Remote detection of volatile organic compounds by passive multispectral infrared imaging measurements

Automated pattern recognition methodology is described for the detection of signatures of volatile organic compounds from passive multispectral infrared imaging data collected from an aircraft platform. Data are acquired in an across-track scanning mode with a downward-looking line scanner based on 8 to 16 spectral channels in the 8-14 and 3-5 microm spectral ranges. Two controlled release experiments are performed in which plumes of ethanol are generated and detected from aircraft overflights at altitudes of 2200 to 2800 ft (671 to 853 m). In addition, a methanol release from a chemical manufacturing facility is monitored. Automated classifiers are developed by application of piecewise linear discriminant analysis to the calibrated, registered, and preprocessed radiance data acquired by the line scanner. Preprocessing steps evaluated include contrast enhancement, temperature-emissivity separation, feature selection, and feature extraction/noise reduction by the minimum noise fraction (MNF) transform. Successful classifiers are developed for both compounds and are tested with data not used in the classifier development. Separation of temperature and emissivity by use of the alpha residual calculation is found to reduce false positive detections to a negligible level, and the MNF transform is shown to enhance detection sensitivity.     

Photoinitiated polymerization of ethyl cyanoacrylate by phosphonium salts

The photoinitiated polymerization of ethyl cyanoacrylate (ECA) by benzyl triphenylphosphonium hexafluoroantimonate (BP⁺) and (anthracen-9-ylmethyl)triphenylphosphonium hexafluoroantimonate (MAP⁺) was studied. Zwitterionic and free radical mechanisms which involved homolytic and heterolytic decomposition of the phosphonium salts are discussed. The anthracene-sensitized photopolymerization of ECA was also demonstrated.     

Halloysite Nanotubes/Polyethylene Nanocomposites for Active Food Packaging Materials with Ethylene Scavenging and Gas Barrier Properties

Novel polymeric active food packaging films comprising halloysite nanotubes (HNTs) as active agents were developed. HNTs which are hollow tubular clay nanoparticles were utilized as nanofillers absorbing the naturally produced ethylene gas that causes softening and aging of fruits and vegetables; at the same time, limiting the migration of spoilage-inducing gas molecules within the polymer matrix. HNT/polyethylene (HNT/PE) nanocomposite films demonstrated larger ethylene scavenging capacity and lower oxygen and water vapor transmission rates than neat PE films. Nanocomposite films were shown to slow down the ripening process of bananas and retain the firmness of tomatoes due to their ethylene scavenging properties. Furthermore, nanocomposite films also slowed down the weight loss of strawberries and aerobic bacterial growth on chicken surfaces due to their water vapor and oxygen barrier properties. HNT/PE nanocomposite films demonstrated here can greatly contribute to food safety as active food packaging materials that can improve the quality and shelf life of fresh food products.     

Review of Dendritic Cells,Their Role in Clinical Immunology,and Distribution in Various Animal Species

Dendritic cells (DCs) are cells derived from the hematopoietic stem cells (HSCs) of the bone marrow and form a widely distributed cellular system throughout the body. They are the most efficient, potent, and professional antigen-presenting cells (APCs) of the immune system, inducing and dispersing a primary immune response by the activation of naïve T-cells, and playing an important role in the induction and maintenance of immune tolerance under homeostatic conditions. Thus, this review has elucidated the general aspects of DCs as well as the current dynamic perspectives and distribution of DCs in humans and in various species of animals that includes mouse, rat, birds, dog, cat, horse, cattle, sheep, pig, and non-human primates. Besides the role that DCs play in immune response, they also play a pathogenic role in many diseases, thus becoming a target in disease prevention and treatment. In addition, its roles in clinical immunology have also been addressed, which include its involvement in transplantation, autoimmune disease, viral infections, cancer, and as a vaccine target. Therefore, based on the current knowledge and understanding of the important roles they play, DCs can be used in the future as a powerful tool for manipulating the immune system.     

Elemental analyses and determination of lead content in kohl (stone) by laser-induced breakdown spectroscopy

Elemental analyses of kohl (stone) samples collected from three different parts of the world were performed using laser-induced breakdown spectroscopy (LIBS). The analyses indicated that lead (Pb), copper (Cu), silver (Ag), iron (Fe), calcium (Ca), aluminum (Al), silicon (Si), and sodium (Na) were present in all the kohl samples. In addition to these elements, the sample from Madina, Kingdom of Saudi Arabia (KSA), contained the elements tin (Sn), zirconium (Zr), and antimony (Sb). The sample from Mount Toor, Egypt, also contained Sn. Also, quantitative analysis for lead was carried out by the standard addition method using the LIBS technique. The result showed the presence of 14.12 ± 0.28% by weight of Pb in the sample from Madina, which compares well with the measurement done using atomic absorption spectroscopy (AAS) (13.31 ± 0.46%). The standard addition method used three calibration curves drawn for three emission lines of the LIBS spectra of Pb. The limits of detection (LoD) for these calibration curves varied from 0.27% to 1.16% by weight. The lead contents of the samples from Mount Toor and the local market of Bangladesh were also measured by the AAS technique, and the results were 14.61 ± 0.48% and 8.98 ± 0.35% by weight, respectively. The reason for determining only the lead content in kohl, which may be used as an eye cosmetic, is the adverse effect that lead has on health.     

Diffusion kinetics of borided AISI 52100 and AISI 440C steels

In this study, the case properties and diffusion kinetics of AISI 440C and AISI 52100 steels borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1173 and 1223 K for 2, 4 and 8 h.The boride layer was characterized by optical microscopy, X-ray diffraction technique and micro-Vickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe₂B and CrB compounds.The thickness of boride layer increases by increasing boriding time and temperature for all steels. The hardness of the boride compounds formed on the surface of steels AISI 52100 and AISI 440C ranged from 1530 to 2170 HV_0.05 and 1620 to 1989 HV_0.05, respectively whereas Vickers hardness values of untreated steels AISI 440C and AISI 52100 were 400 HV_0.05 and 311 HV_0.05, respectively. The activation energies (Q) of borided steels were 340.426 kJ/mol for AISI 440C and 269.638 kJ/mol for AISI 52100. The growth kinetics of the boride layers forming on the AISI 440C and AISI 52100 steels and thickness of boride layers were also investigated.     

Clean fuel options with hydrogen for sea transportation: A life cycle approach

In this study, two potential fuels, namely hydrogen and ammonia, are alternatively proposed to replace heavy fuel oils in the engines of sea transportation vehicles. A comparative life cycle assessments of different types of sea transportation vehicles are performed to investigate the impacts of fuel switching on the environment. The entire transport life cycle is considered in the life cycle analyses consisting of production of freight ship and tanker; operation of freight ship and tanker; construction and land use of port; operation, maintenance and disposal of port; production and transportation of these clean fuels. Various environmental impact categories, such as global warming, marine sediment ecotoxicity, marine aquatic ecotoxicity, acidification and ozone layer depletion are selected in order to examine the diverse effects of switching to clean fuels in maritime transportation. As a carbon-free fuel for marine vehicle engines, ammonia and hydrogen, yield considerably lower global warming impact during the operation. Furthermore, numerous production methods of alternative fuels are evaluated to comparatively show environmentally benign options. The results of this study demonstrate that if ammonia is even partially utilized in the engines of ocean tankers as dual fuel (with heavy fuel oils), overall life cycle greenhouse gas emissions per tonne-kilometer can be decreased about 27% whereas it can be decreased by about 40% when hydrogen is used as dual fuel.     

Developing a Shade Range on Wool by Madder (Rubia cordifolia) Root Extract with Gallnut (Quercus infectoria) as Biomordant

Environmental issues inspire the revival of natural dyes that exhibit better biodegradability and more compatibility over synthetic ones. This research is aimed to investigate the effect of color and fastness properties on wool yarn substrate with natural anthraquinone colorants extracted from madder roots using gallnut (Quercus infectoria) extract as anchoring agent. Prior to the dyeing with Indian Madder (Rubia cordifolia), wool fibers were pre and post-treated with different concentrations of gallnut extract (viz 1–5% o.w.f) to get a broad range of beautiful and color fast shades. The feasibility of gallnut extract as an anchoring agent and its effect on color strength and color fastness to light, rubbing, and washing was investigated. Results of color characteristics showed that the color coordinates of the dyed samples were situated in the red-yellow quadrant of the CIELabcolor space. Bio-mordanting with gallnut extract produced shades of practically acceptable color depth, color fastness to light, washing and rubbing. Pre-treatment with gallnut extract is dominated over post-treatment in terms of better colorimetric and fastness results.