Analysis of the nature of injuries in victims of fall from height

Aim of study: To assess the types and extent of injuries sustained by victims of fall from height depending on the height of fall. Material and methods: The study included 338 bodies of victims of fatal falls from different heights (from the 1st to 10th floors) who were subjected to medico-legal autopsy at the Department of Forensic Medicine, Jagiellonian University Medical College, between 1995 and 2014. For each individual, selected data were collected including gender, age, body height, injury types and presence of alcohol or other intoxicants in blood. The analysis comprised injuries to the brain, thoracic and abdominal organs, fractures of the skull, extremities, ribs and spine, and fractures of the scapula, clavicle and sternum (considered together). The study focused on determining the frequency of occurrence of different injuries in relation to one another and depending on the height of fall. Results : The number and extent of injuries was found to increase along with the height of fall. Three injury types, including injuries to the mesentery and both kidneys and fractures of upper extremity small bones, were shown to occur from the threshold heights of the 3rd, 4th and 6th floors. Eleven injuries demonstrated a statistically significant correlation with the height of fall. The study also revealed a number of correlations between the frequencies of occurrence of different injuries. Conclusions : Injuries found from the threshold value may suggest the minimal height of fall. The presence of injuries which correlate with increasing height, and the overall number of injuries observed in victims of fall from height, may be useful for inferring the height of the fall

Gas sensing properties of TiO2-SnO2 nanomaterials

Nanocomposites of TiO2/SnO2 for hydrogen detection have been prepared by mechanical mixing of TiO2 and SnO2 nanopowders with different specific surface area SSA = 150.9 m2/g (TiO2) and SSA = 18.3 m2/g (SnO2). Nanocomposites consist of two distinct components: larger - grain (21-28 nm) cassiterite SnO2 and smaller - grain (8-11 nm) rutile TiO2 as indicated by X-ray diffraction measurements and transmission electron microscope, TEM, images. Nanopowders of 50 mol% TiO2/50 mol% SnO2 are composed of small, elongated TiO2 forms mixed with larger SnO2 grains of regular shape as demonstrated by TEM. Scanning electron microscopy, SEM of gas sensing tablets, prepared by pressing nanopowders under 25 MPa at 400 °C reveal a high degree of agglomeration. Sensor responses in the electrical resistivity over a wide range of concentrations from 50 to 3000 ppm H2 at a constant temperature chosen within the interval 250-400 °C have been measured and analyzed before and after sample conditioning at 500 °C in Ar + 7% H2 atmosphere. Sensing tablets of 50 mol% TiO2/50 mol% SnO2 display the highest sensitivity to hydrogen at moderate temperatures of 250-300 °C. Kinetics of the sensor responses are improved and the recovery time is significantly reduced as a result of annealing in the reducing atmosphere

TiO2-based nanopowders and thin films for photocatalytical applications

TiO2-based nanopowders are elaborated by flame spray synthesis, FSS from organic precursors of titanium and chromium with the Cr content changing from 0 to 15 at.%. Well-crystallized nanopowders with high specific surface area SSA reaching 107 m2/g for undoped TiO2 and 177 m2/g for TiO2+15 at.% Cr are obtained. Thin films are deposited by rf reactive sputtering from metallic Ti and Ti-Cr targets in Ar+O2 flow controlled atmosphere. The adjustable area of Cr/Ti allows to obtain up to 16 at.% Cr in TiO2 thin films. X-ray diffraction, transmission electron spectroscopy, TEM, atomic force microscopy, AFM and optical spectrophotometry over the ultraviolet UV and visible VIS range of the light spectrum have been performed in order to characterize the nanomaterials. The particle size of nanopowders is within the range of 5-42 nm. Anatase is the predominating polymorphic form while the amount of rutile increases with Cr content to reach of about 25 wt.% at 15 at.% Cr. The post-deposition annealing of thin films in air at temperatures from 770 K to 1280 K modifies the phase composition, leads to irreversible transformation from anatase to rutile and affects the surface roughness. Structural and optical properties of TiO2-based nanopowders and thin films are compared. The effect of grain size and the level of chromium doping on the band gap Eg is discussed. Photocatalytic activity of the nanopowders is tested for degradation of methylene blue, MB

Structural and electrical properties of magnetron sputtered Ti(ON) thin films:The case of TiN doped in situ with oxygen.

International audienceIncorporation of oxygen into TiN lattice results in formation of titanium oxynitrides, TiOxNy that have become particularly interesting for photocatalytic applications. Elaboration as well as characterization of TiN and in situ oxygen-doped thin films is the subject of this paper. Thin films, 250–320nm in thickness, have been deposited by dc-pulsed magnetron reactive sputtering from Ti target under controllable gas flows of Ar, N2 and O2. Optical monitoring of Ti plasma emission line at = 500nm has been implemented in order to stabilize the sputtering rate. Scanning electron microscopy (SEM), X-ray diffraction in grazing incidence (GIXRD), micro-Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), optical spectrophotometry and four-point probe electrical resistivity measurements have been performed in order to follow evolution of film physical parameters as a function of the oxygen flow rate O2 at which the films were deposited. The relationship between O2 expressed in standard cubic centimetres per minute, sccm and the nitrogen/oxygen content in thin films has been established by means of the analysis of the XPS spectra. GIXRD studies indicate that incorporation of oxygen results in a progressive loss of preferential orientation in 111 direction, a change in the grain size from 16nm for TiN to about 3 nmfor films deposited at O2 = 1.32 sccm and a decrease in the lattice constant. A systematic shift of all X-ray diffraction (XRD) lines towards higher diffraction angles is consistent with substitution of oxygen for nitrogen. Micro-Raman investigations indicate amorphisation of thin films upon oxidation. Binding energies determined fromfitting of the XPS results concerning the N1s and Ti2p lines give evidence of the presence of TiOxNy compound. Red-shift of the plasma reflectance edge upon TiN oxidation is correlated with a decreased carrier concentration. Metal–semiconductor transition can be expected on the basis of the electrical conductivity decrease and development of the fundamental absorption across the forbidden band of TiO2 upon increase in the oxygen flow rate. Additional absorption feature in the visible range, being a consequence of coexistence of free-electron and interband absorption within almost the same spectral range ( = 400–600 nm) seems to be very promising for photocatalytic applications of titanium oxynitride thin films

Chemical composition, crystallographic structure and impedance spectroscopy of titanium oxynitride TiNxOy thin films

Titanium oxynitride TiNxOy thin films have been deposited by DC-pulsed magnetron sputtering from Ti target in the Ar + N2 + O2 reactive atmosphere controlled by plasma emission spectroscopy. Correlation between chemical composition and crystallographic structure of thin films has been determined and presented in the form of the pseudo-equilibrium ternary phase diagram. The atomic N/Ti and O/Ti ratios have been derived from Rutherford backscattering (RBS) measurements. X-ray diffraction at grazing incidence has revealed formation of defective TiN-TiO solid solutions. The surface roughness estimated from atomic force microscopy (AFM) surface images decreases with increasing oxygen content in the films, in accordance with the progressive sample amorphisation. Impedance spectroscopy measurements indicate that the electrical conductivity changes its character from metallic to semiconducting with increasing oxygen content in TiNxOy thin films

Influence of Cr on structural and optical properties of TiO2:Cr nanopowders prepared by flame spray synthesis

Influence of chromium incorporation on structural and optical properties of titanium dioxide nanopowders obtained by flame spray synthesis, FSS is studied by means of: X-ray diffraction, XRD; Raman spectroscopy; transmission electron spectroscopy, TEM; photoelectron spectroscopy, XPS and optical spectrophotometry over the ultraviolet, UV and visible range of the light spectrum from 250 nm to 2200 nm. The specific surface area, SSA, of the powders has been adjusted from 48 m2/g for TiO2 + 0.1at.% Cr to 177 m2/g for TiO2 + 15 at.% Cr which is accompanied by a decrease in the anatase grain size from 21 nm to 5 nm. The anatase-to-rutile ratio changes with Cr3+ concentration but there is no evidence of precipitation of chromium oxides or chromium titanates. Incorporation of Cr3+ into TiO2 lattice, as proved by XPS, is found to affect the electronic structure of TiO2, as indicated by the optical spectrophotometry. The impurity band is formed within the forbidden band gap of titanium dioxide which results in the additional absorption within the visible range of the light spectrum. The general aim of this work is to improve the visible light absorption and hence the efficiency of photocatalytic decomposition of organic contaminants

RBS, XRR and optical reflectivity measurements of Ti-TiO2 thin films deposited by magnetron sputtering

Single-, bi- and tri-layered films of Ti–TiO2 system were deposited by d.c. pulsed magnetron sputtering from metallic Ti target in an inert Ar or reactive Ar + O2 atmosphere. The nominal thickness of each layer was 50 nm. The chemical composition and its depth profile were determined by Rutherford backscattering spectroscopy (RBS). Crystallographic structure was analysed by means of X-ray diffraction (XRD) at glancing incidence. X-ray reflectometry (XRR) was used as a complementary method for the film thickness and density evaluation. Modelling of the optical reflectivity spectra of Ti–TiO2 thin films deposited onto Si(1 1 1) substrates provided an independent estimate of the layer thickness. The combined analysis of RBS, XRR and reflectivity spectra indicated the real thickness of each layer less than 50 nm with TiO2 film density slightly lower than the corresponding bulk value. Scanning Electron Microscopy (SEM) cross-sectional images revealed the columnar growth of TiO2 layers. Thickness estimated directly from SEM studies was found to be in a good agreement with the results of RBS, XRR and reflectivity spectra