Mitigating Carbon Emissions:A Comprehensive Analysis of Transitioning to Hydrogen-Powered Plants in Japan’s Energy Landscape Post-Fukushima

One of the impacts of the Fukushima disaster was the shutdown of all nuclear power plants in Japan,reaching zero production in 2015.In response,the country started importing more fossil energy including coal,oil,and natural gas to fill the energy gap.However,this led to a significant increase in carbon emissions,hindering the efforts to reduce its carbon footprint.In the current situation,Japan is actively working to balance its energy requirements with environmental considerations,including the utilization of hydrogen fuel.Therefore,this paper aims to explore the feasibility and implications of using hydrogen power plants as a means to reduce emissions,and this analysis will be conducted using the energy modeling of the MARKAL-TIMES Japan framework.The hydrogen scenario(HS)is assumed with the extensive integration of hydrogen into the power generation sector,supported by a hydrogen import scheme.Additionally,this scenario will be compared with the Business as Usual(BAU)scenario.The results showed that the generation capacities of the BAU and HS scenarios have significantly different primary energy supplies.The BAU scenario is highly dependent on fossil fuels,while the HS scenario integrates hydrogen contribution along with an increase in renewable energy,reaching a peak contribution of 2,160 PJ in 2050.In the HS scenario,the target of reducing CO_(2) emissions by 80%is achieved through significant hydrogen penetration.By 2050,the total CO_(2) emissions are estimated to be 939 million tons for the BAU scenario and 261 million tons for the Hydrogen scenario.In addition,the contribution of hydrogen to electricity generation is expected to be 153 TWh,smaller than PV and wind power.

Multiscale design and biomechanical evaluation of porous spinal fusion cage to realize specified mechanical properties

Backgrou nd Dense titanium(Ti)fusion cages have been commonly used in transforaminal lumbar interbody fusion.However,the stiffness mismatch between cages and adjacent bone endplates increases the risk of stress shielding and cage subsidence.Methods The current study presents a multiscale optimization approach for porous Ti fusion cage development,including microscale topology optimization based on homogenization theory that obtains a unit cell with prescribed mechanical properties,and macroscale topology optimization that determines the layout of framework structure over the porous cage while maintaining the desired stiffness.The biomechanical performance of the designed porous cage is assessed using numerical simulations of fusion surgery.Selective laser melting is employed to assists with fabricating the designed porous structure and porous cage.Results The simulations demonstrate that the designed porous cage increases the strain energy density of bone grafts and decreases the peak stress on bone endplates.The mechanical and morphological discrepancies between the as-designed and fabricated porous structures are also described.Conclusion From the perspective of biomechanics,it is demonstrated that the designed porous cage contributes to reducing the risk of stress shielding and cage subsidence.The optimization of processing parameters and post-treatments are required to fabricate the designed porous cage.The present multiscale optimization approach can be extended to the development of cages with other shapes or materials and further types of orthopedic implants.

Circumferential variation in mechanical characteristics of porcine descending aorta

Arterial characterization of healthy descending thoracic aorta(DTA)is indispensable in determining stress distributions across wall thickness and different regions that may be responsible for aorta inhomogeneous dilation,rupture,and dissection when aneurysm occurs.Few studies have shown the inhomogeneity of DTA along the aorta tree considering changes in circumferential direction.The present study aims to clarify the circumferential regional characterization of DTA.Porcine DTA tissues were tested according to region and orientation using uniaxial tension.For axial test,results show that the difference in circumferential direction was mainly in collagen fiber modulus,where the anterior collagen fiber modulus was significantly lower than the posterior quadrant.For circumferential test,the difference in circumferential direction was mainly in the recruitment parameter,where the circumferential stiffness is significantly higher in the posterior region at physiological maximum stress.The proximal posterior quadrant and left quadrant showed significantly lower axial collagen fiber stiffness than the right and anterior quadrants,which may be a factor in aneurysm development.Furthermore,the constitutive parameters for similar detailed regions can be used by biomedical engineers to investigate improved therapies and thoroughly understand the initial stage of aneurysm development.The regional collagen fiber modulus can help improve our understanding of the mechanisms of arterial dilation and aortic dissection.

Friction behaviors in the metal cutting process:state of the art and future perspectives

Material removal in the cutting process is regarded as a friction system with multiple input and output variables.The complexity of the cutting friction system is caused by the extreme conditions existing on the tool–chip and tool–workpiece interfaces.The critical issue is significant to use knowledge of cutting friction behaviors to guide researchers and industrial manufacturing engineers in designing rational cutting processes to reduce tool wear and improve surface quality.This review focuses on the state of the art of research on friction behaviors in cutting procedures as well as future perspectives.First,the cutting friction phenomena under extreme conditions,such as high temperature,large strain/strain rates,sticking–sliding contact states,and diverse cutting conditions are analyzed.Second,the theoretical models of cutting friction behaviors and the application of simulation technology are discussed.Third,the factors that affect friction behaviors are analyzed,including material matching,cutting parameters,lubrication/cooling conditions,micro/nano surface textures,and tool coatings.Then,the consequences of the cutting friction phenomena,including tool wear patterns,tool life,chip formation,and the machined surface are analyzed.Finally,the research limitations and future work for cutting friction behaviors are discussed.This review contributes to the understanding of cutting friction behaviors and the development of high-quality cutting technology.

Amine-functionalized mesoporous UiO-66 aerogel for CO_(2) adsorption

A mesoporous UiO-66-NH_(2) aerogel is prepared via a straightforward sol-gel method without using any binders or mechanical pressures, in which the amine groups are directly introduced into the matrix by using 2-aminoterephthalic acid. The novel UiO-66-NH_(2) aerogel also exhibits high specific surface area and mesopore-dominated structure, implying its highly potential use in CO_(2) adsorption. For ulteriorly investigating the effect of amine loading on the CO_(2) adsorption ability, a series of UiO-66-NH_(2) aerogel with different amino content is fabricated by changing the ligand/metal molar ratio. When the molar ratio is 1.45, the CO_(2) adsorption capacity reaches the optimum value of 2.13 mmol·g^(-1) at 25 ℃ and 0.1 MPa, which is 12.2% higher than that of pure UiO-66 aerogel. Additionally, UiO-66-NH_(2)-1.45 aerogel also has noticeable CO_(2) selectivity against N_(2) and CH_(4) as well as good regeneration stability. Such results imply that it has good application prospect in the field of CO_(2) adsorption, and also contains the potential to be applied in catalysis, separation and other fields.

Mechanism and Method of Testing Fracture Toughness and Impact Absorbed Energy of Ductile Metals by Spherical Indentation Tests

To address the problem of conventional approaches for mechanical property determination requiring destructive sampling, which may be unsuitable for in-service structures, the authors proposed a method for determining the quasi-static fracture toughness and impact absorbed energy of ductile metals from spherical indentation tests (SITs). The stress status and damage mechanism of SIT, mode I fracture, Charpy impact tests, and related tests were frst investigated through fnite element (FE) calculations and scanning electron microscopy (SEM) observations, respectively. It was found that the damage mechanism of SITs is diferent from that of mode I fractures, while mode I fractures and Charpy impact tests share the same damage mechanism. Considering the diference between SIT and mode I fractures, uniaxial tension and pure shear were introduced to correlate SIT with mode I fractures. Based on this, the widely used critical indentation energy (CIE) model for fracture toughness determination using SITs was modifed. The quasi-static fracture toughness determined from the modifed CIE model was used to evaluate the impact absorbed energy using the dynamic fracture toughness and energy for crack initiation. The efectiveness of the newly proposed method was verifed through experiments on four types of steels: Q345R, SA508-3, 18MnMoNbR, and S30408.

Engine Performance Using Blended Fuels of Biodiesel and Eco Diesel

Diesel engines is an internal combustion engine with high thermal efficiency,which also uses biodiesel fuel,an environmentally friendly,non-toxic,and low sulfur content.Biodiesel has been around for a long time due to its similar characteristics to diesel fuels which has limited availability.However,several disadvantages are associated with biodiesel,such as poor volatility and high viscosity,which reduces engine performance.Therefore,this study was carried out to improve the diesel engine performance by mixing biodiesel with ecodiesel(ED),an additive produced from natural ingredients that is dissolvable in biodiesel.The biodiesel fuel properties used are density 860 kg/m3,dynamic viscosity 4.50E-06 m2/s,cetane number 45,and flashpoint 52°C.The results showed that biodiesel-ED mixture could improve engine performance and the optimum performance was at a speed of 3000 rpm on 43.30(kW),124.93(N.m)of the engine torque,and 2.45E–5(kg/kW.s)of the specific fuel consumption.According to paired sample t-test,the difference in the engine performance is only experienced in the torque,which has a significant increase in the composition of the biodiesel+ED by 0.07 gr mixture.

Determination of penetration depth at high velocity impact using finite element method and artificial neural network tools

Determination of ballistic performance of an armor solution is a complicated task and evolved significantly with the application of finite element methods(FEM) in this research field.The traditional armor design studies performed with FEM requires sophisticated procedures and intensive computational effort,therefore simpler and accurate numerical approaches are always worthwhile to decrease armor development time.This study aims to apply a hybrid method using FEM simulation and artificial neural network(ANN) analysis to approximate ballistic limit thickness for armor steels.To achieve this objective,a predictive model based on the artificial neural networks is developed to determine ballistic resistance of high hardness armor steels against 7.62 mm armor piercing ammunition.In this methodology,the FEM simulations are used to create training cases for Multilayer Perceptron(MLP) three layer networks.In order to validate FE simulation methodology,ballistic shot tests on 20 mm thickness target were performed according to standard Stanag 4569.Afterwards,the successfully trained ANN(s) is used to predict the ballistic limit thickness of 500 HB high hardness steel armor.Results show that even with limited number of data,FEM-ANN approach can be used to predict ballistic penetration depth with adequate accuracy.

The Use of Single-Phase Immersion Cooling by Using Two Types of Dielectric Fluid for Data Center Energy Savings

Data centers are recognized as one of the most important aspects of the fourth industrial revolution since conventional data centers are inefficient and have dependency on high energy consumption,in which the cooling is responsible for 40%of the usage.Therefore,this research proposes the immersion cooling method to solving the high energy consumption of data centers by cooling its component using two types of dielectric fluids.Four stages of experimentalmethods are used,such as fluid types,cooling effectiveness,optimization,and durability.Furthermore,benchmark software is used to measure the CPU maximum work with the temperature data performed for 24 h.The results of this study show that the immersion cooling reduces 13℃ lower temperature than the conventional cooling method which means it saves more energy consumption in the data center.The most optimum variable used to decrease the temperature is 1.5 lpm of flow rate and 800 rpm of fan rotation.Furthermore,the cooling performance of the dielectric fluids shows that the mineral oil(MO)is better than the virgin coconut oil(VCO).In durability experiment,there are no components damage after five months immersed in the fluid.

Astrocyte and ions metabolism during epileptogenesis:A review for modeling studies

As a large group of cells in a central nervous system, astrocytes have a great influence on ion and energy metabolism in a nervous system. Disorders of neuronal ion and energy metabolism caused by impaired astrocytes play a key role in the pathogenesis of epilepsy. This paper reviews the existing computational models of epileptogenesis resulting from impaired astrocytes and presents several open perspectives with regard to ion and energy metabolism-induced epileptogenesis in a neuron-astrocyte-capillary coupled model.

Research progress of laser cladding self-fluxing alloy coatings on titanium alloys

Laser cladding is a new surface modification technology, and is widely used for fabricating wear and corrosion resistant composites coatings. Self-fluxing alloys have many advantages, such as excellent properties of deoxidizing and slagging, high wear resistance, low melting point and easy cladding, and are often used in laser cladding to improve wear and corrosion resistance of titanium and its alloys. In this paper, the recent development of Ni-based and Co-based self-fluxing alloy coatings which includes the influenee of rare earth and ceramic particles in coatings are summarized. Besides, the effects of processing parameters, such as laser power and scanning speed, on coatings are reviewed. Finally, the trend of development in the future is forecasted.

Revisiting the elastic solution for an inner-pressured functionally graded thick-walled tube within a uniform magnetic field

In this paper, the mechanical responses of a thick-walled functionally graded hollow cylinder subject to a uniform magnetic field and inner-pressurized loads are studied. Rather than directly assume the material constants as some specific function forms displayed in pre-studies, we firstly give the volume fractions of different constituents of the functionally graded material(FGM) cylinder and then determine the expressions of the material constants. With the use of the Voigt method, the corresponding analytical solutions of displacements in the radial direction, the strain and stress components, and the perturbation magnetic field vector are derived. In the numerical part, the effects of the volume fraction on the displacement, strain and stress components, and the magnetic perturbation field vector are investigated. Moreover, by some appropriate choices of the material constants, we find that the obtained results in this paper can reduce to some special cases given in the previous studies.

Machinability Investigation and Optimization of Process Parameters in Cryogenic Assisted Sustainable Turning of AISI‑L6 Tool Steel

The application of cutting fluid is significantly increased in the machining sector to improve productivity.However,the inherent characteristics of cutting fluids on ecology,environment,and society shift the interest of researchers to work on environmentally friendly cooling conditions such as cryogenic cooling.Here,the effect of cutting speed and feed rate on the machining performance of the AISI‑L6 tool steel is investigated under cryogenic cooling conditions.Then,the L9 Taguchi based grey relational analysis(GRA)is conducted to investigate the essential machining indices such as cutting energy,surface roughness,tool wear,and material removal rate(MRR).The results indicate that the cutting speed of 160 m/min and feed rate of 0.16 mm/r are the optimum parameters that significantly improves the machining performance of AISI‑L6 tool steel.

SIMILARITY SOLUTIONS FOR CREEPING FLOW AND HEAT TRANSFER IN SECOND GRADE FLUID

The two dimensional equations of motions for the slowly flowing and heat transfer in second grade fluid are written in Cartesian coordinates neglecting the inertial terms. When the inertia terms are simply omitted from the equations of motions the resulting solutions are valid approximately for Re1. This fact can also be deduced from the dimensionless form of the momentum and energy equations. By employing Lie group analysis, the symmetries of the equations are calculated. The Lie algebra consists of four finite parameter and one infinite parameter Lie group transformations, one being the scaling symmetry and the others being translations. Two different types of solutions are found using the symmetries. Using translations in x and y coordinates, an exponential type of exact solution is presented. For the scaling symmetry, the outcoming ordinary differential equations are more involved and only a series type of approximate solution is presented. Finally, some boundary value problems are discussed.

SIMILARITY SOLUTIONS OF BOUNDARY LAYER EQUATIONS FOR A SPECIAL NON-NEWTONIAN FLUID IN A SPECIAL COORDINATE SYSTME

Two dimensional equations of steady motion for third order fluids are expressed in a special coordinate system generated by the potential flow corresponding to an inviscid fluid. For the inviscid flow around an arbitrary object, the streamlines are the phi-coordinates and velocity potential lines are psi-coordinates which form an orthogonal curvilinear set of coordinates. The outcome, boundary layer equations, is then shown to be independent of the body shape immersed into the flow. As a first approximation,assumption that second grade terms are negligible compared to viscous and third grade terms. Second grade terms spoil scaling transformation which is only transformation leading to similarity solutions for third grade fluid. By using Lie group methods,infinitesimal generators of boundary layer equations are calculated. The equations are transformed into an ordinary differential system. Numerical solutions of outcoming nonlinear differential equations are found by using combination of a Runge-Kutta algorithm and shooting technique.

Thermal Efficiency for Each Zone of a Solar Pond

A salt gradient solar pond with a surface area of 3.5×3.5 m^(2) and a depth of 2 m is built.Two collapsible covers are used to reduce thermal energy loss from the surface of the solar pond during the night and to increase the thermal efficiency of the pond solar energy harvesting during daytime.The covers can be rotated between 0 and 180°by a controlled electric motor and has insulation and reflection properties.The thermal efficiency for each solar pond zone is investigated theoretically and experimentally.

Molecular composition and indigenity of organic matter in Late Neoproterozoic sedimentary rocks from the Yangtze region, South China

从迟了的 Neoproterozoic Nantuo tillites 的 Diamictites (～ 6 00 妈) ，并且从在 Yangtze 区域的 overlying Dousantuo 和 Dengying 形成的白云石，南部的中国，为溶剂被分析可引出的烃。尽管所有这些样品有 TOC 的低内容并且在成熟热进化上经历了，有仍然保存了相当大量烃。由煤气的 chromatography-massspectrometry (GCMS ) 的摘录的分析揭示了 n 链烷的存在，常规非循环的 isoprenoids， tricyclicterpanes，惊讶格子， gammacerane， steranes，和 polyaromatic 烃。严格的试验性的大小在分析过程被执行阻止任何潜在的沾染物被介绍。所有这些沥青把前寒武纪的特征和没有外部 organics 的分子的标记从当前的污染事件导出或从更年轻的阶层移植了烃。为沥青的成熟参数显示烃具有在成熟上，它与主人岩石的热成熟一致。因而，这被结束在 Yangtze 区域的迟了的 Neoproterozoic 沥青，华南，对他们的主人岩石土生土长，它为我们关于“雪球土”的器官的 geochemical 研究提供基础并且“寒武纪的爆炸。''

Prospects and Challenges of Utilizing Solar Energy for the COVID-19 Vaccine Cold Storage in Remote Clinics of Tropical Countries:Review

The rapid spread of COVID-19 pandemic has forced several countries in the world to store vaccines in cold storage towards ensuring their protection from being damaged and to maintain their stability.However,most remote clinics,especially those in the equator and islands,are faced with the challenges of hot climates and the inability to afford electricity resources needed to power the cold storage facility.Meanwhile,the hot equatorial region has abundant solar energy to power the vaccine cold storage but previous studies showed that several field workers do not have the ability to maintain the vaccine storage temperature as indicated by the manufacturer’s recommendations.Therefore,this literature review study examines the prospects and challenges of implementing solar-powered cold storage to provide cooling space for remote clinics.This is expected to contribute significantly to cold chain vaccine management technology.The findings showed that four technology integration schemes including Cold Storage Ice Maker,Cold Storage Ice Maker-PCM,Refrigerator-Ice Maker and,Absorbing Cooling-PV-Ice Maker have the potential to be applied in clinics situated in certain tropical regions.

Stepwise Pyrolysis by LBCR Downstream to Enhance of Gasoline Fraction of Liquid Fuel from MMSW

Pyrolysis is one of the thermal cracking methods to convert hydrocarbon to liquid fuel.The quantity and quality of the process are dependent on several condition including temperature,reaction time,catalyst,and the type of reactor.Meanwhile,a gasoline fraction was maximum product to be considered in the pyrolisis process.Therefore,this study aims to increase the gasoline fraction in liquid fuel using stepwise pyrolysis with a long bed catalytic reactor downstream(LBCR).The LBCR downstream was equipped with the top and bottom outlet and the fed source was mixed municipal solid waste(MMSW).The activated natural dolomite at 500℃ was used to allow the repetition of the secondary cracking.Also,the reactor temperature was setup at around 200℃-300℃ and the pyrolizer was 400℃.To analyze the gasoline fraction and physical properties of liquid fuel,Gas Chromatography-Mass Spectroscopy(GC-MS)and ASTM standard were employed.The experimental results showed there was a significant increase in the gasoline fraction of liquid fuels compared to using direct catalytic cracking and absence of catalysts.By using a LBCR at 250℃,the liquid fuel obtained at top outlet(TO)and bottom outlet(BO)have 84.08 and 56.94 percent peak area of gasoline fraction(C5-C12),respectively.The average value(TO and BO)of the fraction at 250℃ by LBCR was 70.51 percent peak area and it was increased by about 93.6%and 51.14%compared to without catalyst and direct catalytic,respectively.Furthermore,pyrolytic liquid oils were found to have kinematic viscosity of 2.979 and 0.789 cSt,density of 0.781 and 0.782 g/cm^(3),and flash point<−5℃ for BO-250 and TO-250 liquid fuel,respectively.These results showed BO liquid fuel was comparable to diesel conventional fuel while TO liquid fuel was comparable to gasoline.Evidently,the presence of LBCR made a major contribution to generate multi secondary cracking and to produce more gasoline fraction from mixed MMSW feedstock,as well as to increase the physical properties of liquid fuel.

Experimental Investigation of Organic Rankine Cycle (ORC) for Low Temperature Geothermal Fluid: Effect of Pump Rotation and R-134 Working Fluid in Scroll-Expander

Organic Rankine Cycle(ORC)is one of the solutions to utilize a low temperature geothermal fluid for power generation.The ORC system can be placed at the exit of the separator to extract energy from brine.Furthermore,one of the main components of the system and very important is the pump.Therefore,in this research,the pump rotation is examined to investigate the effect on power output and energy efficiency for low temperature geothermal fluid.The rotation is determined by using an inverter with the following frequencies:7.5,10,12.5,15 and 17.5 Hz,respectively.R-134 working fluid is employed with 373.15 K evaporator temperature in relation to the low temperature of the geothermal fluid.Furthermore,the condenser temperature and fluid pressure were set up to 293.15 K and 5×10^(5) Pa,respectively.This research uses a DC generator with a maximum power of 750 Watt and the piping system is made from copper alloy C12200 ASTM B280 with size 1.905×10^(−2) m and a thickness of 8×10^(−4) m.The results showed that there is an increase in mass flow rate,enthalpy and generator power output along with increasing pump rotation.In addition,it showed that the maximum generator output power was 377.31 Watt at the highest pump rotation with a frequency of 17.5 Hz.