Relationship between Changes in Material Technology and Construction Productivity

There have been substantial changes in both material technology and construction productivity over the past several decades. By analyzing the changes in both material technology and productivity among 100 construction activities from 1977 to 2004, this research examines the strength and types of relationships that exist within these two occurrences. Through analysis of variance (ANOVA) and regression analyses, the researchers found that activities experiencing significant changes in material technology have also experienced substantially greater long-term improvements in both their labor and partial factor productivity. The research did find that a stronger relationship exists between changes in material technology and partial factor productivity than in labor productivity. The research also found that changes in the unit weight of materials had a significant relationship to labor productivity, while changes in installation and modularity had a significant relationship to partial factor productivity. The research findings will help industry practitioners to better understand how they may leverage technology to improve construction productivity, while also helping researchers understand the theoretical relationships between technology and construction productivity.     

Synthesis and EMI shielding studies of polyaniline grafted conducting nanohybrid

Polyaniline (PANI) grafted conducting nanohybrids are successfully synthesized by emulsion graft polymerization. Maximum grafting of 644% is obtained on sepiolite at optimized concentrations and reaction conditions. The Fourier transform infrared (FT-IR) spectra of sepiolite grafted polyaniline (MS-g-PANI) nanohybrid revealed the presence of stretching vibrations of C=C bonds of polyaniline at 1580 and 1490 cm⁻¹ along with the characteristic peaks of sepiolite. Increased thermal stability of the nanohybrid is observed with the increase in polyaniline grafting. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to study the structural changes caused by grafting. A progressive increase in electrical conductivity is observed with the increase in grafting yield. Maximum electrical conductivity of 0.427 Scm⁻¹ is observed in the nanohybrid having 644% grafting. 24.2 dB (>99% attenuation) EMI shielding effectiveness has been exhibited by the developed nanohybrids in X-band frequency range.     

Improved wear properties of magnesium matrix composite with the addition of fullerene using semi powder metallurgy

The present study aims to fabricate fullerene (C60) reinforced magnesium matrix composite via semi powder metallurgy in hot press system under high purity argon atmosphere. Improvement of wear resistance of pure magnesium with the addition of fullerene is also aimed with this study. Hardness and wear tests at room temperature were performed to investigate the mechanical effect of fullerene nanoparticles. Microstructures of fabricated composites were characterized using Scanning Electron Microscope (SEM). Results clearly show that hardness performance was improved up to 0.5 wt. % fullerene addition directly. A uniform distribution was also achieved according to the mapping and line EDX analysis for the lower content of fullerene. Agglomeration of fullerene was observed for 1 wt. % reinforced composite. Wear performances of pure magnesium were also improved when harder fullerene reinforcements incorporated into the matrix. Abrasion and oxidation were main wear mechanism for unreinforced and fullerene reinforced composites. Enhancement of hardness and wear performances might be attributed to the high specific surface area of fullerene and achievement of uniform distribution of reinforcement in magnesium matrix.     

Fabrication of basalt embedded composite fiber membrane using electrospinning method and response surface methodology

In this study, a novel basalt embedded fiber membranes was prepared by the electrospinning method. The effects of the feed rate, voltage, tip to collector distance, and the basalt content on the prepared composite fiber membranes were investigated and optimized using the response surface method. Four models were built to compare the fibers in terms of deionized water flux (DWF), activated sludge flux, chemical oxygen demand (COD) removal, and porosity of fiber membranes. All the developed models were significant and adequately precise. The maximum flux of DWF was obtained when the voltage was 17.25 kV, the tip to collector distance of 19 cm, and a basalt content in polymer of 1.25%. COD removal decreased at higher voltage values as the feed rate increased. The porosity, pore size, and the contact angle values decreased for basalt embedded fiber membrane. The increases in the basalt percentage in polymer increased the hydrophilicity of the fiber. The flux decline for the basalt embedded fiber membrane was compared with the pristine fiber membrane. The permeate fluxes of pristine and basalt embedded fiber membranes were 42.3 and 59.6 L/m²/h, respectively. The biofouling performances of pristine and basalt embedded fiber membranes were also examined. Irreversible fouling decreased from 42.9% to 8.0%, and reversible fouling increased from 56.5% to 91.1% after modification of the membrane with basalt powder. Scanning electron microscopy with energy dispersive X-ray analysis (SEM–EDX) analysis showed that basalt powder was successfully embedded into polyether sulfone polymer.     

Bloch Lines Constituting Antiskyrmions Captured via Differential Phase Contrast

Much scientific capital has been directed toward exotic magnetic spin textures called Bloch lines, that is, Néel-type line boundaries within domain walls, because their geometry promises high-density magnetic storage. While predicted to arise in high-anisotropy magnets, bulk soft magnets, and thin films with in-plane magnetization, Bloch lines also constitute magnetic antiskyrmions, that is, topological antiparticles of skyrmions. Most domain walls occur as Bloch-type or Néel-type, in which the magnetization rotates parallel or perpendicular to the domain wall across its profile, respectively. The Bloch lines’ Néel-type rotation and their minute size make them difficult to directly measure. This work utilizes differential phase contrast (DPC) scanning transmission electron microscopy (STEM) to measure the in-plane magnetization of Bloch lines within antiskyrmions emergent in a non-centrosymmetric Heusler magnet with D_2d symmetry, Mn_1.4Pt_0.9Pd_0.1Sn, in addition to Bloch-type skyrmions in an FeGe magnet with B20-type crystal structure to benchmark the DPC technique. Both in-focus measurement and identification of Bloch lines at the antiskyrmion's corners are provided.     

SEISMIC EVENTS IN THE UPPER MIOCENE – PLIOCENE SEDIMENTARY SUCCESSION IN THE GULF OF İZMİR (WESTERN ANATOLIA): IMPLICATIONS FOR HYDROCARBON PROSPECTIVITY

An analysis of multi-channel seismic reflection data integrating reflection tomography, pre-stack depth migration, AVO analysis, seismic modelling and seismic attribute analysis was used to investigate the Miocene – Quaternary stratigraphy of the Gulf of İzmir, western Anatolia. In this area, the east-west oriented Gediz graben intersects with the NE-SW oriented Bakırçay Graben. A velocity-depth model together with pre-stack depth migration allowed two seismic stratigraphic units (SSU1 and SSU2) to be distinguished. These units can be correlated with the stratigraphic succession at the offshore Foça-1 well and correspond to the Upper Miocene to Recent Bozköy, Ularca and Bayramiç Formations with a combined thickness of 1.75 km. The units rest on acoustic basement (SSU3) which has a basin-and-ridge morphology, and which corresponds to the Lower-Middle Miocene Yuntdağ Volcanics. A number of lateral velocity variations were identified. In particular, a ~90 m wide and ~500 m long lenticular-shaped low-velocity zone with an interval velocity of 1.68 km/s was identified in the Quaternary Bayramiç Formation. The structure is bounded by negative reflections whose amplitude increases with offset at the top and by strong positive reflections whose amplitude increases with offset at the base, interpreted as possible bright and flat spots respectively. These amplitude events point to the presence of gas-saturated sediments within the study area. The lenticular structure is bounded by strike-slip faults on either side, and by a Miocene – Pliocene unconformity surface below and by shales of the Bayramiç Formations above. It is therefore interpreted as a possible structural – stratigraphic trap. The strike-slip faults may allow the migration of hydrocarbons from source rocks located at greater depths. The presence of a low-velocity zone above the lenticular structure reaching up to seafloor may indicate the upward leakage of hydrocarbons from the trap. These observations will contribute to future hydrocarbon exploration activities in the study area.     

Accuracy and precision in amino acid analysis

Five laboratories collaborated in a two-part study to improve and measure the accuracy and precision of amino acid analysis. The results of the unpublished first part allowed each laboratory the opportunity to optimise their own procedure. In the second part of the study reported here, three purified and six conventional proteins were analysed, each after three different preparation procedures (normal and extended acid hydrolysis, and following preliminary oxidation). Preparative effects reported in the literature were confirmed though not uniformly, and there were other, often unique, preparative effects. Well documented preparative effects are essential in matching analytical work to differing requirements. Results from one laboratory were excluded from further statistical analysis because of high replicate variation. The repeatability (within laboratory) coefficient of variation was 4.1% and for reproducibility (between laboratory) it was 13.1%. Discrepancies between best amino acid estimates for purified proteins and estimates calculated from published sequences (P < 0.01) provided evidence of bias in five amino acids from one laboratory and in one from another. When P < 0.01 was used as the discard threshold for conventional protein results, a total of 9.9% of best estimates were discarded: 8.1% were biased, 3.2% were outliers and 1.3% were both biased and outliers. When these values were discarded, 19 of 96 mean values changed by up to 4%, nine changed by 4-8%, eight changed by larger amounts and the pooled coefficient of variation fell from 8.2% to 5.4%. At this threshold between zero and 31% of each laboratory's data on conventional proteins was discarded. A lower threshold (P < 0.05) doubled the discard rate but had marginal effects on mean values and residual variation. At P < 0.01 less than 20% of biased estimates were also outliers and less than half the outliers were also biased. This means that only studies which examine both accuracy and precision will achieve maximum improvement in either.     

Earthquake‐induced hydrodynamic pressures on a 3D rigid dam–reservoir system using DRBEM and a radiation matrix

The dual reciprocity method is applied to determine the hydrodynamic pressure distribution in a three‐dimensional dam–reservoir system subjected to earthquake excitation. The reservoir domain is idealized as a finite region of irregular geometry adjacent to the dam followed by an infinite domain of uniform cross‐section in the upstream direction. The reservoir hydrodynamic pressure response is governed by the Helmholtz equation subject to free surface, dam–reservoir interface, absorbing bottom/banks and radiation boundary conditions. A three‐dimensional (3D) dual reciprocity model is developed to determine the hydrodynamic pressure in the finite reservoir domain. A radiation matrix is developed and introduced to relate the hydrodynamic pressure and its normal derivative on the interface between the finite and infinite domains. The three‐dimensional radiation model used is developed by applying a two‐dimensional dual reciprocity formulation along the interface of the finite and infinite reservoirs together with a continuum solution in the upstream direction of the infinite domain. The model is compared for the hydrodynamic response of a three‐dimensional rectangular reservoir and found to be in excellent agreement with results obtained from a model based on the analytical formulation existing in the literature. Copyright © 2003 John Wiley & Sons, Ltd.     

Detection of bacillus Calmette-Guerin in the blood by the polymerase chain reaction method of treated bladder cancer patients

PURPOSE: Following intravesical bacillus Calmette-Guerin (BCG) instillation, we attempted to detect BCG in the blood using the polymerase chain reaction (PCR) method and correlate these findings with the occurrence of major complications due to this treatment. MATERIALS AND METHODS: Intravesical BCG immunotherapy was given to 22 consecutive patients with superficial bladder tumors. In 2 patients the BCG instillation had to be discontinued due to serious side effects of therapy. Blood samples (252 aliquots) were obtained from 126 BCG courses in 22 cases, and 2 additional samples (4 aliquots) were obtained from 1 patient 1 and 3 months after cessation of therapy. All blood samples were analyzed by the PCR technique for detection of deoxyribonucleic acid tuberculosis Mycobacterium tuberculosis. RESULTS: Of the 126 blood samples 9 (7.1%) were PCR positive for M. tuberculosis. These 9 positive samples belonged to 3 patients, all of whom were among those 4 patients who had major clinical side effects. CONCLUSIONS: We demonstrated that rapid and sensitive detection of mycobacteremia by PCR correlated with the clinical course of these patients. We also demonstrated that PCR can be used to monitor BCG in the blood after antituberculous therapy. The early, fast and accurate diagnosis of BCG in the blood by PCR may alter the serious clinical course of these patients by initiation of specific treatment early. However, further extensive studies are needed to validate these results.     

Multicriteria Analysis For Water Productivity in the Jordan Valley

Abstract

Multiple variables associated with agricultural sector, including crop water consumption, salinity tolerance, marketing, evapotranspiration and other factors related to industrial sector, were incorporated into a multi-criteria analysis (MCA). The MCA utilized Analytical Hierarchy Process (AHP) which resulted in the prioritization of water use for management in the Jordan Valley. The inputs to the MCA were generated through metrological variables for the Jordan Valley for the period 1980 to 1999. Soil data and crop data were evaluated using the EVAPOT program, the KCISA program, and the ISAREG model to estimate reference evapotranspiration, crop coefficiency, crop water requirement, and calculations of water productivity for agricultural and industrial sectors. The results of the MCA make recommendations for enhancing long-term sustainability of water resources in the Jordan Valley, while allowing for water utilization and economic growth. The MCA ranked the date palm as the highest priority crop with respect to the goal of sustainable agricultural use of water. Apparel manufacturing was the most sustainable industry. Overall, the industrial sector seems to perform better with regards to water productivity than the agricultural sector. It can be concluded that the MCA tool and ISAREG model are potentially positive contributions to the process of decision- making for selection and ranking of alternatives for help in solving problems that include conflicting criteria.