Abstract Surface quality is a key factor in determining the mechanical performance of metallic materials. In this study, the influence of surface roughness on quasi-static mode tensile and low fatigue behavior of electron beam melted (EBMed) Ti‐6Al‐4V was studied. The results showed that the microstructure of the EBMed Ti‐6Al‐4V is mainly composed of α and β phases. It was found that the yield strength of the as-polished EBMed sample was about 200 MPa higher than the original EBMed sample, and the fatigue life was three times that. The fatigue crack initiation and propagation were explored, and it was found that the fatigue life was reduced on account of the thermal stress concentration that was generated as a result of the solidification shrinkage and the local stress concentration.
摘要表面质量是决定金属材料力学性能的关键因素。本文研究了表面粗糙度对电子束熔化(EBMed) Ti - 6Al - 4V准静态模式拉伸和低疲劳行为的影响。结果表明:EBMed Ti - 6Al - 4V的微观结构主要由α相和β相组成;结果表明，抛光后的EBMed试样的屈服强度比原EBMed试样提高了约200 MPa，疲劳寿命是原EBMed试样的3倍。研究了疲劳裂纹的萌生和扩展过程，发现由于凝固收缩和局部应力集中而产生的热应力集中降低了疲劳寿命。
{"title":"Study on the influence of surface roughness on tensile and low-cycle fatigue behavior of electron beam melted Ti‐6Al‐4V","authors":"Dongye Yang, Ke Si, Wenqi Tian, Xinqi Zhang","doi":"10.1515/ijmr-2022-0131","DOIUrl":"https://doi.org/10.1515/ijmr-2022-0131","url":null,"abstract":"Abstract Surface quality is a key factor in determining the mechanical performance of metallic materials. In this study, the influence of surface roughness on quasi-static mode tensile and low fatigue behavior of electron beam melted (EBMed) Ti‐6Al‐4V was studied. The results showed that the microstructure of the EBMed Ti‐6Al‐4V is mainly composed of α and β phases. It was found that the yield strength of the as-polished EBMed sample was about 200 MPa higher than the original EBMed sample, and the fatigue life was three times that. The fatigue crack initiation and propagation were explored, and it was found that the fatigue life was reduced on account of the thermal stress concentration that was generated as a result of the solidification shrinkage and the local stress concentration.","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135810448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Bone tissue is the second most affected organ in the human body after blood. Tissue engineering is the area whereby a scaffold is used to regenerate the lost bone. However, the scaffold’s effectiveness is primarily based on the material and the fabrication process. The patient-specific structures are affected because of the fabrication process used to fabricate the scaffold as per requirement. In this regard, rheology plays an important role in the fabrication of the patient-specific scaffold, and it is a study of the flow of ink. This primarily affects both the conventional as well as the non-conventional fabrication processes. In this paper, the scaffold and bone tissue engineering, the different fabrication processes, and the importance of the rheological characterization are presented. In addition to this, the rheological properties of the developed HA/β-TCP composite slurry are evaluated for the extrusion-based additive manufacturing process. The developed ink’s rheological properties show that the flow behavior index of about 0.0497 ± 0.009, minimum flow stress required to make the ink flow of about 51.076 Pa at a strain rate of 0.111 %, and shape retention upto 75 % after 175 s are obtained. Also, different orientations are 3D printed using the developed slurry.
{"title":"The influence of rheology in the fabrication of ceramic-based scaffold for bone tissue engineering","authors":"Jameer K. Bagwan, Bharatkumar B. Ahuja","doi":"10.1515/ijmr-2022-0245","DOIUrl":"https://doi.org/10.1515/ijmr-2022-0245","url":null,"abstract":"Abstract Bone tissue is the second most affected organ in the human body after blood. Tissue engineering is the area whereby a scaffold is used to regenerate the lost bone. However, the scaffold’s effectiveness is primarily based on the material and the fabrication process. The patient-specific structures are affected because of the fabrication process used to fabricate the scaffold as per requirement. In this regard, rheology plays an important role in the fabrication of the patient-specific scaffold, and it is a study of the flow of ink. This primarily affects both the conventional as well as the non-conventional fabrication processes. In this paper, the scaffold and bone tissue engineering, the different fabrication processes, and the importance of the rheological characterization are presented. In addition to this, the rheological properties of the developed HA/β-TCP composite slurry are evaluated for the extrusion-based additive manufacturing process. The developed ink’s rheological properties show that the flow behavior index of about 0.0497 ± 0.009, minimum flow stress required to make the ink flow of about 51.076 Pa at a strain rate of 0.111 %, and shape retention upto 75 % after 175 s are obtained. Also, different orientations are 3D printed using the developed slurry.","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135849896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Wire arc melting is considered one of the most efficient processes in additive manufacturing in terms of material printed to material consumed ratio. 304 stainless steel is one of the prominent stainless steels with superior corrosion resistance and mechanical properties. 304 stainless steel components were deposited by wire arc additive manufacturing, depositing subsequent layers in the same and perpendicular directions. Mechanical properties, microstructure, XRD and microtexture studies were done by EBSD have been done for both the conditions and compared. Mechanical properties were found to be similar for both the conditions whereas the microstructure and microtexture showed equiaxed grains for depositing in the same direction and columnar grains for deposition in the perpendicular direction.
{"title":"Mechanical behaviour, microstructure and texture studies of wire arc additive manufactured 304L stainless steel","authors":"Minnam Reddy Suryanarayana Reddy, Guttula Venkata Sarath Kumar, Topalle Bhaskar, Subhasis Sahoo, Mekala Chinababu, Katakam Sivaprasad","doi":"10.1515/ijmr-2022-0302","DOIUrl":"https://doi.org/10.1515/ijmr-2022-0302","url":null,"abstract":"Abstract Wire arc melting is considered one of the most efficient processes in additive manufacturing in terms of material printed to material consumed ratio. 304 stainless steel is one of the prominent stainless steels with superior corrosion resistance and mechanical properties. 304 stainless steel components were deposited by wire arc additive manufacturing, depositing subsequent layers in the same and perpendicular directions. Mechanical properties, microstructure, XRD and microtexture studies were done by EBSD have been done for both the conditions and compared. Mechanical properties were found to be similar for both the conditions whereas the microstructure and microtexture showed equiaxed grains for depositing in the same direction and columnar grains for deposition in the perpendicular direction.","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"2015 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135759990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Harish T. Mani, Jerome Savarimuthu, Sathwic R. Varma, Muraleekrishnan B. Muraleedharan, Nibin K. Suni, Yadhukrishna Nandakumar
Abstract This work aims to fabricate the functionally graded Inconel 600 on stainless steel 304 block using the wire arc additive manufacturing process. The main goal of this study was to additively create a built block with Inconel 600 filler wire. Inconel 600 is a very interesting material because of its resistance to non-magnetic, corrosive media, stress corrosion cracking due to chlorine ions is non-existent, outstanding mechanical properties, good weldability and high strength under a variety of temperature conditions. Inconel 600 alloy was studied in this work utilizing metal inert gas based wire arc additive manufacturing. Torch travel speed 5 mm s −1 and current 140 A. The bottom, middle and top layers of the newly developed fabricated block were mechanically and metallurgically characterized. The microstructure and texture evolution were characterized by means of optical microscopy, and scanning electron microscopy with energy dispersive X-ray spectroscopy. Mechanical characterization was done using the Vickers hardness test and tensile testing. Results reveal that the wire arc additively manufactured top portion has a crystalline structure showing better strength and hardness. The average hardness value was found to be 197.97 HV, the average ultimate tensile strength obtained was 616.22 MPa for the fabricated component.
{"title":"Investigation of mechanical and microstructure properties of metal inert gas based wire arc additive manufactured Inconel 600 superalloy","authors":"Harish T. Mani, Jerome Savarimuthu, Sathwic R. Varma, Muraleekrishnan B. Muraleedharan, Nibin K. Suni, Yadhukrishna Nandakumar","doi":"10.1515/ijmr-2022-0350","DOIUrl":"https://doi.org/10.1515/ijmr-2022-0350","url":null,"abstract":"Abstract This work aims to fabricate the functionally graded Inconel 600 on stainless steel 304 block using the wire arc additive manufacturing process. The main goal of this study was to additively create a built block with Inconel 600 filler wire. Inconel 600 is a very interesting material because of its resistance to non-magnetic, corrosive media, stress corrosion cracking due to chlorine ions is non-existent, outstanding mechanical properties, good weldability and high strength under a variety of temperature conditions. Inconel 600 alloy was studied in this work utilizing metal inert gas based wire arc additive manufacturing. Torch travel speed 5 mm s −1 and current 140 A. The bottom, middle and top layers of the newly developed fabricated block were mechanically and metallurgically characterized. The microstructure and texture evolution were characterized by means of optical microscopy, and scanning electron microscopy with energy dispersive X-ray spectroscopy. Mechanical characterization was done using the Vickers hardness test and tensile testing. Results reveal that the wire arc additively manufactured top portion has a crystalline structure showing better strength and hardness. The average hardness value was found to be 197.97 HV, the average ultimate tensile strength obtained was 616.22 MPa for the fabricated component.","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136128119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-08DOI: 10.1557/s43578-023-01150-2
Azade Yelten, Yasemin Kenar, I. Mutlu, S. Yilmaz
17–4 PH martensitic stainless steel foams are frequently used in surgery and dental tools. Porous morphology may increase the usage fields of these foams for biomedical aims. In this work, highly porous 17–4 PH martensitic stainless steel foams were produced with the space holder technique and coated with α-Al2O3 to improve chemical stability and surface properties. Mixing stainless steel, boron powders, and urea with polyvinyl alcohol, pressing the mixture at 180 MPa, removing the urea by dissolving it in water at room temperature, and then removing the binder in the raw pellets through sintering were sequentially performed to prepare the foams. Afterwards, the foams were dip-coated in sol–gel derived AlOOH gel for 7–14-21 days and, finally, heat-treated at 1260 °C to transform AlOOH into α-Al2O3. The physical, microstructural, and electrochemical properties of the foams were characterized. The metal ion release from the samples decreased thanks to the α-Al2O3 layer.
{"title":"Production and electrochemical properties of the sol–gel α-Al2O3 coated stainless steel foams","authors":"Azade Yelten, Yasemin Kenar, I. Mutlu, S. Yilmaz","doi":"10.1557/s43578-023-01150-2","DOIUrl":"https://doi.org/10.1557/s43578-023-01150-2","url":null,"abstract":"17–4 PH martensitic stainless steel foams are frequently used in surgery and dental tools. Porous morphology may increase the usage fields of these foams for biomedical aims. In this work, highly porous 17–4 PH martensitic stainless steel foams were produced with the space holder technique and coated with α-Al2O3 to improve chemical stability and surface properties. Mixing stainless steel, boron powders, and urea with polyvinyl alcohol, pressing the mixture at 180 MPa, removing the urea by dissolving it in water at room temperature, and then removing the binder in the raw pellets through sintering were sequentially performed to prepare the foams. Afterwards, the foams were dip-coated in sol–gel derived AlOOH gel for 7–14-21 days and, finally, heat-treated at 1260 °C to transform AlOOH into α-Al2O3. The physical, microstructural, and electrochemical properties of the foams were characterized. The metal ion release from the samples decreased thanks to the α-Al2O3 layer.","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"1 1","pages":"4385 - 4394"},"PeriodicalIF":0.8,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83124991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-08DOI: 10.1557/s43578-023-01155-x
Takayuki Semba, Jacob McKibbin, Ryosuke Jinnouchi, Ryoji Asahi
{"title":"Molecular dynamics simulations using machine learning potential for a-Si:H/c-Si interface: Effects of oxygen and hydrogen on interfacial defect states","authors":"Takayuki Semba, Jacob McKibbin, Ryosuke Jinnouchi, Ryoji Asahi","doi":"10.1557/s43578-023-01155-x","DOIUrl":"https://doi.org/10.1557/s43578-023-01155-x","url":null,"abstract":"","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"13 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82558278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the major challenges in medicine is the preparation of a controlled drug release system sensitive to environmental stimuli via a simple method. In the present work, the association of ibuprofen with (3-aminopropyl) triethoxysilane (APTES) was studied in detail. Then a mesoporous SiO2 (m-SiO2) drug release systems were synthesized via the simplified sol–gel method using the associates of ibuprofen and APTES as templates. Also, the m-SiO2 were in situ modified by UV-responsive groups to fabricate particles sensitive to pH and UV stimulus. On–off release behaviors were realized by further association of UV-responsive groups of the particles with β-cyclodextrins. Although slight harm of the particles to Gram-negative E. coli was observed due to the introduction of UV-responsive groups, it could be overcome by slight enlargement of the particle size. Therefore, the fabricated m-SiO2 particles were smart drug release systems.
{"title":"In situ synthesis of UV-responsive mesoporous SiO2 drug release systems using the associates of anionic drugs and cationic silica source as templates","authors":"Hanxia Tang, Yuqing Xue, Zhiming Wu, Wenqian Zhu, Fengzhu Lv, Yihe Zhang","doi":"10.1557/s43578-023-01148-w","DOIUrl":"https://doi.org/10.1557/s43578-023-01148-w","url":null,"abstract":"One of the major challenges in medicine is the preparation of a controlled drug release system sensitive to environmental stimuli via a simple method. In the present work, the association of ibuprofen with (3-aminopropyl) triethoxysilane (APTES) was studied in detail. Then a mesoporous SiO2 (m-SiO2) drug release systems were synthesized via the simplified sol–gel method using the associates of ibuprofen and APTES as templates. Also, the m-SiO2 were in situ modified by UV-responsive groups to fabricate particles sensitive to pH and UV stimulus. On–off release behaviors were realized by further association of UV-responsive groups of the particles with β-cyclodextrins. Although slight harm of the particles to Gram-negative E. coli was observed due to the introduction of UV-responsive groups, it could be overcome by slight enlargement of the particle size. Therefore, the fabricated m-SiO2 particles were smart drug release systems.","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"27 1","pages":"4357 - 4368"},"PeriodicalIF":0.8,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80948891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-05DOI: 10.1557/s43578-023-01149-9
S. S. Muthulakshmi, S. Shailajha, B. Shanmugapriya, Hap Hydroxyapatite
CaSiO3 wollastonite biomaterials were synthesized by hydrothermal approach in three different weight percentages of SiO2 and CaO (CA—25:75, CB—50:50, and CC—75:25) extracted from silica sand and limestone. In vitro biological testing revealed the materials bioactivity in SBF and their antibacterial efficacy against Streptococcus aureus and Escherichia coli. By direct contact with the L929 mouse fibroblast cell line, the cell viability against synthesized biomaterials was examined. These bio-properties were interlinked with the degradation rate of biomaterials in biofluid, which was observed under Tris–Hcl immersion. The regulated degradation of synthesized biomaterial simultaneously constrained the alkaline pH shift, which is beneficial for bioactivation and biocompatibility. It attained a compressive strength of 73 MPa without failure, which is equivalent to or higher than conventional bioglass and suitable for load-bearing sites. The synthesized biomaterials acquire excellent bioactivity, biocompatibility, and mechanical stability through controlled degradation versus bone apatite formation in a balanced manner, supported by porously fused structure.
{"title":"Bio-physical investigation of calcium silicate biomaterials by green synthesis- osseous tissue regeneration","authors":"S. S. Muthulakshmi, S. Shailajha, B. Shanmugapriya, Hap Hydroxyapatite","doi":"10.1557/s43578-023-01149-9","DOIUrl":"https://doi.org/10.1557/s43578-023-01149-9","url":null,"abstract":"CaSiO3 wollastonite biomaterials were synthesized by hydrothermal approach in three different weight percentages of SiO2 and CaO (CA—25:75, CB—50:50, and CC—75:25) extracted from silica sand and limestone. In vitro biological testing revealed the materials bioactivity in SBF and their antibacterial efficacy against Streptococcus aureus and Escherichia coli. By direct contact with the L929 mouse fibroblast cell line, the cell viability against synthesized biomaterials was examined. These bio-properties were interlinked with the degradation rate of biomaterials in biofluid, which was observed under Tris–Hcl immersion. The regulated degradation of synthesized biomaterial simultaneously constrained the alkaline pH shift, which is beneficial for bioactivation and biocompatibility. It attained a compressive strength of 73 MPa without failure, which is equivalent to or higher than conventional bioglass and suitable for load-bearing sites. The synthesized biomaterials acquire excellent bioactivity, biocompatibility, and mechanical stability through controlled degradation versus bone apatite formation in a balanced manner, supported by porously fused structure.","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"5 1","pages":"4369 - 4384"},"PeriodicalIF":0.8,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74977256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-05DOI: 10.1557/s43578-023-01143-1
M. Deepa, S. Sahaya, Jude Dhas, S. B. Dhas
Single crystals of l-alaninium maleate (LAM) were successfully grown by utilizing the Sankaranarayanan–Ramasamy (SR) method. The cut and polished crystal of LAM was subjected to shock waves of 1.7 Mach number. The dynamic shock wave impact on the test crystal in terms of morphological, structural, optical, and dielectric properties was analyzed using optical microscope, powder X-ray diffractometer, UV–Visible spectrometer, and impedance analyzer, respectively. From the observed data under shock-loaded conditions, LAM crystal exhibits a good structural stability against shock waves. The obtained values of optical transmittance of the test crystal for different number of shock pulses show that there is a slight reduction of transmission because of the induced defects and deformations formed under shocked conditions. From the dielectric study, it is observed that the values of dielectric constant and dielectric loss are reduced substantially under shock-loaded conditions.
{"title":"Impact of shock waves on morphological, structural, optical and dielectric properties of l-alaninium maleate crystals","authors":"M. Deepa, S. Sahaya, Jude Dhas, S. B. Dhas","doi":"10.1557/s43578-023-01143-1","DOIUrl":"https://doi.org/10.1557/s43578-023-01143-1","url":null,"abstract":"Single crystals of l-alaninium maleate (LAM) were successfully grown by utilizing the Sankaranarayanan–Ramasamy (SR) method. The cut and polished crystal of LAM was subjected to shock waves of 1.7 Mach number. The dynamic shock wave impact on the test crystal in terms of morphological, structural, optical, and dielectric properties was analyzed using optical microscope, powder X-ray diffractometer, UV–Visible spectrometer, and impedance analyzer, respectively. From the observed data under shock-loaded conditions, LAM crystal exhibits a good structural stability against shock waves. The obtained values of optical transmittance of the test crystal for different number of shock pulses show that there is a slight reduction of transmission because of the induced defects and deformations formed under shocked conditions. From the dielectric study, it is observed that the values of dielectric constant and dielectric loss are reduced substantially under shock-loaded conditions.","PeriodicalId":14079,"journal":{"name":"International Journal of Materials Research","volume":"40 1","pages":"4303 - 4313"},"PeriodicalIF":0.8,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73553596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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