Classification using proximity catch digraphs

Machine Learning - We employ random geometric digraphs to construct semi-parametric classifiers. These data-random digraphs belong to parameterized random digraph families called proximity catch...     

Nitrification of fertilizer wastewaters in a biofilm reactor

The nitrification characteristics of fertilizer wastes were investigated in a biofilm system using a submerged aerated filter. The attachment of biomass on packing media was studied. Supplement of organic carbon in the form of glucose and yeast extract enhanced biofilm formation although the nitrifiers did not require organic carbon for growth. After an attachment period, continuous operation of the reactor at different loading rates and dissolved oxygen levels was investigated. The maximum achievable nitrification rate was strongly dependent on the dissolved oxygen. In the dissolved oxygen range of 3·2–3·5 mg dm⁻³, the maximum ammonia removal rate was about 0·17 kg NH₄ N m⁻³ day⁻¹. When the dissolved oxygen was increased to 4·9 mg dm⁻³, removal rates as high as 0·41 kg NH₄ N m⁻³ day⁻¹ could be obtained. Nitrite accumulation depended on the bulk nitrogen and dissolved oxygen concentrations.     

Efficiency of Gold Nano Particles on the Autoxidized Soybean Oil Polymer: Fractionation and Structural Analysis

Polyunsaturated plant oils have gained great interest as monomers to produce biodegradable polymers obtained from renewable resources due to the limited existing sources of petroleum oil and environmental issues. Soybean oil was autoxidized by exposure to atomospheric oxygen at room temperature with or without the presence of gold nanoparticles (Au NPs) 5–41 days. When the autoxidation process was catalyzed with Au NPs, the molecular weight of the oxidized oil was increased in 5 days. In contrast to this, without Au NPs, the oxidized oil was still a fluidized liquid. Autoxidized soybean oil polymer in toluene solution with gold NP showed a surface plasmon resonance at λ_max = 540 nm in a UV–VIS spectrometer and a fluorescence emission spectrum at λ_max = 450 nm, when it was irradiated at λ_max = 390 nm. The higher molecular weight of the polymeric oils was successively fractionated by the extraction from the solvent‐non‐solvent mixture CHCl₃/petroleum ether with the volume ratio of 5:15. Three polymeric oils fractions with different molecular weight (ca 1000, 4000, and 40,000 g/mol) were obtained. GC–MS analysis, ¹H‐NMR and GPC techniques were used in the structural analysis of the fractionated polymeric oils.     

Dipole moments of styrene/4-vinylpyridine copolymers—II: Relation to microstructure

Mean-square dipole moment values of styrene/4-vinylpyridine (S4VP) copolymers determined at 25–60°C in 1,4-dioxane solutions were related to the microstructure of the chains. Data on the synthesis and dipole moments of S4VP copolymers were used to calculate the distribution of triad fractions and effective dipole moments of styrene, S-centred, and 4-vinylpyridine, V-centred, fractions in the copolymer chains. The relative magnitudes of the effective dipole moment values calculated for each type of triad reflect the effect of dipole–dipole interactions on these values.     

How accurately do drivers evaluate their own driving behavior? An on-road observational study

Self-assessment of driving skills became a noteworthy research subject in traffic psychology, since by knowing one's strenghts and weaknesses, drivers can take an efficient compensatory action to moderate risk and to ensure safety in hazardous environments. The current study aims to investigate drivers’ self-conception of their own driving skills and behavior in relation to expert evaluations of their actual driving, by using naturalistic and systematic observation method during actual on-road driving session and to assess the different aspects of driving via comprehensive scales sensitive to different specific aspects of driving. 19–63 years old male participants (N = 158) attended an on-road driving session lasting approximately 80 min (45 km). During the driving session, drivers’ errors and violations were recorded by an expert observer. At the end of the driving session, observers completed the driver evaluation questionnaire, while drivers completed the driving self-evaluation questionnaire and Driver Behavior Questionnaire (DBQ). Low to moderate correlations between driver and observer evaluations of driving skills and behavior, mainly on errors and violations of speed and traffic lights was found. Furthermore, the robust finding that drivers evaluate their driving performance as better than the expert was replicated. Over-positive appraisal was higher among drivers with higher error/violation score and with the ones that were evaluated by the expert as “unsafe”. We suggest that the traffic environment might be regulated by increasing feedback indicators of errors and violations, which in turn might increase the insight into driving performance. Improving self-awareness by training and feedback sessions might play a key role for reducing the probability of risk in their driving activity.     

Photoinitiated synthesis of poly(poly(ethylene glycol) methacrylate-co-diethyl amino ethyl methacrylate) superabsorbent hydrogels for dye adsorption

Random copolymers of poly(ethylene glycol) methacrylate (PEGM), and diethyl amino ethyl methacrylate (DEAEM) were synthesized at low, and high conversions by photoinitiation. Crosslinked poly(PEGM-co-DEAEM) samples were obtained, and characterized by FTIR, SEM, DSC, TGA, and elemental analyses. Swelling behavior of the copolymers revealed that the copolymers acted as superabsorbent hydrogels. The monomer reactivity ratios were calculated using Fineman Ross, Extended Kelen Tüdøs , and Mayo Lewis methods that gave r₁(PEGM) = 0.90, r₂(DEAEM) = 0.14 at low conversions. At high conversions r₁ and r₂ values were calculated as 1.01 and 0.40, respectively. Adsorption isotherms of methyl orange (MO) onto hydrogels were studied using Langmuir, Freundlich, and Temkin models. The experimental data fitted well with the Langmuir equation. The maximum adsorption capacity for MO was 212.7 mg g⁻¹ at pH = 3. The adsorption data gave best fit with the pseudo-second order kinetic model. Thermodynamic evaluation showed spontaneous nature for MO adsorption onto poly(PEGM-co-DEAEM) hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47707.     

Optical Imaging Approaches to Monitor Static and Dynamic Cell‐on‐Chip Platforms: A Tutorial Review

Miniaturized laboratories on chip platforms play an important role in handling life sciences studies. The platforms may contain static or dynamic biological cells. Examples are a fixed medium of an organ‐on‐a‐chip and individual cells moving in a microfluidic channel, respectively. Due to feasibility of control or investigation and ethical implications of live targets, both static and dynamic cell‐on‐chip platforms promise various applications in biology. To extract necessary information from the experiments, the demand for direct monitoring is rapidly increasing. Among different microscopy methods, optical imaging is a straightforward choice. Considering light interaction with biological agents, imaging signals may be generated as a result of scattering or emission effects from a sample. Thus, optical imaging techniques could be categorized into scattering‐based and emission‐based techniques. In this review, various optical imaging approaches used in monitoring static and dynamic platforms are introduced along with their optical systems, advantages, challenges, and applications. This review may help biologists to find a suitable imaging technique for different cell‐on‐chip studies and might also be useful for the people who are going to develop optical imaging systems in life sciences studies.     

Synthesis,characterization, and drug release properties of macroporous dual stimuli responsive stereo regular nanocomposites gels of poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide) and graphene oxide

Nanocomposite stereoregular hybrid gels of poly(N-isopropylacrylamide) were prepared in 1:1 methanol–water mixture in the presence rare earth yttrium trifluoromethanesulfonate Lewis acid and graphene oxide (GO). The nanocomposite gels were characterized by swelling ratio measurements at different temperatures and different pH, deswelling kinetics, scanning electrone microscopy, FTIR, thermogravimetric analysis, powder XRD, Raman spectroscopy, LCST measurement by DSC etc. Drug release experiments also done by using tramadol hydrochloride as a model drug to check their suitability in application. All results were explained on the basis of porosity, cononsolvency of the synthesis solvents, hydrophilicity, isotacticity, pH effect, interactions between solvents and polymer molecules, interactions between polymer and GO or interactions between GO and solvents etc.