Debris Analysis Research Articles

Analysis of Petroleum Products in Fire Debris Residues by Gas Chromatography: A Literature Review

This review gives a brief overview of developments in the analysis of petroleum products (PP) in fire debris residues (FDR) by gas chromatography (GC). The review covers different aspects of analysis such as the substrates involved, isolation procedures, column and mobile phase used, and subsequent detection in tabular form. This paper covers detection of PP such as petrol, kerosene, and diesel in various types’ of samples of interest to fire debris analysts. Solid phase microextraction is most frequently used along with gas chromatography-mass spectrometry (GC-MS) for the extraction and identification of PP from FDR. Chemometric tools should be used to improve the significance and reliability of results obtained from the analysis of FDR. However, the potential utility of portable GC-MS in fire debris analysis cannot be ignored, and its proper development and validation is required before using it for this purpose.

Fire debris analysis for forensic fire investigation using laser induced breakdown spectroscopy

The possibility verification of the first attempt to apply LIBS to arson investigation was performed. LIBS has capabilities for real time in-situ analysis and depth profiling. It can provide valuable information about the fire debris that are complementary to the classification of original sample components and combustion residues. In this study, fire debris was analyzed to determine the ignition source and existence of a fire accelerant using LIBS spectra and depth profiling analysis. Fire debris chemical composition and carbon layer thickness determines the possible ignition source while the carbon layer thickness of combusted samples represents the degree of sample carbonization. When a sample is combusted with fire accelerants, a thicker carbon layer is formed because the burning rate is increased. Therefore, depth profiling can confirm the existence of combustion accelerants, which is evidence of arson. Also investigation of fire debris by depth profiling is still possible when a fire is extinguished with water from fire hose. Such data analysis and in-situ detection of forensic signals via the LIBS may assist fire investigation at crime scenes.

Virtual sensing for gearbox condition monitoring based on kernel factor analysis

Vibration and oil debris analysis are widely used in gearbox condition monitoring as the typical indirect and direct sensing techniques. However, they have their own advantages and disadvantages. To better utilize the sensing information and overcome its shortcomings, this paper presents a virtual sensing technique based on artificial intelligence by fusing low-cost online vibration measurements to derive a gearbox condition indictor, and its performance is comparable to the costly offline oil debris measurements. Firstly, the representative features are extracted from the noisy vibration measurements to characterize the gearbox degradation conditions. However, the extracted features of high dimensionality present nonlinearity and uncertainty in the machinery degradation process. A new nonlinear feature selection and fusion method, named kernel factor analysis, is proposed to mitigate the aforementioned challenge. Then the virtual sensing model is constructed by incorporating the fused vibration features and offline oil debris measurements based on support vector regression. The developed virtual sensing technique is experimentally evaluated in spiral bevel gear wear tests, and the results show that the developed kernel factor analysis method outperforms the state-of-the-art feature selection techniques in terms of virtual sensing model accuracy.

Effect of the microstructure and residual stress on tribological behavior of induction hardened GCr15 steel

A systematic experimental investigation was conducted to study the effects of microstructure and residual stress on the tribological behavior of induction hardened GCr15 steel. Dry sliding wear tests of the hardened steel had been performed using a reciprocating ball-on-flat apparatus under different normal loads of 20, 50, and 100 N. The results indicate that the quenched layer microstructure is composed of martensite and retained austenite. The analysis of worn surface and wear debris of quenched layer showed that the wear mechanism was mainly abrasive wear at low load and delamination wear at high load. Typically, the compressive stress in the hardening layer has a significant positive influence on the wear resistance whereas the tensile stress has a negative effect.

Experimental study on thermal-hydraulic behaviour of LBE and water interface

For the design and safety studies of steam generator in the China LEAd-based Reactor (CLEAR) project, it is necessary to investigate the consequences of a Steam Generator Tube Rupture (SGTR) accident which could result in a reaction between Lead-Bismuth Eutectic (LBE) and highly pressurised water. Some experiments have been conducted to investigate the thermal-hydraulic behaviour of the molten LBE/water interface; the whole fragmentation processes of these experiments were visually observed with a high-speed video camera, and the transient pressure histories were measured by high-frequency piezoelectric pressure sensors. The effects of LBE temperature, water temperature, nozzle diameter and injection velocity were investigated. Visualisation films indicated that the explosion phenomenon happened readily at lower water temperature. The peak pressure decreased with increasing water temperature, nozzle diameter and injection velocity. However, the peak pressure first increased and then decreased as the LBE temperature increased. The shape of the debris became round at higher water temperature, and a needle-like shape was observed at lower temperatures. Debris analysis results showed that the debris sizes of 2.8–6.7 mm had the largest mass fraction. By comparison with the theoretical calculation, it was found that the fragment diameters measured in the present study agreed well with Weber number theory. Thus, it was demonstrated that the fragmentation mechanism was controlled by shearing stress under the present experimental conditions.

Validation of an HS-MS method for direct determination and classification of ignitable liquids

Fire debris analysis is a key step in fire investigation. Most of the analytical methods used for the analysis of ignitable liquid residues in fire debris require pre-concentration of the ignitable liquid residues prior to the chromatographic analysis. The standard method, ASTM E1412, involves a passive headspace concentration with activated charcoal strips to isolate the ignitable liquid residues from fire debris followed by a desorption procedure from the carbon strip with carbon disulfide.In this study a non-separative analytical method based on HS-MS eNose (headspace mass spectrometry electronic nose) in combination with chemometric tools, including hierarchical cluster analysis and linear discriminant analysis, has been used to detect and classify ignitable liquid residues in fire debris into the classes defined by the ASTM E1618 standard method. This method allows a direct analysis of fire debris in 10min and avoids the use of solvent and sorbents.The method was validated by analyzing a set of burned samples by GC–MS according to the standard methods ASTM E1412 and ASTM E1618. The results obtained on using the method proposed in this study were comparable to those obtained with the reference method. The correct classification rates for assigning ignitable liquid residues into ASTM E1618 classes were in the range of 90% for both methods. In comparison to the standard methods HS-MS does have specific advantages. Apart from the speed of the analysis and the fact that the sample does not require sample pre-concentration, this technique is also safer and ecofriendly since it does not use any solvents or produce any residues.

Coastal debris analysis in beaches of Chonburi Province, eastern of Thailand as implications for coastal conservation

This study quantified coastal debris along 3 beaches (Angsila, Bangsaen, Samaesarn) in eastern coast of Thailand. Debris samples were collected from lower and upper strata of these beaches during wet and dry seasons. The results showed that Bangsaen had the highest average debris density (15.5m−2) followed by Samaesarn (8.10m−2), and Angsila (5.54m−2). Among the 12 debris categories, the most abundant debris type was plastics (>45% of the total debris) in all beach locations. Coastal debris distribution was related to economic activities in the vicinity. Fishery and shell-fish aquaculture activities were primary sources of debris in Angsila while tourism activities were main sources in Bangsaen and Samaesarn. Site-specific pollution control mechanisms (environmental awareness, reuse and recycling) are recommended to reduce public littering. Management actions in Angsila should focus on fishery and shell-fish culture practices, while Bangsaen and Samaesarn should be directed toward leisure activities promoting waste management.

Methods of analysing chemicals associated with microplastics: a review

Analytical approaches and methods applied to the chemical analysis of microplastics and plastic debris from the marine environment were reviewed.

Update on Recent Activities at the Arkansas Archeological Survey’s Henderson State University Research Station in Arkadelphia

The Arkansas Archeological Survey’s Henderson State University Research Station (ARAS/HSU) has been active with several small field projects this year, as well as on-going work in the lab. In February and March 2016, Mary Beth Trubitt and Katie Leslie advised Hot Springs National Park personnel on placement of four soil moisture monitors so as to avoid cultural features at 3GA22, a significant novaculite quarry with prehistoric and historic components. In the process, we were able to map additional quarry features, most of which are associated with early twentieth century whetstone procurement. Our fieldwork and documentation resulted in extending the site boundaries. Eight shovel tests were excavated during the park’s installation of soil monitoring equipment. This represents the first subsurface archeological testing at this quarry. The novaculite debris from shovel tests included quarry waste and natural talus, but few flakes and no tools or diagnostic artifacts were found. After analysis of lithic debris, a report was prepared that outlines past research on the site and its significance, and summarizes the results of the project.

Quantitative Analysis of Debris and Plastic Pollution on Beaches in Northern Madagascar

Quantitative Analysis of Debris and Plastic Pollution on Beaches in Northern Madagascar

Effectiveness of Nd:YAG Laser on the elimination of debris and Smear Layer. A comparative study with two different irrigation solution: EDTA and QMix® in addition to NaOCl.

BackgroundThe aim of this study was to evaluate the effectiveness in dentin debris and smear layer removal from root canal walls using EDTA and QMix® alone and also activated with Nd:YAG laser.Material and Methods50 single-rooted teeth were instrumented and divided in 5 groups according to irrigation protocol: 17% EDTA, QMix®, Nd:YAG laser alone, and combination of 17% EDTA - Nd:YAG laser and QMix® - Nd:YAG laser. Samples were evaluated using SEM. Statistical analysis was done using Chi-Square Fisher exact test and McNemar test.ResultsDentinal debris analysis showed statistically significant differences when comparing 17% EDTA vs Laser and Laser vs QMix® in combination with Laser at the apical third. The Smear Layer analysis also showed statistically significant differences at the apical third when comparing 17% EDTA vs Laser, QMix® vs QMix® in combination with Laser and Laser vs QMix® in combination with Laser.Conclusions17% EDTA was the most efficient irrigant showing the best results. Laser alone was not effective removing either dentinal debris or smear layer. Key words:Laser, endodontics, Smear Layer.

Tribochemistry of Sugar Mill Roller Shaft Materials

Study of laboratory simulated conditions of tribological behavior of sugar mill roller shaft has shown that the cracks initiated on the surface were consequences from the tribological phenomenon at the sliding interface. The contaminated interface with sugar cane juice and dried waste called bagasse resulted in a tribofilm which played important role in the sliding behavior. The work was undertaken to characterize wear debris formed and study the tribochemical reactions during sliding wear of shaft material EN8 against E52100 steel under different sliding conditions. Fourier transform infrared (FTIR) and Thermo gravimetric analysis (TGA) was used for understanding of physical and chemical changes of shaft material caused by friction. Debris analysis suggests that the compositional changes within the wear particles accelerate the wear.

Detection and characterization of volatile organic compounds from burned human and animal remains in fire debris

Debris collected from various test sites where mammalian remains (human and porcine) had been burned in a variety of full-scale fire scenarios was evaluated for the presence of volatile residues that could be characteristic of those remains. Levels of volatiles were measured using the method commonly used for fire debris analysis: gas chromatography–mass spectrometry. Homologous n-aldehydes (from n-pentanal to n-nonanal) proved to be a significant indicator of the presence of burned animal tissue as they were observed in nearly all of the samples. Such aldehydes are created by the combustion of animal fats. One aldehyde, n-hexanal, appeared more frequently than the other aldehydes, n-pentanal, n-heptanal, n-octanal, and n-nonanal. Ethanol was detected in two-thirds of the samples, while acetone appeared in about three-fourths of the samples, but both were detected at much lower concentrations than n-hexanal. These appear to have been combustion products of the substrates on which each body burned, rather than originating from the combustion of the body. There appeared to be no qualitative distinction between volatile products produced from burned porcine carcasses and those from human cadavers. Since a homologous series of C5–C9n-aldehydes is not produced as a dominant species by the pyrolysis or combustion of any normally encountered substrate (carpet, bedding, wood products or upholstery), their detection by normal fire debris methods appears to be a valid indicator of the presence of burned animal remains. These data will also provide guidance to fire debris analysts as to the nature of volatiles associated with the combustion of human bodies in real-world fires.

An intelligent system for machinery wear debris analysis using evolutionary algorithms

An intelligent system for machinery wear debris analysis using evolutionary algorithms

Immunohistochemical Analysis of Debris Captured by Filter-Type Distal Embolic Protection Devices for Carotid Artery Stenting

Little is known about the micro-debris captured in filter-type distal embolic protection devices (EPD) used for carotid stenting (CAS). This study aimed to determine the histological and immunohistochemical characteristics of such debris by using a new liquid-based cytology (LBC) technique. Fifteen patients who underwent CAS using a filter-type distal EPD (FilterWire EZ; Boston Scientific, Marlborough, MA, USA) were included in the study. After gross inspection of each recovered filter device, micro-debris were collected using a new LBC technique (SurePath; TriPath Imaging, Inc., Burlington, NC). Histological and immunohistochemical analysis of the recovered debris was performed. The pre- and postoperative brain magnetic resonance imaging and neurological status of each patient were also reviewed. No patient developed ipsilateral symptomatic stroke due to a thromboembolic event. All 15 patients (100%) had microscopically identifiable debris in the filters, whereas gross inspection detected visible debris only in 5 patients (33.3%). Histological analysis revealed various types of structural components in an advanced atheromatous plaque, including fragments of fibrous cap, calcified plaque, smooth muscle cells, and necrotic tissue fragment infiltrated with monocytes and macrophages. Filter-type EPDs may contribute to reducing the risk of CAS-related embolic events by capturing micro-debris even when gross inspection of the recovered filter shows no visible debris in the device.

Local Ion Signatures (LIS) for the examination of comprehensive two-dimensional gas chromatography applied to fire debris analysis

Forensic examination of fire debris evidence is a notoriously difficult analytical task due to the complexity and variability of sample composition. The use of comprehensive two-dimensional gas chromatography with mass spectrometry detection (GC×GC–MS) allows the coupling of orthogonal retention mechanisms and therefore a high peak capacity.We demonstrate recent innovations in combining chemometric techniques for data reduction and feature selection, with evaluation of the evidence for forensic questions pertaining to the detection and subsequent classification of ignitable liquid residue (ILR) in fire debris samples. Chromatograms are divided into non-overlapping spatially delimited regions; for each of these regions a Local Ion Signature (LIS) is computed by summing the intensities, per nominal mass/charge over all points contained within each region. This yields a reduced feature space representing the original data as a set of consolidated ion traces. Subsequent feature selection is performed by evaluating the individual efficacy of each feature using a univariate score-based likelihood ratio (LR) approach for discriminating between pairs of same or different type samples. The retained features are used to model each ILR class using linear discriminant analysis (LDA).Results are demonstrated for 155 arson samples containing a diversity of substrate compounds and several known ignitable liquids. ILR detection is performed at 84% accuracy with fewer than 1% false positives followed by subsequent classification. Likelihood ratio distributions are presented referring to both detection and classification tasks.

TCT-706 Histological Findings and Predictors for Cerebral Debris from Transcatheter Aortic Valve Replacement – the ALSTER experience

Histopathologic analyses of debris captured by a cerebral protection system (CPS) during transcatheter aortic valve replacement (TAVR) have been reported but it was not possible to determine the origin of the debris nor to define risk factors. Embolic debris captured in 322 filters of a dual-

Histological Findings and Predictors of Cerebral Debris From Transcatheter Aortic Valve Replacement: The ALSTER Experience.

BackgroundHistopathological analyses of debris captured by a cerebral protection system during transcatheter aortic valve replacement have been reported, but the origin of the captured debris was not determined and risk factors were not defined.Methods and ResultsEmbolic debris was analyzed from 322 filters used in a dual‐cerebral‐filter protection system implemented during transcatheter aortic valve replacement for 161 patients (mean age 81 years, 82 male [51%], logistic EuroSCORE 19% [interquartile range 12–31%]). The debris capture rate was high, with debris from 97% of all patients (156 of 161). No differences by filter location were found (brachiocephalic trunk 86% [139 of 161], left carotid artery 91% [147 of 161]; adjusted P=0.999). Five prevalent types of debris were identified: thrombus (91%), arterial wall tissue (68%), valve tissue (53%), calcification (46%), and foreign material (30%). Female sex (P=0.0287, odds ratio 1.364, 95% CI 1.032–1.812) and diabetes mellitus (P=0.0116, odds ratio 1.474, 95% CI 1.089–2.001) were significant risk factors for embolic debris. Additional analysis showed significantly more valve tissue in patients with predilation (P=0.0294). Stroke and transient ischemic attack rates were 0.6% each (1 of 161).ConclusionThis study showed a high rate of embolic debris consisting of typical anatomic structures known to be altered in patients with aortic stenosis undergoing transcatheter aortic valve replacement. Female patients with diabetes mellitus have increased risk of embolic debris and should be protected by a cerebral protection system during transcatheter aortic valve replacement. Because valve tissue embolizes more often in patients with predilation, procedural planning should consider this finding. Both cerebral arteries (brachiocephalic trunk, left carotid artery) should be protected in the same way.

THE DEBRIS PARTICLES ANALYSIS OF RSG GAS COOLANT TO ANTICIPATE SEDIMENT INDUCED CORROSION

THE DEBRIS PARTICLES ANALYSIS OF RSG-GAS COOLANT TO ANTICIPATE SEDIMENT-INDUCED CORROSION. The reliability of the structures, systems and components (SSC) of the G.A. Siwabessy Multipurpose Research Reactor (RSG-GAS) should be maintained to keep the reactor operates safely. Chemical control and management of coolant is one factor which determines the SSC’s reliability. The debris sedimentation in the primary coolant system must be examined. Debris occurs in the reactor pool, originating from airborne dust from the engineering hall. Several elements contained by the sediment can induce corrosion. This research was conducted to identify the trace elements which were contained in the sediments and determine their concentrations. The objective was to anticipate the occurrence of galvanic and pitting corrosion due to the presence of elements which are more noble than aluminum. The measurement methodology is Neutron Activation Analysis (NAA). Two groups of samples were analyzed; the first group was sampled from the debris trapped in the mechanical filter after the resin column, or known as the resin trap, and second was sampled from the debris which adhered to the heat exchanger tube. The primary coolant debris analysis showed that the neutron-activated sediment contained Na-24, Na-25, Al-28, Mg-27, Cr-51, Mn-54, Mn-56, Co-58, Co-60, Ni-65, and Fe-59. The Mn, Cr, Co, Ni, and Fe are more noble than aluminum can induce galvanic corrosion while Na, Ba, Al, and Mg are not. The radionuclides contained by the result of neutron activation of sediment from the heat exchanger tube are Mn-56, Na-24, As-76, Br-82, Fe-59, Zn-65, Cr-51, La-140, and Sc-46 which are mostly carbon steel corrosion products. Those elements do not initiate galvanic corrosion. The prevention of galvanic corrosion can be done by periodic maintenance.Key Words : sediment, debris, corrosion, galvanic, pitting, RSG Gas

Macroscale Superlubricity of Multilayer Polyethylenimine/Graphene Oxide Coatings in Different Gas Environments.

Friction and wear decrease the efficiency and lifetimes of mechanical devices. Solving this problem will potentially lead to a significant reduction in global energy consumption. We show that multilayer polyethylenimine/graphene oxide thin films, prepared via a highly scalable layer-by-layer (LbL) deposition technique, can be used as solid lubricants. The tribological properties are investigated in air, under vacuum, in hydrogen, and in nitrogen gas environments. In all cases the coefficient of friction (COF) significantly decreased after application of the coating, and the wear life was enhanced by increasing the film thickness. The COF was lower in dry environments than in more humid environments, in contrast to traditional graphite and diamond-like carbon films. Superlubricity (COF < 0.01) was achieved for the thickest films in dry N2. Microstructural analysis of the wear debris revealed that carbon nanoparticles were formed exclusively in dry conditions (i.e., N2, vacuum), and it is postulated that these act as rolling asperities, decreasing the contact area and the COF. Density functional theory (DFT) simulations were performed on graphene oxide sheets under pressure, showing that strong hydrogen bonding occurs in the presence of intercalated water molecules compared with weak repulsion in the absence of water. It is suggested that this mechanism prevents the separation graphene oxide layers and subsequent formation of nanostructures in humid conditions.