Practical design considerations for secondary air injection in wood-burning cookstoves: An experimental study

Billions of households worldwide cook using biomass fires and suffer from the toxic smoke emitted into their homes. Laboratory studies of wood-burning cookstoves demonstrate that secondary air injection can greatly reduce the emission of harmful air pollution, but these experimental advancements are not easily translated into practical cookstove designs that can be widely adopted. In this study, we use a modular cookstove platform to experimentally quantify the practical secondary air injection design requirements (e.g., flow rate, pressure, and temperature) to reduce mass emissions of particulate matter (PM), carbon monoxide (CO), and black carbon (BC) by at least 90% relative to a traditional cooking fire. Over the course of 111 experimental trials, we illuminate the physical mechanisms that drive emission reductions, and outline fundamental design principles to optimize cookstove performance. Using the experimental data, we demonstrate that low-cost (<$10) fans and blowers are available to drive the secondary flow, and can be independently powered using an inexpensive thermoelectric generator mounted nearby. Furthermore, size-resolved PM measurements show that secondary air injection inhibits particle growth, but the total number of particles generated remains relatively unaffected. We discuss the potential impacts for human health and investigate methods to mitigate the PM formation mechanisms that persist

A case report of intracranial vertebral-basilar artery hypoplasia presenting with episodic dizziness

Basilar artery hypoplasia (BAH) is usually accompa-nied with unilateral vertebral artery hypoplasia (VAH); however, BAH with bilateral VAHs composing verte-bral-basilar artery hypoplasia (VBAH) is indeed a rare curiosity. A 61-year-old woman presented with epi-sodic dizziness for ten years. It accompanied with headache, bilateral tinnitus and blurred vision. Time-of-flight magnetic resonance angiogram with T2 true fast imaging in steady state precession confirmed the VBAH, rather than a stenosis. Symptoms subsided after daily oral aspirin and life-style change has been recommended for three months. The following one year was uneventful, and hearing improved. Finally, we conclude that the episodic dizziness with sensori-neural hearing impairment might attribute to the VBAH. It appears that life-style change was the main therapy and the antiplatelet was simply a supplementary on

Light Hadron Spectroscopy and Decay at BESIII

Light hadron spectroscopy plays an important role in understanding the decay dynamics of unconventional hadronic states, such as strangeonium and glueballs. BESIII provides an ideal avenue to search for these exotic states thanks to a huge amount of data recorded at various energy points in the tau-charm mass region including J/psi resonance. This report summarizes recent results of the BESIII experiment related to the glueballs and strangeonium-like states.Comment: 6 pages, 5 figures, Conference proceeding of FPCP-201

Adding limestone fines to reduce heat generation of curing concrete

It is well known that the heat generation of curing concrete may be reduced by decreasing the cement paste volume of the concrete. However, as the cement paste must be more than sufficient to fill the voids between aggregate particles, the cement paste volume should not be limitlessly decreased. Herein, it is proposed to add an inert filler, such as limestone fines, to fill into the voids between aggregate particles so that a smaller cement paste volume may be used and the heat generation of the concrete may be further reduced. To study the effectiveness of adding limestone fines in reducing the heat generation of curing concrete, a series of concrete mixes with water/cement ratios ranging from 0.35 to 0.60 and different amounts of limestone fines added were tested for their workability, strength and heat generation. The results revealed that the addition of limestone fines to decrease the cement paste volume would significantly increase the strength and, more importantly, substantially reduce the heat generation of the concrete.published_or_final_versio

Origin of lymph node-derived lymphocytes in human hepatic allografts

Hepatic allograft-derived lymph nodes were examined in the post-transplant period on order to determine the origin of lymphocytes and structural elements of the lymph node. Histologic assessment and immunohistochemical studies verified that T-cell infiltration of donor lymph nodes by recipient-derived lymphocytes occurred early in the post-transplant period. These T cells bore T-cell activation markers, e.g. TAC receptor and HLA-DR antigens. In addition, functional analysis demonstrated alloreactive T cells in secondary proliferation assays. The pattern of alloreactivity in these assays was dependent upon the phenotypic make-up (and therefore origin) of the lymphocytes within the lymph node. A gradual shift in predominance of donor-derived lymphocytes to recipient-derived lymphocytes occurred, but even late in the post-transplant course the stromal elements and a residium of lymphocytes within the lymph nodes continued to bear donor HLA antigens. The possible role of these 'passenger' lymphocytes in allograft immunity is discussed

Macrobenthic Community in Tolo Harbour, Hong Kong and its Relations with Heavy Metals

The present study investigated the macrobenthic community in Tolo Harbour, Hong Kong, aiming at linking heavy metal concentrations to differences in macrobenthic community. The stations investigated in Tolo Harbour have widely contrasting features, with some areas located in the Plove Cove displaying both high species richness and abundance while other areas displaying quite impoverished or even void of macrobenthos. High diversity and abundance of macrobenthos in areas with low heavy metal concentrations were recorded. Strong negative correlation between macrobenthic diversity and heavy metal concentrations was found, and this implicated the pollution-induced degradation of macrobenthos in some locations in Tolo Harbour. These results support the Pearson-Rosenberg model for succession along a pollution gradient. © 2010 Coastal and Estuarine Research Federation.published_or_final_versionSpringer Open Choice, 01 Dec 201

A new multivariate CUSUM chart using principal components with a revision of Crosier's chart

postprin

Novel methods of fabrication and metrology of superconducting nanostructures

As metrology extends toward the nanoscale, a number of potential applications and new challenges arise. By combining photolithography with focused ion beam and/or electron beam methods, superconducting quantum interference devices (SQUIDs) with loop dimensions down to 200 nm and superconducting bridge dimensions of the order 80 nm have been produced. These SQUIDs have a range of potential applications. As an illustration, we describe a method for characterizing the effective area and the magnetic penetration depth of a structured superconducting thin film in the extreme limit, where the superconducting penetration depth $lambda$ is much greater than the film thickness and is comparable with the lateral dimensions of the device

Effects of superplasticiser on rheology and cohesiveness of CSF cement paste

Superplasticiser (SP) is now an indispensable ingredient for the production of concrete. However, its proper use is a great concern because its over-dosage could lead to drastic reduction in the cohesiveness of concrete. Furthermore, experience has indicated that the SP demand, saturation dosage and dosage causing segregation are highly dependent on the powder content and therefore the effects of SP are not simple functions of dosage. This study aims to evaluate the effects of SP dosage on the fresh properties of cement paste containing condensed silica fume (CSF). A number of cement paste samples with different SP dosages and CSF contents were tested. The results showed that the addition of SP would improve the packing density, flowability and rheology but impair the cohesiveness of cement paste. It would also render the cement paste shear thickening. To cater for the effects of powder fineness, it is proposed that the SP dosage should be measured in terms of the quantity of SP per surface area of the powder content. © 2012 Thomas Telford Ltd.published_or_final_versio

Epidemiological characteristics of Pandemic Influenza A (H1N1-2009) in Zhanjiang, China

Background: A novel influenza A virus strain (H1N1-2009) spread first in Mexico and the United Stated in late April 2009, leading to the first influenza pandemic of the 21st century. The objective of this study was to determine the epidemiological and virological characteristics of the pandemic influenza A (H1N1-2009) in Zhanjiang, China. Methods: The case and outbreak reports of influenza-like illness (ILI) were collected from the Chinese information system of disease control and prevention and the influenza surveillance system of Zhanjiang city. Real-time RT-PCR was conducted, and epidemic and virological characteristics of the virus were analyzed using descriptive epidemiological methods and Chi-square trend tests. Results: A total of 276 reported cases were confirmed from July 16, 2009 to June 30, 2010. The attack rate of outbreak was from 1.1% to 6.0%. The disease peak occurred in December 2009, after which the outbreak subsided gradually. The last case was confirmed in April 2010. Conclusion: The main population struck by the H1N1-2009 virus was young adults, youths and children. The outbreaks most frequently occurred in schools, and most cases were acquired locally