In Forensic Documentoscopy, it is frequently questioned if a particular document was written with one or more pens. Different methods have been developed to distinguish pen inks from each other, but ...some of these techniques require the ink extraction, destructing the document, and other techniques uses high cost instruments. PhotoMetrix PRO®, an app for mobile devices, is a qualitative and colorimetric analysis tool that applies uni- and multivariate analysis. Amongst them, Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA) and Partial Least Squares Discriminant Analysis (PLS-DA) can be obtained from digital images’ decomposing data. It is a non-destructive and a simple method, of easily use and low cost. Chemometric knowledge is important for results interpretation. This study aims to evaluate the PhotoMetrix PRO® capacity on blue ballpoint pens differentiation. Three experiments were performed with different ballpoint pens, including colorful pens as an app functionality control. The results showed appropriate differentiation between colorful ballpoint pens, and there was a satisfactory tendency of separation for different brands of blue ballpoint pens, most used in Brazil. This method is interesting to confirm subjective results, eliminating visual differences, intrinsic for each observer, which can be useful in places with an instrument deficiency, like the Video Spectral Comparator®. New studies to evaluate writing pressure’s influence on data collection and the inks’ age, as well as different mobile’s camera quality, are recommended. This study introduces a new technology that might be further studied for practical application in Forensic Documentoscopy and other Forensic areas.
A wavelength monitor based on a pair of tilted fiber Bragg gratings is reported. The monitor exhibits a subpicometer wavelength selectivity over a broad wavelength range (>30 nm), and a low insertion ...loss (<1 dB) for laser light with polarization matching the reference polarization of the device. Simulations show that a wavelength coverage up to 100 nm is possible and that the resolution degradation due to changes in the polarization state can be avoided by proper design of the gratings.
•A probability survey with drivers who had drank on alcohol outlets was conducted.•Drivers were breathalyzed and had their saliva collected for drug screening.•Benzodiazepines (3.9%) and cocaine ...(3.8%) were the most frequently detected drugs.•Among drivers who were going to drive, 11% had at least one other drug detected.•A BAC>0.06% was associated with higher chance of a positive drug screening.
Driving under the influence of multiple substances is a public health concern, but there is little epidemiological data about their combined use and putative impact on driving in low and middle-income countries where traffic crashes have been clustering in recent years. The aim of this study is to estimate the prevalence of alcohol and drug use – as well as their associated factors – among drivers in the context of alcohol outlets (AOs).
A probability three-stage sample survey was conducted in Porto Alegre, Brazil. Individuals who were leaving AO were screened, with the selection of 683 drivers who met the inclusion criteria. Drivers answered a structured interview, were breathalyzed, and had their saliva collected for drug screening. Prevalences were assessed using domain estimation and logistic regression models assessed covariates associated with substance use.
Benzodiazepines 3.9% (SE 2.13) and cocaine 3.8% (SE 1.3) were the most frequently detected drugs in saliva. Among drivers who were going to drive, 11% had at least one drug identified by the saliva drug screening, 0.4% two, and 0.1% three drugs in addition to alcohol. In multivariable analyses, having a blood alcohol concentration (BAC)>0.06% was found to be associated with a 3.64 times (CI 95% 1.79–7.39) higher chance of drug detection, compared with interviewees with lower BACs.
To drive under the influence of multiple substances is likely to be found in this setting, highlighting an association between harmful patterns of consume of alcohol and the misuse of other substances.
Essential oils of B. articulata, B. crispa, B. microcephala, Baccharis milleflora, B. myriocephala, B. stenocephala, B. trimera and B. usterii, all of sect. Caulopterae, have been analyzed by GC and ...GC/MS. Despite the morphological similarity among these species, differences in composition of their essential oil obtained by hydrodistillation and hexane extract could be observed. Special attention was given to Baccharis trimera and B. crispa since their differentiation during early stages is not possible due to the absence of synflorescences. Carquejyl acetate is suggested as a marker for Baccharis trimera, and a fast method of detection of this compound is given.
An all-fiber electrically tunable loss filter that is based on photoinduced long-period grating coated by Ti-Pt metal coating was developed and investigated. Maximum wavelength tuning of 11 nm with ...an applied power of 0.67 W was achieved for the HE17 cladding mode resonance peak.
Changes in axial stress and refractive index have been measured as a function of the total UV-irradiation fluence during the formation of Bragg gratings in B/Ge- and Sn/Ge-codoped core fibers. For ...the B/Ge-codoped core fiber, a fast development of the type-I grating with a significant increase in refractive index and tensile stress in the fiber core is followed by a slow growth of the type-IIA grating with a gradual decrease of refractive index and tensile core stress. A strong UV-induced reduction of the core stress and a domination of the type-IIA grating are observed for the Sn/Ge-codoped fiber. The index changes of the type-I and type-IIA gratings are believed to be governed by the compaction of the UV-irradiated core network and its dilation, respectively.
An electrically tunable reflection filter based on a platinum-coated single-mode optical fiber that contains an intracore Bragg grating has been demonstrated. The device shows a dc tuning range of ...2.15 nm with a corresponding electrical power of 0.54 W. Wavelength modulation (WM) has been observed at frequencies lower than 100 Hz. The wavelength shift depends linearly on the electrical input power. A maximum efficiency of 4.1 nm/W is obtained for dc tuning.
A new alkaloid identified as 3
β,6
β-ditigloyloxynortropane as 3
β,7
β-ditigloyloxynortropane, 4-hydroxyhygrinic acid, methylecgonidine and tropacocaine have been isolated from the leaves of
...Erythroxylum argentinum. The new structure was established by means of spectroscopic techniques. Four other species
E. deciduum,
E. microphyllum,
E. pelleterianum and
E. cuneifolium collected in the state of Rio Grande do Sul were screened for methylecgonidine and tropacocaine by CG/MS. Two of these plants contain tropacocaine and two contain methylecgonidine. GC/MS analysis of all 5 species for cocaine proved fruitless. The chemotaxonomic significance of these results is discussed.
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