Smart scientific instruments based on smartphones: a brief review

Smartphone has gone beyond a communication hub to be a measurement device itself, thanks to various built-in sensors. This article reviewed achievements in transforming ubiquitous smartphones into cost-effective scientific instruments for educational laboratories, environmental studies, point-of-care diagnostics, home-based health monitoring, and rehabilitation. Magnetic fields were precisely measured by built-in magnetometers, leading to demonstrations for engineering and medical applications. The smartphone-based joint-angle measurement was a viable alternative to traditional goniometers. Characterizations of optical signals captured by cameras led to portable spectrophotometers and colorimeters for both educational and practical uses. Interestingly, smartphones became a platform for high-resolution microscopes and fluorescence microscopes were developed with add-on components. These smart instruments become even more attractive options in the pandemic period with limited facility and laboratory access

Modernizing Batik Clothes for Community Enterprises Using Creative Design and Colorimetry

The objective of this study was to modernize batik clothes, a cultural heritage of Southeast Asia, through creative design, color characterization, and collection presentation. Three community enterprises from the southern regions of Thailand participated in designing batik motifs based on their local identities. The pattern of the first manufacturer group was influenced by stones and ancient beads of vivid orange and blue shades. The second community was inspired by the nearby sea, resulting in ocean blue, white, and emerald green colors on batik fabrics. Floras in the south of Thailand dominated the design of the final manufacturer group. Smartphone colorimetry was then used to characterize the batik fabrics. It was demonstrated that this proposed color quantification was not confined to the laboratory, and could easily be carried out by vendors or customers. The collaboration encouraged local batik artisans to use a variety of inspirations, new tools, as well as professional design and production methods. To introduce modernized batik to the public, collections of these newly designed clothes were displayed in a fashion show staged under the theme “Southern Chic.” The presentation of Thai batik clothes in seasonal collections highlighted the transformations of local manufacturers and products with increasing appeal to younger people. In addition to conservation and commercial advantages, the modernized approach is accessible and attractive for education purposes, engaging students in cultural heritage. Doi: 10.28991/esj-2021-01319 Full Text: PD

Comparison of closed-form solutions to experimental magnetic force between two cylindrical magnets

The force between permanent magnets implemented in many engineering devices remains an intriguing problem in basic physics. The variation of magnetic force with the distance x between a pair of magnets cannot usually be approximated as x-4 because of the dipole nature and geometry of magnets. In this work, the force between two identical cylindrical magnets is accurately described by a closed-form solution. The analytical model assumes that the magnets are uniformly magnetized along their length. The calculation, based on the magnetic field exerted by one magnet on the other along the direction of their orientation, shows a reduction in the magnetic force with the distance x and a dependence on the size parameters of magnets. To verify the equation, the experiment was set up by placing two cylindrical neodymium iron boron type magnets in a vertical tube. The repulsive force between the identical upper and lower magnets of 2.5 cm in diameter and 7.5 cm in length was measured from the weight on the top of the upper magnet. The resulting separation between the magnets was recorded as x. The forces measured at x=0.004-0.037 m differ from the values calculated using the analytic solution by -0.55 % to -13.60 %. The calculation also gives rise to a practical remnant magnetic field of 1.206 T. When x is much large than the equation of force is approximated as a simple form proportional to 1/x-4. The finding can be directly used in magnetic levitation as well as applied in calculating magnetic fields and forces in other systems incorporating permanent magnets

In vitro bioactivity and stem cells attachment of three-dimensionally ordered macroporous bioactive glass incorporating iron oxides

Three-dimensionally ordered macroporous bioactive SiO2-CaO-Na2O-P2O5 glass (3DOM-BG) is synthesized by using the sol-gel method. After an in vitro test in simulated body fluid (SBF), the hydroxyapatite (HAp) crystalline phase is clearly formed on its surface as confirmed by X-ray diffractometry (XRD) and Raman spectroscopy. Magnetic 3DOM-BG/Fe samples are synthesized by partial substitution of SiO2 with iron oxide. Whilst the HAp layer is not confirmed, energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and XRD analysis reveal calcium phosphate layer on the surface of 3DOM-BG/Fe samples after the SBF soaking. The growth of HAp-like layer is slower with increasing iron oxides. The initial mechanism that thought to induce bone formation is reduced due to the replacement of Ca2+ with Fe ions in the glass network. The formation of HAp-like layer is modified by the sedimentation of Ca and P while the nonmagnetic 3DOM-BG forms the calcium phosphate by the ionic exchange following the Hench mechanism. The adult human adipose tissue-derived stem cells (hADSCs) can be closely attached and well spread on the flat-plate of all 3DOM-BG/Fe and 3DOM-BG. Without detectable cytotoxicity possibly induced by iron oxides, the osteoblast can be grown and proliferated. In addition to these bioactivity and biocompatibility, porous structures can allow their possible use in targeted drug delivery and magnetic properties of 3DOM-BG/Fe can essentially be implemented in hyperthermia therapy

Recent Developments in 3D Printing of Rare-Earth-Free Permanent Magnets

This article reviews the advances in additive manufacturing of magnetic ceramics and alloys without rare-earth elements. Near-net-shaped permanent magnets with varying shapes and dimensions overcome traditional limitations of the cast, sintered, and bonded magnets. The published articles are categorized based on material types and 3D printing techniques. Selective laser melting and electron beam melting were predominantly used to produce alnico magnets. In addition to the electron beam melting, manganese aluminium-based alloys were successfully printed by fuse filament fabrication. By incorporating magnetic powders in polymers and then printing via extrusion, the fuse filament fabrication was also used to produce strontium ferrite magnets. Moreover, hard ferrites were printed by stereolithography and extrusion free-forming, without drawing composites into filaments. Magnetic properties in some cases are comparable to those of conventional magnets with the same compositions. Currently, available software packages can simulate magnetic fields for designing magnets and optimize the integration in electrical machines. These developments open up opportunities for next-generation permanent magnet applications

Publications of Walailak University from 2007 to 2014 in ISI, SCOPUS and TCI Databases

Publications from Walailak University in ISI Web of Science, SCOPUS and Thai-Journal Citation Index (TCI) databases are analyzed. From 2007 to 2014, the number of publication in the ISI database has increased from about 20 to almost 70 research articles reaching the maximum publications in both ISI and TCI databases in 2013. With the total of 489 articles found on SCOPUS, the highest number of publication per staff over 0.25 is also obtained in 2013. The largest contribution in each year belongs to School of science whereas School of allied health science and public health and School of medicine have impressive growths of international publication in recent years. The majority of the published articles are from collaborations between Walailak University and other institutions in Thailand. International collaborations approximately accounted for one third of all international publications. Since the publications have vastly accumulated, the number of citations in the ISI database has substantially raised from 106 times in 2008 to 502 times in 2014. doi:10.14456/WJST.2015.5

Low-cost Sensors Based on the GMI Effect in Recycled Transformer Cores

Sensors based on the giant magnetoimpedance (GMI) effect in silicon steelswere constructed. Strips of silicon steels (0.500 mm-thick, 35.0 mm-long) with widthsranging from 0.122 to 1.064 mm were cut from recycled transformer cores. Since amaximum GMI ratio of 300% and a maximum field sensitivity of 1.5%/Oe were observedin a 1.064 mm-wide sample at 200 kHz, the 1.064 mm-wide strips were chosen as sensingelements in a slot key switch, angular velocity sensor, current sensor and force sensor. Thesensing elements were integrated into electronic circuits and the changes in impedancewere monitored. Variations in voltage due to these changes were typically small and musttherefore be amplified by the electronic circuits. For the current sensor and force sensor,the variation in the voltage drop across the GMI sensing element had non-linear variationswith either current or force and a conversion formula from a computer program wastherefore needed. The performance of the systems was tested. These sensing systems werestable, highly sensitive, hysteresis-free and could be produced on a mass scale. Based ontheir GMI effect, the silicon steels are versatile alternative low-cost sensors

Colorimetric parameters for bloodstain characterization by smartphone

AbstractThis smartphone colorimetry investigated RGB (red, green and blue), HSV (hue, saturation and value of brightness) and CMYK (cyan, magenta, yellow and key) color parameters for characterizing bloodstains. Blood samples, separately deposited on cotton cloths and tissue papers, were analyzed by the ‘Colorimeter X’ application on an iPhone XR after 1, 5, 7, 9 and 11 days. The reductions in RGB and V values recorded by the smartphone application are consistent with darker bloodstain over time. Bloodstain colors are sensitive to the substrate and person-to-person variation, but a similar correlation with time could be established by a linear least squares fitting. With the highest coefficient of determination averaged from four samples, the V value is the most effective parameter for describing bloodstain ageing. For other color spaces, the R and K almost match the V value in measuring the bloodstains. Because these three values may be susceptible to the deviation in the measurement, the B value is suggested as an additional parameter in the bloodstain characterization. This small-scale study demonstrates the potential of colorimetric parameters in an on-site analysis by a cost-effective smartphone

Publications in Walailak Journal of Science and Technology from 2004 to 2009

Publications in the Walailak Journal of Science and Technology from 2004 to 2009 are analyzed according to their types, research fields, sources of submission and authorships. The amount of submitted manuscripts is rather constant during this period with a rejection ratio about 0.12. Issued twice a year, one hundred and eighteen published papers are mostly full-length original articles with a small number of minireview articles and short communications. Most contributors and corresponding authors of the journal are Walailak University academic staff but there are on average 3 articles in each volume which are not attached to Walailak University. The journal covers diversified areas of science and technology classified as Science (38.14 %), Agricultural technology (25.42 %), Engineering and resources (24.58 %) and Health science (10.17 %). All contributions have placed Walailak Journal of Science and Technology in the Thai Citation Index (TCI) since 2006 and achieved the highest ranking in the top-ten list in that year

Walailak Journal of Science and Technology - A Scientometric Analysis from 2010 to 2015

The growth of Walailak Journal of Science and Technology is chronicled through a scientometric analysis from 2010 to 2015. The number of submissions has vastly increased since the online submission system was introduced in 2011 and surpassed 400 manuscripts per year in 2014 - 2015. It follows that the acceptance ratio has been reduced to the minimum of 25 % in 2015. The 339 published papers, mostly full-length research articles, are categorized into Science (46.61 %), Agricultural technology (23.30 %), Engineering (17.70 %), Health sciences (6.78 %) and Information technology (4.72 %). The journal is benefited from demographic diversity of authors. Papers submitted from 27 different countries were published during this 6-year period. Furthermore, domestic reviewers and editorial board members have become the minority since 2012. The citation recorded in SCOPUS database has continued to improve with the reduction in self-citation ratio. The lastest Scimago Journal Rank (SJR) obtained in 2014 is 0.207 with 33 citations and average 0.33 citations per paper