28 research outputs found
An Overview of Three Promising Mechanical, Optical, and Biochemical Engineering Approaches to Improve Selective Photothermolysis of Refractory Port Wine Stains
During the last three decades, several laser systems, ancillary technologies, and treatment modalities have been developed for the treatment of port wine stains (PWSs). However, approximately half of the PWS patient population responds suboptimally to laser treatment. Consequently, novel treatment modalities and therapeutic techniques/strategies are required to improve PWS treatment efficacy. This overview therefore focuses on three distinct experimental approaches for the optimization of PWS laser treatment. The approaches are addressed from the perspective of mechanical engineering (the use of local hypobaric pressure to induce vasodilation in the laser-irradiated dermal microcirculation), optical engineering (laser-speckle imaging of post-treatment flow in laser-treated PWS skin), and biochemical engineering (light- and heat-activatable liposomal drug delivery systems to enhance the extent of post-irradiation vascular occlusion)
The potential impact of media commentary and social influence on consumer preferences for driverless cars
The emerging technology of autonomous vehicles (AVs) is envisaged to substantially alter transport systems and travel behaviour. However, this impact is conditional on the level and rate of AV market penetration. This study examines consumers’ consideration to adopt AVs, with a particular focus on the impact of informational cues from different communication channels. Data for our analysis is collected through an online survey conducted in December 2019, and our sample comprises 862 residents from Sydney, Australia. The survey asks respondents about their social networks, and their use of different mass and social media platforms. Respondents are subsequently presented a discrete choice experiment where we systematically vary informational cues about AVs from each of these communication channels, and respondents are asked to indicate their willingness to consider AVs under each scenario. This data is used to develop a latent class choice model of AV consideration as a function of the informational cues received from different communication channels. Our model also considers the level of trust that respondents associate with their social contacts when modelling the effect of word-of-mouth from these social contacts. The results reveal eleven segments in the sample that differ from one another in terms of sociodemographic attributes, evaluation of social contact trust, and the relative importance they attach to different communication channels. The findings show social media sentiment has the highest effect on AV consideration for 90 per cent of the sample. Also 3.8 per cent of the sample never consider adopting AVs, regardless of the informational cues
Improvement of NOM Removal from Water Resources by Modifying the Coagulation Process
As a result of the regulations on DBPs, interest in NOM removal is
increasing and many water treatment plants in developed countries have
started to measure the concentration of TOC in their finished waters.
Promulgation of the rules will substantially increase these efforts in
other countries too. Since the cost of TOC (and DBPs) determination was
high, it was decided to study the traditional analysis of COD as a
surrogate measure to detect the organic constituents in raw water and
the extent to which optimized coagulation with ferric chloride can
increase COD removal. The two water samples studied belonged to Karaj
and Jajrood Rivers. For both samples the observed values of COD removal
by coagulation at lower pH (about 1-1.5 pH values less than the regular
pH) were about 85-95 percent without making water turbidity
unacceptable. In order to determine the effects of organic content on
coagulation, synthetic samples were also prepared with much higher COD
values. Again, considerable increases in COD removal have been observed
for most of these samples only by decreasing 0.5-2 pH value. The
results indicated that a modified coagulation process without need to
much increasing the amount of coagulant can be developed for these
water samples
Control of disinfection by products formation potential by enhanced coagulation
Jar-test experiments were conducted to study enhanced coagulation
effectiveness in removal of disinfection by products (DBPs) from
Zayandehrud River at Isfahan Province-the center part of Iran- in 2004.
In this study, the removal of suspended and colloidal particles and
natural organic matter (NOM) at various coagulant doses and coagulation
pHs was assessed through raw and treated water measurements of
turbidity, UV254 absorbance, TOC, and dissolved organic carbon (DOC).
The trihalomethane formation potential (THMFP) was also determined by a
mathematical relationship with TOC. Results indicated that NOM removal
was a function of coagulant type, coagulant dose, and pH of
coagulation. In general, TOC, DOC, and UV254 absorbance removal
enhanced with increasing coagulant dose. However, further increases in
coagulant dosage had little effect on disinfection by-products
precursors removal. Ferric chloride was consistently more effective
than alum in removing NOM. Coagulation pH was appeared to be a
determining factor for maximum NOM removal and the removal of DBPs
precursors by enhanced coagulation was significantly enhanced at pH 5.5
in comparison with initial pH of water. Furthermore, it is specified
that preadjustment of pH with sulfuric acid reduced the coagulant
dosage and thus, production of sludge. The reduction in THMFP was
consistent with the trends observed for DBPs precursors removal data
(i.e. UV254 and TOC data)
Effect of laser contour scan parameters on fatigue performance of A20X fabricated by laser powder bed fusion
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