Evaluation of UV-PCO Air Cleaners Performance at Low Level VOCs Concentration

Volatile organic compounds (VOCs) constitute the vast majority of indoor air contaminants. In design of ultraviolet photo-catalytic oxidation (UV-PCO) air cleaner system, the focus must be in selecting an appropriate catalyst that can transform all contaminants to harmless gases. Some produced contaminants may promote or inhibit the photocatalytic reactions, or even lead to deactivation of the catalyst. The PCO reactions of two classes of VOCs, light alcohols and alkanes (C5-C10) were studied with different types of nano titanium dioxide catalysts. The influence of relative humidity on oxidation rate of tested VOCs was discussed in detail to establish ideal operational conditions for the selected group of VOCs. A series of laboratory experiments was conducted with a pilot four-parallel duct system setup to test the VOCs in very low concentration levels which represents a typical indoor air environment. The experiments were carried out with different types of nano TiO2 catalysts with UV lamps. A new type of titanium dioxide catalyst was specifically developed for this study to enhance the efficiency of PCO system. A systematic method was used to develop and test the synthesized photocatalysts, which helped to improve the overall performance of test system. The performance of different catalysts was studied at different humidity conditions and different VOCs concentrations. The research objective was to develop a correlation between the PCO kinetic rate constants and physical characteristics of indoor VOCs. These correlations may be employed to eliminate the need of further experiments with every individual VOCs and they also could facilitate the design process of future PCO air cleaner. The physical characteristics of VOCs were used to estimate the performance of the PCO catalysts in a steady-state environmental test condition. The photocatalytic removal efficiency of VOCs and formation of intermediates and byproducts were studied with and without ozone generation UV lamps

A Knowledge-based Energy-saving Approach to PWM Control of a Novel Integrated Pneumatic Valve

As manufacturers, the automotive industry, and many other sectors face an increasingly competitive global business environment; they seek opportunities to reduce production costs by reducing energy consumption. Energy costs have become one of the fastest-rising expenses of doing business, and the industrial sector is rushing to implement new energy conservation initiatives. Pressurized air, as an important source of energy, has been widely used by various industries, providing simple solutions for automated lines. In this project, an Accumulator-Based Equalization (ABE) strategy was combined with a knowledge-based PWM (Pulse Width Modulation) protocol, and then incorporated into an integrated solenoid valve to increase the energy efficiency of pneumatic systems through the optimization of ow consumption. Modeling and simulation of the proposed system was carried out to assess the proposed ideas and reduce the cost of system developments. An experimental setup was constructed to assess the performance of the proposed strategy when implemented on configured pneumatic control valves. Equalization was performed at home positions of a typical linear actuator, where the chambers of the pneumatic actuators were momentarily connected to each other. Furthermore, during the extension and retraction, a knowledge-based PWM signal was applied to the valves to maintain the actuator dynamics in an acceptable posture. To obtain the knowledge-based PWM signal, an expert-fuzzy controller was designed to control the speed of the actuator. This knowledge-based protocol was based on fuzzy structures, which were implemented on the configured pneumatic valves in an open-loop fashion to decrease the amount of ow consumption without compromising the dynamic performance of the pneumatic actuators. The identified duty cycles profiles from the expert fuzzy controller were implemented on an open-loop system. It was observed that, while an open-loop system is used, the pressurized air can be saved about 20% under 50 N load and almost 10% under 150 N load. "Smoothness index" was defined as a measure of the piston motion smoothness when applying the proposed strategies. In addition to smoothness of the motion in the closed-loop control methods, the energy-saving results were compared to the results of the open-loop system and the performance under different conditions was evaluated

Isolation and pathogenicity of Phytophthora species from declining Rubus anglocandicans

Rubus anglocandicans is the most widespread and abundant blackberry species within the European blackberry (Rubus fruticosus) aggregate in Western Australia (WA). European blackberry is also one of the 32 Weeds of National Significance in Australia. A disease recorded as 'blackberry decline' was first observed in some blackberry sites in WA in 2006. A disease survey was conducted in the Manjimup-Pemberton region along the Warren and Donnelly River catchments in WA between 2010 and 2012. Phytophthora amnicola, P. bilorbang, P. cryptogea, P. inundata, P. litoralis, P. multivora, P. taxon personii, P. thermophila and a P. thermophila × amnicola hybrid were recovered from declining and adjacent decline-free sites, as well as from streams and rivers. Phytophthora cinnamomi was isolated from dying Banksia and Eucalyptus species from two non-decline sites. Of these species, P. bilorbang and P. cryptogea were more pathogenic than the others in under-bark inoculations using excised stems (primocanes), in planta primocane inoculations in blackberry growing wild in native forest stands, and in glasshouse pot trials. It was concluded that blackberry decline is a complex syndrome and Phytophthora species, in particular P. bilorbang and P. cryptogea, together with temporary inundation, are major biotic and abiotic factors contributing to blackberry decline

What we need to know about the germ-free animal models

The gut microbiota (GM), as a forgotten organ, refers to the microbial community that resides in the gastrointestinal tract and plays a critical role in a variety of physiological activities in different body organs. The GM affects its targets through neurological, metabolic, immune, and endocrine pathways. The GM is a dynamic system for which exogenous and endogenous factors have negative or positive effects on its density and composition. Since the mid-twentieth century, laboratory animals are known as the major tools for preclinical research; however, each model has its own limitations. So far, two main models have been used to explore the effects of the GM under normal and abnormal conditions: the isolated germ-free and antibiotic-treated models. Both methods have strengths and weaknesses. In many fields of host-microbe interactions, research on these animal models are known as appropriate experimental subjects that enable investigators to directly assess the role of the microbiota on all features of physiology. These animal models present biological model systems to either study outcomes of the absence of microbes, or to verify the effects of colonization with specific and known microbial species. This paper reviews these current approaches and gives advantages and disadvantages of both models

Gene Diversity of Trichomonas vaginalis Isolates

Background: Trichomonas vaginalis is protozoan parasite responsible for trichomoniasis and is more common in high-risk behavior group such as prostitute individuals. Interest in trichomoni­asis is due to increase one's susceptibility to viruses such as herpes, human papillomavirus and HIV. The aim of this study was to find genotypic differences between the isolates.Methods: Forty isolates from prisoners' women in Tehran province were used in this study. The random amplified polymorphic DNA (RAPD) technique was used to determine genetic differ­ences among isolates and was correlated with patient's records. By each primer the banding pat­tern size of each isolates was scored (bp), genetic differences were studied, and the genealogical tree was constructed by using NTSYS software program and UPGMA method.Results: The least number of bands were seen by using primer OPD8 and the most by using OPD3. Results showed no significant difference in isolates from different geographical areas in Iran. By using primer OPD1 specific amplified fragment with length 1300 base pair were found in only 8 isolates. All these isolates were belonged to addicted women; however, six belonged to asymptomatic patients and two to symptomatic ones.Conclusion: There was not much genetic diversity in T vaginalis isolates from three different geo­graphical areas

In vitro and in vivo antifungal properties of silver nanoparticles against Rhizoctonia solani, a common agent of rice sheath blight disease

Sheath blight disease in rice has caused major crop losses worldwide. Managing the causal agent of disease Rhizoctonia solani Kühn is difficult because of its broad host range and formation of sclerotia which can survive in harsh environmental conditions; therefore developing innovative disease management methods without application of hazardous chemicals has been considered as the main concern to maintain sustainable agriculture. This presented research has revealed the negative impact of Silver nanoparticles (SNPs) on R. solani and disease progress both in vitro and in vivo. The adverse effects of the SNPs on R. solani are significantly dependent on the quantity of SNPs, sprayed at different concentrations in vitro. The highest inhibition level against sclerotia formation and mycelia growth are 92 and 85%, respectively, at a SNPs concentration of 50 ppm. In vivo glasshouse experiments also showed that SNPs at the same concentration favorably affects both the fresh and dry weight of rice plants with a remarkable suppressive effect on the lesion development in leaves