11,573 research outputs found
Feasibility study of dissimilar metal joining by laser riveting of Ti-6Al-4V to AA6061
Full text linkNote: Paper published as part of the special topic on Proceedings of the International Congress of Applications of Lasers & Electro-Optics 2021© 2021 Author(s). Aluminum of cylindrical profile (of diameter 1–4 mm) was trailed by laser metal wire deposition for potential riveting applications. The rivet was built onto a Ti6Al4V substrate through a hole in an AA6061 sheet. The built feature was postprocessed by a high-frequency laser washing technique to obtain the desired finish. Parameter optimization has allowed increased productivity by almost seven times while achieving required wetting conditions and metallurgical properties. It is found that the quality (both morphology and metallurgy) of the laser rivet joint is highly dependent on the laser wash parameters. The rivet crown and welding areas improved by the postwash process were directly reflected in the microhardness and shear tests and increased by 90% and 62%, respectively, compared with those in an unwashed rivet.Brunel University London; The Welding Institute (TWI)
Enhanced electrical and optical properties of room temperature deposited Aluminium doped Zinc Oxide (AZO) thin films by excimer laser annealing
No full textHigh quality transparent conductive oxides (TCOs) often require a high thermal budget fabrication process. In this study, Excimer Laser Annealing (ELA) at a wavelength of 248 nm has been explored as a processing mechanism to facilitate low thermal budget fabrication of high quality aluminium doped zinc oxide (AZO) thin films. 180 nm thick AZO films were prepared by radio frequency magnetron sputtering at room temperature on fused silica substrates. The effects of the applied RF power and the sputtering pressure on the outcome of ELA at different laser energy densities and number of pulses have been investigated. AZO films deposited with no intentional heating at 180 W, and at 2 mTorr of 0.2% oxygen in argon were selected as the optimum as-deposited films in this work, with a resistivity of 1×10−3 Ω.cm, and an average visible transmission of 85%. ELA was found to result in noticeably reduced resistivity of 5×10−4 Ω.cm, and enhancing the average visible transmission to 90% when AZO is processed with 5 pulses at 125 mJ/cm2. Therefore, the combination of RF magnetron sputtering and ELA, both low thermal budget and scalable techniques, can provide a viable fabrication route of high quality AZO films for use as transparent electrodes
Low-Cost Laser-Based Localization System for Agricultural Machines
Full text linkThis paper describes the design and test of a low-cost localization system for agricultural applications, which determines a tractor position in fields up to 0.5 km with an uncertainty of about 1 m. The proposed system employs a standard unmodified laser head, which is commonly used for field leveling, plus a reference ground-fixed laser receiver and requires neither laser modulation nor expensive time-of-flight measurements of light beam
PERENCANAAN BISNIS SISTEM INFORMASI PERCETAKAN ONLINE BERBASIS APLIKASI WEB.
Full text linkPersaingan bisnis dewasa ini tak hanya bertumpu pada kualitas produk, melainkan lebih pada kualitas layanan, yang lebih mendorong pelanggan untuk kembali membeli produk atau menggunakan solusi yang ditawarkan. Namun, tidak berarti produk yang dipasarkan boleh yang tidak bermutu, terutama jika produk yang ditawarkan memiliki pesaing yang kurang lebih sama. Lain halnya untuk produk-produk yang secara esensial bersifat unik, bermutu tinggi dan memiliki diferensiasi yang kuat, sehingga pelanggan akan memiliki value yang jelas, meskipun ada produk-produk yang sejenis. Untuk membuka wirausaha perlu dipertimbangkan secara matang mengenai perencanaan usahanya yang akan dijalankan. Perencanaan yang matang akan menentukan hasil sesuai dengan apa yang diharapkan, sehingga usahanya dapat berlangsung terus-menerus. Penelitian ini bertujuan untuk membuat suatu model perencanaan bisnis percetakan online berbasis aplikasi web dan mengetahui model perencanaan bisnis yang layak untuk direalisasikan. Perencanaan bisnis percetakan online berbasis aplikasi web akan menjelaskan perencanaan bisnis yang mengoptimalkan fungsi teknologi informasi sebagai pendukung kegiatan transaksi dan operasional usaha tersebut. Kata kunci: Perencanaan bisnis, teknologi informasi, percetakan online berbasis aplikasi web
The effect of trust of a political party as a moderating variable on the leadership towards voters' loyalty
No full textMeasuring industry-science links through inventor-author relations: A profiling method
Full text linkIn this pilot study we examine the performance of text-based profiling in recovering a set of validated inventor-author links. In a first step we match patents and publications solely based on their similarity in content. Next, we compare inventor and author names on the highest ranked matches for the occurrence of name matches. Finally, we compare these candidate matches with the names listed in a validated set of inventor-author names. Our text-based profile methodology performs significantly better than a random matching of patents and publications, suggesting that text-based profiling is a valuable complementary tool to the name searches used in previous studies.innovation; industry-science links; text-based profiling;
An automated, 0.5Hz nano-foil target positioning system for intense laser plasma experiments
Get PDFWe report on a target system supporting automated positioning of nano-targets with a precision resolution of in three dimensions. It relies on a confocal distance sensor and a microscope. The system has been commissioned to position nanometer targets with 1Hz repetition rate. Integrating our prototype into the table-top ATLAS 300 TW-laser system at the Laboratory for Extreme Photonics in Garching, we demonstrate the operation of a 0.5Hz laser-driven proton source with a shot-to-shot variation of the maximum energy about 27% for a level of confidence of 0.95. The reason of laser shooting experiments operated at 0.5Hz rather than 1Hz is because the synchronization between the nano-foil target positioning system and the laser trigger needs to improve.DFG Cluster of Excellence Munich-Centre for Advanced Photonics (MAP); Centre for Advanced Laser Applications; China Scholarship [201508080084]SCI(E)ARTICLE
Hardness determination of bio-ceramics using laser-induced breakdown spectroscopy.
Full text linkLaser-Induced Breakdown Spectroscopy (LIBS) was applied to the analysis of bioceramic
samples. The relationship between sample hardness and LIBS plasma
properties was investigated, with comparison to conventional Vickers hardness
measurements. The plasma excitation temperature Te was determined using the lineto-
continuum ratio for the Si (I) 288.16 nm emission line; we have demonstrated a
linear relationship between sample surface hardness and plasma temperature. Results
indicate that hardness determination based on measurements of Te offers greater
reproducibility than Vickers hardness measurements, under the conditions considered
here. The validity of spectroscopic diagnostics based on LTE was confirmed
Fiber design for high-power low-cost Yb:Al-doped fiber laser operating at 980nm
Full text linkWe investigated an Yb:Al-doped depressed-clad hollow optical fiber (DCHOF) for cladding-pumped 980nm laser operation. With a careful design, the nonzero fundamental-mode cutoff characteristics of a DCHOF allows the competing 1030-1060nm emission to be filtered out, despite being quite close to 980nm. The laser yielded over 3W of output power in a diffraction limited beam (M -parameter degrades to 2.7, as a result of increased cladding-mode lasing, as the cladding thickness is reduced
Investigation into laser re-melting of inconel 625 HVOF coating blended with WC
Full text linkHigh velocity oxy-fuel (HVOF) spraying of Diamalloy 1005 powders mixed with WC particles onto steel (304) is considered and laser re-melting of the resulting coatings is examined. Laser re-melting process is modeled to determine the melt layer thickness while temperature increase is formulated using the Fourier heating law. The morphological and metallurgical analyses prior and post laser re-melting process are carried out using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). X-ray diffraction (XRD) technique is used to determine the residual stress developed in the coating while the analytical formulation is adopted to predict the residual stress levels at the coating base material interface. The indentation tests are carried out to determine the Young’s modulus and fracture toughness of the coating prior to laser re-melting. Corrosion resistance of coating is measured using potentiodynamic polarization technique prior and post laser treatment process. The predictions of the melt layer thickness are in good agreement with experimental results. The presence of WC particles modifies temperature rise and its gradient in the coating while affecting the Young’s modulus, residual stress levels, and fracture toughness of the coating. The differences in the thermal properties of Inconel 625 powders and WC particles result in formation of small size cellular structure through polyphase solidification. WC dissolution in the central region of the large polycrystalline cells is observed due to the loss of carbon through carbonic gas formation. The results of corrosion tests prevail that significant improvement of corrosion resistance can be achieved after laser treatment process
- …
