Search results for: oxygen deficient clusters

Authors: J. Barilla, M. Lokajíček, H. Pisaková, P. Simr

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The final biological effect of ionizing particles may be influenced strongly by some chemical substances present in cells mainly in the case of low-LET radiation. The influence of oxygen may be particularly important because oxygen is always present in living cells. The corresponding processes are then running mainly in the chemical stage of radio biological mechanism. The radical clusters formed by densely ionizing ends of primary or secondary charged particles are mainly responsible for final biological effect. The damage effect depends then on radical concentration at a time when the cluster meets a DNA molecule. It may be strongly influenced by oxygen present in a cell as oxygen may act in different directions: at small concentration of it the interaction with hydrogen radicals prevails while at higher concentrations additional efficient oxygen radicals may be formed. The basic radical concentration in individual clusters diminishes, which is influenced by two parallel processes: chemical reactions and diffusion of corresponding clusters. The given simultaneous evolution may be modeled and analyzed well with the help of Continuous Petri nets. The influence of other substances present in cells during irradiation may be studied, too. Some results concerning the impact of oxygen content will be presented.

Keywords: radiobiological mechanism, chemical phase, DSB formation, Petri nets

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Authors: Shuwen Wu, Zhi LI

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Atomically dispersed Fe‒N₄ catalysts are proven as promising alternatives to commercial Pt/C for the oxygen reduction reaction. Most reported Fe‒N₄ catalysts suffer from inferior O‒O bond-breaking capability due to superoxo-like O₂ adsorption, though the isolated dual-atomic metal sites strategy is extensively adopted. Atomic Fe clusters hold greater promise for promoting O‒O bond cleavage by forming peroxo-like O₂ adsorption. However, the excessively strong binding strength between Fe clusters and oxygenated intermediates sacrifices the activity. Here, we first report a Fex/Cu‒N@CF catalyst with atomic Fe clusters functionalized by adjacent single Cu‒N₄ sites anchoring on a porous carbon nanofiber membrane. The theoretical calculation indicates that the single Cu‒N₄ sites can modulate the electronic configuration of Fe clusters to reduce O₂* protonation reaction free energy, which ultimately enhances the electrocatalytic performance. Particularly, the Cu‒N₄ sites can increase the overlaps between the d orbitals of Fe and p orbitals of O to accelerate O‒O cleavage in OOH*. As a result, this unique atomic catalyst exhibits a half potential (E1/2) of 0.944 V in an alkaline medium exceeding that of commercial Pt/C, whereas acidic performance E1/2 = 0.815 V is comparable to Pt/C. This work shows the great potential of single atoms for improvements in atomic cluster catalysts.

Keywords: Hierarchical porous fibers, atomic Fe clusters, Cu single atoms, oxygen reduction reaction; O-O bond cleavage

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Authors: Ashna Babu, Deepshikha Jaiswal Nagar

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Cuprate high-temperature superconductors (HTSCs) have been immensely studied during the past few decades because of their structure which is described as a superlattice of superconducting CuO₂ layers. In particular, YBa₂Cu₃O₆₊δ (YBCO), with its critical temperature of 93 K, has received the most attention due to its well-defined metal stoichiometry and variable oxygen content that determines the carrier doping level. Substitution of metal ions at the Cu site is known to increase the critical current density without destroying superconductivity in YBCO. The construction of vortex phase diagrams is very important for such doped YBCO materials both from a fundamental perspective as well as from a technological perspective. By measuring field-dependent magnetization on annealed single crystals of Al-doped YBCO, YBa₂Cu₃₋ₓAlₓO₆₊δ (Al-YBCO), we were able to observe a second magnetization peak anomaly (SMP) in a very large part of the phase diagram. We were also able to observe the SMP anomaly in temperature-dependent magnetization measurements, the first observation to our knowledge. Critical current densities were calculated using Bean’s critical state model, flux jumps associated with symmetry reorientation of vortex lattice were studied, the oxygen cluster distribution was also analysed, and by incorporating all observations, we made a vortex phase diagram for oxygenated Al-YBCO single crystal.

Keywords: oxygen deficient clusters, second magnetization peak anomaly, flux jumps, vortex phase diagram

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Authors: Samuel Mejorado

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C. Reinahrdtii serves as one of the most promising organisms from which to obtain biological hydrogen. However, its production catalyst, [FeFe]-hydrogenase, is largely inhibited by the presence of oxygen. In recent years, researchers have identified a Proton Gradient Regulation 5 (PGR5) deficient mutant, which shows enhanced respiration and lower accumulations of oxygen within the system. In this research, we investigated the effects of varying nutrient conditions on PGR5 mutants' ability to produce hydrogen. After growing PGR5 mutants in varying nutrient conditions under 55W fluorescent lamps at 30℃ with constant stirring at 200 rpm, a common water displacement method was utilized to obtain a definitive volumetric reading of hydrogen produced by these mutants over a period of 12 days. After the trials, statistical t-tests and ANOVAs were performed to better determine the effect which nutrient conditions have on PGR5 mutants' ability to produce hydrogen. In this, we report that conditions of sulfur deprivation most optimally enhanced hydrogen production within these mutants, with groups grown under these conditions demonstrating the highest production capacity over the entire 12-day period. Similarly, it was found that when grown under conditions of nitrogen deprivation, a favorable shift towards carbon fixation and overall lipid/starch metabolism was observed. Overall, these results demonstrate that PGR5-deficient mutants stand as a promising source of biohydrogen when grown under conditions of sulfur deprivation. To date, photochemical characteristics of [FeFe]-hydrogenase in these mutants have yet to be investigated under conditions of sulfur deprivation.

Keywords: biofuel, biohydrogen, [FeFe]-hydrogenase, algal biofuel

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Authors: Musa Alhassan, Alhaji Mohammed Mustapha

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Review of studies carried out on the use of bagasse ash in the improvement of deficient soils in Nigeria, with emphasis on lateritic and black cotton soils is presented. Although, the bagasse ash is mostly used as additive to the conventional soil stabilizer (cement and lime), the studies generally showed improvement of geotechnical properties of the soils either modified or stabilized with the ash. This showed the potentials of using this agricultural waste (bagasse ash) in the improvement of geotechnical properties of deficient soils. Thus suggesting that using this material at large scale level, in geotechnical engineering practice could help in the provision of stable and durable structures, reduce cost of soil improvement and also reduces environmental nuisance caused by the unused waste in Nigeria

Keywords: bagasse ash, black cotton soil, deficient soil, laterite, soil improvement

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Authors: Pil Seong Park

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Homemade HPC clusters are widely used in many small labs, because they are easy to build and cost-effective. Even though incremental growth is an advantage of clusters, it results in heterogeneous systems anyhow. Instead of adding new nodes to the cluster, we can extend clusters to include some other Internet servers working independently on the same LAN, so that we can make use of their idle times, especially during the night. However extension across a firewall raises some security problems with NFS. In this paper, we propose a method to solve such a problem using SSH tunneling, and suggest a modified structure of the cluster that implements it.

Keywords: extension of HPC clusters, security, NFS, SSH tunneling

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Authors: Ahmad N. Shuid, Azri Jalil, Sabarul A. Mokhtar, Mohd F. Khamis, Norliza Muhammad

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Micro-CT provides a 3-D image of fracture callus, which can be used to calculate quantitative parameters. In this study, micro-CT was used to assess the fracture healing of orchidectomised rats, an androgen-deficient osteoporosis model. The effect of testosterone (hormone replacement) on fracture healing was also assessed with micro-CT. The rats were grouped into orchidectomised-control (ORX), sham-operated (SHAM), and orchidectomised; and injected with testosterone intramuscularly once weekly (TEN). Treatment duration was six weeks. The fracture was induced and fixed with plates and screws in the right tibia of all the rats. An in vitro micro-CT was used to scan the fracture callus area which consisted of 100 axial slices above and below fracture line. The analysis has shown that micro-CT was able to detect a significant difference in the fracture healing rate of ORX and TEN groups. In conclusion, micro-CT can be used to assess fracture healing in androgen-deficient osteoporosis. This imaging tool can be used to test agents that influence fracture healing in the androgen-deficient model.

Keywords: androgen, fracture, orchidectomy, osteoporosis

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Authors: Robin Singh, Mayank Nautiyal, Priyank Jain, Vatasta Koul, Vaibhav Sharma

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The curiosity to investigate the space and its mysteries was dependably the main impetus of human interest, as the particle of livings exists from the "debut de l'Univers" (beginning of the Universe) typified with its few other living things. The sharp drive to uncover the secrets of stars and their unusual deportment was dependably an ignitor of stars investigation. As humankind lives in civilizations and states, stars likewise live in provinces named ‘clusters’. Clusters are separates into 2 composes i.e. open clusters and globular clusters. An open cluster is a gathering of thousand stars that were moulded from a comparable goliath sub-nuclear cloud and for the most part; contain Propulsion I (extremely metal-rich) and Propulsion II (mild metal-rich), where globular clusters are around gathering of more than thirty thousand stars that circles a galactic focus and basically contain Propulsion III (to a great degree metal-poor) stars. Futurology of this paper lies in the spectroscopic investigation of globular clusters like M92 and NGC419 and open clusters like M34 and IC2391 in different color bands by using software like VIREO virtual observatory, Aladin, CMUNIWIN, and MS-Excel. Assessing the outcome Hertzsprung-Russel (HR) diagram with exemplary cosmological models like Einstein model, De Sitter and Planck survey demonstrate for a superior age estimation of respective clusters. Colour-Magnitude Diagram of these clusters was obtained by photometric analysis in g and r bands which further transformed into BV bands which will unravel the idea of stars exhibit in the individual clusters.

Keywords: color magnitude diagram, globular clusters, open clusters, Einstein model

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Authors: W. Fatmi, F. Kriba, Z. Kechrid

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The aim of this study was to investigate the effect of vitamin C on blood biochemical parameters, tissue zinc, and antioxidants enzymes in diabetic rats fed a zinc-deficient diet. For that purpose, Alloxan-induced diabetic rats were divided into four groups. The first group was fed a zinc-sufficient diet while the second group was fed a zinc-deficient diet. The third and fourth groups received zinc-sufficient or zinc-deficient diets plus oral vitamin C (1mg/l) for 27 days. Body weight and food intake were recorded regularly during 27 days. On day 28, animals were killed and glucose, total lipids, triglycerides, protein, urea, serum zinc , tissues zinc concentrations, liver glycogen, GSH, TBARS concentrations and serum GOT, GPT, ALP and LDH, liver GSH-Px, GST and Catalase activities were determined. Body weight gain and food intake of zinc deficient diabetic animals at the end of experimental period was significantly lower than that of zinc adequate diabetic animals. Dietary zinc intake significantly increased glucose, lipids, triglycerides, urea, and liver TBARS levels of zinc deficient diabetic rats. In contrast, serum zinc, tissues zinc, protein, liver glycogen and GSH levels were decreased. The consumption of zinc deficient diet led also to an increase in serum GOT, GPT and liver GST accompanied with a decrease in serum ALP, LDH and liver GSH-Px, CAT activities. Meanwhile, vitamin C treatment was ameliorated all the previous parameters approximately to their normal levels. Vitamin C supplementation presumably acting as an antioxidant, and it probably led to an improvement of insulin activity, which significantly reduced the severity of zinc deficiency in diabetes.

Keywords: antioxidant, experimental diabetes, liver enzymes, vitamin c, zinc deficiency

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Authors: S. K. Pyne, M. Mondal, G. Samanta

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A survey was carried out in red lateritic zone of West Bengal to compare the mineral status in plasma of livestock grazing over red lateritic region. Sufficient number of samples of soil, feeds, fodder and blood were collected from four districts of red lateritic zone namely, West Midnapore, Birbhum, Bankura and Purulia respectively. The samples were analysed for Calcium (Ca), Phosphorus (P), Copper (Cu), Zinc (Zn), Manganese (Mn) and Iron (Fe). Concentration of Cu, Mn and Fe in soil were above the minimum critical level, whereas, Zn deficiency is wide spread in red lateritic soil. Paddy straw is deficient in Ca, P, Zn and Mn in the region. Green fodders are also deficient in P, Cu, Zn. The richness of iron (Fe) in soil, feeds, fodder and tree leaves is the characteristics of this region. Phosphorus is deficient in plasma of all categories of livestock with the exception of bullock. Cu is deficient in plasma of calf. Plasma Mn and Fe were higher (p<0.01) in the animals of red lateritic zone. The study reveals that the overall deficiency of phosphorus in different categories of livestock and there is need of dietary supplementation.

Keywords: mineral, red lateritic zone, grazing livestock, plasma

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Authors: Imèn Khanchouch, Malika Charrad, Mohamed Limam

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The interpretation of the quality of clusters and the determination of the optimal number of clusters is still a crucial problem in clustering. We focus in this paper on multi-SOM clustering method which overcomes the problem of extracting the number of clusters from the SOM map through the use of a clustering validity index. We then tested multi-SOM using real and artificial data sets with different evaluation criteria not used previously such as Davies Bouldin index, Dunn index and silhouette index. The developed multi-SOM algorithm is compared to k-means and Birch methods. Results show that it is more efficient than classical clustering methods.

Keywords: clustering, SOM, multi-SOM, DB index, Dunn index, silhouette index

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Authors: Muhammad Habib, Xuefan Zhou, Lin Tang, Guoliang Xue, Fazli Akram, Dou Zhang

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Defect engineering approach is a well-established approach for the customization of functional properties of perovskite ceramics. In modern technology, the high multiferroic properties for elevated temperature applications are greatly demanding. In this work, the Bi-nonstoichiometric lead-free 0.67Biy-xSmxFeO3-0.33BaTiO3 ceramics (Sm-doped BF-BT for Bi-excess; y = 1.03 and Bi-deficient; y = 0.975 with x = 0.00, 0.04 and 0.08) were design for the high-temperature multiferroic property. Enhanced piezoelectric (d33  250 pC/N and d33* 350 pm/V) and magnetic properties (Mr  0.25 emu/g) with a high Curie temperature (TC  465 ℃) were obtained in the Bi-deficient pure BF-BT ceramics. With Sm-doping (x = 0.04), the TC decrease to 350 ℃ a significant improvement occurred in the d33* to 504 pm/V and 450 pm/V for Bi-excess and Bi-deficient compositions, respectively. The structural origin of the enhanced piezoelectric strain performance is related to the soft ferroelectric effect by Sm-doping and reversible phase transition from the short-range relaxor ferroelectric state to the long-range order under the applied electric field. However, a slight change occurs in the Mr 0.28 emu/g value with Sm-doping for Bi-deficient ceramics, whereas the Bi-excess ceramics shows completely paramagnetic behavior. Hence, the origin of high magnetic properties in the Bi-deficient BF-BT ceramics is mainly attributed to the proposed double exchange mechanism. We believe that this strategy will provide a new perspective for the development of lead-free multiferroic ceramics for high-temperature applications.

Keywords: BiFeO3-BaTiO3, lead-free piezoceramics, magnetic properties, defect engineering

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Authors: Ramin Amirmardfar

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Throughout Necessary oxygen should be supplied for all cells of a mammal at any moment through blood to make it possible remain alive all cells the mammal’s body. In case a mammal’s bulk is large, there is a farther distance between cells in different tissues and mammals’ heart. Therefore red blood cells in bulky mammal’s body should be capable of conveying oxygen to farther distances. To make it practical, oxygen should be glued red blood cells tenaciously. In other words, cohesion strength of oxygen to red blood cell of bulky mammal’s blood should be much more than the same of small mammal’s blood. In mammal’s bodies, the controlling factor of amount of cohesion of oxygen to red blood cell, are organic phosphates (like DPG). The less DPG in red blood cells of a mammal, the more cohesion of oxygen to red blood cell (at the same rate). As much as oxygen is glued more tenacious to red blood cells, oxygen could been carried to farther distance and as much as oxygen could be conveyed to farther points of heart, bulk of mammal could be larger at the same rate.

Keywords: mammals size, animals size, organic phosphates, DPG, red blood cell, metabolism

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Authors: Sadia Basar, Naila Habib, Awais Adnan

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The paper presents the Technique for Image Segmentation Using K-Means Clustering Classification. The presented algorithms were specific, however, missed the neighboring information and required high-speed computerized machines to run the segmentation algorithms. Clustering is the process of partitioning a group of data points into a small number of clusters. The proposed method is content-aware and feature extraction method which is able to run on low-end computerized machines, simple algorithm, required low-quality streaming, efficient and used for security purpose. It has the capability to highlight the boundary and the object. At first, the user enters the data in the representation of the input. Then in the next step, the digital image is converted into groups clusters. Clusters are divided into many regions. The same categories with same features of clusters are assembled within a group and different clusters are placed in other groups. Finally, the clusters are combined with respect to similar features and then represented in the form of segments. The clustered image depicts the clear representation of the digital image in order to highlight the regions and boundaries of the image. At last, the final image is presented in the form of segments. All colors of the image are separated in clusters.

Keywords: clustering, image segmentation, K-means function, local and global minimum, region

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Authors: Danuvasin Charoen

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This research investigates cluster development in the area called the Greater Mekong Subregion (GMS), which consists of Thailand, the People’s Republic of China (PRC), the Yunnan Province and Guangxi Zhuang Autonomous Region, Myanmar, the Lao People’s Democratic Republic (Lao PDR), Cambodia, and Vietnam. The study utilized Porter’s competitiveness theory and the cluster mapping approach to analyze the competitiveness of the region. The data collection consists of interviews, focus groups, and the analysis of secondary data. The findings identify some evidence of cluster development in the GMS; however, there is no clear indication of collaboration among the components in the clusters. GMS clusters tend to be stand-alone. The clusters in Vietnam, Lao PDR, Myanmar, and Cambodia tend to be labor intensive, whereas the clusters in Thailand and the PRC (Yunnan) have the potential to successfully develop into innovative clusters. The collaboration and integration among the clusters in the GMS area are promising, though it could take a long time. The most likely relationship between the GMS countries could be, for example, suppliers of the low-end, labor-intensive products will be located in the low income countries such as Myanmar, Lao PDR, and Cambodia, and these countries will be providing input materials for innovative clusters in the middle income countries such as Thailand and the PRC.

Keywords: cluster, GMS, competitiveness, development

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Authors: Xin Chang, Daping Chu

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Oxygen gas sensing technology has progressed since the last century and it has been extensively used in a wide range of applications such as controlling the combustion process by sensing the oxygen level in the exhaust gas of automobiles to ensure the catalytic converter is in a good working condition. Similar sensors are also used in industrial boilers to make the combustion process economic and environmentally friendly. Different gas sensing mechanisms have been developed: ceramic-based potentiometric equilibrium sensors and semiconductor-based sensors by oxygen absorption. In this work, we present a highly sensitive and low-cost oxygen gas sensor based on Zinc Oxide nanoparticles (average particle size of 35nm) dispersion in ethanol. The sensor is able to measure the pressure range from 103 mBar to 10-5 mBar with a sensitivity of more than 102 mA/Bar. The sensor is also erasable with heat.

Keywords: nanoparticles, oxygen, sensor, ZnO

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Authors: Vytautas Galvanauskas, Vykantas Grincas, Rimvydas Simutis

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This paper investigates a possible practical solution for reasonable oxygen supply during the pluripotent stem cells expansion processes, where the stem cells propagate as aggregates in stirred-suspension bioreactors. Low glucose and low oxygen concentrations are preferred for efficient proliferation of pluripotent stem cells. However, strong oxygen limitation, especially inside of cell aggregates, can lead to cell starvation and death. In this research, the oxygen concentration profile inside of stem cell aggregates in a stem cell expansion process was predicted using a modified oxygen diffusion model. This profile can be realized during the stem cells cultivation process by manipulating the oxygen concentration in inlet gas or inlet gas flow. The proposed approach is relatively simple and may be attractive for installation in a real pluripotent stem cell expansion processes.

Keywords: aggregated stem cells, dissolved oxygen profiles, modeling, stirred-tank, 3D expansion

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Authors: Valeria M. Bastos, Myrian A. Costa, Matheus Ambrozio, Nelson F. F. Ebecken

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In this paper a very simple and effective user administration view of computing clusters systems is implemented in order of friendly provide the configuration and monitoring of distributed application executions. The user view, the administrator view, and an internal control module create an illusionary management environment for better system usability. The architecture, properties, performance, and the comparison with others software for cluster management are briefly commented.

Keywords: big data, computing clusters, administration view, user view

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Authors: Myoung Ah Kim, Dong Ho Sin, Chul Gyu Song

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Blood oxygen saturation system is a well-established, noninvasive photoplethysmographic method to monitor vital signs. Conventional blood oxygen saturation measurements for the two LED light source is the ambiguity of the oxygen saturation measurement principle and the measurement results greatly influenced and heat and motion artifact. A high accuracy in order to solve these problems blood oxygen saturation measuring method has been proposed using a broadband light source that can be easily understood by the algorithm. The measurement of blood oxygen saturation based on broad-band light source has advantage of simple testing facility and easy understanding. Broadband light source based on blood oxygen saturation measuring program proposed in this paper is a combination of LabVIEW and MATLAB. Using the wavelength range of 450 nm-750 nm using a floating light absorption of oxyhemoglobin and deoxyhemoglobin to measure the blood oxygen saturation. Hand movement is to fix the probe to the motor stage in order to prevent oxygen saturation measurement that affect the sample and probe kept constant interval. Experimental results show that the proposed method noticeably increases the accuracy and saves time compared with the conventional methods.

Keywords: oxygen saturation, broad-band light source, CCD, light reflectance theory

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Authors: Debesh R. Roy

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The fundamental issue in understanding the origin and growth mechanism of nanomaterials, from a fundamental unit is a big challenging problem to the scientists. Recently, an immense attention is generated to the researchers for prediction of exceptionally stable atomic cluster units as the building units for future smart materials. The present study is a systematic investigation on the stability and electronic properties of a series of bimetallic (semiconductor-alkaline earth) clusters, viz., BxMg3 (x=1-5) is performed, in search for exceptional and/ or unusual stable motifs. A very popular hybrid exchange-correlation functional, B3LYP as proposed by A. D. Becke along with a higher basis set, viz., 6-31+G[d,p] is employed for this purpose under the density functional formalism. The magic stability among the concerned clusters is explained using the jellium model. It is evident from the present study that the magic stability of B4Mg3 cluster arises due to the jellium shell closure.

Keywords: atomic clusters, density functional theory, jellium model, magic clusters, smart nanomaterials

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Authors: Francky Fouedjio

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Multivariate geostatistical data have become omnipresent in the geosciences and pose substantial analysis challenges. One of them is the grouping of data locations into spatially contiguous clusters so that data locations within the same cluster are more similar while clusters are different from each other, in some sense. Spatially contiguous clusters can significantly improve the interpretation that turns the resulting clusters into meaningful geographical subregions. In this paper, we develop an agglomerative hierarchical clustering approach that takes into account the spatial dependency between observations. It relies on a dissimilarity matrix built from a non-parametric kernel estimator of the spatial dependence structure of data. It integrates existing methods to find the optimal cluster number and to evaluate the contribution of variables to the clustering. The capability of the proposed approach to provide spatially compact, connected and meaningful clusters is assessed using bivariate synthetic dataset and multivariate geochemical dataset. The proposed clustering method gives satisfactory results compared to other similar geostatistical clustering methods.

Keywords: clustering, geostatistics, multivariate data, non-parametric

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Authors: Choukri Lekbir, Mira Mokhtari

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Hydrogen-Materials interaction and mechanisms can be modeled at nano scale by quantum methods. In this work, the effect of hydrogen on the electronic properties of a cluster material model «nickel» has been studied by using of density functional theoretical (DFT) method. Two types of clusters are optimized: Nickel and hydrogen-nickel system. In the case of nickel clusters (n = 1-6) without presence of hydrogen, three types of electronic structures (neutral, cationic and anionic), have been optimized according to three basis sets calculations (B3LYP/LANL2DZ, PW91PW91/DGDZVP2, PBE/DGDZVP2). The comparison of binding energies and bond lengths of the three structures of nickel clusters (neutral, cationic and anionic) obtained by those basis sets, shows that the results of neutral and anionic nickel clusters are in good agreement with the experimental results. In the case of neutral and anionic nickel clusters, comparing energies and bond lengths obtained by the three bases, shows that the basis set PBE/DGDZVP2 is most suitable to experimental results. In the case of anionic nickel clusters (n = 1-6) with presence of hydrogen, the optimization of the hydrogen-nickel (anionic) structures by using of the basis set PBE/DGDZVP2, shows that the binding energies and bond lengths increase compared to those obtained in the case of anionic nickel clusters without the presence of hydrogen, that reveals the armor effect exerted by hydrogen on the electronic structure of nickel, which due to the storing of hydrogen energy within nickel clusters structures. The comparison between the bond lengths for both clusters shows the expansion effect of clusters geometry which due to hydrogen presence.

Keywords: binding energies, bond lengths, density functional theoretical, geometry optimization, hydrogen energy, nickel cluster

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Authors: Ghassan Al-Dulaimi

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This paper studied the biochemical parameter (BOD5) and (DO) for the Thames River (Canada-Ontario). Water samples have been collected from Thames River along different points between Chatham to Woodstock and were analysed for various water quality parameters during the low flow season (April). The study involves the application of the stream water quality model QUAL2K model to simulate and predict the dissolved oxygen (DO) and biochemical oxygen demand (BOD5) profiles for Thames River in a stretch of 251 kilometers. The model output showed that DO in the entire river was within the limit of not less than 4 mg/L. For Carbonaceous Biochemical Oxygen Demand CBOD, the entire river may be divided into two main reaches; the first one is extended from Chatham City (0 km) to London (150 km) and has a CBOD concentration of 2 mg/L, and the second reach has CBOD range (2–4) mg/L in which begins from London city and extend to near Woodstock city (73km).

Keywords: biochemical oxygen demand, dissolved oxygen, Thames river, QUAL2K model

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Authors: Satam Alotibi, Muhammad J. Al-Zahrani, Fahd K. Al-Naqidan, Turki S. Hussein, Moteb Alotaibi, Mohammed Alyami, Mahdy M. Elmahdy, Abdellah Kaiba, Fatehia S. Alhakami, Talal F. Qahtan

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Water pollution is a critical global challenge that demands scalable and effective solutions for water decontamination. In this captivating research, we unveil a groundbreaking strategy for harnessing solar energy to synthesize silver (Ag) clusters on stable titanium dioxide (TiO₂) nanoparticles dispersed in water, without the need for traditional stabilization agents. These Ag-loaded TiO₂ nanoparticles exhibit exceptional photocatalytic activity, surpassing that of pristine TiO₂ nanoparticles, offering a promising solution for highly efficient water decontamination under sunlight irradiation. To the best knowledge, we have developed a unique method to stabilize TiO₂ P25 nanoparticles in water without the use of stabilization agents. This breakthrough allows us to create an ideal platform for the solar-driven synthesis of Ag clusters. Under sunlight irradiation, the stable dispersion of TiO₂ P25 nanoparticles acts as a highly efficient photocatalyst, generating electron-hole pairs. The photogenerated electrons effectively reduce silver ions derived from a silver precursor, resulting in the formation of Ag clusters. The Ag clusters loaded on TiO₂ P25 nanoparticles exhibit remarkable photocatalytic activity for water decontamination under sunlight irradiation. Acting as active sites, these Ag clusters facilitate the generation of reactive oxygen species (ROS) upon exposure to sunlight. These ROS play a pivotal role in rapidly degrading organic pollutants, enabling efficient water decontamination. To confirm the success of our approach, we characterized the synthesized Ag-loaded TiO₂ P25 nanoparticles using cutting-edge analytical techniques, such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and spectroscopic methods. These characterizations unequivocally confirm the successful synthesis of Ag clusters on stable TiO₂ P25 nanoparticles without traditional stabilization agents. Comparative studies were conducted to evaluate the superior photocatalytic performance of Ag-loaded TiO₂ P25 nanoparticles compared to pristine TiO₂ P25 nanoparticles. The Ag clusters loaded on TiO₂ P25 nanoparticles exhibit significantly enhanced photocatalytic activity, benefiting from the synergistic effect between the Ag clusters and TiO₂ nanoparticles, which promotes ROS generation for efficient water decontamination. Our scalable strategy for synthesizing Ag clusters on stable TiO₂ P25 nanoparticles without stabilization agents presents a game-changing solution for highly efficient water decontamination under sunlight irradiation. The use of commercially available TiO₂ P25 nanoparticles streamlines the synthesis process and enables practical scalability. The outstanding photocatalytic performance of Ag-loaded TiO₂ P25 nanoparticles opens up new avenues for their application in large-scale water treatment and remediation processes, addressing the urgent need for sustainable water decontamination solutions.

Keywords: water pollution, solar energy, silver clusters, TiO₂ nanoparticles, photocatalytic activity

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Authors: Nathakhun Wiroonsri

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There are various cluster validity measures used for evaluating clustering results. One of the main objectives of using these measures is to seek the optimal unknown number of clusters. Some measures work well for clusters with different densities, sizes and shapes. Yet, one of the weaknesses that those validity measures share is that they sometimes provide only one clear optimal number of clusters. That number is actually unknown and there might be more than one potential sub-optimal option that a user may wish to choose based on different applications. We develop two new cluster validity indices based on a correlation between an actual distance between a pair of data points and a centroid distance of clusters that the two points are located in. Our proposed indices constantly yield several peaks at different numbers of clusters which overcome the weakness previously stated. Furthermore, the introduced correlation can also be used for evaluating the quality of a selected clustering result. Several experiments in different scenarios, including the well-known iris data set and a real-world marketing application, have been conducted to compare the proposed validity indices with several well-known ones.

Keywords: clustering algorithm, cluster validity measure, correlation, data partitions, iris data set, marketing, pattern recognition

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Authors: Anucha Taiwong, Nirobol Kanogsunthornrat

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This predictive research aimed to investigate the symptom clusters that influence the quality of life among patients with chronic kidney disease, as indicated in the Theory of Unpleasant Symptoms. The purposive sample consisted of 150 patients with stage 3-4 chronic kidney disease who received care at an outpatient chronic kidney disease clinic of a tertiary hospital in Roi-Et province. Data were collected from January to March 2016 by using a patient general information form, unpleasant symptom form, and quality of life (SF-36) and were analyzed by using descriptive statistics, factor analysis, and multiple regression analysis. Findings revealed six core symptom clusters including symptom cluster of the mental and emotional conditions, peripheral nerves abnormality, fatigue, gastro-intestinal tract, pain and, waste congestion. Significant predictors for quality of life were the two symptom clusters of pain (Beta = -.220; p < .05) and the mental and emotional conditions (Beta=-.204; p<.05) which had predictive value of 19.10% (R2=.191, p<.05). This study indicated that the symptom cluster of pain and the mental and emotional conditions would worsen the patients’ quality of life. Nurses should be attentive in managing the two symptom clusters to facilitate the quality of life among patients with chronic kidney disease.

Keywords: chronic kidney disease, symptom clusters, predictors of quality of life, pre-dialysis

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Authors: Wichan Lertlop

Abstract:

This research is to study the solubility of oxygen in water taking the form of aeration pipes that have different shaped objectives of the research to compare the amount of oxygen dissolved in the water, whice take the form of aeration pipes. Shaped differently When aeration 5 minutes on air for 10 minutes, and when air fills 30 minutes, as well as compare the durability of the oxygen is dissolved in the water of the inlet air refueling shaped differently when you fill the air 30 minutes and when. aeration and 60 minutes populations used in this study, the population of pond water from Rajabhat University in February 2014 used in this study consists of 1. Aerator 2. Hose using a hose to fill the air with 3 different shape, different shapes pyramid whose base is on the water tank. Shaped rectangular water tank onto the ground. And shapes in a vertical pipe. 3 meter, dissolved oxygen, dissolved in water to get the calibration standard. 4. The clock for timer 5. Three water tanks which are 39 cm wide, 51 cm long and 32 cm high.

Keywords: aeration, dissolve oxygen, different shapes

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Authors: Zhanzhao Fu, Chongyi Ling, Jinlan Wang

Abstract:

Water splitting and rechargeable air-based batteries are emerging as new renewable energy storage and conversion technologies. However, the discovery of suitable catalysts with high activity and low cost remains a great challenge. In this work, we report a single-atom trifunctional catalyst, namely Ti₃C₂O₂ supported single Pd atom (Pd1@Ti₃C₂O₂), for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). This catalyst is selected from 12 candidates and possesses low overpotentials of 0.22 V, 0.31 V and 0.34 V for the HER, OER and ORR, respectively, making it an excellent electrocatalyst for both overall water splitting and rechargeable air-based batteries. The superior OER and ORR performance originates from the optimal d band center of the supported Pd atom. Moreover, the excellent activity can be maintained even if the single Pd atoms aggregate into small clusters. This work offers new opportunities for advancing the renewable energy storage and conversion technologies and paves a new way for the development of multifunctional electrocatalysts.

Keywords: DFT, SACs, OER, ORR, HER

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Authors: Shruti Malviya, Chris Bowler

Abstract:

Environmental processes acting at multiple spatial scales control marine diatom community structure. However, the contribution of local factors (e.g., temperature, salinity, etc.) in these highly complex systems is poorly understood. We, therefore, investigated the diatom community organization as a function of environmental predictors and determined the relative contribution of various environmental factors on the structure of marine diatoms assemblages in the world’s ocean. The dataset for this study was derived from the Tara Oceans expedition, constituting 46 sampling stations from diverse oceanic provinces. The V9 hypervariable region of 18s rDNA was organized into assemblages based on their distributional co-occurrence. Using Ward’s hierarchical clustering, nine clusters were defined. The number of ribotypes and reads varied within each cluster-three clusters (II, VIII and IX) contained only a few reads whereas two of them (I and IV) were highly abundant. Of the nine clusters, seven can be divided into two categories defined by a positive correlation with phosphate and nitrate and a negative correlation with longitude and, the other by a negative correlation with salinity, temperature, latitude and positive correlation with Lyapunov exponent. All the clusters were found to be remarkably dominant in South Pacific Ocean and can be placed into three classes, namely Southern Ocean-South Pacific Ocean clusters (I, II, V, VIII, IX), South Pacific Ocean clusters (IV and VII), and cosmopolitan clusters (III and VI). Our findings showed that co-occurring ribotypes can be significantly associated into recognizable clusters which exhibit a distinct response to environmental variables. This study, thus, demonstrated distinct behavior of each recognized assemblage displaying a taxonomic and environmental signature.

Keywords: assemblage, diatoms, hierarchical clustering, Tara Oceans

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Authors: Hong Seung Kim, Chang Hoi Kim, Lili Yue

Abstract:

Single-phase, high band gap energy Zn0.5Mg0.5O films were grown under oxygen pressure, using pulse laser deposition with a Zn0.5Mg0.5O target. Structural characterization studies revealed that the crystal structures of the ZnX-1MgXO films could be controlled via changes in the oxygen pressure. TEM analysis showed that the thickness of the deposited Zn1-xMgxO thin films was 50–75 nm. As the oxygen pressure increased, we found that one axis of the crystals did not show a very significant increase in the crystallization compared with that observed at low oxygen pressure. The X-ray diffraction peak intensity for the hexagonal-ZnMgO (002) plane increased relative to that for the cubic-ZnMgO (111) plane. The corresponding c-axis of the h-ZnMgO lattice constant increased from 5.141 to 5.148 Å, and the a-axis of the c-ZnMgO lattice constant decreased from 4.255 to 4.250 Å. EDX analysis showed that the Mg content in the mixed-phase ZnMgO films decreased significantly, from 54.25 to 46.96 at.%. As the oxygen pressure was increased from 100 to 150 mTorr, the absorption edge red-shifted from 3.96 to 3.81 eV; however, a film grown at the highest oxygen pressure tested here (200 mTorr).

Keywords: MgO, UV LED, ZnMgO, ZnO

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