Highway Construction Productivity Measurement with a Wireless Real-Time Productivity Measurement System

Seonghoon Kim, Yong Bai, Yang-Ki Jung, and Dukgeun Yun, Highway Construction Productivity Measurement with a Wireless Real-Time Productivity Measurement System, Transportation Research Record: Journal of the Transportation Research Board (Volume: 2228 issue: 1) pp. 26-33. Copyright © 2011 SAGE Publications. DOI: 10.3141/2228-04.Improving the quality of construction schedules calls for development of an advanced productivity measurement system. Existing on-site construction productivity measurement methods have some common limitations, such as not providing data necessary for engineers and project managers to conduct real-time analyses and share data with other project participants. A wireless real-time productivity measurement (WRITE) system was developed to address those shortfalls. The field experiment was conducted at two different stages: asphalt paving projects, including hot-mix asphalt and hot-in-place recycling, and a bridge reconstruction project. Productivity data collected from the WRITE system were also compared with productivity data collected from construction documents, such as contractors' daily logs and pay estimate documents, to identify the feasibility of this system for measuring the performance of construction projects. For data analyses, statistical methods such as normality test, paired t-test, and Wilcoxon signed-rank test were used. The result of statistical analyses proved that the developed system generated identical productivity measurements compared with the stopwatch method and construction documents. The success of this research project made several major contributions to the advancement of the construction industry. First, the research advanced the application of wireless technology in highway construction operations. Second, it provided an advanced technology for engineers and project managers to determine productivity in real time. Third, productivity data can be shared between project participants via the Internet. With these advancements, communication and coordination will be improved at construction sites. Consequently, the WRITE system will enhance owners' and contractors' ability to manage construction projects

Localizing Gravitational Wave Sources with Single-Baseline Atom Interferometers

Localizing sources on the sky is crucial for realizing the full potential of gravitational waves for astronomy, astrophysics, and cosmology. We show that the mid-frequency band, roughly 0.03 to 10 Hz, has significant potential for angular localization. The angular location is measured through the changing Doppler shift as the detector orbits the Sun. This band maximizes the effect since these are the highest frequencies in which sources live several months. Atom interferometer detectors can observe in the mid-frequency band, and even with just a single baseline can exploit this effect for sensitive angular localization. The single baseline orbits around the Earth and the Sun, causing it to reorient and change position significantly during the lifetime of the source, and making it similar to having multiple baselines/detectors. For example, atomic detectors could predict the location of upcoming black hole or neutron star merger events with sufficient accuracy to allow optical and other electromagnetic telescopes to observe these events simultaneously. Thus, mid-band atomic detectors are complementary to other gravitational wave detectors and will help complete the observation of a broad range of the gravitational spectrum.Comment: 16 pages, 3 figures, 2 table

Solitary Necrotic Nodules of the Liver Mimicking Hepatic Metastasis: Report of Two Cases

We present two cases of solitary necrotic nodules of the liver which on radiologic images mimicked hepatic metastasis. Solitary necrotic nodule of the liver is a rare but benign entity which histopathologically consists of an outer fibrotic capsule with inflammatory cells and a central core of amorphous necrotic material. The lesion was seen on contrast-enhanced CT as an ovoid-shaped hypoattenuating nodule; on CT during hepatic arteriography as enhancing nodule; on intraoperative US as a target-appearing hypoechoic nodule; on T2WI as a hyperintensity nodule, and on dynamic MR as a subtle peripheral enhancing nodule. Although the radiologic features are not specific, solitary necrotic nodule of the liver should be included in the differential diagnosis of hepatic metastasis

Fatty liver disease and the risk of erosive oesophagitis in the Korean population: a cross-sectional study

Objectives To investigate an association between fatty liver disease (FLD) and erosive oesophagitis. Design and setting This was a cross-sectional study of subjects selected from examinees who underwent health check-up, including oesophagogastroduodenoscopy in one hospital between 2004 and 2011. Erosive oesophagitis was classified according to the Los Angeles classification and FLD was diagnosed with ultrasonography. The anthropometric and laboratory data of the subjects were analysed using X-2 test and multivariate logistic regression. Additionally, we have analysed our data with two-stage least square estimation using the Baltagi-Chang one-way model to clarify unobserved confounding variable. Primary outcome measure The effect of FLD on erosive oesophagitis. Results Among the 14 723 eligible subjects, 4232 (28.7%) subjects diagnosed with FLD were classified into the fatty liver group and 10 491 (71.3%) subjects without FLD were classified into the non-fatty liver group. The incidence rate of erosive oesophagitis was significantly higher in the fatty liver group than in the non-fatty liver group (10.4% vs6.1%, p< 0.0001). The multivariate analysis revealed that the fatty liver group was significantly associated with erosive oesophagitis (OR 1.19, 95% CI 1.03 to 1.37, p= 0.016). Conclusion FLD diagnosed by ultrasonography is an independent risk factor of erosive oesophagitis. It suggests that FLD-related metabolic abnormality may be associated with erosive oesophagitis

Thermal Degradation and Kinetics of Alginate Polyurethane Hybrid Material Prepared from Alginic Acid as a Polyol

Abstract Alginate polyurethane hybrid materials are prepared by varying mole ratio of 2, 4-TDI as a di-isocyanate and alginic acid as a polyol in presence of dimethyl sulfoxide (DMSO) as a solvent. FT-IR and 13 C onedimensional (1D) solid state NMR (SSNMR) spectroscopy indicates that alginic acid is converted into alginate-polyurethane hybrid material via urethane linkage. Surface morphology of alginate-polyurethane hybrids changes by varying alginic acid: TDI ratio. The peak at near 221°C in DSC thermogram of alginic acid (Alg) is shifted to higher temperature in alginate-polyurethane hybrid (Algpu1 and Algpu2). TGA study shows that alginate-polyurethane hybrid prepared using alginic acid: TDI = 1:1 (Algpu2) is more stable than alginic acid: TDI = 1:0.5 (Algpu1) at 300°C. Kinetic analysis was performed to fit with TGA data, where the entire degradation process has been considered as three consecutive 1st order reactions. This study shows that thermal stability of alginate-polyurethane hybrid material was increased by adjusting mole ratio of 2, 4-TDI and alginic acid

Complete Binocular Blindness as the First Manifestation of HIV-Related Cryptococcal Meningitis

Ocular complications of HIV-related cryptococcal meningitis are reasonably common, but complete binocular blindness as the first manifestation of HIV is extremely rare. A 58-year-old man presented with binocular blindness. He experienced blurred vision for 3 days before the blindness. Mild pleocytosis was present in the cerebrospinal fluid, from which Cryptococcus neoformans was cultured. Serology revealed positivity for HIV antibody. He was treated with antifungal and antiretroviral therapy. This case indicates that HIV-related cryptococcal meningitis should be taken into consideration when determining the cause of unexpected sudden binocular blindness

Factors affecting the long-term outcomes of idiopathic membranous nephropathy

Abstract Background We attempted to describe the clinical features and determine the factors associated with renal survival in idiopathic membranous nephropathy (iMN) patients with nephrotic syndrome (NS) and to determine the factors associated with spontaneous complete remission (sCR) and progression to NS in iMN patients with subnephrotic proteinuria. Methods This retrospective study involved 166 iMN patients with NS and 65 patients with subnephrotic proteinuria. The primary end point was a doubling of serum creatinine or initiation of dialysis. In patients with subnephrotic proteinuria, we determined the factors associated with sCR and factors associated with progression to NS. Results Remission of NS was achieved in 125 out of 166 patients (75.3%). Of those who reached remission, 26 patients (20.8%) experienced relapse that was followed by second remission. The relapse or persistence of proteinuria was associated with the primary end points (hazard ratio [HR] = 12.40, P = 0.037, HR = 173, P < 0.001, respectively). In patients with subnephrotic proteinuria, sCR occurred in 35.4% of the patients. The patients with sCR had lower proteinuria and serum creatinine levels and higher serum albumin concentrations at baseline. The serum albumin level at diagnosis was a prognostic factor for progression to NS (Odds ratio [OR] = 0.015, P < 0.001). Conclusions The occurrence of relapse or persistence of proteinuria had negative effects on renal survival in iMN patients with NS, and low serum albumin levels at baseline were associated with non-achievement of sCR and progression to NS

Four Cases of a Cerebral Air Embolism Complicating a Percutaneous Transthoracic Needle Biopsy

A percutaneous transthoracic needle biopsy is a common procedure in the practice of pulmonology. An air embolism is a rare but potentially fatal complication of a percutaneous transthoracic needle biopsy. We report four cases of a cerebral air embolism that developed after a percutaneous transthoracic needle biopsy. Early diagnosis and the rapid application of hyperbaric oxygen therapy is the mainstay of therapy for an embolism. Prevention is the best course and it is essential that possible risk factors be avoided