Characterization of the thermal and fluid flow behavior of industrial ribbon burners

This study focuses on the key parameters that enhance the stability of ribbon burners used in various industrial processes, characterizing the flame environment and flow regimes that the burner creates under changing operating conditions. The research includes the exploration of ribbon-pack configurations in order to define the effects of separation distance and port arrangement on flame stability and thermal and fluid flow. Flow visualization studies reveal that burners having a 1.5–2.0 mm division between rows appear to be the most stable. More than four rows of ports in the ribbon-pack are required to resist entrainment of ambient air as a result of impinging surface motion. The flame environment created by the ribbon burner experiences higher levels of mixing, at a lower Reynolds number in comparison to a single non-reacting jet due to combustion-induced turbulence and jet interaction. Under these high flow velocity conditions there is little entrainment of ambient air along the impingement surface and a very stable flame environment is created.     

Microbial UV fluence-response assessment using a novel UV-LED collimated beam system

A research study has been performed to determine the ultraviolet (UV) fluence-response of several target non-pathogenic microorganisms to UV light emitting diodes (UV-LEDs) by performing collimated beam tests. UV-LEDs do not contain toxic mercury, offer design flexibility due to their small size, and have a longer operational life than mercury lamps. Comsol Multiphysics was utilized to create an optimal UV-LED collimated beam design based on number and spacing of UV-LEDs and distance of the sample from the light source while minimizing the overall cost. The optimized UV-LED collimated beam apparatus and a low-pressure mercury lamp collimated beam apparatus were used to determine the UV fluence-response of three surrogate microorganisms (Escherichia coli, MS-2, T7) to 255 nm UV-LEDs, 275 nm UV-LEDs, and 254 nm low-pressure mercury lamps. Irradiation by low-pressure mercury lamps produced greater E. coli and MS-2 inactivation than 255 nm and 275 nm UV-LEDs and similar T7 inactivation to irradiation by 275 nm UV-LEDs. The 275 nm UV-LEDs produced more efficient T7 and E. coli inactivation than 255 nm UV-LEDs while both 255 nm and 275 nm UV-LEDs produced comparable microbial inactivation for MS-2. Differences may have been caused by a departure from the time-dose reciprocity law due to microbial repair mechanisms.     

湖北省麻城市乘马岗镇列宁小学滑坡及边坡防治工程处治技术

勘察分析滑坡及周边环境地质条件时,在查明滑坡体的规模、形态、稳定性分析评价及潜在危害程度的基础上,提出对滑坡及边坡采用经济合理的处治技术,采用片石护坡、浆砌石肋墙、拱肋与支墩联合护坡形式等综合治理措施,通过治理和监测,滑坡防治工程运行状态良好。对滑坡的防治取得了较好的成功经验,可对山区丘陵一带滑坡和不稳定边坡的防治提供借鉴。     

Thermal inactivation of avian influenza and Newcastle disease viruses in chicken meat

Avian influenza viruses (AIV) and Newcastle disease viruses (NDV) of high pathogenicity cause severe systemic disease with high mortality in chickens and can be isolated from the meat of infected chickens. Although AIV and NDV strains of low pathogenicity are typically not present in chicken meat, virus particles in respiratory secretions or feces are possible sources of carcass contamination. Because spread of AIV and NDV is associated with movement of infected birds or their products, the presence of these viruses in chicken meat is cause for concern. This study presents thermal inactivation data for two viruses of high pathogenicity in chickens (AIV strain A/chicken/Pennsylvania/1370/1983 and NDV strain APMV-1/ chicken/California/S0212676/2002) and two viruses of low pathogenicity in chickens (AIV strain A/chicken/Texas/298313/ 2004 and NDV strain APMV-1/chicken/Northern Ireland/Ulster/1967). Under the conditions of the assay, high-pathogenicity AIV was inactivated more slowly in meat from naturally infected chickens than in artificially infected chicken meat with a similar virus titer. In contrast, high-pathogenicity NDV was inactivated similarly in naturally and artificially infected meat. Linear regression models predicted that the current U.S. Department of Agriculture-Food Safety and Inspection Service time-temperature guidelines for cooking chicken meat to achieve a 7-log reduction of Salmonella also would effectively inactivate the AIV and NDV strains tested. Experimentally, the AIV and NDV strains used in this study (and the previously studied H5N1 high-pathogenicity AIV strain A/chicken/Korea/ES/2003) were effectively inactivated in chicken meat held at 70 or 73.9 degrees C for less than 1 s.     

Effect of recrystallisation on Al3Zr dispersoid behaviour in thick plates of aluminium alloy AA7150

The ageing responses of surface/centre layer materials from a commercially produced AA7150 thick plate have been studied after both water quenching (WQ) and air cooling (AC). The results show that the higher degree of recrystallisation near the plate surface decreases its age hardening response in AC condition. Quench-induced phases have been found to precipitate preferentially on Al₃Zr dispersoids in recrystallised grains. Microstructural observations show that Al₃Zr dispersoids in recrystallised grains exhibit the same crystal structure and orientation as those in adjacent subgrains.     

The effect of test conditions on apparent smoke density from various materials

Four samples of thermoplastics and nine samples of wood were evaluated for smoke evolution in the Aminco-NBS smoke chamber under piloted (flaming) conditions, using two different types of pilot burners, and in the Arapahoe chamber.     

Medications prescribed for children with mood disorders: Effects of a family-based psychoeducation program.

Few controlled trials have examined psychotropic medications in children with mood disorders. Multiple medications are often prescribed for these children, who frequently suffer from several comorbid conditions. However, this polypharmacy has been infrequently studied and may lead to adverse drug-drug interactions. Multi-Family Psychoeducation Groups (MFPGs) are an 8-session, manual-driven treatment for children with mood disorders, designed as an adjunct to current medications and psychotherapy. In part, MFPG teaches parents and children to be better consumers of mental health care, including medications. This study examined the effect of MFPG on medications taken by 165 children, ages 8-11, with mood disorders. The authors hypothesized that MFPG would not affect the mean number of medications taken but that the variance in number of medications would decrease from pre- to posttreatment (i.e., the number of medications prescribed for any given child should become more closely distributed around the sample mean). Approximately 70% of participants were diagnosed with bipolar spectrum disorders, and 30% were diagnosed with depressive spectrum disorders. Most had both comorbid behavioral (97%) and anxiety (69%) disorders. Information regarding medications was gathered 4 times: at baseline, 6, 12, and 18 months. Approximately half (n=78) of the participants were randomized into immediate treatment, and half (n=87) were randomized into a 1-year wait-list condition. All were encouraged to continue treatment as usual throughout the study. As hypothesized, no significant pre- to posttreatment differences were found between groups for the mean number of current medications, but variance declined significantly from pre- to posttreatment. Implications and future research goals are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The developmental role of intuitive principles in choosing mathematical strategies.

This study investigated the relation between the development of understanding principles that govern a problem and the development of mathematical strategies used to solve it. College students and 2nd, 5th, 8th, and 11th graders predicted the resulting temperature when 2 containers of water were combined. Students first estimated answers to the problems and then solved the problems using math. The pattern of estimated answers provided a measure of the intuitive understanding of task principles. Developmental differences in intuitive understanding were related to the type of math strategy students used. Analysis of individual data patterns showed that understanding an intuitive principle was necessary but not sufficient to generate a math strategy consistent with that principle. Implications for the development of problem solving are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EEG coherence following acute and chronic clozapine in treatment-resistant schizophrenics.

Electroencephalographic (EEG) coherence is an index of brain regional coupling that has been found to be abnormal in people with schizophrenia but has not been systematically examined in response to neuroleptics. EEG coherence in slow (delta and theta) frequencies was assessed in 17 treatment-resistant people with schizophrenia at baseline, 2 hr after their first oral dose (25 mg) and after 6 weeks of clozapine treatment. Compared with EEG norms, participants exhibited significant interhemispheric and intrahemispheric coherence abnormalities prior to treatment. Both acute and chronic treatments altered coherence but differed with respect to their relationship to symptom reduction and their ability to normalize or augment pretreatment abnormalities. Findings are discussed in relation to "disconnection" theories of schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)