1,721,043 research outputs found
Computer control of powder flow for solid freeforming by acoustic modulation
No full textThis communication describes a method for both on/off and flow rate control of dry powders in open capillaries using acoustic vibration. In a glass capillary attached to an electromagnetic transducer, the wave characteristics of the forced vibration control both flow rate and switching of powder flow. The valve is free from relative movement of parts that may wear or seize in the presence of fine powders. The versatility of the flow controller has been demonstrated by playing popular music to a sample of H13 tool steel powder. The on/off switching and the flow rate of the powder correspond to the waveform of the musi
Studies on ultrasonic microfeeding of fine powders
No full textMicrofeeding can be used, inter alia, for solid freeforming, colour management and pharmaceutical dosing. In this work, a computer-controlled microfeeding system using ultrasonic vibration of a capillary was built. This paper describes the powder structures in the microfeeding process and defines the main processing factors affecting the mean dose mass. The experimental results show that the particle structures in the capillary tube can be divided into three types: arching, plugging and blocking. The nozzle diameter, transmission fluid depth, waveforms, voltage amplitude, frequency and oscillation duration all influence the dose mass. Among these factors, the nozzle diameter, voltage amplitude and oscillation duration can be used to control the dose mass. © 2006 IOP Publishing Ltd.status: Publishe
Solid freeforming of Braille patterns on clay products
No full textAn aqueous suspension of clay was delivered through an electromagnetic ink-jet printer head onto partially dried clay tile to produce patterns in relief. The patterns formed Braille symbols intended for tactile recognition by visually impaired persons (VIP). This solid freeforming procedure means that conventional clay products such as wall tile, although mass-produced, can acquire individuation so that tactile information can be delivered to VIPs to assist, for example, in navigation in the built environmen
Detection of alpha-fetoprotein in magnetic immunoassay of thin channels using biofunctional nanoparticles
No full text[[abstract]]This paper presents the use of fluorescent biofunctional nanoparticles (10-30 nm) to detect alpha-fetoprotein (AFP) in a thin-channel magnetic immunoassay. We used an AFP model biomarker and s-shaped deposition zones to test the proposed detection method. The results show that the detection using fluorescent biofunctional nanoparticle has a higher throughput than that of functional microparticle used in previous experiments on affinity reactions. The proposed method takes about 3 min (versus 150 min of previous method) to detect 100 samples. The proposed method is useful for screening biomarkers in clinical applications, and can reduce the run time for sandwich immunoassays to less than 20 min. The detection limits (0.06 pg/ml) and linear ranges (0.068 pg/ml-0.68 ng/ml) of AFP using fluorescent biofunctional nanoparticles are the same as those of using functional microparticles within experimental errors. This detection limit is substantially lower and the linear range is considerably wider than those of enzyme-linked immunosorbent assay (ELISA) and other methods in sandwich immunoassay methods. The differences between this method and an ELISA in AFP measurements of serum samples were less than 12 %. The proposed method provides simple, fast, and sensitive detection with a high throughput for biomarkers.[[note]]SC
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Preparation of porous hydroxyapatite materials
No full textThe aim of the paper was to obtain a porous hydroxyapatite(HA)biomaterial that was used to manufacture artificial implants. The technique of impregnating a polyurethane sponge with slurry containing HA powder, water and additives was applied and proved to be more successful. The process of preparations was discussed and the porous HA with desired properties was obtained at las
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
