Quality Of Layers Research Articles

Effects of supplementing a polyphenol-rich sugarcane extract through drinking water on egg production and quality of laying hens.

Polyphenols are a wide group of naturally occurring compounds found in plants and have the potential to safeguard living cells. The objective was to evaluate whether the inclusion of a polyphenol-rich sugarcane extract (PRSE) in drinking water could improve egg production and the quality of commercial layers. A total of 120 Shaver Brown hens, aged 43 weeks, were randomly allocated to 12 litter-floor pens in two open-sided poultry houses. The pens were divided into two treatment groups: one receiving 0% (control) and the other 0.05% PRSE in drinking water throughout the study duration. The treatments were prepared by adding PRSE manually into the drinking water daily, and water was given ad libitum. The birds were given commercial layer feed throughout the study. The number of eggs produced, abnormal eggs, and mortality were recorded daily. Egg weight, yolk colour, yolk height, albumen height, Haugh units, and antioxidant properties, were measured at weeks 45, 47 and 49. Supplementing PRSE in the drinking water did not impact hen-day egg production, hen-housed egg production, egg weight, egg mass, or feed conversion ratio. However, there was a trend toward significance in egg weight at week 45. The results indicated that PRSE supplementation led to a significant reduction in yolk colour during week 45 (P = 0.001), although no differences were observed in subsequent weeks. Yolk height, thick albumen height, and haugh units were unaffected by the treatment, while thin albumen height showed a trend towards reduction in the PRSE group at weeks 47 and 49 (P = 0.05). The DPPH assay revealed a significant increase in antioxidant capacity in the PRSE group at week 45 (P = 0.02). The 0.05% PRSE supplementation in drinking water initially enhanced antioxidant capacity but later adversely affected yolk color and thin albumen height.

Crystallographic properties of the HgCdTe layers grown by MBE on CdZnTe(211)B substrates

A review of the specificity of the growth Hg1-xCdxTe layers by molecular beam epitaxy (MBE) and results of experimental studies of several Hg1-xCdxTe layers grown on CdyZn1-yTe (CZT) substrates are presented. It is well known that the performance of Hg1-xCdxTe -based detectors strongly depends on the substrate material and its orientation. CZT substrates are among the most commonly used due to their very good lattice match with Hg1-xCdxTe absorber material with different Cd content. In the present work, the authors focused on optimizing the MBE growth parameters in order to obtain the best possible crystalline quality of Hg1-xCdxTe layers grown on CZT substrates with (211)B orientation, in particular in terms of minimizing the number of defects. Experimental results of the selected structures showed that the obtained undoped Hg1-xCdxTe layers of different x have high crystallographic and optical quality, as well as good surface morphology. In particular, high-resolution X-ray diffraction (HRXRD) measurements and their analysis showed that the best structure has a full width at half maximum of rocking curve (FWHMRC) as low as 21.5 arcsec, and that the intensity distribution of diffraction peaks does not indicate the influence of mosaicisity and dislocation density.

Effects of the Salvia miltiorrhiza, Ligustrum lucidum, and Taraxacum mongolicum ultra-fine powder formula on meat quality of aged layers by multi-omics.

This study was aimed to identify the targets of 1% ultra-fine Chinese medicine formula (UCMF, 0.5% Salvia miltiorrhiza Bge. + 0.25% Ligustrum lucidum Ait. + 0.25% Taraxacum mongolicum Hand.-Mazz.) in delaying aging and explore its impacts on meat quality of aged layers. The effective components of the above three Chinese herbs were screened, and the network pharmacology analysis identified 91 common targets and enriched pathways between herbs and aging. The results showed that cellular response to chemical stimulus, response to oxidative stress, and response to oxygen-containing compound pathways were crucial for UCMF to resist aging. Further in vivo analyses confirmed that UCMF supplementation enhanced the antioxidant function in breast muscles of aged layers by upregulating (P < 0.05) the SOD2 gene expression. Meanwhile, UCMF supplementation reduced (P < 0.05) yellowness (b* value) and drip loss while enhancing (P < 0.05) cooked meat percentage of aged layers. For the health lipid indices in breast muscles, UCMF supplementation increased (P < 0.05) polyunsaturated fatty acids/saturated fatty acids and hypocholesterolemic/hypercholesterolemic ratios and decreased (P < 0.05) the thrombogenic index. The UCMF supplementation optimized the cecal microbiota of aged layers by enhancing the relative abundance of Firmicutes and reducing the relative abundances of Bacteroidetes and Spirochaetes (P < 0.05), which may be related to improving meat quality. In conclusion, dietary UCMF supplementation may be an effective strategy for improving antioxidant function and the meat quality of aged layers.

Multi-band single bio-molecule detection through inverse-designed graphene-folded spherical particle dimers

The present research employs graphene-coated spherical nano-particles as the basis of optical dimers for multi-frequency refractive index sensing applications. Under parallelly polarized incoming waves, dual operating bands are attained owing to the presence of localized surface plasmon resonances (LSPRs) on graphene shells. Thus, enormous local near-field enrichment is detected at the gap middle as a result of plasmonic hybridization and strong coupling. The potential usage of the proposed dimer as a dual-band high-performance refractive index sensor, with the typical sensitivity of S1 = 2.8143 × 104 nm/RIU and figure of merit of FOM1 = 213.2860 RIU-1 in the first band, and sensitivity of S2 = 1.8070 × 104 nm/RIU and figure of merit of FOM2 = 305.1521 RIU-1 in the second band, is illustrated. Importantly, the enormous near-field enhancement is maintained for particles with different radii, making the element suitable for single bio-molecule recognition of various types by tuning the quality of the graphene layer. The spectral tuning is correspondingly viable after production by imposing a suitable Fermi level on the graphene shells. Finally, machine learning forward and reverse problems based on the random forest (RF), decision tree (DT), and eXtreme Gradient Boosting (XGBoost) algorithms are implemented to propose a method respectively for analysis of the sensor's performance and to design an appropriate sensor for each desired molecule.

Tailoring selenization dynamics: How heating rate manipulates nucleation and growth boosts efficiency in kesterite solar cells.

Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) has emerged as a promising photovoltaic material due to its low cost and high stability. The CZTSSe film for high-performance solar cells can be obtained by annealing the deposited CZTS precursor films with selenium (a process known as selenization). The design of the selenization process significantly affects the quality of the absorber layer. In this work, we systematically investigate the impact of heating rate on the selenization kinetics and the microstructural characteristics of the films using a two-step selenization method. The results indicate that a slow heating rate promotes surface crystallization, resulting in a thick and dense layer of large grains at the film surface that impedes the diffusion of Se vapor. Conversely, a rapid heating rate enhances the diffusion of Se into the interior of the film, synthesizing more low-melting-point intermediate compounds that facilitate grain growth and reduce the thickness of fine grains at the film bottom. Ultimately, a CZTSSe solar cell with an efficiency of 10.17% was fabricated at a heating rate of 200 °C/min. This research deepens the understanding of thin film growth mechanisms and advances the development of high-performance solar cells.

Low-Impedance Hybrid Carbon Structures on SiOX: A Sequential Gas-Phase Coating Approach.

Carbon coating on SiOX surface is crucial for enhancing initial Coulombic efficiency (ICE) and cycling performance in batteries, while also buffering volume expansion. Despite its market prevalence, the effects of the carbon layer's quality and structure on the electrochemical properties of SiOX remain underexplored. This study compares carbon layers produced via gas-phase and solid-phase coating methods, introducing an innovative technique that sequentially uses two gases to develop a low-impedance hybrid carbon structure. In this approach, C3H8 is first deposited to create a short-range, vertically ordered carbon architecture, followed by C2H2 to establish a long-range, layered structure, effectively filling the gaps. This results in a dense hybrid carbon layer characterized by minimal defects, high crystallinity, and excellent electronic conductivity. The dominant vertical configuration enhances Li-ion migration. The SiO@C3H8@C2H2 prepared through this method yields a specific surface area of 1.14 m2 g⁻¹ and a high reversible capacity of 1574.9 mAh g⁻¹, alongside an ICE of 83.7%. It showcases remarkable cycling stability, retaining 86.6% capacity after 1000 cycles at room temperature, and performs effectively under varied temperatures and discharging conditions. This low-impedance carbon structure provides a significant reference for other anodes that also require a carbon layer.

Research on the Influence of Magnetic Field Assistance on the Quality of an Electro-Spark Deposition Layer

Aimed at solving the problems of single control measures in the electro-spark deposition (ESD) process, difficulty controlling the micro-process using heterogeneous materials (for the electrode and matrix), and the unstable quality and reliability of repairs to the deposition layer, a method of magnetic-field-assistance electro-spark deposition (MFESD) was proposed. An MFESD device was built, and a Ni electrode was used for deposition on the surface of 45 steel under the conditions of deposition voltages of 30 V, 60 V, and 90 V, respectively. This study examined the impact of the magnetic field’s intensity and frequency on the microstructure and mechanical properties of electro-spark deposition layers. The results show that the sputtering and protrusion of the electrode material on the surface of the deposition layer gradually decrease with an increase in the magnetic field’s intensity and frequency, defects such as pores and cracks are obviously improved, and the structure is uninterrupted and compact. The surface roughness of the deposited layer decreases with an increase in the magnetic field’s intensity and frequency, and its surface roughness decreases by 44.3%. The cross-section effect of the deposited layer is improved. The thickness of the deposited layer increases with an increase in the magnetic field’s intensity and frequency; the thickness of the deposited layer increases by 13.39%, and its maximum thickness can reach 54.396 μm. At the same time, the microhardness of the deposited layer increases with an increase in the two aforementioned properties of the magnetic field, and its hardness increases by 5.32%. Using a magnetic field to control ESD can effectively control the microscopic process of deposition and obtain high-quality deposition coatings, which have important significance in the surface remanufacturing of key components of high-end equipment.

In Situ Focused Ion Beam Redeposition Surface Coatings for Site-Specific, Near-Surface Characterization by Atom Probe Tomography.

Atom probe tomography (APT) enables three-dimensional chemical mapping with near-atomic scale resolution. However, this method requires precise sample preparation, which is typically achieved using a focused ion beam (FIB) microscope. As the ion beam induces some degree of damage to the sample, it is necessary to apply a protective layer over the region of interest (ROI). Herein, the use of redeposition, a (frequently considered negative) side effect of FIB sputtering, is explored as a technique for targeted surface coatings in site-specific, near-surface APT investigations. In addition, the concept of "self-coating" is presented, which is the application of a capping layer using material from the same, or a similar, sample. It is shown to provide a pathway for high-quality coatings, as well as a method of minimizing the field evaporation threshold difference at the cap-sample interface, thus greatly reducing the likelihood of premature fractures. In situ redeposition surface coatings are shown to be versatile, with four materials used in the coating and analysis of two Si-based semiconductors and a Fe-Mn alloy. Several factors are discussed, such as the specimen yield, the capping layer quality, and the ease of ROI identification, all of which demonstrate its effectiveness in routine sample preparation workflows.

Decision Support for Selecting Blockchain-Based Application Design Patterns with Layered Taxonomy and Quality Attributes

Decision Support for Selecting Blockchain-Based Application Design Patterns with Layered Taxonomy and Quality Attributes

Investigations of modulation method and stress mechanism for the growth of AlGaN channel heterostructures.

In this work, the strong connection between the channel and the barrier layer of AlGaN channel heterostructures has been investigated in detail. Unlike GaN as a channel material, AlGaN channel layers significantly influence the transport characteristics and quality of AlGaN barrier layers with increasing Al composition. Furthermore, the stress mechanism in the growth of the AlGaN layer has been thoroughly discussed. It has been revealed that the modulation of the channel layer stress alters its relaxation and enhances the consistency of the in-plane lattice constant, thereby improving channel layer quality. Moreover, this process reduces the tensile stress on the barrier layer, and improves the barrier layer quality and heterostructures performance. This work is not only beneficial for the achievement of high breakdown voltage and new generations of high-power RF devices, but is also instructive to the optimization and realization of the AlGaN material in deep-UV devices.

Enhancing the performance and stability of organometal halide perovskite by using a feasible and economical interface material

AbstractOrganometal halide perovskites (OHPs) are one of the viable options for solar absorber materials because their power conversion efficiencies are getting better and better over time. In the conventional n-i-p-based configuration, TiO2 has been widely used as an electron transport layer (ETL). However, a number of constraints, such as low electron mobility and a mismatched band alignment with perovskite, restrict future advances in solar performance and device environmental stability. As a result, SnO2 has garnered a lot of interest as a potential replacement due to the comparatively low manufacturing temperature, better electron mobility and appropriate energy alignment w.r.t perovskite. In this experimental work, the primary emphasis was placed on enhancing the efficiency as well as the stability of OHPs by performing interface engineering at the ETL (SnO2)/perovskite interface. We improved the surface quality of the SnO2 ETL layer by using a material called 8-Hydroxyquinoline, which was quite inexpensive, and we prepared a favourable plane for the deposition of perovskite. Remarkably, the proposed surface modification material made the SnO2 layer easier to wet and impacted the growth of perovskite grains. This made the perovskite layer more compact and smooth. Our experimental findings imply that the OHPs’ enhanced charge recombination resistance and decreased charge transfer resistance are caused by effective defect passivation at the junction of the SnO2 and perovskite films, as well as a decrease in recombination due to unwanted trap states. The fabricated cell produced a power conversion efficiency (PCE) of 20.42%, higher than a PCE of 17.9% obtained for a device without surface modification. The proposed material for changing the surface also made OHPs more stable by reducing the surface paths for the reaction with humidity and reducing the amount of extra PbI2 in the perovskite layer. Various research groups have investigated the modification of SnO2 ETL using interfacial engineering methods and have contributed to enhancing OHPs’ solar performance and device stability.

Increasing the Resistance of Steel and Austenitic Stainless Steels Against Pitting Corrosion by a γ-Irradiated Self-Assembled Amphiphilic Molecular Layer

This study, based on our previous research, aims to quantitatively determine the enhanced protection of austenitic stainless steels against pitting corrosion in NaCl solution by self-assembled molecular (SAM) layers, in their original form and after γ-irradiation. This study focuses on four stainless steels of varying compositions, covered by self-assembled undecenyl phosphonic acid layers. The metal dissolution in corrosion experiments was measured by a special, highly sensitive analytical technique using the inductively coupled plasma–optical emission spectrometry (ICP-OES). The comparison of the dissolved metal ion concentrations measured in the presence of different metals with and without nanocoatings allowed the evaluation of the anticorrosion effectiveness of nanofilms as well as the importance of the alloying elements. The ICP-OES results demonstrated that the quality of layers have a significant impact on anticorrosion efficacy. The γ-irradiated self-assembled layers were the most effective in controlling the dissolution of stainless steels. The mechanisms of the inhibition in the presence of these nanolayers were elucidated by infrared spectroscopy. First of all, it revealed the differences in the adsorption of the undecenyl phosphonic acid self-assembled layer, both with and without γ-irradiation. The other important observation that confirmed the increased anticorrosion efficiency after γ-irradiation proved the formation of a more compact, polymer-like layer over the metal surface. The increased anticorrosion efficacy, defined as the enhancement in Pitting Resistance Equivalent Numbers (PRENs) in the presence of self-assembled layers (either pre- or post-γ-irradiation), can be documented.

Nutrient Distribution in the Soil Profile Under Different Tillage Practices During a Long-Term Field Trial

Conservation tillage practices are increasingly used in agricultural systems. However, these practices require a complex approach regarding soil nutrition. Adequate nutrient content in soils is important for crop production, as reduced and no-tillage practices change the distribution of nutrient contents (P, K, Mg, and Ca) in the soil profile, necessitating new approaches for agronomists in crop nutrition. Little is known about the time changes in nutrient distribution in the soil profile under conservation tillage practices. Long-term field experiments with conventional (CT—plowing to 20–22 cm), reduced (RT—chiseling to 8–10 cm), and no-tillage (NT) practices were established in Prague–Ruzyně (Czech Republic) in 1995. This four-year crop rotation consisted of winter wheat changing with oilseed rape or pea. The soil nutrient contents have been determined since 2009 using the Mehlich 3 method and through extraction in 0.5 M ammonium acetate. The obtained results showed that P, K, and, to a lesser extent, Mg contents increased in the soil surface layer (0–10 cm) under the reduced and no-tillage practices, whereas Ca and pH values showed an opposite trend. We found an unbalanced ratio of nutrients in the upper soil layer in RT and NT caused by a high concentration of the monovalent cation K+ and the leaching of the divalent cations Ca2+ and Mg2+ into the deeper soil layers. In conventional practices, the ion contents are equalized throughout the topsoil due to the soil inverting during plowing. The determination of nutrient contents in deeper soil layers revealed that, over time, calcium, magnesium, and potassium were transported to deeper parts of the soil profile under RT and especially NT. Low nutrient ratios were found in the surface layer under RT and NT, negatively affecting the quality of the soil surface layer, including its structure. Fertilizer management and nutrient ratios in soils under RT and NT should be considered to maintain and possibly improve sustainable agricultural practices in fields with reduced or no-tillage practices. Furthermore, nutrient contents and their mutual ratios should be evaluated in more soil layers under these systems, enabling the detection of eventual problems in the upper layer that must be addressed by changing fertilization.

Optimization of selective powder deposition for multi-material powder bed fusion: process innovations and applications

AbstractAdditive manufacturing processes based on powder bed fusion offer a high degree of design flexibility and enable the processing of a wide range of materials, including metals, ceramics, and polymers, while maintaining minimal porosity. However, production of multi-material components with locally tailored properties to meet specific requirements by incorporating different materials with a high degree of spatial selectivity remains an elusive challenge. Essential prerequisites for achieving this selectivity are specialized selective powder deposition techniques, their development, characterization, and subsequent implementation. In order to investigate optimization potentials and to identify research gaps in the field of selective powder deposition techniques, an evaluation of the current literature is performed in this study, ultimately highlighting promising potentials for vibration-assisted approaches. Key considerations include the reduction of implementation complexity and the downscaling of associated devices to increase their applicability. To achieve implementation simplification, this study derives dimensionless quantities that facilitate a targeted calculation of control parameters by associating powder layer quality metrics with relevant input quantities. The validity of the derived dimensionless quantities is verified by discrete-element method simulations and physical experiments employing a novel miniaturized vibration-assisted device. Metal, ceramic and polymer powders are used as representative samples to demonstrate the versatility of the method for different classes of materials. Ultimately, the presented methods enable a significant improvement in the applicability of vibration-assisted devices and represent an integrative component that provides a suitable basis for further research efforts in the field of combined processing of multiple materials by additive manufacturing technologies that utilize powder beds.

Laser Cladding Performance and Process Parameter Optimization for Fe90 Alloy

Fe90 alloy has a high weld hardness, good toughness, and high oxidation resistance, and is often used as a cladding material to repair the surfaces of 42CrMo steel structures of large shearer picks. The influence of the laser cladding processing parameters on the microstructure, properties, and formation mechanism of Fe90 alloy layers on the surface of 42CrMo steel was studied. Simulations were conducted to investigate how these processing parameters affect the temperature field and internal stress of the cladding layer. A complex nonlinear relationship between variables and residual stresses in the laser cladding layers obtained by additive manufacturing was fitted. An optimization model for residual stress in the cladding layer was established and an improved genetic algorithm was used for optimization, which resulted in a 15.88% reduction in residual stress. The results show that optimizing the processing parameters increased the amount of Ni-Cr-Fe solid solution in the cladding layer, enhancing its strength and corrosion resistance. The amount of residual stresses rose with increases in laser power, but at higher powers, increasing the scanning speed and spot diameter reduced stresses. At lower powers, the amount of residual stresses initially increased and then decreased with the scanning speed, with more significant changes occurring with larger spot diameters. Analyzing temperature and residual stress changes allowed us to improve the cladding layer quality, providing a theoretical basis for laser cladding on 42CrMo.

Growth of InxGa1−xAs Films on GaAs (100): Inserting an Ultrathin InxGa1−xAs Buffer Using a Surface Technology

ABSTRACTThe mechanism of the In‐catalyzed reaction of GaAs with In metal to form InxGa1−xAs was explained by comparing the interfacial reactions of metallic In and GaAs at high and low temperatures. Specifically, GaAs dissolved in In metal at the defects under the catalysis of In, and then In diffused into the GaAs crystals to replace Ga in the lattices. Based on this mechanism, a new method was developed for preparing an InxGa1−xAs buffer layer on GaAs by combining the ion‐sputtering method and annealing. The buffer layer and its effect on the quality of the epitaxial layer grown on GaAs were verified and analyzed by transmission electron microscopy, X‐ray diffraction, Hall effect measurements, and Raman scattering. The buffer layer was found to adopt the original dislocations on the GaAs surface, which prevented substrate dislocations from entering the epitaxial layer and reduced the dislocations generated due to the mismatch between the substrate and buffer layer. When the composition of the epitaxial layer is similar to that of the buffer layer, the quality of the epitaxial layer is significantly improved.

Impact of Dried Thyme Leaf Meal on Production Performance, Egg Quality and Blood Parameters of Laying Hens.

The use of commercially extracted phytogenic compounds to maintain poultry health and productivity in the absence of in-feed antibiotics is prohibitively costly in developing countries. The goal of the study is to determine the effect of dietary supplementation with Thymus schimperi leaf meal (TLM) on production performance, egg quality and haemato-biochemical parameters of Bovan brown layers. A total of 96 laying hens at 25 weeks of age were randomly assigned to 4 treatments with 6 replications each. The treatments include the control (standard commercial laying diet), TLM1.5 (control+1.5% TLM), TLM2.5 (control+2.5% TLM) and TLM3.5 (control+3.5% TLM). Egg production, feed intake and feed conversion ratio were recorded for each replicate. Two eggs per replication were used to measure internal and external egg quality traits on a monthly basis. At the end of the trial, blood samples were collected from 2 birds/replicate for the determination of albumin, uric acid, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, luteinizing hormone, prolactin and progesterone. All blood parameters were within the normal ranges of the breed. Egg production, feed conversion ratio, internal egg quality traits and external egg quality traits of hens fed diets containing 2.5% TLM were significantly higher than the control. Furthermore, diets containing 2.5% TLM led to a significantly reduced feed conversion ratio compared to all other dietary treatments. In conclusion, 2.5% TML is recommended to improve egg production and egg quality without adverse effect on hen health.

Ultra-thin sealing surface treatments for solar radiation screening on asphalt facing dams

Bituminous materials are widely used in a large range of hydraulic applications due their excellent waterproofing properties. More than 300 asphalt facing reservoirs were built in the last century, presenting higher mechanical and hydraulic performance when compared with other facing alternatives, such as cement concrete or steel membranes. On the other hand, the dark colour of bitumen may lead to high temperatures inside asphalt paved system, affecting long term ageing of binder and jeopardizing the quality of the impervious layer. Recently, multifunctional ultra-thin surface treatments are becoming an alternative to demolition-reconstruction of the impervious layer, significantly abating the quantity of energy and raw materials required for maintenance. High-reflective surface treatments may represent also an effective solution to reduce the temperature of asphalt layers, extending the service life of the dam embankment and reducing the need of maintenance. In fact, there is a lack of literature concerning the assessment of thermal impact on asphalt dams. In the light of above, a number of different combinations of sealing surface treatments were investigated in this study. An ad hoc testing equipment and procedure were designed to perform an artificial solar irradiance test. A complete colorimetry analysis was performed and the outcomes were compared with temperature data, making use of a thermal camera and of embedded sensors for surface and base temperature measurements, respectively. Major results and their relationships have been commented in-depth along with proposed further research activities.

Achieving 2.1% Efficiency in Alpha‐Voltaic Cell Based on Silicon Carbide Transducer

Alpha‐voltaic cell is a type of micro nuclear battery that provides several decades of reliable power in the nanowatt to microwatt range, supplying for special applications where traditional chemical batteries or solar cells are difficult to operate. However, the power conversion efficiency of the alpha‐voltaic cells reported are still far behind the theoretical limit, making the development of alpha‐voltaic cell challenging. Developing advanced semiconductor transducers with higher efficiency in converting the energy of alpha particles into electric energy is proving to be necessary for realizing high‐power conversion efficiency. Herein, we propose an alpha‐voltaic cell based on SiC PIN transducer that includes a sensitive region with an area of 1 cm2, a width of 51.2 μm, and a charge collection efficiency of 95.6% at 0 V bias. We find that optimizing the unintentional doping concentration and crystal quality of the SiC epitaxial layer can significantly increase the absorption and utilization of the energy of alpha particles, resulting in a 2.4‐fold enhancement in power conversion efficiency compared with that of the previous study. Electrical properties of the SiC alpha‐voltaic cell are measured using an He‐ion accelerator as the equivalent α‐radioisotopes, with the best power conversion efficiency of 2.10% and maximum output power density of 406.66 nW cm−2 is obtained. Our research makes a big leap in SiC alpha‐voltaic cell, bridging the gap between micro nuclear batteries and practical applications in micro‐electromechanical systems, micro aerial vehicles, and tiny satellites.

Study on the influence of shielding effect for plasma cloud on multi-field coupling mechanism during laser cladding

Laser is a kind of electromagnetic wave. During laser cladding, metal vapor will be produced when the temperature reaches the material sublimation point, and plasma clouds will be produced after vapor atoms are ionized by laser. When the laser beam passes through the plasma cloud, it will be absorbed or refracted, resulting in the decrease of laser energy reaching the substrate surface. Plasma cloud shielding effect will directly affect the multi-field coupling behavior during laser cladding. It is significant to quantitatively reveal the influence mechanism of plasma cloud on multi-field coupling during laser cladding for improving the cladding layer quality. In the paper, a multi-field coupled numerical model for laser cladding of Fe60 with ASTM 1045 disk laser was established. The interaction between the waist beam of cladding powder jet, plasma cloud and laser beam was considered in the modeling. The influence of plasma cloud shielding effect on transient evolution for the temperature field, flow field, and stress field during laser cladding was compared and analyzed. The results show that the maximum temperature of molten pool is less than 2700 K, no plasma cloud will be produced during cladding. When the temperature is higher than 2700 K, the plasma cloud initiates. Under the same conditions, the molten pool temperature slightly decreases, the velocity decreases, and the stress increases slightly due to the shielding effect of the plasma cloud. And with the increase of laser power, the shielding effect of plasma cloud is more and more significant.