Nozzle Head Research Articles

Comparison of innovative metallization approaches for silicon heterojunction solar cells

Within this study, different metallization approaches were investigated and compared with respect to their applicability for silicon heterojunction (SHJ) solar cells. A printed line width of 34 µm with an aspect ratio of 0.59 was reached by double fine-line screen printing. In parallel, ink jet printing and its applicability regarding in-situ curing was evaluated. It was found that spreading of the ink is substantially reduced by choosing the optimum substrate temperature, enabling for a line width of 32 µm. Successful dispensing of a low-temperature silver paste was achieved by using a ten nozzle print head. By means of screen printed contact grids on both sides, solar cells with a conversion efficiency of 21.9 % were produced with industrial precursor wafers.

ВИЗНАЧЕННЯ РЕЖИМІВ РОЗПИЛУ УДОБРЮЮЧИХ ХІМІЧНИХ РЕЧОВИН ДЕФЛЕКТОРНИМ ПУЛЬВЕРИЗАТОРОМ В РАМКАХ КОНЦЕПЦІЇ ТОЧНОГО ЗЕМЛЕРОБСТВА

A mathematical model of the process of sputtering chemical fertilizers by means of a deflector spray with flat-flare spraying, whose work is based on the Venturi effect, is proposed. Several operating modes of the atomizer with the adjustment of the flow velocity and the angle of the spraying nozzle are examined by changing the geometric parameters of the nozzle head. The most rational parameters of the flow of the components of the atomized medium, as well as the geometric parameters of the atomizer, are taken into account, taking into account the speed of the aircraft and the effect of the screen from the watering surface.

Synthesis of CoAl2O4/Al2O3 nanoparticles for ceramic blue pigments

Abstract The demand for pigments for industrial ceramic ink-jet printing is increasing steadily. The main challenge is the availability of ceramic pigments comprised of small-sized particles in order to avoid clogging of the printer head nozzle. This work presents a novel way to prepare ceramic blue pigment as a shell/core structure of CoAl 2 O 4 /Al 2 O 3 nanoparticles through a simple and low-cost process. In this process, the colour tone of nano-pigment can be tuned by the selection of the cobalt precursor/Al 2 O 3 ratio and calcining temperature.

Evaluation of Interface Defects in Inaccessible Reactor Shrink Fit Nozzle Welds Using Ultrasonic Waves

This study proposes an effective method to inspect inaccessible nuclear power reactor head nozzles using interface waves that propagate along the shrink fit boundary of a reactor head. The reactor head is relatively thick, which makes it difficult to inspect from the outside by conventional ultrasonic testing. However, interface waves can propagate a long distance from a fixed transducer position. The inside of the nuclear reactor has limited access due to the high radiation, so the transducers are located outside the nuclear reactor head, and interface waves propagate into the nuclear reactor to detect defects. A numerical simulation and experiments were carried out to validate the method. Various defect cases that simulate field failures are also presented, and the proposed technique shows satisfactory defect classification.

국내 사과원의 재배형태 및 농약 살포방법 조사

A survey was conducted to research on planting system and pesticide spray methods including spray volume, sprayer types, and spray nozzles used in apple orchards. The survey was deployed to 395 farmers in 17 cities and towns including 7 regions which are major producers of apple via interview. Major apple varieties were Fuji (79.2%) and Hongro (50.9%) and high density planting system was mainly used in apple orchards (distance between rows: 4.0-4.5 m (73.1%); planting distance: 1.5-3.5 m (88.6%); canopy height: 3.0-4.5 m (88.2%)). The percentages of sprayer types were 77.6% and 22.1% for speed sprayer (airblast sprayer) and power sprayer, respectively. Spray volumes per 10a were 250-300 L in April, the month of spraying the lowest volume, and 300-400 L in June-August, the months of spraying the highest volume. Significant difference in spray volumes were not observed between conventional planting and high density planting, but regional spray volume showed significant difference. The main nozzles used by apple farmers using power sprayers were super jet nozzle (45%), super wide nozzle (26%), and 2-3 vertical head nozzle (25%). The results will helpful to establish practical agrochemicals management policy including suggestion of pesticide spray volume and evaluation of pesticide residue data and efficacy data.

Discussion on Flow-Through Phenomena in the Air Gauge Cascade

Abstract In the paper, the flow-through phenomena in the air gauge are under discussion form the thermodynamic and gasodynamic perspective. The main elements of the cascade are considered the inlet nozzle (restriction), measuring chamber and the measuring nozzle with the measuring slot (displacement between the nozzle head and measured surface). The purpose of the analysis was to point out the impact on the metrological characteristics of the air gauge. In particular, attention was paid to the airflow through the measuring slot. Here, the complex phenomena take place, among others the supersonic areas and a “bubble ring,” which cause discontinuity and hysteresis in the static characteristic. On the other hand, the air stream expansion after the restriction (inlet nozzle) is observed in the measuring chamber. The point of the above discussion was to work out some recommendation on the nozzles geometry and the localization of the back-pressure measuring point in the chamber.

Micronization of Ceramic Pigments for Digital Ink-Jet Printing Process

Ink-jet printing techniques with ceramic ink, which contains ceramic pigments as colorant, are in increasingly use in the ceramic industry. Generally, ceramic pigments that are produced by conventional method show diameters of several micrometers; these micrometer sized particles in the ink-jet printing process can cause undesirable behavior such as print head nozzle clogging. To prevent this problem, a particle size reduction process is required. In this study, CMYK (cyan, magenta, yellow, black) pigments were synthesized via solid state method. Each pigment particle was milled to submicron size by an attrition mill. The effects of micronizing on the morphology, mechanical property, crystal structure and color property of the CMYK ceramic pigments were investigated by field emission scanning electron microscopy (FE-SEM), particle size analysis (PSA), X-ray diffraction (XRD) and CIE L*a*b*.

Effect of Sandblasting Angle and Distance on Biaxial Flexural Strength of Zirconia-based Ceramics.

Surface treatment is necessarily required for bonding of zirconia to the veneering porcelain and luting cements. Sandblasting is the most common and probably the most efficient surface treatment method. Sandblasting roughens the surface and may affect the flexural strength of zirconia. Different sandblasting protocols may yield variable results. This study sought to assess the effect of sandblasting angle and distance on the biaxial flexural strength of zirconia-based ceramics. This in vitro experimental study was conducted on 50 zirconia discs measuring 1.2 ± 0.2 mm in thickness and 15 ± 0.2 mm in diameter, which were randomly divided into five groups (n = 10) of one control and four experimental groups subjected to sandblasting with 110 μm aluminum oxide particles under 2 bar pressure for 10 seconds at 15 and 25 mm distances and 45 and 90° angles (between the nozzle head and zirconia surface). Surface roughness was measured by a roughness tester and samples were subjected to thermocycling followed by biaxial flexural strength testing according to ISO6872. The data were analyzed using one-way analysis of variance (p < 0.05). No statistically significant difference was noted in the mean biaxial flexural strength of the five groups (p = 0.40). Different sandblasting protocols yielded significantly different surface roughness values (p < 0.001). The highest and the lowest mean surface roughness belonged to 15 mm/90° (0.51 μm) and control (0.001 μm) groups respectively. Change in sandblasting angle and distance had no significant effect on the biaxial flexural strength of zirconia-based ceramic, but surface roughness was significantly different in the study groups. Clinical significances: Regardless of sandblasting angle, increasing distance to 25 mm significantly decreases surface roughness that may negatively affect zirconia bond strength.

核电厂稳压器贯穿接管的修复和结构完整性评估

较早期核电厂的压力容器封头上的贯穿接管材料多为600合金，由于600合金对一回路水环境应力腐蚀开裂的抗性较差，易产生应力腐蚀裂纹贯穿压力边界而导致泄漏，可采用修复方法使用690合金接管更换损坏的接管，重构压力边界。为确保新压力边界能够达到原始设计要求，对重构压力边界的新接管及其焊缝进行结构完整性分析。对稳压器顶盖上的贯穿接管，进行重构压力边界的焊接修复和结构完整性评估，基于有限元分析获得工况瞬态热应力和焊接残余应力的基础上，依据ASME规范进行应力强度校核，并通过断裂力学计算分析假想裂纹在核电厂40年设计寿命内的扩展及稳定性，分析结果表明修复后的结构满足设计和使用要求。 Many NPP pressure vessel head nozzles were manufactured of Alloy 600. Since Alloy 600 is sus-ceptible to PWSCC, the degradation mechanism has been observed in these nozzles. The industry has used several methods to mitigate PWSCC, including replacement of nozzles fabricated of Alloy 690. After the replacement of the nozzle, the structural integrity analysis of new nozzle and welds should be performed to ensure the pressure boundary compliance with the original design re-quirement. The PWR pressurizer top head instrument nozzle is evaluated. Thermal stress of the transients was obtained from 3D FEM analysis and residual stress of J-groove weld was obtained from 2D FEM analysis. Stress intensities and residual stress were conservatively determined and used for the ASME Code, stress intensity analysis, fatigue crack growth analysis and fracture me-chanics analysis. All of the analysis showed that the repaired nozzle satisfies the ASME Code design requirement.

Rancangan Irigasi Sprinkler Portable Tanaman Pakchoy

Salah satu teknologi yang dapat meningkatkan efisiensi dan efektivitas penggunaan air irigasi adalah irigasi sprinkler. Namun dalam penerapan sistem irigasi sprinkler di lapangan masih dijumpai banyak kendala, diantaranya adalah memerlukan biaya investasi awal dan operasional yang tinggi. Oleh karena itu, penelitian ini bertujuan untuk merancang irigasi sprinkler portable yang mudah dipindahkan (portable) dan penggunaannya pada budidaya tanaman pakchoy, khususnya pada luas lahan pertanian yang kecil dan terpisah-pisah (0,10 – 0,30 ha) dan terpisah-pisah tanpa adanya sarana irigasi. Metode yang digunakan dalam penelitian ini adalah penentuan panjang dan diameter pipa berdasarkan analisa hidrolika perpipaan, baik pipa lateral, manifold dan utama; perhitungan debit sprinkler menggunakan metode volumetrik; dan penentuan keseragaman irigasi menggunakan metode Christiansen. Sistem irigasi sprinkler portable yang telah dikembangkan memiliki spesifikasi: nozzle head sprinkler jenis Sprinkler Impact Plactic dengan ukuran nozzle 4 mm, tinggi total stick riser 1,3 meter dengan diameter ¾”, pipa lateral elastis dengan diameter 2” dan panjang 50 meter, pipa sub-main (manifold) dan pipa utama sebesar 2”. Adapun pompa yang digunakan memiliki total head 55 meter dengan tenaga penggerak 5,5 HP, serta selang hisap 2”. Sistem irigasi sprinkler ini dapat beroperasi pada tekanan operasi 1 sampai dengan 4 bar untuk spasi sprinkler dan lateral 10 m x 10 m. Debit sprinkler pada tekanan 1 bar adalah 0,12 l/s. Nilai keseragaman irigasi yang dihasilkan pada tekanan 1 bar sebesar 80%. Untuk memperoleh nilai keseragaman irigasi lebih dari 85%, maka disarankan penggunaan tekanan operasi minimal 2 bar.

A Study of the dimensional accuracy obtained by low cost 3D printing for possible application in medicine

Low cost 3D printing' is a terminology that referred to the fused filament fabrication (FFF) technique, which constructs physical prototypes, by depositing material layer by layer using a thermal nozzle head. Nowadays, 3D printing is widely used in medical applications such as tissue engineering as well as supporting tool in diagnosis and treatment in Neurosurgery, Orthopedic and Dental-Cranio-Maxillo-Facial surgery. 3D CAD medical models are usually obtained by MRI or CT scans and then are sent to a 3D printer for physical model creation. The present paper is focused on a brief overview of benefits and limitations of 3D printing applications in the field of medicine as well as on a dimensional accuracy study of low-cost 3D printing technique.

Material Jetting 3D Printing Process by Thermal Ink Jet Head

A new type of 3D printing process is introduced. The printing mechanism is based on material jetting process by inkjet-printing head to eject and deposit a photopolymer ink as the 3D object building material. The existing material jetting 3D printer adopted multi nozzle piezo-electrical print head. The piezo ink jet head requires complicated head structure, ink supply and maintenance system. The printing area should be large because of wide area of printing head and it causes that the 3D printing machine should be large and expensive for a commercial purpose only. In this study, Thermal ink jet head is applied to the print head for 3D printing process. The thermal head has low cost and compact printing mechanism but it is hard to apply photo polymer ink of material jetting process for jetting fluid because the thermal ink jet head fires the ink droplet by boiling mechanism. The specific building material for jetting in thermal head is applied and a 3D printing process is investigated for stable ejection and deposition on the substrate for building 3D object. The droplet volume of print head is under 20 pico-litters and ejection frequency is 2 kHz and the thickness of single layer deposited for building object is more than 10 micro-meters. The 3D printing system is fabricated and the hollow cylindrical object with high aspect ratio is successfully built and printing process is verified.

Structural Integrity Analysis of Nuclear Power Plant Pressure Vessel Penetration Nozzle Repaired

Primary water stress corrosion cracking (PWSCC) has been observed in CRDM nozzles, BMI nozzles and other penetration nozzles. The industry has used the repair method of replacement of nozzles fabricated of Alloy 690. After the replacement of the nozzle, the structural integrity analysis of new nozzle and welds should be performed to ensure the pressure boundary compliance with the original design requirement. In this paper, the pressurizer top head instrument nozzle of PWR nuclear power plant is evaluated as a typical pressure vessel penetration nozzle. The results showed that the repaired nozzle satisfies the ASME Code design requirement and the crack growth of the postulated flaw in 40 years of the nuclear plant life is acceptable.PWSCC degradation mechanism has been observed in CRDM nozzles, BMI nozzles and other penetration nozzles [1]. In some nuclear power plants built in China earlier, such as DAYABAY nuclear power plant and QINSHAN nuclear power plant, PWSCC degradation mechanism has been found in CRDM nozzle welds which manufactured of Alloy 600 and welded of Alloy 82/182[2]. The repair of the degraded nozzles is the popular choice for the nuclear power plant owners. After the replacement of the nozzle, the structural integrity analysis of new nozzle and welds should be performed to ensure the pressure boundary compliance with the original design requirement. In this paper, the pressurizer top head nozzle of PWR nuclear power plant is evaluated as a typical pressure vessel penetration nozzle. Stress intensities were conservatively determined for pressure and applicable thermal transients and compared to the allowable values of the ASME Code, Section III. Thermal stress of the transients was obtained from 3D finite element model (FEM). Residual stress of J-groove weld was obtained from 2D FEM analysis and used for fracture mechanics analysis. All of the analysis showed that the repaired nozzle satisfies the ASME Code design requirement and the crack growth of the postulated flaw in 40 years of the nuclear plant life is acceptable.

Advanced Wet Clean Technology at Lightly Doped Drain Layers in FinFET

An advanced wet clean method to utilize piezoelectric nozzle head for fine-controlled dual-fluid sprays based on single wafer clean toolset was demonstrated on FinFET production wafers that surface particles were reduced by as much as 26% without sacrifice of gate pattern damage in sensitive lightly doped drain layers. Additionally, about 5% yield improvement was observed for using the new clean method. The fine-controlled dual-fluid sprays improved the cleaning efficiency significantly in the "physicochemical" way and reduced the potential for pattern damage caused by variations in liquid droplet size and velocity.

Ultra-narrow gap welding of thick section of austenitic stainless steel to HSLA steel

A substantially narrow GMAW torch nozzle head has been designed that enables narrowing down of weld groove up to a limit of just accommodating the nozzle in it where the groove wall of thick section virtually acts as a side wall of the nozzle head to produce a narrowest possible butt welding. A model of shielding gas flow dynamics and its flow rate in case of employing newly developed GMAW nozzle head has been studied at different projection angle of torch nozzle inside the narrow groove of butt joint by using ANSYS-CFX(14.5) software. The utility aspect of such a narrow nozzle head from the view point of smooth flow of shielding gas inside a close fitted ultra-narrow weld groove has also been studied. The outcome of the analytical studies has been used to produce a defect free ultra-narrow multi-pass weld by employing P-GMAW process with vertically placed electrode depositing single bead per layer in weld groove.

Parameter study of the injection configuration in a zero boil-off hydrogen storage tank using orthogonal test design

This paper presents a steady-state numerical study of a zero boil-off liquid hydrogen storage tank in microgravity conditions. An injection configuration including a nozzle head and a guide tube is equipped to the ZBO tank. The colder liquid hydrogen injected from the nozzles and the guide tube cools down and mixes the main heated fluid inside the tank. The heated fluid then is driven from the outlet opening towards the external cooling system including a pump, cryocooler and heat exchanger to be cooled down and pumped into the injection configuration again to complete a working cycle. An axisymmetric model is employed to analyze the fluid flow and heat transfer inside the storage tank. Twenty five cases selected by the L25(56) orthogonal array with different geometry settings are performed to quantify the parametric study of the injection configuration. The influence of each parameter and the relatively optimal configuration for the injection are both investigated. The results show that the depth of the nozzle head has more influence than other parameters, the guide tube affects the fluid flow in the bottom region obviously, and properly structural parameters of the injection can improve the cooling and mixing performance of the ZBO tank.

Optimization of slightly acidic electrolyzed water spray for airborne culturable bacteria reduction in animal housing

Slightly acidic electrolyzed water (SAEW) spray has been considered as a novel approach for airborne bacteria reduction in animal housing. This study aimed to optimize the operating parameters of SAEW spray based on the size distribution of sprayed aerosols, the available chlorine travelling loss in sprayed aerosols, and the reduction efficiency of airborne culturable bacteria (CB). The optimized operating parameters were the nozzle orifice diameter and the spray pressure. The size distribution characteristics of sprayed SAEW aerosols under different operating parameters were quantified. The pH and available chlorine concentrations of the original SAEW solution and the SAEW aerosols collected at 0 m, 0.25 m, 0.50 m, 0.75 m, and 1.00 m from the spray nozzle head were analyzed. A bioaerosol nebulizing generator was used to simulate animal housing environment in an environmentally-controlled chamber. Six SAEW spray trials under different operating parameters were conducted at a spray dosage of 80 mL/m2 in the chamber. Airborne CB concentrations before and after spray were measured to investigate the reduction efficiency of airborne CB. Dv(50), the volume-based diameter below which 50% of the particle being present, increased with the nozzle orifice diameter and decreased with the spray pressure. The travelling loss of available chlorine in the sprayed SAEW aerosols was greatly dependent on Dv(50). SAEW spray with medium size sprayed aerosols (Dv(50) = 86.62 μm, 67.94 μm, and 54.53 μm) showed significantly higher airborne CB reduction efficiencies than large (Dv(50)=121.80 μm and 96.00 μm) or small size aerosols (Dv(50) = 42.57 μm). The spray operating parameters that provide medium size sprayed aerosols (Dv(50) ~ 60-90 μm) are recommended for SAEW spray in animal housing. Keywords: animal housing, bioaerosol, available chlorine, size distribution, air quality, poultry and livestock DOI: 10.3965/j.ijabe.20160904.2366 Citation: Zheng W C, Ni L, Hui X, Li B M, Zhang J F. Optimization of slightly acidic electrolyzed water spray for airborne culturable bacteria reduction in animal housing. Int J Agric & Biol Eng, 2016; 9(4): 185－191.

E&amp;P Notes (July 2016)

E&amp;P Notes Small Bubbles, Big Rewards for Separation Technology Reminiscent of the song made famous by late Hawaiian crooner Don Ho, tiny bubbles are the focal point of a new innovation aimed at transforming produced water from a costly byproduct into a valuable asset. Termed nanobubbles, they are several times smaller than a human red blood cell, which allows them to play with the physics of how dissolved gas interacts with liquids, according to Nano Gas Technologies. The suburban Chicago-based startup says its technology is capable of cheaply producing these nanobubbles to treat produced wastewater that is among the “worst of the worst.” The technology works by pushing gas, either oxygen or nitrogen, through a nozzle head that shoots the tiny bubbles into a treatment tank. The result is what the company’s chief executive officer, Len Bland, calls “fluffy water” that causes suspended solids to fall and oil to float to the top where it is easily skimmed off. “If you want to put it in technical terms,” he said, “we change the specific gravity of the liquid so that it enables the oil that is stuck in the water to rise.” Search for Flight MH 370 Shows Durability of AUVs The unprecedented search effort for Malaysian Airlines flight 370 has yet to achieve its main goal of locating the vanished aircraft and the 227 persons on board. However, it has served as an endurance test of sorts for offshore surveying systems such as the autonomous underwater vehicle (AUV), which just a couple of years ago was considered an emerging technology with a small track record. Edward Saade, president of the ocean surveying firm Fugro Pelagos, the company contracted by the Australian government to carry out much of the search operation, said he knows of no other commercial project where AUVs have been successfully deployed for such an extensive period of time. Speaking at the 2016 Offshore Technology Conference in Houston, Saade said that to cover large swaths of subsea terrain as quickly as possible and capture high-resolution data, Fugro first deployed vessels equipped with conventional deep-tow side scanning sonar. Then starting in January of last year, the AUV vessel was deployed from Perth. “The purpose of the AUV was to try and get into all those areas that turned out to be blocked in the side-scan operation, either by the steep slopes or other types of data anomalies,” Saade said. “We would preprogram the AUV, launch it and it would do its thing for about 24–28 hours and very effectively fill in all the gaps.”

New criteria for filament breakup in droplet-on-demand inkjet printing using volume of fluid (VOF) method

A volume of fluid (VOF) numerical study is presented in which new pi number-based criteria are discussed that identify and separate three different regimes for a droplet-on-demand (DOD) print-head system. A trailing filament coalesces into the main droplet while the filament breaks into one or multiple satellite droplet(s). The numerical simulation results are compared with published large-scale experimental results that used a 2 mm diameter inkjet nozzle head, roughly 50 times larger than the actual diameter of inkjet outlets. Liquid filament break-up behavior is predicted using a combination of two pi-numbers, including either Weber (We)-Ohnesorge (Oh) number couplets or Reynolds (Re)-Weber (We) number couplets that are dependent only on the ejected liquid properties and the velocity waveform at the print-head inlet. These new criteria have merit over the currently existing ones that require accurate measurements of actual droplets to determine filament physical features like length and diameter [1].

Influence of Bed Temperature on Heat Shrinkage Shape Error in FDM Additive Manufacturing of the ABS-Engineering Plastic

In case of manufacturing hexahedral ABS (Acrylonitrile Butadiene Styrene) plastic components using a FDM (Fused Deposition Modeling)-based 3D printer, undesirable shape errors occur in the product due to heat shrinkage. This paper experimentally ob-served the influence of the bed temperature change on the deformed shape errors of a hexahedral specimen of 100 × 50 × 50 mm3 produced by using a 3D printer. During printing work, the head nozzle temperature was kept at 240?C and the head speed was set at 50 mm/s. The chamber was enclosed with a PC-plate. 3D printing was conducted at four different bed temperatures; 50?C, 70?C, 90?C, and 110?C. After the produced specimens naturally cooled down to room temperature, their deformed shape errors were measured. As a result, the higher the bed temperature, the lower the deformed shape errors of the specimens were. However, if the bed temperature had exceeded 120?C, laminating adhesion became poor. That seems to occur because of the material phase change and can make 3D printing work very hard as a consequence. Results of this study can be helpful to set optimum bed temperature condition in FDM additive manufacturing.