Shape Of Sheet Research Articles

Air–water interface dynamics and energy transition in air of a sphere passed vertically upward through the interface

The water exit problem is a fundamental problem in fluid dynamics, and the behavior of the air–water interface and the energy transition of an object exiting water have not been thoroughly investigated. In this study, a solid sphere with a density of 2.64×103kg/m3 and diameter of d=25.4 mm was launched vertically upward in water toward the air–water interface. The motion of the sphere and the behavior of the interface were investigated for varying submergence depths H from the launch position of the sphere to the interface. The launch velocity was set so that the Reynolds number immediately after the sphere passed the air–water interface was about 3000 for all cases of H. The kinetic and potential energies of the sphere and the energy lost because of the air–water interface (i.e., interfacial containing energy) were estimated based on the classical law of energy conservation. For H/d⩽3, the ratio between the kinetic energy immediately after passing through the air–water interface and the potential energy at the maximum displacement position decreases with increasing H, but this energy ratio takes a constant value of 0.57 for H/d⩾4. Additionally, for H/d⩾4, kinetic energy is transformed to potential energy and interfacial containing energy at a fixed ratio for each vertical position. The spreading characteristics of the water mass after the sphere has passed the air–water interface and the thickness and width of the interfacial water sheet when the top of the sphere reached the calm free surface were investigated by focusing on their relationship to the energy distribution. For H/d⩾4, where the energy ratio takes a constant value, the increase in the rate of spread of the water mass with increasing H/d is clearly smaller than that of H/d⩽4. Furthermore, for H/d⩾4, the ratio between the thickness and width of the interfacial water sheet is constant. In other words, in the region where the ratio between the kinetic energy of the sphere immediately after passing through the air–water interface and the potential energy at the maximum displacement position has a constant value, the shape of the interfacial water sheet is self-similar. These findings contribute to the determination of variable parameters when modeling the water exit problem.

Synthesis, spectroscopic and photoluminescence studies of novel Eu3+ nanophosphor complex as fluorescent sensor for highly sensitive detection of latent fingerprints and anti-counterfeiting

Great attention has been paid to synthesize novel luminescent hybrid Eu(Thiol)Phen Nanophosphor complex; where (Thiol) = (E)-2-hydroxy-N/-((thiophen-2-yl)methylene)benzohydrazide and (Phen) = 1,10-phenanthroline as co-ligand. Properties like structure, morphology and optical characters were investigated. The results revealed that binary ligand acts as monoanionic tridentate through N-atom, O-atom and S-atom as donor sites. The secondary ligand (Phen) acting as bidentate through two (CN)pyridine groups. TEM image of ternary hybrid Eu(Thiol)Phen phosphor complex was cleared aggregated hybrid morphologies between sheet and rode shapes and their crystal sizes were in nanodomain. A pure red emission of Eu3+ Nanophosphor complex with long lifetime value was obtained, under harmless UVA, UVB and UVC. Optimized photoluminescence (PL) of Nanophosphor complex effectively developed as a novel sensing material for the visualization of latent fingerprints (LFPs) from various forensic relevant materials, including non-porous and porous of multi-color surfaces as well as security ink applications.

A computational study of electric and magnetic properties of silicon carbon (SiC) armchair nanoribbons

SiC is a two-dimensional semiconductor with a direct band gap. Many authors studied its electric and magnetic properties in sheet and ribbon shapes. The previous papers have shown that SiC sheet and full saturated armchair ribbons are non-magnetic (NM) semiconductor while zigzag ribbons are ferromagnetic (FM) semiconductor. In this paper, we saturate only C (CH) and Si (SiH) atoms of armchair ribbon by hydrogen and study its electric and magnetic properties by density functional theory (DFT). Our results show that CH, saturated carbon atoms in armchair ribbon, can show both FM and antiferromagnetic (AFM) semiconductor states while SiH, saturated silicon atoms in armchair ribbon, can show both FM half-metal and AFM metallic states. We found that the total magnetic moment of the unit cell is about 2 μB. Our results confirm that armchair ribbons can show many different magnetic states only by hydrogen saturation.

Direct counting of exosomes in a cell culture medium using neither isolation nor preconcentration

Exosomes are expected to be biomarkers of cancer since they contain information about the cells that excrete them. In this study we developed a method to count the exosomes secreted from cancer cells in a culture medium without the need for isolation and/or preconcentration. This detection system consists of a square capillary on which a laser beam is focused in a sheet shape via the use of two cylindrical lenses. A fluorescently labeled anti-CD63 antibody is used to mark the exosomes that are then flowed into the square capillary. In this study, individual exosomes were observed on a trajectory when passing through the laser beam sheet and were counted for 10 min at a constant flow velocity. The total analysis time was less than 1.5 h including the steps required to remove large particles and allow reaction with the antibody. The results for two samples prepared with and without the isolation of exosomes showed a loss of exosomes in the isolation step. We also determined the number of the exosomes secreted by the cells to a culture medium during cultivation. As expected, the total number of exosomes in a culture medium increased with an increase in the cultivation time, and the number of exosomes released every 12 h either remained constant or showed no more than a slight increase for as long as 72 h. It was unclear whether the number exosomes was dependent on the cell population at confluences of 10–60%.

Influence of exfoliated graphite filler size on the electrical, thermal, and mechanical polymer properties

Exfoliated graphite has attracted significant research interest, especially with respect to composite manufacturing as a sheet shape material for enhancing their mechanical, electrical, and thermal properties with cost-effectiveness. It has been proved in different researches that size of nanoparticles plays a vital role and has significant effect. So, in this study, exfoliated graphite with three different sizes i.e. 50 mesh (large dimension), 100 mesh (medium size), and 150 mesh (small size) are integrated in epoxy to examine their effect on the mechanical/electrical/thermal performance of the material and for each mesh size range of 0.5 wt.% to 20 wt.% is utilized. These three systems of reinforced epoxy with different size of exfoliated graphite are evaluated in DIGIMAT simulation software by investigating their electrical, thermal and mechanical properties. The numerical results showed that integration of exfoliated graphite in neat epoxy drastically improved its electrical, thermal, and mechanical performance. In addition, it was found that the use of the bigger size was more effective on the performance of the material, which is probably because of the enhanced connectivity between the structuring sheets. Moreover, a gradual increase in properties is observed with increasing the percentage of exfoliated graphite content in each system. This numerical study was developed in accordance to validate the experimental study conducted by Debelak et al. This study further provides the evidence of the appropriateness of the DIGIMAT simulation as an investigational load in relevant research.

Untargeted Metabolic Pathway Analysis as an Effective Strategy to Connect Various Nanoparticle Properties to Nanoparticle-Induced Ecotoxicity

Elucidation of the relationships between nanoparticle properties and ecotoxicity is a fundamental issue for environmental applications and risk assessment of nanoparticles. However, effective strategies to connect the various properties of nanoparticles with their ecotoxicity remain largely unavailable. Herein, an untargeted metabolic pathway analysis was employed to investigate the environmental risk posed by 10 typical nanoparticles (AgNPs, CuNPs, FeNPs, ZnONPs, SiO2NPs, TiO2NPs, GO, GOQDs, SWCNTs, and C60) to rice (a staple food for half of the world's population). Downregulation of carbohydrate metabolism and upregulation of amino acid metabolism were the two dominant metabolic effects induced by all tested nanoparticles. Partial least-squares regression analysis indicated that a zerovalent metal and high specific surface area positively contributed to the downregulation of carbohydrate metabolism, indicating strong abiotic stress. In contrast, the carbon type, the presence of a spherical or sheet shape, and the absence of oxygen functional groups in the nanoparticles positively contributed to the upregulation of amino acid metabolism, indicating adaptation to abiotic stress. Moreover, network relationships among five properties of nanoparticles were established for these metabolic pathways. The results of the present study will aid in the understanding and prediction of environmental risks and in the design of environmentally friendly nanoparticles.

Splash sheet characteristics induced by the impingement of multiple jets in a steelmaking converter

ABSTRACT In oxygen steelmaking, one important aspect is to depict the splashing induced by the impingement of multiple jets quantitatively. In this paper, experiments were conducted to investigate the splash sheets. The results demonstrated that with the decrease of lance height, the sheet area increased, while the sheet height decreased. The sheet diameter was much less affected by the gas flow rate compared to the sheet height. The cavity width-to-depth ratio is a critical parameter affecting the sheet shape. The sheet area produced by the 5-nozzle jet was larger than that produced by the 6-nozzle jet. Taking the sheet area reduction as the critical condition where the cavity mode changes from splashing to penetrating, the critical lance height was investigated under various ejecting conditions. This was further represented by the blowing number as a normalized formula. At last, curve fitting illustrating the conditions that lead to the penetrating mode was conducted.

Effect of Delivery Angle on Longitudinal Buckling in Temper Rolling of Thin Steel Strips

In temper rolling of double reduced thin strips, shape defect called “longitudinal buckling” appears. In previous study, the effect of several rolling conditions on the longitudinal buckling was investigated. However, effect of delivery angle over 4 degree has not been experimented. In this paper, effect of large delivery angle is investigated in laboratory rolling. Results show that by increasing delivery angle, the buckling appears clearly and the number of waves decreases, and by the delivery angle over 24 degree the buckling disappears. If the delivery angle is the same, the buckling form does not change by the distance between work roll and auxiliary roll. Next we calculate the buckling characteristics of the sheet which twines around the work roll by the elementary theory. We find that the change of number of waves by the delivery angle calculated from the analysis almost agrees with the experimental result when the delivery angle is larger than 10 degree. It is estimated that the longitudinal buckling is initiated around roll gap and changes under the influence of the shape of sheet which twines around the work roll.

Development of Multi-Objective Optimization Model for Electromagnetic Die Forming of Aa5083 Aluminum Alloy Sheet

Electromagnetic die forming is a high-speed formation method that can be quite effective in increasing the limits on the shape of the metal sheet of low weight and of the strong electrical conductivity content. A coil is an essential instrument for transmitting electrical power to plastic energy, and the geometry of the coil plays a key role in macrofield transmission. Experiments of the electrical composition of 0.5 mm, 0.7 mm and 0.9 mm AA5083 aluminum sheets are performed via the box-behnken technique with a single layer spiral and a flat square-cross section and spiral. Evaluating characteristics like total height, rib height internal diameter, and external diameter for various charge voltage and current was investigated for the forming behaviour. The results show that the efficiency of production is very dependent on the divide and thickness of work pieces.

Investigation of Sheet Metal Forming Using a Rapid Compression Machine.

The primary goal of this work is to understand the deformation behavior of an aluminum alloy (Al) workpiece by using a rapid compression machine (RCM). The primary novelty in this work is that this is the first study on sheet metal forming using RCM. Numerical simulation and experimental results are in excellent agreement, e.g., the dome-shape, the maximum height, the final outer diameter, and the thickness distribution of the deformed workpiece. We demonstrate that the maximum deformation height grows linearly with the peak pressure with an intercept tending to zero. The proposed linear relationship can be effectively used for designing new components for a specific application. Moreover, the proposed numerical model was competent in reproducing the experimental results of damage initiation and evolution in case of high peak pressure as well as the initial misalignment of the workpiece. The results of this investigation revealed that a rapid compression machine can be utilized efficiently for the controlled forming of complex shapes of metal sheets.

A sustainable solution to plastics pollution: An eco-friendly bioplastic film production from high-salt contained Spirulina sp. residues

Plastic products have become a major contaminant in environmental ecology due to their recalcitrant biodegradation, poor management and risky disposal. Therefore, much research attention has been paid to developing the biodegradable bio-based plastics. However, many of the substitute bioplastics derived from agricultural materials may present a potential threat to food security and eco-systems. Herein, we propose a sustainable, eco-friendly and simple procedure to convert the hazardous high-salt contained microalgal residues into bioplastic film. With 35 % poly (vinyl alcohol) (PVA) assistance, the composite bioplastic films achieved 22 MPa tensile strength under alkali condition and 77 % elongation at break under acidic condition. The average maximum contact angle of 94.4° confirmed a desirable water resistance potential. The synthesis mechanism demonstrated that the inorganic salts existed in microalgal residues could act as the filler in shape of sheets under alkali condition or as the cross linker under acidic condition, significantly enhancing the practical feasibility. This work demonstrates a promising biodegradable bioplastics formed from sustainable eco-friendly waste reutilization process, providing a new insight for fundamentally reducing the plastics pollution.

Evaluation of 2-D Transverse Beam Profile Monitor Using Gas Sheet at J-PARC LINAC

A transverse beam profile monitor, which detects ions or luminescence generated by the interaction between the beam and the gas molecules distributed in a sheet shape, has been developed in the J-PARC LINAC. To know about the gas density distribution of the sheet-shaped gas, which affects the intensity distribution of the detected signal, the calculation by the Monte Carlo simulation code was performed. The calculation results showed that the gas with a narrow width along beam direction distributes enough uniformly within a realistic beam cross-sectional size. In addition, the unsaturated region against the MCP voltage and the injected gas pressure are evaluated based on the measurement with a beam. The results showed that the measurement in the low injected gas pressure with the appropriate applied voltage range is important to measure the beam profile in the unsaturated region.

Next-Generation Multimodality of Nanomedicine Therapy: Size and Structure Dependence of Folic Acid Conjugated Copolymers Actively Target Cancer Cells in Disabling Cell Division and Inducing Apoptosis.

Nanomedicine as a multimodality treatment of cancer utilizes the advantages of nanodelivery systems of drugs. They are superior to the clinical administration of different therapeutic agents in several aspects, including simultaneous delivery of drugs to the active site, precise ratio control of the loading drugs and overcoming multidrug resistance. The role of nanopolymer size and structural shape on the internalization process and subsequent intracellular toxicity is limited. Here, the size and shape dependent mechanism of a functionalized copolymer was investigated using folic acid (FA) covalently bonded to the copolymer poly (styrene-alt-maleic anhydride) (SMA) on its hydrophilic exterior via a biological linker 2,4-diaminobutyric acid (DABA) to target folic acid receptors (FR) overly expressed on cancer cells actively. We recently reported that unloaded FA-DABA-SMA copolymers significantly reduced cancer cell viability, suggesting a secondary therapeutic mechanism of action of the copolymer carrier post-internalization. Here, we investigated the size and shape dependent secondary mechanism of unloaded 350 kDa and 20 kDa FA-DABA-SMA. The 350 kDa and 20 kDa copolymers actively target folic acid receptors (FR) to initialize internationalization, but only the large size and sheet shaped copolymer disables cell division by intracellular disruptions of essential oncogenic proteins including p53, STAT-3 and c-Myc. Furthermore, the 350 kDa FA-DABA-SMA activates early and late apoptotic events in both PANC-1 and MDA-MB-231 cancer cells. These findings indicate that the large size and structural sheet shape of the 350 kDa FA-DABA-SMA copolymer facilitate multimodal tumor targeting mechanisms together with the ability to internalize hydrophobic chemotherapeutics to disable critical oncogenic proteins controlling cell division and to induce apoptosis. The significance of these novel findings reveals copolymer secondary cellular targets and therapeutic actions that extend beyond the direct delivery of chemotherapeutics. This report offers novel therapeutic insight into the intracellular activity of copolymers critically dependent on the size and structural shape of the nanopolymers.

Effect of morphology of CsPbBr3 nanocrystals on their optical properties

In this paper, the morphology of CsPbBr3 nanocrystals (NCs) is controlled by changing the molar ratios of oleylamine (OAm) and propionic acid (PA). The relative ratio plays an important role in the evolution of morphology. The CsPbBr3 NCs exhibit monoclinic morphology when the molar ratio of OAm/PA is equivalent. When the molar ratio of OAm/PA deviates from 1:1, CsPbBr3 NCs tend to grow in a sheet shape. The nanosheets with 200∼500 nm and thickness ∼15 nm were synthesized as the molar ratio of OAm/PA (1:4). The PL intensity decreases with the increase of size. The fluorescence lifetime shows a trend of gradual shortening.

Effect of size and shape of graphene sheets on nanoscale peeling process by atomic force microscopy

We numerically studied the effect of size and shape of graphene sheets on nanoscale peeling characteristics by atomic force microscopy (AFM). It was clarified that the simulated peeling processes of the graphene sheet connected to the cantilever spring of AFM were classified into typical four types of the peeling force curves. This classification of the peeling process could be clearly understood in the phase diagram plotted as a function of the length and width of the peeled graphene sheet.

Evaporation-driven crumpling and assembling of two-dimensional (2D) materials: A rotational spring – mechanical slider model

Crumpling of suspended two-dimensional (2D) materials by droplet evaporation creates a new form of aggregation-resistant ultrafine particles with more scalable properties such as high specific surface areas. However, the underpinned fundamental mechanics theory that addresses large deformation, severe instability and self-assembly of 2D sheets under dynamic solid-liquid interactions during liquid evaporation is lacking. In the present study, we propose a theoretical mechanics framework to quantitatively describe the simultaneous process of crumpling and self-assembling of 2D materials and their competition during droplet evaporation. In this theory, a rotational spring is developed to describe the out-of-plane deformation of crumpling sheets, and a mechanical slider is implemented to describe the interactive binding energy in self-folding of a single sheet or overlapping of neighboring sheets. The spring-slider mechanics model is calibrated with the energy-based continuum mechanics analysis by crumpling a single sheet, and is further extended to a network model to characterize the crumpling and assembling of multiple sheets in the droplet. An equivalent pressure model is developed to unify the resultant forces associated with liquid evaporation including capillary force, vapor pressure, gas pressure, vapor recoil pressure and capillary flow-induced force. A coarse-grained model of 2D materials is developed and its dynamic interaction with liquid molecules during evaporation is mimicked by proposing a controllable virtual van der Waal force field. Molecular dynamics simulation results show remarkable agreement with theoretical predictions, from crumpling and assembling energies of graphene during liquid evaporation to overall size and accessible area of the crumpled particles after the complete evaporation of liquid. Besides, both theoretical predictions and simulation results agree well with independent experiments. The effect of concentration, size, shape, number and size distribution of 2D material graphene sheets in liquid droplets on crumpling and self-assembling energy and shape, size and surface morphology of crumpled particles is also discussed. The mechanics theories and coarse-grained modeling established here are expected to offer immediate and quantitative application guidance to control the crumpling and self-assembling process of 2D materials by liquid solution evaporation processing to fine tune particle size and morphology. More importantly, the fundamental understanding of large deformation, instability, and self-assembly of 2D materials in such dynamic liquid environments could be extended to aerosol-like processing of a broad scope of other low-dimensional nanomaterials such as lipid membranes, nanowires, nanotubes, nanofibers and nanoparticles, for their emerging applications including ultrafine particle manufacturing and various printing processes.

Efficacy of silicone sheet as a personalized barrier for preventing adhesion reformation after hysteroscopic adhesiolysis of intrauterine adhesions.

PurposeTo evaluate the efficacy of silicone sheet as a new type of barrier for preventing adhesion reformation following hysteroscopic adhesiolysis of intrauterine adhesions (IUAs).MethodsHysteroscopic adhesiolysis was performed for 36 patients with IUAs. The adhesion reformation rate was retrospectively compared between 26 patients treated with silicone sheet (group 1) and 10 patients treated with an intrauterine device wrapped in oxidized regenerated cellulose as a barrier (group 2). For patients in group 1, a 1‐mm‐thick silicone sheet was cut to fit the size and shape of the individual uterine cavity as a personalized barrier.ResultsThe size and shape of each silicone sheet used for patients in group 1 differed significantly. The adhesion reformation rate was significantly lower in group 1 (4/26, 15.4%) than in group 2 (4/10, 40.0%; P = 0.03), although the pregnancy rate (14/20, 70.0% vs. 5/10, 50.0%; P = 0.28) and miscarriage rate (2/14, 14.3% vs. 1/5, 20.0%; P = 0.72) were not significantly different.ConclusionUse of silicone sheets appears to be effective for preventing adhesion reformation following hysteroscopic adhesiolysis of IUAs. This is the first study to investigate the efficacy of silicone sheet used as a personalized barrier for preventing IUAs.

Microstructural evolution and mechanical behavior of Mg/Al laminated composite sheet by novel corrugated rolling and flat rolling

AZ31B Mg/5052 Al laminated composite sheet with superior mechanical property and good sheet shape was fabricated by novel corrugated roll/flat roll corrugating rolling and flat roll/flat roll flat rolling (CFR) at elevated temperatures. The microstructural evolution and mechanical behavior variation of the composite sheet under CFR hot rolling condition were investigated by experimental and numerical simulation methods. The results show that first-pass corrugated rolling induces relatively high and inhomogeneous shear strain in the Mg side and various corrugated interface positions at a low reduction of 35%. It leads to significant grain refinement, outstanding basal texture modification as well as tensile twin activation Mg alloy, which perfectly coordinates the plastic deformation between hard-to-deform Mg and ductile Al and achieve the strong interface metallurgy bonding in Mg/Al sheet and also significantly improves the mechanical properties of Mg/Al composite sheet. The annealing before second-pass flat rolling causes the pronounced static recrystallization and grain growth of Mg alloy in corrugated-rolling Mg/Al sheet, and the formation of ~25 μm thick interfacial compound layer consisted of Mg17Al12 and Al3Mg2 two sublayers. Second-pass flat rolling with a reduction of 30% further imposes severe inhomogeneous shear deformation on the composite sheet, which results in the formation of a wave-shape three-dimensional bonding interface, and the interface compound layers cracking at peak and waist interface positions or fragmenting into well-aligned discrete particles to the bonding interface, in addition to substantial matrix microstructure refinement, texture modification and twin activation in Mg alloy. Such interface structure greatly enhances the interface bonding force of the Mg/Al composite sheet by the larger interface contact area, mechanical gearing effect as well as particle pinning effect. Hence the significant microstructural refinement, strong interface bonding and low residual stress induced by CFR process account for the excellent performance of the Mg/Al laminated composite sheet.

Effect of multi-step laser shocking on forming behaviors of metal sheet shaped into a deep conical cup

This paper presents the method to shape a deep conical cup with multi-step laser shocking forming. Finite element method was employed to simulate the process of three-step laser shocking forming (TSLSF), and the process of sheet deformation at each step was analyzed. Especially, sheet deformation behaviors including deforming velocity, strain, residual stress, and geometrical shape were discussed in detail. The sheet-forming experiments were carried out to validate the simulation results. The numerical predictions of the deformed sheet shape in each step were compared and discussed with the corresponding experimental forming values. The experimental results display that three geometrical cups have been fabricated by TSLSF. The experimental results are well accordance with the corresponding numerical predicted data, which validates the established prediction model of sheet forming. It also indicates that MSLSF is a feasible forming process when the flat sheet needs to be formed into a deep-depth workpiece.

Surface Modification of Polycarbonate by an Atmospheric Pressure Argon Microwave Plasma Sheet.

The specific properties of an atmospheric pressure plasma make it an attractive tool for the surface treatment of various materials. With this in mind, this paper presents the results of experimental investigations of a polycarbonate (PC) material surface modification using this new type of argon microwave (2.45 GHz) plasma source. The uniqueness of the new plasma source lies in the shape of the generated plasma—in contrast to other microwave plasma sources, which usually provide a plasma in the form of a flame or column, the new ones provides a plasma in the shape of a regular plasma sheet. The influence of the absorbed microwave power and the number of scans on the changes of the wettability and morphological and mechanical properties of the plasma-treated PC samples was investigated. The mechanical properties and changes in roughness of the samples were measured by the use of atomic force microscopy (AFM). The wettability of the plasma-modified samples was tested by measuring the water contact angle. In order to confirm the plasma effect, each of the above-mentioned measurements was performed before and after plasma treatment. All experimental tests were performed with an argon of flow rate up to 20 L/min and the absorbed microwave power ranged from 300 to 850 W. The results prove the capability of the new atmospheric pressure plasma type in modifying the morphological and mechanical properties of PC surfaces for industrial applications.