Thin Shape Research Articles

High-resolution 7T fMRI reveals the visual zone of the human claustrum

Abstract The claustrum is a thin grey matter structure located between the insular cortex and the putamen. The function of the claustrum is largely unknown with diverse hypotheses ranging from multisensory integration and consciousness to attention and cognitive control. Much research on the function of the claustrum relies on invasive techniques in animal models, as the claustrum’s uniquely thin shape makes it difficult to image non-invasively in human subjects. In the current proof-of-concept study, we used high-resolution ultra-high field (7 Tesla) functional magnetic resonance imaging (fMRI) to measure activity in the human claustrum during the processing of naturalistic stimuli. We presented short video clips as visual only, auditory only or audiovisual conditions while participants performed a central fixation task. We found distinct visual responses in both the left and the right claustrum at a consistent spatial location across participants, hemispheres and sessions. We also found deactivations in response to auditory stimulation. These deactivations were confined to the right claustrum and did not overlap with visual activity. The deactivation in response to auditory stimulation demonstrates the complexity of claustrum’s functional organization and suggests functional differentiation within the claustrum. This is the first study to demonstrate sensory-specific effects within the human claustrum. It opens the possibility for studying the claustrum’s role in higher-level aspects of sensory processing in humans.

Chinese yam polysaccharide-loaded aluminium hydroxide nanoparticles used as vaccine adjuvant to induce potent humoral and cellular immune responses

Due to their safety and efficacy, aluminium salts (Alum) are considered the most important adjuvants in human vaccines. However, Alum adjuvants are unable to elicit a cellular immune response, which is vital for the prevention of various chronic infectious diseases and cancers. Herein, we isolated and purified a water-soluble polysaccharide from Chinese yam, named CYP, which was primarily composed of →4)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and α-D-Glcp-(1→. Meanwhile, we prepared aluminium hydroxide nanoparticles (Al NPs) with a nanometer-scale size and thin stick-like shape. Being an immunostimulant, the CYP was then loaded onto the Al NPs to obtain a novel adjuvant delivery system (CYP-Al NPs) that enhances the immunostimulatory activity of CYP. Our findings showed that the CYP-Al NPs facilitated macrophages activation and promoted the antigen uptake by macrophages. The in vivo experiment showed that the CYP-Al NPs, as the adjuvant to ovalbumin, promoted the activation of dendritic cells and germinal center B cells in draining lymph nodes, induced a durable and strong antibody response, especially the Th1-type IgG2a antibody response, and improved the cytotoxic T lymphocytes response. These results demonstrated that the CYP-Al NPs could generate robust humoral and cellular responses, and has the great potential to serve as an adjuvant delivery system.

Sensor-Less Control of Mirror Manipulator Using Shape Memory Polyimide Composite Actuator: Experimental Work.

Integrated thin film-based shape memory polyimide composites (SMPICs) are potentially attractive for efficient and compact design, thereby offering cost-effective applications. The objective of this article is to design and evaluate a mirror manipulator using an SMPIC as an actuator and a sensor with control. A sensor-less control strategy using the SMPIC (a self-sensing actuator) with a proportional derivative combined variable structure controller (PD-VSC) is proposed for position control of the mirror in both the vertical and angular directions. The mirror manipulator is able to move the mirror in the vertical and angular directions by 3.39 mm and 10.5 deg, respectively. A desired fast response is obtained as the performance under control. In addition, some benefits from the proposed control realization include good tracking, stable switching, no overshoot, no steady state oscillations, and robust disturbance rejection. These superior properties are experimentally validated to reflect practical feasibility.

Standardization Of Rakik Maco By Ulakan Tapakis Padang Pariaman

It was found that the quality of Rakik Maco differed from one seller to another. Like Rakik Maco's texture, some are fragile, some are tough and hard, some are thin and some are thick. In terms of color, there is Rakik Maco with a golden yellow color and a brownish yellow tone. In terms of taste, some are savory and some are bland. In processing Rakik Maco, sellers usually measure the ingredients using glass and some only look at the texture and viscosity of the dough, so the resulting quality varies, both in terms of texture, taste, aroma and color. Food quality is very important for Rakik Maco sellers to pay attention to. To maintain product quality, it is necessary to have appropriate standardization regarding the materials used, tools used and the process of making Rakik Maco.The focus of this research is the standardization of the Rakik Maco recipe in Ulakan Tapakis, Padang Pariaman Regency, which includes the measurements of ingredients and tools used, the manufacturing process and product quality (shape, color, aroma, texture and taste). To maintain product quality, standardization is necessary. Standardization is carried out regarding materials, tools and manufacturing processes. The quality of Rakik Maco can be seen from several aspects such as: shape, color, aroma, texture and taste. The following are the results of the Rakik Maco quality test: Rakik Maco has a thin round shape, with the use of a mold that makes Rakik Maco uniform and neat, the color of quality Rakik Maco is packaged yellow, the aroma of Rakik Maco is created from the distinctive aroma of rice flour and supported by the aroma of turmeric leaves , Rakik Maco has a crunchy texture, and Rakik Maco has a savory taste.

The Effect of Milkfish Bone Meal (Chanos chanos) Addition and Sodium Bicarbonate (NaHCO3) Concentration on the Physicochemical and Organoleptic Characteristics of Tortilla Chips

Tortillas are a corn-based snack, yellow, and have a thin shape and crunchy texture. The addition of fish bone meal can increase calcium levels but also decrease the texture of the tortilla. The addition of sodium bicarbonate aims to improve the texture by increasing the swelling power and crispness of the product. This research aims to determine the effect of the substitution of milkfish bone meal with the addition of sodium bicarbonate on the physicochemical and organoleptic characteristics of tortilla chips. This study used a Completely Randomized Design (CRD) with two factors and two replications, factor I was the concentration of milkfish bone meal (10%, 15%, and 20%) and factor II was the concentration of sodium bicarbonate (0.25%, 0.50 %, and 0.75%). The data obtained were analyzed using ANOVA and continued with the Duncan Multiple Range Test (DMRT) at the 5% level. The results of the research show that there is a real interaction with ash content, protein content, fat content, and calcium content. The research results of the best treatment based on physicochemical parameters were tortilla chips with the addition of fish bone meal 10% and a sodium bicarbonate concentration of 0.75%. This is the best-treated tortilla chip product with a water content value of 5.080%; ash content 2.995%; protein content 5.87%; fat content 5.380%; carbohydrates 82.521%, calcium 3.396%, expansion volume 19.912%; breaking power 278,350 gf; amylose 37.750%; and starch content 62.516%;

Feasibility Study of Single-Point Incremental Forming for Discontinuous-Fiber CFRP Using Oil-Bath Heating

Although, three-dimensional printing has several advantages, however there are currently many limitations. In particular, printed products using composite materials such as fiber-reinforced plastic have yet to achieve the same mechanical properties as those obtained from conventional manufacturing methods. In addition, fabricating thin plates or thin shell shapes with sufficient strength is challenging. Incremental forming enables high-mix, low-volume production of thin sheets. This method applies incremental deformation to thin sheets, the desired shape is obtained by accumulating the deformation, and no dies are required. Carbon-fiber-reinforced plastic (CFRP) materials have high specific strength. Discontinuous-fiber CFRP is capable of large plastic deformation under appropriate conditions due to the discontinuity of the reinforcement, and its mechanical properties are nearly isotropic due to the random fiber arrangement. The authors focused on this property and studied the application of single-point incremental forming to discontinuous carbon-fiber-reinforced polyamides. In this study, the workpiece was formed by heating it locally to a deformable temperature by the frictional heat between the rotating tool and the workpiece. The forming experiment was also conducted in an oil bath to keep the entire material at a suitable forming temperature. The results showed that the spindle speed affected forming results even in an oil bath and that heating using an oil bath suppressed deviations from the sine law for thickness and wall angle due to elastic deformation.

Study of Tensile and Compressive Behavior of ECO-Mg97Gd2Zn1 Alloys Containing Long-Period Stacking Ordered Phase with Lamellar Structure

A suitable heat treatment in the Mg97Gd2Zn1 (at.%) alloy in the as-cast condition results, after extrusion at high temperature, in a two-phase lamellar microstructure consisting of magnesium grains with thin lamellar shape precipitates and long fibers of the 14H-Long-Period Stacking Ordered (LPSO) phase elongated in the extrusion direction. The magnesium matrix is not fully recrystallized and highly oriented coarse non-dynamically recrystallized (non-DRXed) grains (17% volume fraction) elongated along the extrusion direction remain in the material. The deformation mechanisms of the extruded alloy have been studied measuring the evolution of the internal strains during in situ tension and compression tests using synchrotron diffraction radiation. The data demonstrate that the macroscopic yield stress is governed by the activation of the basal slip system in the randomly oriented equiaxed dynamic recrystallized (DRXed) grains. Non-DRXed grains, due to their strong texture, are favored oriented for the activation of tensile twinning. However, the presence of lamellar-shape precipitates strongly delays the propagation of lenticular thin twins through these highly oriented grains and they have no effect on the onset of the plastic deformation. Therefore, the tension–compression asymmetry is low since the plasticity mechanism is independent of the stress mode.

Investigating thin-film thermoelectric generators: Leg shape, TEG configuration, and contact resistance analysis

Thermoelectric generators (TEGs) are made of parallel p-type and n-type semiconducting legs which can directly convert temperature gradients into electricity. Theoretical studies have extensively explored the impact of the thermoelectric (TE) leg size and shape on the conversion efficiency of such bulk TEGs. However, in recent years, geometrically thin and film-shaped TEGs have gained attention for integration into wearable and flexible electronic devices, tapping into body heat as a power source. There is currently a lack of research on film-shaped TEGs, particularly regarding the performance of asymmetric TE leg shapes. This study investigates seven different TE leg shapes in thin-film TEGs, analyzing their electrical performance using COMSOL Multiphysics software. Results show that certain asymmetric TE leg shapes can yield over a 30% improvement in the produced open circuit voltage, as compared to conventional rectangular-shape TE legs. Furthermore, various configurations of thin-film TEGs were designed and analyzed, aiming to maximize device output power. Additionally, the study delves into the influence of electrical contact resistance on the performance of the optimal asymmetric TEGs. The proposed thin TE leg shapes and TEG configurations ae easily manufacturable and scalable using printing technology.

Triplex steel powder design to avoid hot cracking in laser-powder bed fusion using computational thermodynamics

High manganese steels offer exceptional combinations of high strength and ductility, resulting in weight reduction when utilized in structural applications. Nevertheless, the conventional manufacturing routes of these steels is hindered by many production problems. Additive Manufacturing (AM) has emerged as a reliable solution to fabricate thin or complex shape compounds using these steel grades. Indeed, several studies have demonstrated the success to fabricate high manganese twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) steels by laser-powder bed fusion (L-PBF). However, a recent study on a high manganese triplex steel composition has revealed the occurrence of both hot cracking and micro segregation during rapid solidification in L-PBF, highlighting potential processability issues of this family of high alloy steels. In this study, the hot cracking susceptibility of different triplex steels is evaluated, focusing on the impact of the composition on the solidification paths and final microstructures. A Computer Coupling of Phase Diagrams and Thermochemistry (CALPHAD) approach is employed to predict alloy-dependent hot cracking susceptibility so as to establish guidelines for preventing hot cracking and provide insights into alloy design for AM. Microstructural observations are used to determine the accuracy of CALPHAD predictions in terms of elemental segregation, phase formation and hot cracking susceptibility. To this end, scanning transmission electron microscopy is used to evaluate elemental segregation at grain boundaries, while the local distribution of phases and their relative amount is measured by electron backscattered and X-ray diffraction, respectively. Hot cracking susceptibility is experimentally evaluated by measuring the length of cracks (when present) in the cross section of printed specimens.

Defining signals that promote human alveolar type I differentiation.

Alveolar type I (ATI) cells cover >95% of the lung's distal surface and facilitate gas exchange through their exceptionally thin shape. ATI cells in vivo are replenished by alveolar type II cell division and differentiation, but a detailed understanding of ATI biology has been hampered by the challenges in direct isolation of these cells due to their fragility and incomplete understanding of the signaling interactions that promote differentiation of ATII to ATI cells. Here, we explored the signals that maintain ATII versus promote ATI fates in three-dimensional (3-D) organoid cultures and developed a human alveolar type I differentiation medium (hATIDM) suitable for generating ATI cells from either mixed distal human lung cells or purified ATII cells. This media adds bone morphogenetic protein 4 (BMP4) and removes epidermal growth factor (EGF), Wnt agonist CHIR99021, and transforming growth factor-beta (TGF-β) inhibitor SB431542 from previously developed alveolar organoid culture media. We demonstrate that BMP4 promotes expression of the ATI marker gene AGER and HOPX, whereas CHIR99021 and SB431542 maintain expression of the ATII marker gene SFTPC. The human ATI spheroids generated with hATIDM express multiple molecular and morphological features reminiscent of human ATI cells. Our results demonstrate that signaling interactions among BMP, TGF-β, and Wnt signaling pathways in alveolar spheroids and distal lung organoids including IPF-organoids coordinate human ATII to ATI differentiation.NEW & NOTEWORTHY Alveolar type I (ATI) epithelial cells perform essential roles in maintaining lung function but have been challenging to study. We explored the signals that promote ATI fate in 3-D organoid cultures generated from either mixed distal human lung cells or purified alveolar type II (ATII) cells. This work fills an important void in our experimental repertoire for studying alveolar epithelial cells and identifies signals that promote human ATII to ATI cell differentiation.

Management of Gestational Gigantomastia with Goldilocks Procedure after Mastectomy: A Case Report and Review of Literature.

Gestational gigantomastia is characterized by the rapid growth of breasts during pregnancy. The treatment method of gestational gigantomastia is unclear; if the medical treatment is ineffective, surgery is considered. However, sufficient research on which method is best to perform breast reconstruction for the gestational gigantomastia patient has not yet been conducted. Our patient was young and had aesthetic needs; thus, we did not recommend modified radical mastectomy. However, it was difficult for the patient to consider active reconstruction using an implant or autologous tissue because of the expected complications and economic problems. The patient had a thin body shape and very large breasts compared with the trunk. Therefore, breast volume was not significantly required after reconstruction. Additionally, we expected that a considerable portion of skin would remain after mastectomy as a tubular-shaped breast. It was expected that the Goldilocks technique would be sufficient to meet the patient's volume needs. Therefore, we proceeded with total mastectomy and reconstruction using the Goldilocks procedure. No complications were recorded after the operation; most of the patient's discomfort was resolved, and the shape and size of the breasts were satisfactory.

Surface Modification of Bi2Te3 Nanoplates Deposited with Tin, Palladium, and Tin/Palladium Using Electroless Deposition

Surface-modified nanoplate-shaped thermoelectric materials can achieve good thermoelectric performance. Herein, single-crystalline Bi2Te3 nanoplates with regular hexagonal shapes were prepared via solvothermal techniques. Surface modification was performed to deposit different metals onto the nanoplates using electroless deposition. Nanoparticle-shaped tin (Sn) and layer-shaped palladium (Pd) formed on the Bi2Te3 nanoplates via electroless deposition. For the sequential deposition of Sn and Pd, the surface morphology was mostly the same as that of the Sn-Bi2Te3 nanoplates. To assess the thermoelectric properties of the nanoplates as closely as possible, they were compressed into thin bulk shapes at 300 K. The Sn-Bi2Te3 and Sn/Pd-Bi2Te3 nanoplates exhibited the lowest lattice thermal conductivity of 1.1 W/(m·K), indicating that nanoparticle-shaped Sn facilitated the scattering of phonons. By contrast, the Pd-Bi2Te3 nanoplates exhibited the highest electrical conductivity. Thus, the highest power factor (15 μW/(m∙K2)) and dimensionless ZT (32 × 10−3) were obtained for the Pd-Bi2Te3 nanoplates. These thermoelectric properties were not as high as those of the sintered Bi2Te3 samples; however, this study revealed the effect of different metal depositions on Bi2Te3 nanoplates for improving thermoelectric performance. These findings offer venues for improving thermoelectric performance by sintering nanoplates deposited with appropriate metals.

Preparation and Lithium-Ion Capacitance Performance of Nitrogen and Sulfur Co-Doped Carbon Nanosheets with Limited Space via the Vermiculite Template Method.

Nitrogen and sulfur co-doped graphene-like carbon nanosheets (CNSs) with a two-dimensional structure are prepared by using methylene blue as a carbon source and expanded vermiculite as a template. After static negative pressure adsorption, high-temperature calcination, and etching in a vacuum oven, they are embedded in the limited space of the vermiculite template. The addition of an appropriate number of mixed elements can improve the performance of a battery. Via scanning electron microscopy, it is found that the prepared nitrogen-sulfur-co-doped carbon nanosheets exhibit a thin yarn shape. The XPS results show that there are four elements of C, N, O, and S in the carbon materials (CNS-600, CNS-700, CNS-800, CNS-900) prepared at different temperatures, and the N atom content shows a gradually decreasing trend. It is mainly doped into a graphene-like network in four ways (graphite nitrogen, pyridine nitrogen, pyrrole nitrogen, and pyridine nitrogen oxide), while the S element shows an increasing trend, mainly in the form of thiophene S and sulfur, which is covalently linked to oxygen. The results show that CNS-700 has a discharge-specific capacity of 460 mAh/g at a current density of 0.1 A/g, and it can still maintain a specific capacity of 200 mAh/g at a current density of 2 A/g. The assembled lithium-ion capacitor has excellent energy density and power density, with a maximum power density of 20,000 W/kg.

Experimental Study on Warpage Phenomenon of Wax Parts Manufactured by Fused Filament Fabrication.

Warpage is one of the prominent issues in Fused Filament Fabrication. The cause of this is the rapid cooling of the polymer during extrusion. The residual thermal stresses accumulated within the print part result in a shape distortion and subsequent detachment of the object from the print bed. In this study, both experimental and numerical approaches were used to identify the stresses due to thermal shrinking that occurs in soft polymers such as wax. A temperature sweep test was performed using a rotational rheometer to measure the magnitude of axial forces that are generated due to the thermal shrinking of a thin layer of 3D printable wax. The thermal stresses responsible for warpage were computed analytically and using the FEA. It was found that due to thermal processes, the stress magnitude can reach a value of 1.17 MPa. This value is enough to cause the plastic deformation in the wax part having a thin elongated shape. In addition, Taguchi's robust design has identified two major FFF parameters that impact the warpage in amorphous soft polymers. They are the printing speed and the print bed temperature. To achieve a low level of warpage, it is important to make sure that the layer deposition occurs at medium speeds and the print bed temperature is moderately high according to the findings of this study.

Implicit Finite Difference Simulation of Hybrid Nanofluid along a Vertical Thin Cylinder with Sinusoidal Wall Heat Flux under the Effects of Magnetic Field

A numerical analysis of magnetohydrodynamic natural convection along a thin vertical cylinder with a sinusoidal heat flux at the wall immersed in copper (Cu) and aluminum-oxide (Al2O3) hybrid nanofluids has been studied. A 2D vertical thin cylinder shape geometry has been considered with a radius of R. The fluid flow is considered laminar and incompressible with the Prandtl number of Pr = 6.2 and 10% concentration of hybrid nanoparticles. The nondimensional governing equations have been solved numerically by using the implicit finite difference method. An in-house FORTRAN 90 code is used for solving this problem and the code is validated with the available benchmark results. Numerical simulations have been performed for a wide range of governing parameters, Hartmann number from Ha = 0 to Ha = 4, nanoparticles volume fractions ϕ = 0.0 to ϕ = 0.1, and the amplitude of the wall heat flux ε = 0.0–0.3. The findings have been illustrated in terms of streamlines, isotherms, local skin friction coefficients, local Nusselt numbers, velocity, and temperature distributions. The flow field and temperature distribution within the boundary layer are deceased by the effects of the wall heat flux amplitudes. It is also noted that the rate of heat transfer increases with particle volume fraction and the amplitude of the wall heat flux. According to the findings, Nu increases by 24.72% as ϕ increases from 0 to 0.1 while ε = 0.3, and 27.66% while ε increases from 0.0 to 0.3 at 5% hybrid nanoparticles. The local skin frictions and Nusselt number diminish with the increment of the Hartman number due to the effects of the Lorenz force. The findings of this study can lead to a better understanding of the fundamental principles regarding the behavior of hybrid nanofluids under complex conditions, such as a vertical thin cylinder with a sinusoidal wall heat flux. Understanding the behavior of hybrid nanofluids in the presence of a magnetic field and a nonuniform wall heat flow can also lead to the development of innovative heat transfer enhancement strategies.

SECONDARY TECHNICAL OPERATIONS USED TO FORM THE CROWN OF THE TREES IN THE CHERRY ORCHARDS ON GISELA 6 IN THE FIRST YEARS AFTER PLANTING

The study was carried out in the spring of 2020 in the north of the country, variety Grace Star grafted on the rootstock Gisela 6, thin spindle crown shape. Planting distance 4.2x1.8 m. In spring 2021 was organized with the following gradation: 1. Trees trained after the thin spindle crown (control); 2. Solitary incision above the buds and processing the cut with water; 3. Solitary incision above the buds and treatment of the cut with growth regulator Progerbalin LG; 4. Circular incision at 25-30 cm distance on the axis with processing of the cut with Progerbalin LG growth regulator; 5. Extirpation removal of 4-5 axillary buds from top to bottom of the leader while keeping a bud intact. It was established that, to increase the branching potential of the tree axis when training intervened with solitary incisions above the buds and circular incisions at a distance of 25-30 cm on the axis with the processing of the cut with the growth regulator Progerbalin LG in the ratio one part of product to 8-10 parts of latex paint.

Variations of single event transient induced by line edge roughness (LER) and temperature in FinFET

The impacts of line edge roughness (LER) and temperature effect on single event transient (SET) in Silicon-On-Insulator (SOI) FinFET at 14 nm technology node are studied. Based on the calibrated model of the rectangle FinFET, all of possible fin structures induced by LER in the vertical direction are proposed by considering the correlation between the line edges. When an energetic particle hits, due to the corporate effects of the gate control capability from the equivalent gate width and the current density from the cross section, thin fin shape represents more immunity to SET with the relative decrement in current peak, collected charge, deposited charge, pulse width and bipolar amplification coefficient by 23.78 %, 31.61 %, 19.16 %, 23.77 % and 15.40 %, respectively. However, the SET responses of big bottom and fat fin structures indicate that they are more sensitive to SET. Because of the driven current increase induced by the inversion of the temperature effect in FinFET, as the environment temperature increases, the SET responses of all of fin shapes decrease and their relative decrements are close. When the temperature increases from 258K to 398K, the average relative decrements in current peak, and collected charge are 24.22 %, 20.90 %, respectively.

Formulation and characterization of 3D printed chickpea protein isolate-mixed cereal dysphagia diet

The feasibility study of making 3D printed dysphagia diet was undertaken. A mixture of corn flour and buckwheat flour was used as the model cereal and chickpea protein isolate (CPI) was used as the model protein. Printing gels (inks) of the mixed cereal (control) and CPI-cereal mixture were produced by heating the formulations at 95 °C for 30 min and then cooling them to room temperature. The results showed that all the ink formulations containing CPI had higher apparent viscosity, preferable shear thinning behavior and shape supporting characteristics than that of the control. The cohesiveness and shape supporting ability of 10%CPI-cereal and 20%CPI-cereal formulations were poor and could not produce stable printing shape. The 30%CPI-cereal and 40%CPI-cereal formulations had suitable apparent viscosity, shear thinning behavior, storage modulus, yield stress and printing accuracy and the 3D printed products were stable. The control ink and 10%CPI-cereal ink had low cohesion and also could not pass the spoon tilt test. The 50%CPI-cereal formulation had high hardness and also could not pass the fork pressing test. The 30 % to 40 % CPI-cereal formulations were found to be suitable as dysphagia products as they could be classified as level 5 dysphagia diet.

Study of the effect of the combination of protective gases on the structure of the weld bead for the GMAW process using pulsed arc and short circuit

A weld bead's geometry directly influences the welded joint's physical characteristics and mechanical performance. The composition of the shielding gas directly affects the form of metal transfer during the welding process and, therefore, modifies the geometry of the weld seam obtained. In addition, metal transfer methods also influence the configuration of the weld bead profile. The objective is to analyze the geometry of the weld bead with different combinations of shielding gases and metal transfer modes in the continuous wire electric arc welding process with gas shielding (GMAW). To achieve this objective, a methodology is proposed to analyze the weld bead's penetration and other geometric parameters. This is achieved by varying the percentages of the gas mixture between Ar and CO2 and by employing different types of metal transfer, such as short circuit, pulsed, and PMC multi-control pulsed. Generally, when using only CO2 as shielding gas, a wide, round weld bead is obtained. If Ar alone is used, the weld bead profile has a very thin shape and deep penetration. With the mixture of Ar and CO2, a bead is obtained with good penetration and sufficient width to cover the two test tubes without empty spaces between the base and filler materials. The macrographic analysis of the chords with their respective measurements is presented, and the geometric parameters of the obtained chords are tabulated. The penetration of the bead is directly proportional to the percentage of CO2 present in the mixture. In a comparison between the three transfer modes used with the same gas composition, it is found that the pulsed spray mode produces greater penetration.

Recent research of materials for emissive layer of OLED

As time has gone on, a lot of changes in display technology have taken place. Organic light-emitting diode (OLED) is the one of the many types of display technology. They have attracted many interests in the academic filed and commercial worlds, and developed rapidly since their earliest introduction. They are now highly regarded and used in the display and lighting industries due to a number of promising characteristics, such as environmentally friendly, high energy efficiency, large area, light weight, and thin shape. Among various light emitting materials, polymers have higher glass transition temperature. Therefore, polymer-based OLEDs exhibit higher stability and have received wide attention. The development of OLED devices can be divided into three main generations of emitter materials based on the technique of the emissive layer of OLEDs. The first generation of OLED is fluorescent OLED (FOLED), the second generation is phosphorescent OLED (POLED), and the third generation is thermally activated delayed fluorescence (TAFD). In this article, device structure, mechanism and development of polymer-based OLEDs are introduced. Specifically, working principles and materials of the three generations are presented with a focus on TADF-based OLEDs. In addition, their device performances including quantum efficiency and lifetime are compared quantitatively.