This study focuses on the covalent functionalization of the carboxylated graphene oxide layers with human serum albumin for developing new nanoplatforms capable of efficient drug loading and release for antitumor therapy. Thus, new GO-HSA conjugates have been developed and their interactions with methotrexate (MTX) molecules were evidenced through FT-IR, UV-Vis and Raman spectroscopy. The cumulative in vitro release profiles of MTX drug from GO-HSA-MTX nanoplatforms were analyzed through UV-Vis spectroscopy showing a more controlled release behavior of MTX drug under acidic conditions that simulate the tumor microenvironment demonstrating the potential use of GO-HSA-MTX as antitumoral nanocarriers.
{"title":"The Development of New Nanoplatforms Based on Albumin and Graphene Oxide for Aticancer Therapy","authors":"Elena Iuliana Bîru, Andrei Sarbu, H. Iovu","doi":"10.37358/mp.23.4.5682","DOIUrl":"https://doi.org/10.37358/mp.23.4.5682","url":null,"abstract":"\u0000This study focuses on the covalent functionalization of the carboxylated graphene oxide layers with human serum albumin for developing new nanoplatforms capable of efficient drug loading and release for antitumor therapy. Thus, new GO-HSA conjugates have been developed and their interactions with methotrexate (MTX) molecules were evidenced through FT-IR, UV-Vis and Raman spectroscopy. The cumulative in vitro release profiles of MTX drug from GO-HSA-MTX nanoplatforms were analyzed through UV-Vis spectroscopy showing a more controlled release behavior of MTX drug under acidic conditions that simulate the tumor microenvironment demonstrating the potential use of GO-HSA-MTX as antitumoral nanocarriers.\u0000","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139449990","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}
Metal-composite joints, or hybrid joints are prevalent in aerospace structures due to their high strength and low weight. Such structures are usually found in areas where because of the load configuration, the use of composite materials is possible. Thereby, the analysis of such areas needs to consider both components, the metallic and the composite part. In this paper a hybrid joint is analyzed, consisting of a metallic stiffener, a multilayered honeycomb composite material, and joining fasteners, which constitute the joint between the isotropic and orthotropic materials. The present article has two main purposes: the first is to illustrate a pre-design procedure aimed to evaluate the load-carrying capability of a hybrid joint structure, thereby giving an estimate if the structure can withstand the given loading conditions; the second purpose is to present two types of finite element modeling techniques, one that captures the real geometric structure of the composite material and another which uses a simplified equivalent model, based on the desired level of evaluation of the composite material part. A comparison between the two models is made, highlighting the advantages and disadvantages of the two forms of evaluations. For the metallic parts - stiffener and fasteners, both static and fatigue analyses were performed, as fatigue failure represents the common service failure mode for this type of structural components.
{"title":"Preliminary Hybrid Joint Analysis for Aircraft Structures","authors":"Raul Cormoş, C. Neagoe, Miruna Ciolca","doi":"10.37358/mp.23.4.5687","DOIUrl":"https://doi.org/10.37358/mp.23.4.5687","url":null,"abstract":"\u0000Metal-composite joints, or hybrid joints are prevalent in aerospace structures due to their high strength and low weight. Such structures are usually found in areas where because of the load configuration, the use of composite materials is possible. Thereby, the analysis of such areas needs to consider both components, the metallic and the composite part. In this paper a hybrid joint is analyzed, consisting of a metallic stiffener, a multilayered honeycomb composite material, and joining fasteners, which constitute the joint between the isotropic and orthotropic materials. The present article has two main purposes: the first is to illustrate a pre-design procedure aimed to evaluate the load-carrying capability of a hybrid joint structure, thereby giving an estimate if the structure can withstand the given loading conditions; the second purpose is to present two types of finite element modeling techniques, one that captures the real geometric structure of the composite material and another which uses a simplified equivalent model, based on the desired level of evaluation of the composite material part. A comparison between the two models is made, highlighting the advantages and disadvantages of the two forms of evaluations. For the metallic parts - stiffener and fasteners, both static and fatigue analyses were performed, as fatigue failure represents the common service failure mode for this type of structural components.\u0000","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139449682","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}
This study aimed to investigate the water sorption levels of 3 different condensable bulk fill composites, two flowable bulk fill composites, two microhybrid composites, one nanofilled composite, and one nanohybrid composite material polymerized with the same beam device on the 14th and 30th days.We evaluated nine different composite materials. The materials were prepared as cylindrical blocks (n=7) with a diameter of 7 mm and a thickness of 2 mm and polymerized. Each sample was kept in distilled water for specified times and measured by the ISO 4049 method.We used The Kruskal-Wallis test to compare more than two independent groups where numerical variables had no normal distribution. The Dwass-Steel-Critchlow-Fligner test evaluated differences between the groups if the non-parametric tests were applied. We used The Wilcoxon test to compare the numerical variables without normal distribution (water sorption values in the 14th and 30th-day measurements for each cement material).For water sorption, there was no statistically significant difference between the water sorption values of the resin composite materials on the 14th and 30th days. No statistically significant difference was found in comparing water sorption values between the 14th and 30th measurements for each resin composite material. There is a need for more extended studies by keeping the conditions constant for the evaluated composites and for bulk fill composites to be evaluated with 4mm samples.
{"title":"An Analysis of Water Sorption of Some Composites Used in Dentistry","authors":"Özlem Akyüz Bege�, Hakan Bege�","doi":"10.37358/mp.23.2.5663","DOIUrl":"https://doi.org/10.37358/mp.23.2.5663","url":null,"abstract":"\u0000This study aimed to investigate the water sorption levels of 3 different condensable bulk fill composites, two flowable bulk fill composites, two microhybrid composites, one nanofilled composite, and one nanohybrid composite material polymerized with the same beam device on the 14th and 30th days.We evaluated nine different composite materials. The materials were prepared as cylindrical blocks (n=7) with a diameter of 7 mm and a thickness of 2 mm and polymerized. Each sample was kept in distilled water for specified times and measured by the ISO 4049 method.We used The Kruskal-Wallis test to compare more than two independent groups where numerical variables had no normal distribution. The Dwass-Steel-Critchlow-Fligner test evaluated differences between the groups if the non-parametric tests were applied. We used The Wilcoxon test to compare the numerical variables without normal distribution (water sorption values in the 14th and 30th-day measurements for each cement material).For water sorption, there was no statistically significant difference between the water sorption values of the resin composite materials on the 14th and 30th days. No statistically significant difference was found in comparing water sorption values between the 14th and 30th measurements for each resin composite material. There is a need for more extended studies by keeping the conditions constant for the evaluated composites and for bulk fill composites to be evaluated with 4mm samples.\u0000","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48363727","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}
Ion Durbacă, Nicoleta Sporea, G. Tomescu, A. Dumitrescu
The present paper considers the use of the results of the evaluations carried out by applying the Six Sigma statistical method to improve the vulcanization times of elastomeric composites on the external manufacturing cycle of several size types of car tires. This statistical approach aims to verify the distribution of the measured values of the external vulcanization times between the normal specification limits to optimize them and improve the performance, efficiency, and quality of the automotive tire vulcanization processes. Through the analysis carried out, the operations that caused delays and defects were identified, a program of corrective measures was carried out and after its execution, the fulfillment of the purpose was verified, namely the optimization of external vulcanization times and reducing the number of faulty tires. The new measured values of the vulcanization times were within the normal limits of the imposed specifications (LSS = 2.5). This situation corresponds to achieving a maximum level of performance and represents the successful completion of the quality improvement project.
{"title":"Application of the Six Sigma Method to Improve Vulcanization Times in Automotive Tires","authors":"Ion Durbacă, Nicoleta Sporea, G. Tomescu, A. Dumitrescu","doi":"10.37358/mp.23.2.5660","DOIUrl":"https://doi.org/10.37358/mp.23.2.5660","url":null,"abstract":"\u0000The present paper considers the use of the results of the evaluations carried out by applying the Six Sigma statistical method to improve the vulcanization times of elastomeric composites on the external manufacturing cycle of several size types of car tires. This statistical approach aims to verify the distribution of the measured values of the external vulcanization times between the normal specification limits to optimize them and improve the performance, efficiency, and quality of the automotive tire vulcanization processes. Through the analysis carried out, the operations that caused delays and defects were identified, a program of corrective measures was carried out and after its execution, the fulfillment of the purpose was verified, namely the optimization of external vulcanization times and reducing the number of faulty tires. The new measured values of the vulcanization times were within the normal limits of the imposed specifications (LSS = 2.5). This situation corresponds to achieving a maximum level of performance and represents the successful completion of the quality improvement project.\u0000","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48651407","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}
A. I. Rădoi, M. Stănescu, D. Bolcu, C. Miriţoiu, A. Rosca, M. Bogdan, C. Nicolicescu
In this research some composite materials built in sandwich type style are studied. The lower and upper layers, that reinforce the samples, are made from poplar strips. The core is made from crushed corn cob and the adhesion of all parts (layers and core) is made by using hybrid resins based on a combination from dammar resin and the synthetic acrylic one (with its hardener). The static and dynamic mechanical behaviour by testing the samples to tensile and bending were studied. Two types of hybrid resins were used: one abbreviated as type B with the percentage of 60% dammar and 40% acrylic resin with hardener and one abbreviated as type C with the percentage of 65% dammar and 35% acrylic resin with hardener. A general conclusion from this study it was: the mechanical properties decrase with the dammar percentage increase. This fact can be explained by the decreased mechanical properties of the natural dammar resin compared to the synthetic acylic on
{"title":"About Some Mechanical Properties Regarding Sandwich Samples Reinforced with Poplar Strips and the Core from Crushed Corn Cobs with Hybrid Dammar-Based Matrix","authors":"A. I. Rădoi, M. Stănescu, D. Bolcu, C. Miriţoiu, A. Rosca, M. Bogdan, C. Nicolicescu","doi":"10.37358/mp.23.2.5666","DOIUrl":"https://doi.org/10.37358/mp.23.2.5666","url":null,"abstract":"\u0000In this research some composite materials built in sandwich type style are studied. The lower and upper layers, that reinforce the samples, are made from poplar strips. The core is made from crushed corn cob and the adhesion of all parts (layers and core) is made by using hybrid resins based on a combination from dammar resin and the synthetic acrylic one (with its hardener). The static and dynamic mechanical behaviour by testing the samples to tensile and bending were studied. Two types of hybrid resins were used: one abbreviated as type B with the percentage of 60% dammar and 40% acrylic resin with hardener and one abbreviated as type C with the percentage of 65% dammar and 35% acrylic resin with hardener. A general conclusion from this study it was: the mechanical properties decrase with the dammar percentage increase. This fact can be explained by the decreased mechanical properties of the natural dammar resin compared to the synthetic acylic on\u0000","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43320013","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}
To attain good geometric shape and size, machining of high-strength metal Fiber laminate becomes inevitable in the field of automotive industries. In this research, aluminum foam sandwiched with glass fiber reinforced polymer (GFRP) composites fabricated using a hand layup process. The glass Fiber composite was fabricated using aluminum foam with a thickness of 1 mm. The effect of abrasive water jet parameters such as pressure (P), stand-off distance (L), and nozzle diameter (D) on material removal rate (MRR) and Kerf angle (Ka) and Surface roughness were investigated. The results were compared without aluminum foam composites. Glass fiber composites with aluminum foam reduced the kerf angle by 44.18 %, and surface roughness (Ra) by 41.77 % as compared with glass fiber composites without aluminum foam. From the investigation, it was noticed that maximum pressure (220 Bar) and minimum stand-off distance (1mm) were optimum parameters for reducing the kerf angle and surface roughness. Also, Optical images of the hole were analyzed for surface quality.
{"title":"Effect of Abrasive Water Jet Parameters on the Drilling of Aluminum Foam Sandwiched with Glass Fiber Polymer Composites","authors":"Madhan Kumar Subramani, Sivakumar Krishnamurthy, Chandradass Jeyaseelan","doi":"10.37358/mp.23.2.5658","DOIUrl":"https://doi.org/10.37358/mp.23.2.5658","url":null,"abstract":"To attain good geometric shape and size, machining of high-strength metal Fiber laminate becomes inevitable in the field of automotive industries. In this research, aluminum foam sandwiched with glass fiber reinforced polymer (GFRP) composites fabricated using a hand layup process. The glass Fiber composite was fabricated using aluminum foam with a thickness of 1 mm. The effect of abrasive water jet parameters such as pressure (P), stand-off distance (L), and nozzle diameter (D) on material removal rate (MRR) and Kerf angle (Ka) and Surface roughness were investigated. The results were compared without aluminum foam composites. Glass fiber composites with aluminum foam reduced the kerf angle by 44.18 %, and surface roughness (Ra) by 41.77 % as compared with glass fiber composites without aluminum foam. From the investigation, it was noticed that maximum pressure (220 Bar) and minimum stand-off distance (1mm) were optimum parameters for reducing the kerf angle and surface roughness. Also, Optical images of the hole were analyzed for surface quality.","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48060809","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}
The structure of polyurethane and the physico-chemical properties of its components are considered. The most promising modifiers have been selected: TiO2, CaCO3. The features of the preparation of the studied polyurethane mixture, its composition, manufacturing technology and equipment are described in detail. The geometric properties, manufacturing processes and testing methods of samples are presented. The graphical dependencies of the influence of the parameters of sample preparation on their mechanical properties such as hardness, tensile stress at break, Jung s modulus are given. The rational parameters of the technology for the production of samples modified with fillers to give them stable mechanical properties have been set. The maximum proportions of these fillers in polyurethane rubber are limited to 30-35%. It is proved that the addition of TiО2 and CaCО3 to the composition of polyurethane rubbers gives them special properties that allow them to expand the range of their industrial usage.
{"title":"The Mechanical Properties Improvement of Polyurethane Rubbers by Using Titanium Oxide and Calcium Carbonate Modifiers (Additives)","authors":"Antypas Imad Rezakalla, Sirotenko Andrey","doi":"10.37358/mp.23.2.5667","DOIUrl":"https://doi.org/10.37358/mp.23.2.5667","url":null,"abstract":"\u0000The structure of polyurethane and the physico-chemical properties of its components are considered. The most promising modifiers have been selected: TiO2, CaCO3. The features of the preparation of the studied polyurethane mixture, its composition, manufacturing technology and equipment are described in detail. The geometric properties, manufacturing processes and testing methods of samples are presented. The graphical dependencies of the influence of the parameters of sample preparation on their mechanical properties such as hardness, tensile stress at break, Jung s modulus are given. The rational parameters of the technology for the production of samples modified with fillers to give them stable mechanical properties have been set. The maximum proportions of these fillers in polyurethane rubber are limited to 30-35%. It is proved that the addition of TiО2 and CaCО3 to the composition of polyurethane rubbers gives them special properties that allow them to expand the range of their industrial usage.\u0000","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42315231","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}
Andrei Prada, F. Blaga, Stefan Mihaila, Mihai Agud
In this paper, the authors propose to carry out a case study, on a visual part made of thermoplastic material from the automotive industry. Using the most up-to-date CAE systems, we will try to highlight the main appearance problems in long parts, namely the appearance of weld lines at the meeting of the flow fronts. The part will be processed using sequential, as well as non-sequential injection systems, respectively, in order to highlight the difference between the two, respectively to compare these two tests with the results of rheological simulation (CAE).
{"title":"Experimental Research Regarding the Defects Occurring at the Injection-molding of Long Technical Parts, Made of Thermoplastic Material, Using CAE Systems. Case Study","authors":"Andrei Prada, F. Blaga, Stefan Mihaila, Mihai Agud","doi":"10.37358/mp.23.2.5668","DOIUrl":"https://doi.org/10.37358/mp.23.2.5668","url":null,"abstract":"\u0000In this paper, the authors propose to carry out a case study, on a visual part made of thermoplastic material from the automotive industry. Using the most up-to-date CAE systems, we will try to highlight the main appearance problems in long parts, namely the appearance of weld lines at the meeting of the flow fronts. The part will be processed using sequential, as well as non-sequential injection systems, respectively, in order to highlight the difference between the two, respectively to compare these two tests with the results of rheological simulation (CAE).\u0000","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47484672","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}
A. Bolcu, M. Stănescu, D. Bolcu, I. Ciuca, A. Diniță, M. Bogdan, F. Badea
Using the experimental determinations obtained on the basis of compressive stress, some mechanical properties were studied for composite materials with the matrix of three types of resin, epoxy, unsaturated polyester and hybrid based on Dammar natural resin, which was reinforced with isophthalic resin granules NPG (Neopentyl Glycol) Chromat Kayan / Javari / Payette type. The stress-strain diagrams, compressive yield strength, compressive strength and modulus of elasticity in uniaxial compression were obtained. With the EDS analysis, the graphical distribution of the atomic spectra of the elements identified in the hybrid resin was determined and the image of the fracture surface of a hybrid resin specimen was presented based on the stereomicroscopic analysis (SEM).
{"title":"The Study of Some Mechanical Properties of Some Composite Materials with Different Types of Matrices and Reinforcement from Chromat-type Isophthalic Resin Granules NPG","authors":"A. Bolcu, M. Stănescu, D. Bolcu, I. Ciuca, A. Diniță, M. Bogdan, F. Badea","doi":"10.37358/mp.23.2.5656","DOIUrl":"https://doi.org/10.37358/mp.23.2.5656","url":null,"abstract":"\u0000Using the experimental determinations obtained on the basis of compressive stress, some mechanical properties were studied for composite materials with the matrix of three types of resin, epoxy, unsaturated polyester and hybrid based on Dammar natural resin, which was reinforced with isophthalic resin granules NPG (Neopentyl Glycol) Chromat Kayan / Javari / Payette type. The stress-strain diagrams, compressive yield strength, compressive strength and modulus of elasticity in uniaxial compression were obtained. With the EDS analysis, the graphical distribution of the atomic spectra of the elements identified in the hybrid resin was determined and the image of the fracture surface of a hybrid resin specimen was presented based on the stereomicroscopic analysis (SEM).\u0000","PeriodicalId":18360,"journal":{"name":"Materiale Plastice","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44181002","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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