodal treatments may expand the clinical applications of PDT.

Chemical Durability of Copper Canisters Under Crystalline Bedrock Repository Conditions

1994 ◽  
Vol 353 ◽  
Author(s):  
Rolf Sjöblom ◽  
Hans-Peter Hermansson ◽  
Örjan Amcoff
Keyword(s):  
Copper Surface ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Near Surface ◽  
Crystalline Bedrock ◽  
Reducing Conditions ◽  
Bentonite Buffer ◽  
Long Time ◽  
The Stability ◽  
High Chloride

AbstractIn the Swedish waste management programme, the copper canister is expected to provide containment of the radionuclides for a very long time, perhaps millions of years. The purpose of the present paper, is to analyse prerequisites for assessments of corrosion lifetimes for copper canisters.The analysis is based on compilations of literature from the following areas: chemical literature on copper and copper corrosion, mineralogical literature with emphasis on the stability of copper in near surface environments, and chemical and mineralogical literature with emphasis on the stabilities and thermodynamics of species and phases that may exist in a repository environment.Three main types of situations are identified: (1) under oxidizing and low chloride conditions, passivating oxide type of layers may form on the copper surface; (2) under oxidizing and high chloride conditions, the species formed may all be dissolved; and (3) under reducing conditions, non-passivating sulfide type layers may form on the copper surface.Considerable variability and uncertainty exists regarding the chemical environment for the canister, especially in certain scenarios. Thus, the mechanisms for corrosion can be expected to differ greatly for different situations. The lifetime of a thick-walled copper canister subjected to general corrosion appears to be long for most reasonable chemistries. (It is assumed that the canister has no defects from manufacturing and that the bentonite buffer is intact). Localized corrosion may appear for types (1) and (3) above but the mechanisms are widely different in character. The penetration caused by localized corrosion can be expected to be very sensitive to details in the chemistry.

State of the Art Analysis of Device for “CPM” Rehabilitation of Wrist and Hand

2013 ◽  
Vol 459 ◽  
pp. 519-523
Author(s):  
Francesco Ragazzo
Keyword(s):  
State Of The Art ◽  
Physical Rehabilitation ◽  
The State ◽  
Continuous Passive Motion ◽  
Passive Motion ◽  
Rehabilitation Therapy ◽  
Future Developments ◽  
Long Time ◽  
Art Analysis ◽  
Two Stages

Human wrist and hand are easy to be injured. Physical rehabilitation therapy after a wrist or hand operation always takes a long time. A CPM machine is a mechanism based on the rehabilitation theory of continuous passive motion (CPM). It is properly applied during the first two stages of stiffness acts to pump blood and edema fluid away from the joint and periarticular tissues. CPM is thus effective in preventing the development of stiffness, if full motion is applied immediately following surgery. This paper shows the state of the art of modern devices used in CPM rehabilitation and, as a conclusion suggests future developments especially focusing the correct methods and exercises for CPM rehabilitation.

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