Pipe inspection using a laser-based transducer and automated analysis techniques

This paper presents a new sensing methodology for the automated inspection of pipes. Standard inspection systems, as they are for example used in waste pipes and drains, are based on closed-circuit television cameras which are mounted on remotely controlled platforms and connected to remote video recording facilities. Two of the main disadvantages of such camera-based inspection systems are: 1) the poor quality of the acquired images due to difficult lighting conditions and 2) the susceptibility to error during the offline video assessment conducted by human operators. The objective of this research is to overcome these disadvantages and to create an intelligent sensing approach for improved and automated pipe-condition assessment. This approach makes use of a low-cost lighting profiler and a camera which acquires images of the light projections on the pipe wall. A novel method for extracting and analyzing intensity variations in the acquired images is introduced. The image data analysis is based on differential processing leading to highly-noise tolerant algorithms, particularly well suited for the detection of small faults in harsh environments. With the subsequent application of artificial neural networks, the system is capable of recognizing defective areas with a high success rate. Experiments in a range of waste pipes with different diameters and material properties have been conducted and test results are presented.     

Kinetics of solid vanadium-nitrogen reactions at high temperatures

Thermogravimetric studies were made to determine the kinetics of the reaction between 99.83 pct vanadium sheet and purified nitrogen gas in the temperature range of 1173 to 1723 K, at pressures of 9.3 × 10⁴ to 9.3 Pa (700 to 7 × 10^-2 torr) and times up to 160 h. Metallographic and X-ray diffraction techniques were used to examine the reaction products. The data followed either parabolic, cubic, or linear kinetics. In general it was observed that the initial kinetics were parabolic. At high temperatures and near atmospheric pressures, the reaction kinetics changed from parabolic to cubic at longer times. At the lowest pressure the preparabolic kinetics were linear. Weight gains in the parabolic region were mainly due to solution and diffusion of nitrogen in vanadium with the weight gain shown by the equation (ΔW/A)² = 3.2 × 10^-4 Te162-000/RT _t. The cubic region was related to the formation of an outer layer of VN over an intermediate layer of V₃N and a core of the saturated solution of nitrogen in vanadium with the approximate weight gain shown by the equation (ΔW/A)³ = 1.24 × 10^-3 Te- ^208,000/RT _t Linear weight gains at low pressure were presumed to be controlled by the rate of nitrogen adsorption.     

Phase formation and texture development in mullite/zirconia composites fabricated by templated grain growth

Mullite is a promising candidate for advanced ceramic applications but its low fracture toughness and difficulties in sintering are the main limitations for more widespread industrial applications. Therefore, mullite/zirconia composites were prepared from a reactive mixture of alumina and zircon powders. Additives, TiO₂ and MgO, were used to modify aluminosilicate glass to increase densification and <001> aluminum borate templates were incorporated to texture mullite in [001] by templated grain growth. Mullite/zirconia phase formation was complete at 1450°C in the presence of both templates and additives, as compared to 1500°C for the samples with only additives and to 1600°C for the samples with only templates. Dense mullite/zirconia composites with highly <001>-textured mullite grains (Lotgering factor ∼1) and a retention of ∼13% tetragonal ZrO₂ were fabricated after sintering at 1450°C for 2 h. A high quality of mullite texture with a degree of orientation parameter of 0.22 and a narrow distribution of elongated mullite grains within 8.8° around [001] were successfully obtained in the composites.     

Preparation and antibacterial properties of hybrid-zirconia films with silver nanoparticles

The antimicrobial effect of incorporating silver nanoparticles (AgNps) into zirconia matrix–polyether glycol was studied. AgNps of 4–6 nm in size were synthesized using the inverse micelles method, and different doses of metallic nanoparticles were incorporated into zirconia–polyether glycol mixtures during the ageing procedure. Atomic force microscopy (AFM) of the modified hybrid film showed a homogenous distribution of 20–80 nm diameter AgNps, indicating agglomeration of these structures during film modification; such agglomerations were greater when increasing the dosage of the colloidal system. The AgNps-hybrid films showed higher antimicrobial activity against Gram-positive bacteria than for Gram-negative bacteria. Hybrid films prepared with dioctyl sodium sulfosuccinate (AOT) stabilized AgNps presented enhanced antibacterial activity compared to that obtained through the addition of a high AgNO₃ concentration (0.3 wt%).     

Evolution of endoglucanase activity in olives during ripening and storage and its relationship with cellulolytic microorganisms

Summary Cellulolytic enzymes are responsible for many of the changes associated with the ripening process in olive fruits (Olea europaea). Evolution of endoglucanase activity (EC 3.2.1.4.) was studied in olives during their ripening and softening, both on the tree and after being picked and stored, and was related to the presence of microorganisms. The time course of cellulolytic activity was measured for four stages of ripeness (green, turning colour, black and ripe black) and was related to the total number of cellulolytic bacteria. The increases in activity during ripening and storage gave an indication of how normal flora influences during the olive ripening process.

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Aktivität der Endoglucanase-Entwicklung der Olive während der Reifung und des Weichwerdens und die Beziehung mit cellulolytischen Mikroorganismen

Zusammenfassung Die cellulolytischenEnzyme sind für viele Veränderungen während des Reifens der Olive verantwortlich. Es wurde daher die Aktivität der Enzyme während der Entwicklung der Olive bei der Reifung und dem Weichwerden studiert, und zwar am Baum, nach der Ernte und nach dem Lagern, was auch in Beziehung zu der Gegenwart von Mikroorganismen steht. Es wurde die cellulolytische Aktivitätsentwicklung während der vier Reife-Zustände (grün, farbenwechselnd, schwarz und zartes schwarz) studiert und auf die Gesamtzahl der cellulolytischen Bakterien bezogen. Der Aktivitäts-Zuwachs während des Reifens und Lagerns gibt einen Hinweis, wie die normale Flora auf das Reifen der Oliven einwirkt.

     

Microencapsulated di-ammonium hydrogen phosphate (DAHP) with a polyurethane shell: characterization and its properties in wood

European Journal of Wood and Wood Products - This work deals with the microencapsulation of di-ammonium hydrogen phosphate (DAHP) in polyurethane using an interfacial polymerization method. The...     

Effect of nano aluminum nitride filler on mechanical,thermal, and dielectric properties of the glass/mullite composites for low-temperature co-fired ceramic applications

Mullite/glass/nano aluminum nitride (AlN) filler (1–10 wt% AlN) composites were successfully fabricated for the low-temperature co-fired ceramics applications that require densification temperatures lower than 950°C, high thermal conductivity to dissipate heat and thermal expansion coefficient matched to Si for reliability, and low dielectric constant for high signal transmission speed. Densification temperatures were ≤825°C for all composites due to the viscous sintering of the glass matrix. X-ray diffraction proved that AlN neither chemically reacted with other phases nor decomposed with temperature. The number of closed pores increased with the AlN content, which limited the property improvement expected. A dense mullite/glass/AlN (10 wt%) composite had a thermal expansion coefficient of 4.44 ppm/°C between 25 and 300°C, thermal conductivity of 1.76 W/m.K at 25°C, dielectric constant (loss) of 6.42 (0.0017) at 5 MHz, flexural strength of 88 MPa and elastic modulus of 82 GPa, that are comparable to the commercial low temperature co-fired ceramics products.     

Obstacles for rural American Indians seeking alcohol, drug, or mental health treatment.

The purpose of this study was to identify factors associated with 4 clusters of obstacles (self-reliance, privacy issues, quality of care, and communication and trust) to mental health and substance abuse treatment in 3 treatment sectors for residents of 3 reservations in the United States. Participants (N = 3,084) disclosed whether they had sought treatment for emotional, drug, or alcohol problems in the past year and, if so, whether they had faced obstacles in obtaining care from Indian Health Services, tribal services, and other public or private systems. Correlates of these obstacles included negative social support, instrumental social support, utility of counselors, utility of family doctors, treatment sector, treatment type, diagnosis of an anxiety disorder, and tribe. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preparation of nanometric titanium hydrous oxide particles by vapour phase hydrolysis of titanium tetrabutoxide

Spherical titanium nanoparticles in the range of 60 to 500 nm have been obtained by a vapour-phase hydrolysis procedure using titanium tetrabutoxide as raw material. In this work, different parameters such as alkoxide temperature, water temperature, carrier gas flow rate, inlet pressure, vacuum and dilution of the raw material were tested. The most important parameters in order to obtain nanoparticles of low mean size were the flow rate, the alkoxide temperature and the inlet pressure. When the temperature decreases the mean size decreases obtaining nanoparticles below 100 nm when the temperature is set up to 125°C. On the other hand, as the flow rate that pass through the alkoxide increases the particle size decreases. Same behaviour is observed when the pressure inlet is increased. In all cases, these results are attributed to a minor concentration of the alkoxide (low amount of alkoxide molecules) in the gas stream. The other parameters, vacuum, water temperature and dilution of the alkoxide did not show any important influence in the particle size as the other ones. Polydispersity (broad or narrow particle size distribution) has the same trend. The alkoxide temperature and carrier flow rate generate narrow distributions while the other parameters produces broad distributions. FT-IR analysis of these nanoparticles showed that for sizes below 100 nm the alkoxide is fully hydrolysed and as the particle size increases the nanoparticle has more alkoxide or alcohol retained inside. The heat treatment of these nanoparticles produces a decreasing in the particle size and in all cases, the spherical shape is retained and no blackening in the nanoparticles of higher size is observed.