Reliability of an automatic classifier for brain enlarged perivascular spaces burden and comparison with human performance

In the brain, enlarged perivascular spaces (PVS) relate to cerebral small vessel disease (SVD), poor cognition, inflammation and hypertension. We propose a fully automatic scheme that uses a support vector machine (SVM) to classify the burden of PVS in the basal ganglia (BG) region as low or high. We assess the performance of three different types of descriptors extracted from the BG region in T2-weighted MRI images: (i) statistics obtained from Wavelet transform’s coefficients, (ii) local binary patterns and (iii) bag of visual words (BoW) based descriptors characterizing local keypoints obtained from a dense grid with the scale-invariant feature transform (SIFT) characteristics. When the latter were used, the SVM classifier achieved the best accuracy (81.16%). The output from the classifier using the BoW descriptors was compared with visual ratings done by an experienced neuroradiologist (Observer 1) and by a trained image analyst (Observer 2). The agreement and cross-correlation between the classifier and Observer 2 (κ = 0.67 (0.58–0.76)) were slightly higher than between the classifier and Observer 1 (κ = 0.62 (0.53–0.72)) and comparable between both the observers (κ = 0.68 (0.61–0.75)). Finally, three logistic regression models using clinical variables as independent variable and each of the PVS ratings as dependent variable were built to assess how clinically meaningful were the predictions of the classifier. The goodness-of-fit of the model for the classifier was good (area under the curve (AUC) values: 0.93 (model 1), 0.90 (model 2) and 0.92 (model 3)) and slightly better (i.e. AUC values: 0.02 units higher) than that of the model for Observer 2. These results suggest that, although it can be improved, an automatic classifier to assess PVS burden from brain MRI can provide clinically meaningful results close to those from a trained observer

Empirical investigation to explore potential gains from the amalgamation of Phase Changing Materials (PCMs) and wood shavings

The reduction of gained heat, heat peak shifting and the mitigation of air temperature fluctuations are some desirable properties that are sought after in any thermal insulation system. It cannot be overstated that these factors, in addition to others, govern the performance of such systems thus their effect on indoor ambient conditions. The effect of such systems extends also to Heating, Ventilation and Air-conditioning (HVAC) systems that are set up to operate optimally in certain conditions. Where literature shows that PCMs and natural materials such as wood-shavings can provide efficient passive insulation for buildings, it is evident that such approaches utilise methods that are of a degree of intricacy which requires specialist knowledge and complex techniques, such as micro-encapsulation for instance. With technical and economic aspects in mind, an amalgam of PCM and wood-shavings has been created for the purpose of being utilised as a feasible thermal insulation. The amalgamation was performed in the simplest of methods, through submerging the wood shavings in PCM. An experimental procedure was devised to test the thermal performance of the amalgam and compare this to the performance of the same un-amalgamated materials. Comparative analysis revealed that no significant thermal gains would be expected from such amalgamation. However, significant reduction in the total weight of the insulation system would be achieved that, in this case, shown to be up to 20.94%. Thus, further reducing possible strains on structural elements due to the application of insulation on buildings. This can be especially beneficial in vernacular architectural approaches where considerably large amounts and thicknesses of insulations are used. In addition, cost reduction could be attained as wood shavings are significantly cheaper compared to the cost of PCMs

Microstructural and mechanical characterisation of laser-welded high-carbon and stainless steel

The final publication is available at Springer via http://dx.doi.org/10.1007/s00170-015-7111-5Laser welding is becoming an important joining technique for welding of stainless steel to carbon steel and is extensively used across various sectors, including aerospace, transportation, power plants, electronics and other industries. However, welding of stainless steel to high-carbon steel is still at its early stage, predominantly due to the formation of hard brittle phases, which undermine the mechanical strength of the joint. This study reports a scientific investigation on controlling the brittle phase formation during laser dissimilar welding of high-carbon steel to stainless steel. Attempts have been made to tailor the microstructure and phase composition of the fusion zone through influencing the alloying composition and the cooling rate. Results show that the heat-affected zone (HAZ) within the high-carbon steel has significantly higher hardness than the weld area, which severely undermines the weld quality. To reduce the hardness of the HAZ, a new heat treatment strategy was proposed and evaluated using a finite element analysis-based numerical simulation model. A series of experiments has been performed to verify the developed thermo-metallurgical finite element analysis (FEA) model, and a qualitative agreement of predicted martensitic phase distribution is shown to exist

Irregularity-based image regions saliency identification and evaluation

The file attached to this record is the author's final peer reviewed version. The publisher's final version of record can be found by following the DOI.Saliency or Salient regions extraction form images is still a challenging field since it needs some understanding for the image and the nature of the image. The technique that is suitable in some application is not necessarily useful in other application, thus, saliency enhancement is application oriented. In this paper, a new technique of extracting the salient regions from an image is proposed which utilizes the local features of the surrounding region of the pixels. The level of saliency is then decided based on the global comparison of the saliency-enhanced image. To make the process fully automatic a new Fuzzy-Based thresholding technique has been proposed also. The paper contains a survey of the state-of-the-art methods of saliency evaluation and a new saliency evaluation technique was proposed

Quantum chemical determination of molecular geometries and interpretation of FT-IR and FT-Raman spectra for 3,4-dinitrotoluene

191-201The FT-IR and FT-Raman vibrational spectra of 3,4-dinitrotoluene (3,4-DNT) have been recorded in the region 400-4000 cm<span style="font-family:Symbol;mso-ascii-font-family: " times="" new="" roman";mso-hansi-font-family:"times="" roman";mso-char-type:symbol;="" mso-symbol-font-family:symbol"="" lang="EN-GB">-1 and 50-3500 cm<span style="font-family:Symbol;mso-ascii-font-family: " times="" new="" roman";mso-hansi-font-family:"times="" roman";mso-char-type:symbol;="" mso-symbol-font-family:symbol"="" lang="EN-GB">-1, respectively. The spectra were interpreted with the aid of normal coordinate analysis following full structure optimization and force field calculations based on DFT (Density Functional Theory)-B3LYP using 6-31+G(d,p) and6-311++G(d,p) basis sets. A complete vibrational assignment aided by the theoretical harmonic frequency analysis has been compared with experimental FT-IR and FT-Raman spectra. Stability of the molecule arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) energies confirms the occurrence of ICT (Intramolecular Charge Transfer) within the molecule. The calculated HOMO and LUMO energy gaps also confirm that charge transfer occurs within the molecule. A sufficient general agreement between the theoretical and the experimental spectra has been achieved

Synthesis, growth and characterization of zinc manganese thiocyanate crystal

394-397Single crystals of zinc manganese thiocyanate, ZnMn(SCN)4 (ZMTC) have been successfully synthesized and purity of materials has been increased by repeated recrystallization process. Single crystals have been grown by adopting the slow evaporation solution growth method using water as solvent at room temperature. The good quality single crystal has been harvested in a period of 2 months. Different characterization studies have been carried out for finding its suitability for device fabrications. From the single crystal X-ray diffraction, the crystal system was identified as tetragonal. The Fourier transform infrared spectrum of ZMTC has been recorded in the region 450-4000 cm−1 using KBr pellet technique to identify the presence of functional groups. From the thermal analysis, it was observed that the decomposing temperature of the grown crystal is more significant than comparing with the studies performed in the reported literature. The optical studies have been carried out and it is found that the tendency of transmission observed from the specimen with respect to the wavelength of light is practically more suitable for opto-electronic applications

Synthesis, growth and characterization of copper mercury thiocyanate crystal

340-343Synthesis and growth of nonlinear optical copper mercury thiocyanate, CuHg(SCN)4 (CMTC) single crystals have been successfully carried out by slow evaporation technique using water and ethanol as solvents with dimensions up to 12´8´5 mm3. The grown single crystals have been studied by different characterization techniques in order to know their suitability for various applications. The lattice parameters of the crystal have been obtained by single crystal X-ray diffraction analysis. The presence of functional groups have been identified using FTIR analysis. The thermal stability and thermal decomposition of CMTC crystals have been &nbsp;investigated by using thermo gravimetric analysis and differential thermal analysis. The CMTC crystal exhibits good physio-chemical stability up to 253.8°C. The optical transparency of the grown crystal has been studied by UV-vis-NIR analysis. The lower cutoff wavelength of CMTC crystal occurs at 390 nm and has been discovered as a non linear optical crystal material. The relative second harmonic generation efficiency of the CMTC crystal has been tested by Kurtz - Perry powder technique