Although a number of different methods have been used to quantify soil bacteria, identifying the optimal method(s) for soil bacterial abundance is still in question. No single method exists for ...undertaking an absolute microbial count using culture-dependent methods (CDMs) or even culture-independent methods (CIMs). This study investigated soil storage and pretreatment methods for optimal bacterial counts. Appropriate storage temperature (4°C) and optimal pretreatment methods (sonication time for 3 min and centrifugation at 1400 g) were necessary to preserve bacterial cell viability and eliminate interference from soil particles. To better estimate soil bacterial numbers under various cellular state and respiration, this study also evaluated three CDMs (i.e., colony forming unit, spotting, and most probable number (MPN) and three CIMs (i.e., flow cytometry (FCM), epifluorescence microscopy (EM) count, and DNA quantitation). Each counting method was tested using 72 soil samples collected from a local arable farm site at three different depths (i.e., 10-20, 90-100, and 180-190 cm). Among all CDMs, MPN was found to be rapid, simple, and reliable. However, the number of bacteria quantified by MPN was 1-2 orders lower than that quantified by CIMs, likely due to the inability of MPN to count anaerobic bacteria. The DNA quantitation method appeared to overestimate soil bacterial numbers, which may be attributed to DNA from dead bacteria and free DNA in the soil matrix. FCM was found to be ineffective in counting soil bacteria as it was difficult to separate the bacterial cells from the soil particles. Dyes used in FCM stained the bacterial DNA and clay particles. The EM count was deemed a highly effective method as it provided information on soil mineral particles, live bacteria, and dead bacteria; however, it was a time-consuming and labor-intensive process. Combining both types of methods was considered the best approach to acquire better information on the characteristics of indigenous soil microorganisms (aerobic versus anaerobic, live versus dead).
Recently, adsorption studies of gases for various adsorbents have
been intensive because they are useful in probing the fine structure
of the surface. Meso-sized MgO(100) powder was irradiated by a
...proton beam with a high energy of 35 MeV. Transmission electron
microscope (TEM) investigations revealed no structural change of the
MgO powders after irradiating with the proton beam. After proton
beam irradiation, NO gas isotherm adsorption data were recorded from
the same sample below the triple point (109.8 K). The results
revealed that there was no hint of multi-isotherm step formation,
which indicates the creation of an atomic layer of NO molecules.
Instead, only a monolayer of NO molecules was obtained. It is
understood that pre-existing unwanted impurities, such as water and
carbon-related organic gases, hinder the formation of atomic layers
in a regular fashion on the MgO powder surface. By comparing NO
adsorption data from the pure and the proton-irradiated MgO samples,
we were able to calculate the surface-related thermodynamic
characteristics, including the 2-dimensional compressibility and the
heat of adsorption. KCI Citation Count: 2
Ti-Zr-Ni quasicrystals are new candidates for hydrogen storage applications due to their capabil-
ity of loading a large amount of hydrogen at reasonable temperature and hydrogen pressure. The
...technical applications, however, have been limited because of the presence of a thick oxygen layer,
which must be eliminated prior to introducing hydrogen into a sample. To effectively remove the
oxygen barrier and to enhance the capability of hydrogen absorption, we irradiated Ti39.5Zr39.5Ni21
quasicrystal ingots by using a proton beam at energy of 20 MeV, 15 mA for 30 minutes. The
proton-beam-treated samples were exposed to a hydrogen pressure of 650 psi at 200℃ and the
results were analyzed by monitoring the pressure change of the chamber. The main concerns were
a careful measurement of the weight gain after hydrogenation and an estimate of the peak shifts
in X-ray diffraction. An absorption of hydrogen was observed for the proton-beam-irradiated
samples while little hydrogen loading was noticed for unirradiated ones. Our results demonstrate
that proton irradiation may be used as a new technique that can effectively eliminate the oxygen
barrier and enhance the rates of hydrogen diffusion. However, more systematic investigations
regarding the role of the proton are required before applying the technique for practical applications. KCI Citation Count: 2
A combined thermodynamic and structural investigation of the interaction of argon with a MgO
(100) surface was made. Ar gas adsorption isotherm studies recorded below the triple point showed
the ...formation of at least two atomic layers of argon in the temperature above 77 K. Synchrotron
X-ray diffraction (XRD) data were also recorded from a monolayer film of argon on MgO (100)
surface for a series of different temperatures at the 5A-HFMS beamline of the Pohang Synchrotron
Light Source in Korea. X-ray diffraction peaks from the Ar atomic layer were measured by taking
the difference spectra between monolayer coverage and no argon coverage. Analyzing the data
suggested that the Ar molecules form an 1 × 1 structure on the MgO (100) surface. KCI Citation Count: 0
The International Maritime Organization (IMO) Marine Environment Protection Committee (MEPC) has gradually strengthened the laws regulating ship exhaust emissions. The majority of ships designed for ...international voyages and powered by large two-stroke marine diesel engines use heavy fuel oil (HFO), which has the advantage of a low price compared to other types of fuel. However, HFO generates large amounts of harmful exhaust emissions during combustion in a marine diesel engine. In addition, as fuel costs account for a large portion of the expenditure budgets of the shipping companies that operate and manage such ships, fuel cost reduction is of considerable interest to such companies. In this study, two fuel additives, oil-soluble Ca-based and oil-soluble Fe-based organometallic compounds, which can improve the performance of diesel engines, were injected into HFO at fixed concentrations (1/4000 and 1/6000 of the total fuel, respectively), in attempts to reduce fuel consumption and exhaust emissions. For enhanced experimental accuracy and reproducibility, a large two-stroke diesel engine installed in a land-based power plant was used as the test subject. Evaluative tests were conducted for three engine loads (50%, 75%, and 100%). The engine performance (i.e., the fuel consumption rate, maximum combustion pressure, and exhaust gas temperature) and the exhaust emissions (NOx, particulate matter (PM)) were analyzed before and after the fuel additive insertion.
Limitations in battery capacity has held back the active development of novel applications for the Internet of Things (IoT) or have caused embedded systems researchers to design a number of ..."go-around" schemes, which sacrifice various system performance metrics for energy efficiency. However, with the concept of simultaneous wireless information and power transfer (SWIPT), many researchers accept it as a potential technology that can be the basis of designing various next-generation low-power embedded computing systems. This work presents an experimental validation on RF-based SWIPT techniques. Specifically, using the Powercast P2110 Powerharvester Receiver, we evaluate its potential of being applied to various low-power embedded applications. We analyze the performance of these commercially available energy harvesting RF receivers in packet-based networks to show that energy harvesting in such cases are only possible with packets of long lengths in practical environments. Furthermore, we experimentally show that despite carrying energy, external noise factors on the wireless channel can deteriorate the RF-based energy harvesting performance due to high voltage amplitude fluctuations. Based on such observations, we present a set of system-level suggestions for future SWIPT-based system development.
This work presents SafeFac, an intelligent camera-based system for managing the safety of factory environments. In SafeFac a set of cameras installed on the assembly line are used to capture images ...of workers that approach the machinery under hazardous situations to alert system managers and halt the line if needed. Given a challenging set of practical application-level requirements such as multi-camera support and low response latency, SafeFac exploits a YOLOv3-based light-weight human object detection. To address the latency–accuracy tradeoff, SafeFac incorporates a set of algorithms as pre- and post-processing modules and a novel adaptive camera scheduling scheme.
Our evaluation with a video dataset containing more that 113,000 frames from real assembly line activity shows that SafeFac achieves high precision (99.93%) and recall (96.44%), and SafeFac successfully satisfies such challenging requirements as a ready-for-deployment system for safe factory management.
•Design an intelligent vision-based safety monitoring system for factory environments.•We compile a set of industrial-level system requirements for factory safety monitoring.•We validate our system using videos from a real assembly line to show high accuracy.
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