744 research outputs found
Traffic volume and load data measurement using a portable weigh in motion system: A case study
AbstractTraditionally, traffic loading characteristics are collected for pavement design and performance prediction purposes using permanent roadside weigh-in-motion (WIM) stations. However, high installation and maintenance costs associated with these permanent WIM stations dictate that their deployment be mostly limited to major highways, such as the interstate network. Quite often however, pavement damage on high volume rural highways with heavy truck proportions is more severe than anticipated, and there is no effective way of quantifying the traffic loading on these highways. Therefore, this study was conducted to evaluate the potential application of portable WIM systems as a means for bringing the WIM technology to these high volume rural highways. A portable WIM unit was deployed in the Texas overweight corridor in Hidalgo County (Pharr District) near the USA-Mexico border on highway FM 1016 for collecting traffic data for a minimum of three weeks in each direction. The collected traffic data were analyzed to generate traffic parameters such as volume, load spectra, and overloading information both in terms of the gross vehicle weight (GVW) and axle weight. The computed traffic parameters were successful in partially explaining some of the existing pavement conditions on this highway. Overall, the study findings indicated that the portable WIM unit can be used as a convenient and cost-effective means for collecting reliable traffic information for design, analysis, and monitoring purposes. However, proper in-situ calibration of the portable WIM unit at each site is imperative prior to any real-time traffic data collection
Hemolytic Uremic Syndrome Caused by Enteroviral Infection
A 4-year-old boy presented with enteroviral infection complicated with atypical hemolytic uremic syndrome (aHUS). Enterovirus RNA was detected by reverse transcription polymerase chain reaction (RT-PCR) of both blood and kidney biopsy specimens. A survey of the complement system did not reveal a specific complement defect. Supportive therapy with blood components transfusion, plasma therapy, and immunosuppressants was administered, however, renal function did not recover. The results of this report demonstrate that the enterovirus is the cause of aHUS
Emergency Department Response to SARS, Taiwan
How emergency departments of different levels and types cope with a large-scale contagious infectious disease is unclear. We retrospectively analyzed the response of 100 emergency departments regarding use of personal protective equipment (PPE) and implementation of infection control measures (ICMs) during the severe acute respiratory syndrome outbreak in Taiwan. Emergency department workers in large hospitals were more severely affected by the epidemic. Large hospitals or public hospitals were more likely to use respirators. Small hospitals implemented more restrictive ICMs. Most emergency departments provided PPE (80%) and implemented ICMs (66%) at late stages of the outbreak. Instructions to use PPE or ICMs more frequently originated by emergency department administrators. The difficulty of implementing ICMs was significantly negatively correlated with their effectiveness. Because ability to prepare for and respond to emerging infectious diseases varies among hospitals, grouping infectious patients in a centralized location in an early stage of infection may reduce the extent of epidemics
An analysis of the durations of Swift Gamma-Ray Bursts
We report the systematic analysis of the durations for Swift gamma-ray bursts
(GRBs) and compare the results with those of pre-Swift data. For 95 GRBs with
known redshift, we show that the observed durations have two lognormal
distributions that are clearly divided at s. This is consistent
with the earlier BATSE results. The intrinsic durations also show a bimodal
distribution but shift systematically toward the smaller value and the
distribution exhibits a narrower width compared with the observed one. We find
that the intrinsic distributions of long GRBs between Swift and pre-Swift are
significantly different particularly in the width and the median value. In
addition, the Swift data exhibit a wider dynamic range of duration. Our present
study not only confirms the spectra of short GRBs are in general harder than
the long GRBs in the observer frame but also shows this trend becomes weaker in
the source frame.Comment: 5 pages, 4 figures and 2 table; Accepted to A&A with minor changes;
Note that our previously main conclusions are unchange
Microwave amplification via interfering multi-photon processes in a half-waveguide quantum electrodynamics system
We investigate the amplification of a microwave probe signal by a
superconducting artificial atom, a transmon, strongly coupled to the end of a
one-dimensional semi-infinite transmission line. The end of the transmission
line acts as a mirror for microwave fields. Due to the weak anharmonicity of
the artificial atom, a strong pump field creates multi-photon excitations among
the dressed states. Transitions between these dressed states, Rabi sidebands,
give rise to either amplification or attenuation of the weak probe. We obtain a
maximum amplitude amplification of about 18 %, higher than in any previous
experiment with a single artificial atom, due to constructive interference
between Rabi sidebands. We also characterize the noise properties of the system
by measuring the spectrum of spontaneous emission
High-performance inverted planar heterojunction perovskite solar cells based on lead acetate precursor with efficiency exceeding 18%
Organic-inorganic lead halide perovskites are emerging materials for the next-generation photovoltaics. Lead halides are the most commonly used lead precursors for perovskite active layers. Recently, lead acetate (Pb(Ac)2) has shown its superiority as the potential replacement for traditional lead halides. Here, we demonstrate a strategy to improve the efficiency for the perovskite solar cell based on lead acetate precursor. We utilized methylammonium bromide as an additive in the Pb(Ac)2 and methylammonium iodide precursor solution, resulting in uniform, compact and pinhole-free perovskite films. We observed enhanced charge carrier extraction between the perovskite layer and charge collection layers and delivered a champion power conversion efficiency of 18.3% with a stabilized output efficiency of 17.6% at the maximum power point. The optimized devices also exhibited negligible current density-voltage (J-V) hysteresis under the scanning conditions
A vascular graft infection nightmare secondary to Candida albicans
Femoral-femoral bypass surgery involves creating a bypass around a blocked or narrowed section of the femoral artery, which is a major blood vessel in the leg. During the procedure,
a polytetrafluoroethylene (PTFE) graft, which is a synthetic material commonly used in bypass surgery, is sewn into place to redirect the flow of blood around the blocked area. However, in some cases, the PTFE graft may become infected after surgery, leading to a potentially serious complication. In this case report, we present the case of a patient who developed a Candida albicans infection in a femoral-femoral bypass using a PTFE graft. This rare but serious complication required urgent surgical intervention and long-term antifungal treatment
Molecular Epidemiologic Analysis of Methicillin-Resistant Staphylococcus aureus Isolates from Bacteremia and Nasal Colonization at 10 Intensive Care Units: Multicenter Prospective Study in Korea
We investigated molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolated at 10 intensive care units (ICUs) in Korea. MRSA isolates from bacteremia and nasal colonization were collected prospectively from October 2008 through May 2009 at 10 University-affiliated hospital ICUs. A total of 83 and 175 MRSA strains were isolated from bacteremia and nasal colonization, respectively. Acquired group accounted for 69.9% (n = 58) of bacteremia and 73.1% (n = 128) of nasal colonization. Pulsed-field gel electrophoresis (PFGE) type B (SCCmec type II/ST5) was dominant in the acquired group followed by PFGE type D (SCCmec type IVA/ST72; a community genotype). Seven of 58 (12.1%) acquired bacteremia and 15 of 128 (11.8%) acquired nasal colonizations had SCCmec type IVA/ST72 genotype, which indicated that the community genotype had already emerged as a cause of ICU acquired MRSA infection or colonization. Antibiotic resistance rates to ciprofloxacin, tetracycline, clindamycin and trimethoprim/ sulfamethoxazole were 84.4%, 67.1%, 78.1%, and 12.0%, respectively. Susceptibility to ciprofloxacin best predicted a community genotype (sensitivity 96.5%; specificity 96.9%; odds ratio 861; 95% confidence interval 169-4,390, P < 0.001) and the positive predictive value was 90.2%. Among 23 nasal re-colonized strains, 7 MRSA strains (30.4%) were different from the originally colonized strains on the basis of PFGE types
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