Materials Science and Engineering Commons^™

Tin-Silver As A Novel Biodegradable Metallic Biomaterial, Charley Goodwin

All Dissertations

The Essure device is a non-hormonal, minimally-invasive, permanent female sterilization implant, removed from the market due to an increase in adverse events, hypothesized to be caused by corrosion of the Sn-Ag component of the implant. The goals of this dissertation were to first develop implant retrieval methods for Essure devices and surrounding tissue, documenting signs of degradation and metallic degradation products, then to characterize the electrochemical behavior of Sn-Ag in biologically representative environments and finally, to assess the biological interaction of Sn-Ag. Retrieval analyses developed successful methods, qualifying the degree of corrosion, primarily of the Sn-Ag component and finding Sn …

Sliding Markov Decision Processes For Dynamic Task Planning On Uncrewed Aerial Vehicles, Trent Wiens

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Mission and flight planning problems for uncrewed aircraft systems (UASs) are typically large and complex in space and computational requirements. With enough time and computing resources, some of these problems may be solvable offline and then executed during flight. In dynamic or uncertain environments, however, the mission may require online adaptation and replanning. In this work, we will discuss methods of creating MDPs for online applications, and a method of using a sliding resolution and receding horizon approach to build and solve Markov Decision Processes (MDPs) in practical planing applications for UASs. In this strategy, called a Sliding Markov Decision …

Dynamic Impact Testing And Numerical Analysis Of Non-Proprietary Astm F2656-20 M50 Anti-Ram Barrier Components, Weston Kelley

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

In a post-9/11 world, hostile actors are using vehicles as weapons to inflict civilian casualties. Pedestrians, vulnerable road users, military personnel, and police may be targeted using a vehicle as a weapon. The United States Department of Defense (DoD) also utilizes Entry Control Facilities (ECFs) which are carefully designed transportation corridors to manage how threat vehicles are able to access military facilities. In 2004, DoD started to upgrade all ECFs using both passive and active barriers. Many anti-ram vehicle barriers were evaluated according to the criteria established in ASTM F2656, but to date few options are available which are (1) …

Effects Of Bending And Re-Bending On Mechanical Properties Of Locally-Manufactured Steel Rebars, Patrick W. Waruhiu, Simon I. Marandu, Mussa I. Mgwatu

Tanzania Journal of Science

Steel rebars experience deformation when subjected to bending and re-bending operations. Subsequently, their microstructures are impaired thus affecting the mechanical properties and leading to failure. This study establishes the effects of bending and re-bending the steel rebars on the mechanical properties. Experiments were conducted to determine the effects of bending and re-bending of the steel rebars. Testing was conducted on Ten virgin and Thirty specimens which were bent and re-bent at 45º, 90º, and 180º, and followed by tensile tests. Yield strength, ultimate tensile strength, elongation, and ultimate tensile strength to yield strength ratio (Rm/Re), were recorded. Results showed the …

Study Of Reactive Distillation Equipment For Eterification Process, Abbos Elmanov, Abdulaziz Bakhtiyorov, Adham Norkobilov, Olimjon Maksudov, Zarif Oripov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this work is to study the chemical technological processes for eterification processes, and the reactive distillation unit, which carries out the reaction and separation process in one device, was chosen as the object of research. А reаctive distillаtion system is exаmined to produce for the production of Ethyl Acetate (EtAc) viа eterificаtion of acetic acid (HAc) with ethаnol. Optimizаtion methods using sensitivity analysis аre аlso conducted. Cаlculаtion of vаpor liquid equilibrium of the mixture system is done using UNIFАC model. Heat integration from the distillate stream of the column to the acid feed stream and from bottom …

Numerical Calculation Of The Flame Spreading Over A Methane Hydrate Surface, Otabek Nigmatov, Oksana Ismailova

CHEMISTRY AND CHEMICAL ENGINEERING

The Methane Hydrate is expected as an energy source and is being as a medium distance transport means of natural gas alternative of LNG (Liquefied Natural Gas). During the natural gas transportation, fire accidents are concerned. In the present study, the flame spreading over a methane hydrate surface has been studied numerically as a function of hydrate surface temperature, T_s. When T_s = 173 K (-100℃), lower than the dissociation temperature (T_d = 183 K (-90℃)), the flame spreading speed is around 6.5 mm/s, while the flame spreading speed at T_s = 193 K (-80℃), …

Dft Study Of Quantum Chemical Parameters Of 4-Amino-2-Mercaptobenzimidazole And Their Tautomeric Forms, Dilnoza Rahmonova, Alisher Eshimbetov, Lobar Gapurova, Zuhra Ch. Kadirova, Shakhnoza Kadirova

CHEMISTRY AND CHEMICAL ENGINEERING

Coordination competing donor centers, electronic and geometric structures of the 4-amino-2-mercaptobenzimidazole ligand molecule were studied using quantum chemical calculation by the DFT / 6-31G method (d, p). It was shown that during the formation of the metal complex, the ligand is coordinated through the localized nitrogen atom of the imidazole ring. In this study, the total energies (Etot) of 4-amino-2-mercaptobenzimidazole (1) and its tautomeric forms (2 and 3) were calculated. And also, the energies of boundary molecular orbitals, the energy gap between boundary MOs (ΔE) and the distribution of the total charge on atoms and boundary orbitals were determined. In …

The Effect Of Hydrogen Peroxide And Potassium Amylxanthate On The Surface Properties Of Chalcocite And Enargite, Berdakh T. Daniyarov, Hajime Miki, Daminbek A. Ziyatov, Shahlo Daminova

CHEMISTRY AND CHEMICAL ENGINEERING

The effect on the surface properties and floatability of chalcocite and enargite after oxidative treatment with hydrogen peroxide (H₂O₂) in the presence and absence of potassium amylxanthate (PAX) as a collector was studied. In this research, flotation tests were carried out on mixed and individual minerals. Oxidative treatment with hydrogen peroxide had a negative effect on the floatability of chalcocite and enargite. PAX adsorption analysis shows that enargite adsorbs PAX faster than chalcocite. Moreover, Fourier transform infrared spectroscopy analysis shows that PAX was adsorbed in the form of copper amylxanthate on chalcocite and enargite surfaces. In …

Influence Of The Amount Of Monoethanolamine On The Physicochemical Properties Of Aminolysis Products, Soxibjon A. Egamberdiyev, Muzaffar G. Alimukhamedov, Juraev Asror, Ravshan Adilov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this paper is to investigate the process of aminolysis of secondary polyethylene terephthalate with monoethanolamine at low ratio. The effect of the amount of monoethanolamine on the physical and chemical properties of the aminolysis product of secondary polyethylene terephthalate was studied. With an increase of 1-4 moles of monoethanolamine obtained for synthesis (without the presence of a catalyst), it was observed that the number of amines in the aminolysis product increased from 324 to 503 mgKON/g, and the number of hydroxyls increased from 298 to 491 mgKON/g. The structure of the resulting bis(2-hydroxyethylene)terephthalamide was studied using IR …

Study Of The Structure Of Glass Ionomer Cements Developed Based On Glass System Sio2-Al2o3-Cao-Zno-P2o5-Caf2, Tatyana O. Nam, Mastura X. Aripova, Ripsime V. Mkrtchyan

CHEMISTRY AND CHEMICAL ENGINEERING

The goal was to study the structure of glass ionomer cements (GIC) developed on the basis of glasses of the SiO₂-Al₂O₃-CaO-ZnO-P₂O5-CaF₂ system. Glass powders with sizes less than 50 μm were sealed with a 40% solution of polyacrylic acid and after 72 hours, electron microscopic examination was carried out on a JSM-IT200 scanning microscope (JEOL, Japan). All samples demonstrate a cellular structure consisting of glass particles surrounded by glass elements that have entered into an acid-ion interaction with polyacrylic acid in a polymer matrix. GIC-4 and GIC-6 show the most …

Impact Of Sulfurization On Sputtered Bivo4 Thin Films, Shukur P. Gofurov, Dilbar T. Bozorova, Zuhra Ch, Kadirova, Oksana Ismailova

CHEMISTRY AND CHEMICAL ENGINEERING

The sulfurization method has been used to decrease the band gap of the BiVO₄ structure, reduce the recombination of electrons and holes, and increase the photoelectrochemical performance of this material. It has been observed that incorporation of sulfur into stoichiometric and V_rich BiVO₄ is variously affected changing of properties of the structure. Sulfurization can modify V_rich BiVO₄ structure rather than stoichiometric BiVO₄.

Development Of Clinker And Portland Cement Composition Based On Surkhondaryo Raw Materials, Salohiddin Ramazanov, Abdumalik Nabiyev, Mastura Aripova

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this research work is to develop clinker and Portland cement compositions based on Surkhandarya raw materials for the planned construction of a cement plant, as well as to study their physical and chemical properties. The compositions of clinkers, including limestone, clay from the Yolgizbulok deposit and slag from the Almalyk mining and metallurgical plant, were studied. The optimal clinker composition was selected, on the basis of which Portland cement was obtained. The optimal amount of gypsum addition was determined to achieve a cement stone strength of 43,5 MPa. The developed clinker composition will provide the planned enterprise …

Antibacterial Cerium-Containing Glazes For Ceramic Tiles, Ivan Levitskiy, Mastura Aripova, Mihail Dyadenko, Dar’Ya Kucherova, Artem Golub

CHEMISTRY AND CHEMICAL ENGINEERING

The results of research on the production of semi-fritted cerium-containing glazes used for ceramic tiles are presented.

A multicomponent raw material mixture based on dolomite, cerium dioxide CeO₂, aluminosilicate multicalcium frit and permanent components including feldspar, alumina and clay components (kaolin and refractory clay) is used to produce glazes.

The characteristics of the obtained coatings were studied: appearance, technological and physico-chemical properties, including antibacterial properties in relation to the strains of Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538. The influence of temperature parameters on the formation of glaze coatings, as well as their structure and phase …

Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang

Karbala International Journal of Modern Science

Biaxial-oriented polypropylene (BOPP) films are characterized by unfavorable aging behavior because of their poor susceptibility to high temperatures, humidity, and high electric fields. This makes them unqualified to withstand harsh operating conditions, such as in capacitor applications. This study investigates the impact of annealing BOPP samples at 100 °C for five hours after fluorination at different times (15, 30, and 60 minutes) on their electrical and mechanical performance under electro-thermal stresses. Scanning electron microscope (SEM) images confirm that there is an increase in surface roughness and the formation of a dense layer of fluorine-containing groups monotonically with fluorination time. So, …

Hardness Of Single Phase High Entropy Carbide Ceramics With Different Compositions, Paul M. Brune, Gregory E. Hilmas, William G. Fahrenholtz, Jeremy Lee Watts, Caillin J. Ryan, Chris M. Desalle, Douglas E. Wolfe, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Five High Entropy Carbide Ceramics, (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)C, (Cr0.2,Hf0.2,Ta0.2,Ti0.2,Zr0.2)C, (Hf0.2,Mo0.2,Ta0.2,Ti0.2,Zr0.2)C, (Hf0.2,Ta0.2,Ti0.2,W0.2,Zr0.2)C, and (Hf0.2,Mo0.2,Ti0.2,W0.2,Zr0.2)C, Were Synthesized by Carbothermal Reduction of Oxides and Direct Current Sintering. the Five High Entropy Carbide Ceramics Were Determined to Be Nominally Phase-Pure with Relative Densities of More Than 98.9% and Mean Grain Sizes of Less Than 5 Μm. Average Vickers Hardness Values Ranged from 19.2 ± 0.4 GPa for (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)C at a Load of 2 Kgf to 43.5 ± 0.4 GPa for (Hf0.2,Mo0.2,Ti0.2,W0.2,Zr0.2)C at a Load of 0.05 Kgf. Hardness Generally Increased with Increasing the Valence Electron Concentration and Strain as Measured by the Williamson-Hall Analysis. However, Neither …

Theoretical Model Of Femtosecond Coherence Spectroscopy Of Vibronic Excitons In Molecular Aggregates, Alexander J. Rode, Paul C. Arpin, Daniel B. Turner

Materials Science and Engineering Faculty Publications and Presentations

When used as pump pulses in transient absorption spectroscopy measurements, femtosecond laser pulses can produce oscillatory signals known as quantum beats. The quantum beats arise from coherent superpositions of the states of the sample and are best studied in the Fourier domain using Femtosecond Coherence Spectroscopy (FCS), which consists of one-dimensional amplitude and phase plots of a specified oscillation frequency as a function of the detection frequency. Prior works have shown ubiquitous amplitude nodes and π phase shifts in FCS from excited-state vibrational wavepackets in monomer samples. However, the FCS arising from vibronic-exciton states in molecular aggregates have not been …

Towards A Practical Method For Monitoring Kinetic Processes In Polymers With Low-Frequency Raman Spectroscopy, Robert Vito Chimenti

Theses and Dissertations

Unlike liquids and crystalline solids, glassy materials exist in a constant state of structural nonequilibrium. Therefore, a comprehensive understanding of material kinetics is critical for understanding the structure-property-processing relationships of polymeric materials. Amorphous materials universally display low-frequency Raman features related to the phonon density of states resulting in a broad disorder band for Raman shifts below 100 cm-1, which is related to the conformational entropy and the modulus. This disorder band is dominated by the Boson peak, a feature due to phonon scattering because of disorder and can be related to the transverse sound velocity of the material, and a …

Low Impedance, Durable, Self-Adhesive Hydrogel Epidermal Electrodes For Electrophysiology Recording, Naiyan Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditional electrodes used for electrophysiology recording, characterized by their hard, dry, and inanimate nature, are fundamentally mismatched with the soft, moist, and bioactive characteristics of biological tissues, leading to suboptimal skin-electrode interfaces. Hydrogel materials, mirroring the high water content and biocompatibility of biological tissues, emerge as promising candidates for epidermal electronic materials due to their adjustable physicochemical properties. However, challenges such as inadequate electrical conductivity, elevated skin impedance, unreliable adhesion in moist conditions, and performance decline from dehydration have significantly restricted the efficacy and applicability of hydrogel-based electrodes. In this thesis, we report a high-performance hydrogel epidermal electrode patch for …

Deep Selenium Donors In Zngep2 Crystals: An Electron Paramagnetic Resonance Study Of A Nonlinear Optical Material, Timothy D. Gustafson, Larry E. Halliburton, Nancy C. Giles, Peter G. Schunemann, Kevin T. Zawilski, J. Jesenovec, Kent L. Averett, Jonathan E. Slagle [*]

Faculty Publications

Zinc germanium diphosphide (ZnGeP₂) is a ternary semiconductor best known for its nonlinear optical properties. A primary application is optical parametric oscillators operating in the mid-infrared region. Controlled donor doping provides a method to minimize the acceptor-related absorption bands that limit the output power of these devices. In the present study, a ZnGeP₂ crystal is doped with selenium during growth. Selenium substitutes for phosphorus and serves as a deep donor. Significant concentrations of native defects (zinc vacancies, germanium-on-zinc antisites, and phosphorous vacancies) are also present in the crystal. Electron paramagnetic resonance (EPR) is used to establish the …

Adopting Information System Technologies In Construction Project Management, Hadi Haikal

Harrisburg University Dissertations and Theses

The construction sector has remained late in integrated information systems' adopting process to perform the system improving processes. Lack of adoption of technology has been a root cause of the early issues they faced, such as budgetary and scheduling overshoots, quality defects, safety occurrences, and generally poor communication and coordination among the stakeholders. This research looks into the benefits and challenges, the key success factors, and the implications of using an array of information systems, including building information modeling (BIM), artificial intelligence (AI), Internet of Things (IoT) sensing, and enterprise systems, to comprehensively address issues in project management in construction …

Processing And Testing Commodity And Engineering Cfrtp Composites, Delia M. Derner, Kristine Osorio

Research & Creative Achievement Day

Commodity thermoplastic polymers provide good load transfer to and protection of the reinforcing fibers.  However, their mechanical properties are inferior to high-performance thermoplastic polymer composites.  Findings of preliminary research conducted at WSU showed that continuous fiber reinforced (CFR) commodity polymers such as PETG and PP have better Izod impact resistance than their high-performance CFR counterparts.  Further investigation of these findings is conducted in this research project.  Quasi-isotropic laminates of GF/PETG and GF/PET-am are fabricated and tested in drop weight impact.  The results will be compared with previously determined results of high-performance CF/PPS, CF/PA12 and GF/PPS.  The samples are fabricated using …

Low-Velocity Drop Weight Impact And Compression After Impact Properties Of Symmetric Quasi-Isotropic Cfrtp Composites, Youyi Zhou, Kyungbin Min

Research & Creative Achievement Day

Low-velocity impact properties and residual compression strength after impact performance are used to evaluate composite materials for many applications. In this research, low-velocity drop-weight impact and compression after impact performance of four continuous fiber reinforcement thermoplastic (CFRTP) composites are investigated. Quasi-isotropic samples of GF/PP, CF-PA12, CF-PA6, GF-PA6 were fabricated and tested according to ASTM standards. Three energy levels of 10, 15, and 20 J/mm, were employed in this research. Results indicate that GF/PP exhibits the highest damage resistance and rebound-ability, evidenced by its minimal indentation and damage area, the highest significant damage threshold force, and the highest ratio of impact …

Ergo Carbon Workspace, Ethan C. Atkinson, Joshua N. Hanner, Rachel A. Henderson, Anders Nielsen, Mohamed A. Salat

Research & Creative Achievement Day

The goal of the Ergo Carbon Workspace is to create a monitor stand that is both lightweight and easily transportable, catering to the needs of modern workspaces. Constructed from carbon fiber, epoxy resin, and a honeycomb core, this design emphasizes portability without sacrificing durability. Incorporating aerospace-grade honeycomb core as well as braided carbon fiber epoxy struts bolsters structural integrity while maintaining a lightweight part. The Ergo Carbon Workspace design facilitates effortless assembly and disassembly, simplifying transportation and packaging. Through the utilization of composite materials, the stand achieves an optimal balance of strength and portability. Ergo Carbon Workspace will also incorporate …

Mechanical Characterization Of Hemp, Jute, And Flax Based Natural Fibre Composites For Non-Structural Applications In Aircraft And Automobiles, Ravi Kumar B

Theses and Dissertations

Demand for reducing energy consumption and detrimental environmental impacts after the effective lifetime of an engineering material are the major driving factors for the development of natural fibre reinforced composites (NFRCs) in various sectors. Compared to synthetic fibre like carbon-fibres or Kevlar, natural fibres provide several benefits including light weight, inexpensive, recyclability, superior specific strength, biodegradable, non-toxic during handling, and less energy intensive during manufacturing. This doctoral work presents observations from mechanical tests and interpretations on the suitability of natural fibre reinforced composites for less heavily loaded engineering applications areas.

In the first stage, jute, flax, and hemp fibres were …

Achieving Room Temperature Plasticity In Brittle Ceramics Through Elevated Temperature Preloading, Chao Shen, Jin Li, Tongjun Niu, Jaehun Cho, Zhongxia Shang, Yifan Zhang, Anyu Shang, Bo Yang, Ke Xu, R. Edwin Garcia, Haiyan Wang, Xinghang Zhang

Purdue University Libraries Open Access Publishing Fund

Ceramic materials with high strength and chemical inertness are widely used as engineering materials. However, the brittle nature limits their applications as fracture occurs before the onset of plastic yielding. There has been limited success despite extensive efforts to enhance the deformability of ceramics. Here we report a method for enhancing the room temperature plastic deformability of ceramics by artificially introducing abundant defects into the materials via preloading at elevated temperatures. After the preloading treatment, single crystal (SC) TiO2 exhibited a substantial increase in deformability, achieving 10% strain at room temperature. SC α-Al2O3 also showed plastic deformability, 6 to 7.5% …

Decoding Crystallization Behavior Of Aluminoborosilicate Glasses: From Structural Descriptors To Quantitative Structure – Property Relationship (Qspr) Based Predictive Models, Yingcheng Zhang, Marco Bertani, Alfonso Pedone, Randall E. Youngman, Gregory Tricot, Aditya Kumar, Ashutosh Goel

Materials Science and Engineering Faculty Research & Creative Works

Successful decoding of structural descriptors controlling the crystallization in multicomponent functional glasses can pave the way for the transition from the trial-and-error approach and empirical modeling for glass/glass-ceramic composition design toward more rational and scientifically rigorous Quantitative Structure-Property Relationship (QSPR) based models. However, due to the compositional and structural complexity of multicomponent glasses and the longer time and length scales associated with nucleation, the development and validation of QSPR models are still in it's infancy. The work presented in the article is an attempt to leap forward in this pursuit by combining the strengths of experimental and computational materials science …

Application Of The Immobilized Low-Activity Waste Glass Corrosion Model To The Static Dissolution Of 24 Statistically-Designed Alkali-Borosilicate Waste Glasses, Sebastien N. Kerisit, James J. Neeway, Charmayne E. Lonergan, Benjamin Parruzot, Jarrod V. Crum, Richard C. Daniel, Gary L. Smith, R. Matthew Asmussen

Materials Science and Engineering Faculty Research & Creative Works

Glass corrosion models that capture the complex mechanisms of the glass-water reaction enable the prediction of nuclear waste glass durability in disposal scenarios. Parameterization of such models is challenging because of the need to capture changes in corrosion behavior with time, reaction conditions, and glass composition. Here, we describe and employ the ILAW (immobilized low-activity waste) glass corrosion model (IGCM) in geochemical simulations of static dissolution tests, at two temperatures (40 °C and 90 °C), for a matrix of 24 enhanced low-activity waste (eLAW) glasses statistically designed to cover a processable composition space defined by 8 major glass components (Al …

Detection Of Endocrine-Disrupting Chemicals In Personal Care Products Using A Polyhedral Oligomeric Silsesquioxane-Based Hybrid Material, Aarthi K

Theses and Dissertations

Personal care products (cosmetics) are a diverse group of goods, that includes all the essential routines including the personal hygiene products used in our day-to-day life. It contains a variety of ingredients in its formulation, including preservatives, flavor, UV filters, and other additives. Few of the chemicals utilized are found to impair human health and have serious environmental impacts. The major chemicals include parabens, triclosan, oxybenzone, phthalates, heavy metals, fragrances, etc, Though the Scientific Committee on Consumer Safety (SCCS) has set the usage limits for the chemicals used, exposure to these chemicals from multiple products may exceed the exposure limit. …

Influence Of Eco-Friendly Agar-Derivatives On The Electrochemical Performance Of Carbon Felts Electrodes Of Vanadium Redox Flow Battery, Abdulmonem Fetyan, Ayoob Alhammadi, Zineb Matouk, Anugrah Andisetiawan, Ahmed Bahaa

All Works

In this study, bio-derived natural agar powder was used as an electrocatalyst for application as an electrode in all‑vanadium redox flow batteries. Different concentrations of agar solution were tested, and cyclic voltammetry studies confirmed that agar loaded felts have good catalytic activity toward both redox couples V4+/V5+ at the positive and V2+/V3+ at the negative side. Energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy demonstrated the presence of higher amount of oxygen-functional groups on the surface of the fibers. Contact angle measurements demonstrated an enormous increase in hydrophilicity of the felts treated with agar. Long-term charge/discharge profiles revealed 6 % …

Mechanical Characterization And Evaluation Of Additively Manufactured Titanium 5v-5mo-5al-3cr Alloy, Zachary Casias

Mechanical Engineering ETDs

Ti-5V-5Mo-5Al-3Cr (Ti-5553) is a near beta titanium alloy commonly used in aerospace applications. It is currently being explored for additive manufacturing (AM), but the fatigue behavior of this AM alloy needs to be well-understood for adoption in aerospace applications. The present work examines the tensile and fatigue behavior of LPBF manufactured Ti-5553. The effect of post-print heat treatments, effects of surface roughness, and print defects on the mechanical properties of AM Ti-5553 were also evaluated. Fatigue lives of as-LPBF and BAA material are nearly identical, and both are far below the fatigue lives of conventionally manufactured Ti-5553 of 350 MPa. …