Carbon Trends最新文献

{"title":"Chemical degradation of magnesia–carbon refractories by different gaseous atmospheres","authors":"Marcos N. Moliné ,&nbsp;Pablo G. Galliano ,&nbsp;Analía G. Tomba Martinez","doi":"10.1016/j.cartre.2024.100320","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100320","url":null,"abstract":"<div><p>In this work, we use a novel methodology to analyse how the critical compositional variables of MgO<img>C bricks affect their chemical degradation by oxygen attack; the study focuses on the effect of the graphite content, the presence of aluminium, and the binder type. Oxidation tests are performed at 1000 °C, a typical preheating condition for steelmaking ladles, under two atmospheric conditions: one simulated the oxygen concentration in air, and the other, with a lower amount of oxygen, reproduces the conditions of the inner part of the brick when liquid steel is present. It was found that: a) the addition of Al reduces the carbon oxidation kinetic, mainly at a low O₂ partial pressure, b) increasing the graphite content led to a smaller decarburized area with higher O₂ consumption, and c) mixing CarboRes® with phenolic resin resulted in a higher O₂ consumption but at a slower oxidation rate.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000014/pdfft?md5=296159daa9e32d3bb6d98f786e7d2085&pid=1-s2.0-S2667056924000014-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139109124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electronic phase transition, vibrational properties and structural stability of single and two polyyne chains under external electric field","authors":"Karthik H J,&nbsp;Sarga P K,&nbsp;Swastibrata Bhattacharyya","doi":"10.1016/j.cartre.2023.100319","DOIUrl":"https://doi.org/10.1016/j.cartre.2023.100319","url":null,"abstract":"<div><p>Search for one dimensional (1D) van der Waals materials has become an urgent need to meet the demand as building blocks for high performance, miniaturized, lightweight device applications. Polyyne, a 1D atomic chain of carbon is the thinnest and strongest allotrope of carbon, showing promising applications in new generation low dimensional devices due to the presence of a band gap. A system of two carbon chains held together by van der Waals interaction has been theoretically postulated and shows band gap tunability under structural changes which finds applications in the realms of resistive switching and spintronics. In this study, we use first principles Density Functional Theory (DFT) to show a sharp semiconductor to metal transition along with the emergence of an asymmetry in the spin polarized density of states for single and two polyyne chains under a transverse electric field. The thermodynamic stability of the system has been substantiated through the utilization of <em>Ab Initio</em> Molecular Dynamics (AIMD) simulations, phonon dispersion curve analyses, and formation energy calculations. Furthermore, in addition to its dynamic stability assessment, phonon calculations have served to identify Raman-active vibrational modes which offers an invaluable non-destructive experimental avenue for discerning electronic phase transitions in response to an applied electric field. Our study presents a predictive framework for the prospective utilization of one and two polyyne chains in forthcoming flexible nano-electronic and spintronic devices. The future prospects of the system are contingent upon advancements in nano-electronics fabrication techniques and the precise construction of circuitry for harnessing spin-related applications.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056923000743/pdfft?md5=f7540b10b3767ed89ed153992080697e&pid=1-s2.0-S2667056923000743-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139100120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of highly conductive graphene paper for supercapacitors with a one-step hydrothermal method","authors":"Rajesh Ghosh ,&nbsp;Mohd Salman Siddiqui ,&nbsp;Hemen Kalita","doi":"10.1016/j.cartre.2023.100317","DOIUrl":"10.1016/j.cartre.2023.100317","url":null,"abstract":"<div><p>We present a facile one-step hydrothermal method for the fabrication of free-standing graphene paper using aqueous graphene oxide (GO) dispersion as the starting material. Notably, the method does not require the use of any additives for the reduction and preparation of the graphene paper. The resulting graphene paper exhibits a high degree of reduction, as confirmed by X-ray photoelectron spectroscopy (XPS) analysis, revealing a carbon-to-oxygen (C/O) ratio of ∼7. The fabricated graphene paper also demonstrates excellent conductivity, with a measured value of ∼1900 S/m, and sheet resistance of around 100 Ω/sq. Furthermore, the energy storage capability of the graphene paper based electrode is evaluated, which shows a promising specific capacity of 249 F/g at a current density of 1 A/g in 1M H₂SO₄ as the ionic medium. Additionally, the electrode has also demonstrated remarkable energy density and power density values of 28.68 Wh/Kg and 455 W/Kg, respectively. Overall, the resulting graphene paper exhibits high conductivity and excellent electrochemical performance, making it a promising candidate for various energy storage applications.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266705692300072X/pdfft?md5=6fe214ed832c1f890d51422c1d71837d&pid=1-s2.0-S266705692300072X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138625508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Activated biochars as sustainable and effective supports for hydrogenations","authors":"Somayeh Taghavi ,&nbsp;Elena Ghedini ,&nbsp;Markus Peurla ,&nbsp;Giuseppe Cruciani ,&nbsp;Federica Menegazzo ,&nbsp;Dmitry Yu. Murzin ,&nbsp;Michela Signoretto","doi":"10.1016/j.cartre.2023.100316","DOIUrl":"https://doi.org/10.1016/j.cartre.2023.100316","url":null,"abstract":"<div><p>Activated biochars were obtained from pyrolysis and CO₂-physical activation of four different biomasses including tannery shaving waste (T), vine wood waste (W), barley waste (B) and Sargassum, brown macroalgae of Venice lagoon (A). The potential of obtained carbonaceous materials as the supports of Ni,Al catalysts was investigated in levulinic acid (LA) conversion to γ-valerolactone (GVL) as a model hydrogenation reaction. Al-containing species as the Lewis acid sites for the dehydration step were incorporated to the supports using wet impregnation or precipitation. Ni as a hydrogenation active phase was added to the supports via wet impregnation. Biochar-based supports and catalysts were characterized by AAS, elemental analysis, FTIR, N₂ physisorption, XRD, SEM, EDS, TEM, He-TPD, NH₃-TPD and TPR techniques. The catalysts were tested for LA hydrogenation to GVL in a batch system and aqueous medium. The results showed that Ni supported on activated biochar was not active due to a lack of Lewis acid sites for dehydration. Precipitated Al-containing species on the biochar-based supports demonstrated a better catalytic performance in the reaction compared to impregnated one because of different interactions with the support and Ni species. Among different supports, the activated biochars obtained from T and W acted as the best ones. A higher catalytic efficiency was strongly influenced by the chemical (aromaticity and stability, presence of N,O-doped and functional groups), textural (the porous texture and surface area), and morphological (higher dispersion of active phases) properties of activated biochars obtained from different biomasses with different natures.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056923000718/pdfft?md5=6247a6c8e07f4bf6be21ed8c0c576a4f&pid=1-s2.0-S2667056923000718-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138475416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser writing of preferentially orientated nitrogen-vacancy centers in diamond","authors":"Kohei Kinouchi ,&nbsp;Yasuhiko Shimotsuma ,&nbsp;Mitsuharu Uemoto ,&nbsp;Masanori Fujiwara ,&nbsp;Norikazu Mizuochi ,&nbsp;Masahiro Shimizu ,&nbsp;Kiyotaka Miura","doi":"10.1016/j.cartre.2023.100318","DOIUrl":"https://doi.org/10.1016/j.cartre.2023.100318","url":null,"abstract":"<div><p>Nitrogen-vacancy centers in diamond have gained widespread attention as quantum systems that can be applied in quantum information devices. The excellent properties of quantum devices can be enhanced using preferentially oriented nitrogen-vacancy (NV) centers. However, thus far, orientation control has been achieved only via chemical vapor deposition. In this study, we demonstrate the creation of preferentially oriented NV centers via laser writing. The alignment ratio of ensemble NV centers is biased along the direction parallel to [111], depending on the femtosecond laser polarization, causing an increase of 55 % in contrast to the optically magnetic resonance signal at maximum compared with 25 % in random orientation. Based on time-dependent density-functional theory (TDDFT) simulations and experimental observations, such complex polarization dependence can be attributed to the anisotropy of electron excitation. This technique provides a new optical fabrication method for engineered materials and devices used in quantum technology.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056923000731/pdfft?md5=06352637aafb824b5f27022f6f800d19&pid=1-s2.0-S2667056923000731-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138570272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bio-synthesized silver nanoparticle modified glassy carbon electrode as electrochemical biosensor for prostate specific antigen detection","authors":"Naresh Mandal ,&nbsp;Raja Mitra ,&nbsp;Bidhan Pramanick","doi":"10.1016/j.cartre.2023.100315","DOIUrl":"https://doi.org/10.1016/j.cartre.2023.100315","url":null,"abstract":"<div><p>Prostate cancer is the second leading cause of death for men after lung cancer. Therefore, early detection of cancer proteins or biomarkers is crucial in assessing the disease's reappearance after treatment. Here, we have reported the glassy carbon electrode (GCE) based electrochemical biosensors fabricated using Carbon-Microelectromechanical Systems (C-MEMS) technology for prostate-specific antigen (PSA) quantification. This report also presents the biosensor improvement by modifying the GCE with silver nanoparticles (AgNPs). Moreover, our investigation extends to bio-synthesized AgNPs that bring together advantageous chemical and physical attributes at a reasonable cost. In addition, AgNPs modified GCE have a more comprehensive anodic potential range [˗0.2 V to +0.3 V] than bare glassy carbon (GC). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurements were used to examine the electrochemical response of the biosensors. As a result of the use of AgNPs-modified GCE, we have developed a label-free analytical system for prostate cancer detection, which can provide a linear response in the concentration range of 1 pg/ml - 3 µg/ml in a reasonably simple operation. The developed biosensors may be used for the early detection of prostate cancer in clinical analysis due to the excellent sensitivity demonstrated by this electrochemical biosensor.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056923000706/pdfft?md5=5e55b6439788e686137bfd5061a75d32&pid=1-s2.0-S2667056923000706-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138475417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studies on effect of temperature on carbonization of silk (Bombyx mori) and its application as proximity sensor","authors":"Shubhanth Jain ,&nbsp;R.V. Prajwal ,&nbsp;V. Vedavyas ,&nbsp;S. Vishwas ,&nbsp;Govindaraj Achutharao","doi":"10.1016/j.cartre.2023.100314","DOIUrl":"https://doi.org/10.1016/j.cartre.2023.100314","url":null,"abstract":"<div><p>Silk, a pyroprotein with its unique micro-structural features comprises of soft amorphous <figure><img></figure> regions containing compact <figure><img></figure>-sheet crystals resulting in its potent characteristics. Annealing in inert atmosphere causes carbonization followed by graphitization of these stable <figure><img></figure>-sheet-rich silk fibroins (SFs). Here we carry out systematic studies of annealed silk fibroin (<em>Bombyx mori</em>) in the temperature range of 200-1200<!--> <!-->°C by various analytical techniques. Herein the structural changes in SFs at different annealing temperature have been discussed using Raman, FTIR, XPS, XAES, SEM, XRD characterization techniques. Notably XPS and XAES studies were executed to examine the influence of sp²/sp³ ratio and the presence of hetero-atom on D-parameter value in silk <figure><img></figure>-sheet material on gradual increase in annealing temperature. The mechanical properties of SFs were measured using UTM. The application of carbonized silk fibroins (CSF) as a proximity sensor is also investigated and proposed as a probable active material.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266705692300069X/pdfft?md5=673a9c9365db1ad9bd7493738b8353cf&pid=1-s2.0-S266705692300069X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138454263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and properties of biomorphic carbon scaffolds based on pressed birch and alder wood","authors":"Anton E. Ershov,&nbsp;Tatyana S. Stroganova","doi":"10.1016/j.cartre.2023.100312","DOIUrl":"https://doi.org/10.1016/j.cartre.2023.100312","url":null,"abstract":"<div><p>The effect of prepressing of birch and alder wood on the pyrolysis process, structure and properties of biocarbon scaffolds were investigated. It is shown that after pressing process, internal stresses in the wood are preserved, which leads to a change in shrinkage during pyrolysis, especially in the pressing direction. The limitation of the samples expansion in the pressing direction made it possible to increase the density of biocarbon scaffolds (up to ∼ 1 g/cm³) and to obtain a linear dependence of their density on the density of compressed wood. Deformation of wood did not lead to a noticeable change in the atomic structure of biocarbon, but defects in the cell walls that affect the electrical resistivity of the biocarbon scaffolds were formed. The bending strength of biocarbon samples based on compressed wood was primarily determined by their density and weakly depended on the particular species. The obtained strength values were not inferior to the published data, which indicates that the defects formed during deformation were not stress concentrators.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056923000676/pdfft?md5=b0d7d7eb9f4717f0f1fb6aa902b1f450&pid=1-s2.0-S2667056923000676-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138438279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing the effect of stacking faults in X-ray diffractograms of graphite through atom-scale simulations","authors":"Pascal Puech,&nbsp;Mathilde Jeanningros,&nbsp;David Neumeyer,&nbsp;Marc Monthioux","doi":"10.1016/j.cartre.2023.100311","DOIUrl":"https://doi.org/10.1016/j.cartre.2023.100311","url":null,"abstract":"<div><p>Determining the average contribution and actual distribution of rhombohedral stacking sequences within the average graphitic crystallite remained unsolved. To address this issue, we used a bottom-up approach to simulate X-ray diffractograms of graphite crystallites up to one million atoms in various graphene stacking configurations to find out how to match experimental data. The <em>100–101 2θ</em> range was highly sensitive to the presence of C layers and can be used to accurately characterize the stacking disorder. On the opposite, the <em>110–112 2θ</em> range was not sensitive to stacking disorder and thus can be taken as a reference to obtain the average in-plane size <em>L_a</em> of the crystallites, faulted or not. We used the principle of the <em>L'_c</em> parameter, introduced in a former work, which corresponds to the height of the coherent sub-domains within the average crystallite obtainable through the shape of the <em>hkl</em> peaks involving both in-plane and out-of-plane directions. Three types of defects within a Bernal sequence were analyzed, which do not affect the peaks the same way: <em>(i)</em> a substitution of A or B by C, <em>(ii)</em> an insertion of C leading to destructive interferences, and <em>(iii)</em> a so-called \"block shifting\". It is thus possible to go further in the interpretation of X-Ray diffraction. Finally, we discussed how the overall crystallite size <em>L_c</em> can be obtained from all the <em>00l</em> peaks.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056923000664/pdfft?md5=14a75e393830e589be2c07ff3658279f&pid=1-s2.0-S2667056923000664-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138438138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creep and electrical properties of carbon nanotube yarns for long-term applications","authors":"Fernanda Mazuco Clain ,&nbsp;Carlos Eduardo Marcos Guilherme ,&nbsp;Frantchescole Borges Cardoso ,&nbsp;Fernando Machado Machado ,&nbsp;Rubens Camaratta ,&nbsp;Carlos Perez Bergmann ,&nbsp;Alice Goncalves Osorio","doi":"10.1016/j.cartre.2023.100313","DOIUrl":"https://doi.org/10.1016/j.cartre.2023.100313","url":null,"abstract":"<div><p>One of the primary challenges to turning CNTs into commercial applications is the feasibility to manufacture macroscopic structures that mirror the extraordinary properties of individual CNTs. CNT yarns (CNTY) are an alternative to overcome this challenge. However, most yarn-like structures are exposed to dynamic systems, like creep and/or fatigue, and limited studies are published predicting their behavior. Therefore, the current study aimed to assess the behavior of CNTYs under creep situations and establish a relationship with their electrical properties. Five layers of CNTs were drawn from the MWCNT forest, placed one on top of the other, and scrolled into a 250 mm yarn, that was later twisted to 2000 twists <em>m</em>⁻¹. Afterward, these CNTYs were densified with acetone. Creep experiments were performed with a sustained load of 50, 70, and 80 % of the YBL. The yarn behavior seen during creep experiments was unexpected, which, although partial breakage of the yarn was seen, it sustained the creep load much for longer periods. The mechanism proposed for the phenomenon includes CNT alignment and void elimination at first, followed by partial CNT sliding, with breakage of van der Waals forces. As the creep load continues, CNTs are able to rebind to their neighbors and recover their strength before total failure. Mechanical gripping due to friction is also occurring between nanotubes which favors a strength increase. This behavior indicates that there is a regeneration of van der Waals forces occurring among the CNTs, which recovers the strength of the yarn under constant load, increasing creep lifespan. The time to failure obtained under creep load is about 9, 10, and 11 days to failure for CNTYs at 50, 70 and 80 % of YBL, respectively. Raman results showed that I_D/I_G ratio remained the same after mechanical loads, which indicates that no structural modification is seen in the CNTs when static and/or dynamic mechanical systems are imposed on the yarn. The electrical conductivity of a CNTY is improved after the mechanical tests, increasing by 5.9 and 6.7 % after static tensile and creep, respectively. The improvement of electrical conductivity is attributed to densification, which leads to an enhancement of the intertubes contact area among the nanotubes within the yarn.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056923000688/pdfft?md5=d237044cb7dd53a07a4dc076ae2137fa&pid=1-s2.0-S2667056923000688-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138430301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}