bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of a kinematic laserscanning system
Authors: Vennegeerts Harald , Martin Jens , Becker Matthias , Kutterer Hansjörg 
Published: September 2008

Abstract
The increasing data rate of actual laser scanners qualifies these sensors for kinematic applications. In case of surveying static environments the scanner can be integrated into a moving platform system. Therefore two main tasks are outstanding. Position and orientation of the platform have to be registered throughout a freely driven trajectory. The second challenge is to synchronize the scanned spatial data with the time scale of the positioning unit. This paper presents the specification of a mobile mapping system using a phase-based laser scanner with a hybrid INS (Inertial Navigation System)/GPS solution. Among a description of the system structure it includes a software-based method to synchronize the scanned profiles with the trajectory. No extra hardware unit for time registration of scanned profiles is required. After all a spatial comparison of independently observed control points allows the assessment of the system performance.
Line based reconstruction from terrestrial laser scanning data
Authors: Briese Christian , Pfeifer Norbert 
Published: September 2008

Abstract
The methods for reconstructing objects from dense point clouds, typically acquired by terrestrial laser scanning (TLS), are currently unsatisfying, especially from a geodetic perspective, for a number of reasons. Digitization in the point cloud lacks redundancy and no stochastic measures are provided generally. Reconstruction from primitives, e.g., planes, spheres, and cylinders, enforces strong requirements on (large) object parts, which are strictly valid only for very special cases. In this article we propose a new reconstruction technique for terrestrial laser scanning point clouds addressing those issues. In line with photogrammetric restitution, lines, not necessarily straight, are reconstructed in a process providing precision, i.e. internal quality measures. Methods for reconstructing different types of lines will be presented, in particular break lines, form lines, step edges, and boundary lines. The process features a high degree of automation, reducing the manual interaction to supplying one approximate point or one short segment per relevant line. The method will be presented with two examples.
A contribution to construction machine automation
Authors: Gläser Andreas , Möhlenbrink Wolfgang , Schwieger Volker 
Published: September 2008

Abstract
The requirements concerning surveying tasks on modern construction sites have considerably changed. The time slots for assigning and assuring geometric properties get shorter. Thus the surveying tasks change from static to kinematic methods. Nowadays surveying instruments, e.g. robot-tachymeters, can work in real time due to more powerful CPUs and better synchronisation of internal sensors. Therefore it is possible to integrate robot-tachymeters into the construction process using control loops to fulfil the real time positioning task. Accuracy limiting factors like inclined reflector booms on the construction machine, temperature influence as well as synchronisation and dead time problems are pointed out, too.
In this paper a modular toolbox for solution of geometric guidance and control tasks by robot-tachymeters is developed based on a so-called functional analysis and basic aspects of system design. The tachymeters are integrated into the processes to accomplish geometric control tasks of high precision (standard deviation < 1 cm for the position). The exemplary realisation of the modular system is the automatic guidance of a truck model (1:14) on a known trajectory.
Gridline methods for detection of object displacements and rigid body movements
Authors: von Webern Hauke , Kahmen Heribert 
Published: September 2008

Abstract
If measurements are performed without artificial targets, deformation analysis cannot refer to the points on the objects defined at an initial or prior measurement epoch. This paper describes how an arrangement of virtual lines, so-called grid lines (GL), offers a solution. A total station, measuring distances without a reflector, or a theodolite measurement system can be used to make the measurements. The GLs should intersect the object to be measured, as far as possible, at right angles and they can be arranged in such a way that each of them runs through one of the object points chosen for the initial measurements. Subsequently deformations of the object can be described along the GLs.
The general idea behind this method is to track the virtual lines with the optical axis of a theodolite, until it aims at the points where the GLs intersect the surface. Tracking starts where the GLs intersected the surface of the object during the last measurement epoch. However, if the surface moved this point will be no longer an intersection point and the optical axis hits the surface at another point. Consequently there will be a separation of these two points, and if the theodolite starts tracking the GL, a distance function is obtained. This can be used to determine the new intersection point of the GL if that line is tracked until the value of the distance function is zero.
The following sections describe how this process can be iteratively controlled by algorithms for an one-dimensional search space. The algorithms are based on the binary-search-, so-called parabola-, and regula-falsi method. Simulations and practical tests are used to evaluate the different search algorithms. The accuracy of the intersection points and the number of necessary iteration steps, describing the speed of the algorithms, are used as quality assessment parameters. Both quality characteristics depend on the truncation criteria: a distance and a length of an interval.
Performance evaluation of various aerobic biological systems for the treatment of domestic wastewater at low temperatures
Authors: Sundaresan N. , Philip L. 
Published: September 2008

Studies were undertaken on the performance evaluation of three different types of aerobic reactors, namely, activated sludge process, fluidized bed reactor and submerged bed reactor. Initially synthetic wastewater was used for stabilizing the system and later domestic wastewater of IIT Madras was used as the feed for the biological systems. The hydraulic retention time was maintained as 24 h. The seed sludge was collected from IIT Madras sewage treatment plant. The inlet COD to the reactors with synthetic wastewater was 1,000±20 mg/L and with real wastewater, it was 150 to 350 mg/L. The performance of the reactors was evaluated based on the soluble COD and nitrogen removal efficiency. The pH, temperature, dissolved oxygen (DO) and mixed liquid suspended solid (MLSS) concentration were measured periodically. The reactors were acclimatized at 35°C in batch mode and changed to continuous mode at 30°C. After the systems attained its steady state at a particular temperature, the temperature was reduced from 35°C to 5°C stepwise, with each step of 5°C. The start-up time for submerged bed reactor was slightly more than fluidized and conventional activated sludge process.
The COD removal efficiency of the three reactors was higher with synthetic wastewaters as compared to actual domestic wastewater. Submerged bed reactor was more robust and efficient as compared to activated sludge and fluidized bed reactors. The COD removal efficiency of the reactors was relatively good until the operating temperature was maintained at 15°C or above. At 10°C, submerged bed reactor was able to achieve 40% COD removal efficiency whereas; the fluidized bed and conventional ASP reactors were showing only 20% COD removal efficiency. At 5°C, almost all the systems failed. Submerged bed reactor showed around 20% COD removal efficiency. However, this reactor was able to regain its 90% of original efficiency, once the temperature was raised to 10°C. At higher temperatures, the nitrification efficiency of the reactors was above 80–90%. As the temperature reduced the nitrification efficiency has reduced drastically. In summary, submerged bed reactors seems to be a better option for treating domestic wastewaters at low temperature regions.
Escherichia coli in household drinking water and diarrheal disease risk: evidence from Cambodia
Authors: Brown J. M. , Proum S. , Sobsey M. D. 
Published: September 2008

Escherichia coli counts in household drinking water may or may not reliably indicate the presence of diarrheogenic pathogens originating in feces. The extent to which a bacterial indicator like E. coli predicts risks from all classes of pathogens (viruses and parasites as well as bacteria), especially in tropical waters, is uncertain. To investigate the association between E. coli in household drinking water and diarrheal diseases in Cambodia, we conducted a 22 week cohort study in a rural village in Kandal Province. Episodes of diarrhea (all) and bloody diarrhea (dysentery), water quality, water sources, and other covariates were monitored biweekly in 180 households. Households used a variety of water treatment, storage, and handling practices.
Results suggest a weak but positive association between E. coli counts in household drinking water and diarrhea and for diarrhea with blood (dysentery), after adjusting for clustering within households and within individuals over time. Compared to households with &lt;1 E. coli/100 ml in drinking water, there was no observed increased risk for having 1–10 E. coli/100 ml (LPR = 0.98, 95% CI 0.81–1.2 for diarrheal disease; LPR = 0.75, 95% CI 0.36–1.6 for dysentery). Households with measured E. coli of 11–100/100 ml did report increased diarrhea (LPR = 1.2, 95% CI 1.1–1.3 for diarrheal disease; LPR = 1.4, 95% CI 1.0–1.8 for dysentery), as did those with 101–1,000 E. coli/100 ml (LPR = 1.2, 95% CI 1.2–1.3 for diarrheal disease; LPR = 1.2, 95% CI 1.0–1.4 for dysentery) and those with &gt;1,000 E. coli per 100 ml sample (LPR = 1.2, 95% CI 1.1–1.2 for diarrheal disease; LPR = 1.2, 95% CI 1.0–1.3 for dysentery). Unlike the results of some previous studies, diarrheal disease risks did not increase progressively in magnitude with increasing concentration of E. coli in drinking water.
Influence of irradiation crosslinking on the self‐heating and conduction of an acetylene carbon black filled high‐density polyethylene composite in the electric–thermal equilibrium state
Authors: Song Yihu , Zheng Qiang 
Published: September 2008

AbstractThe electric self‐heating and conduction behaviors of a high‐density polyethylene/acetylene carbon black composite crosslinked with electron‐beam irradiation are studied with respect to the electric field and ambient temperature. On the basis of scaling arguments, the critical fields and current densities for the onsets of self‐heating and global electrical breakdown are discussed with respect to the intrinsic resistivity at a given ambient temperature as well as the irradiation dosage. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A convenient approach to synthesize stable silver nanoparticles and silver/polystyrene nanocomposite particles
Authors: Wang Desong , An Jing , Luo Qingzhi , Li Xueyan , Li Minna 
Published: September 2008

AbstractIn this study, silver nanoparticles were prepared by the reduction of silver nitrate in SDS+ isopentanol/styrene/H2O reverse microemulsion system using sodium citrate as reducing agent. The Ag/PS nanocomposite particles were prepared by in situ emulsion polymerization of the styrene system containing silver nanoparticles that did not separate from the reaction solution. The polymerization dynamic characteristic was studied, at the same time, silver nanparticles and the encapsulation of composite particles were characterized by Fourier‐transform‐infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X‐ray diffraction (XRD) measurement, UV–vis diffuse reflectance spectroscopy, and X‐ray photoelectron spectroscopy (XPS). The results of TEM and UV–vis absorption spectra showed that well‐dispersed silver nanoparticles have a narrow size distribution. XRD showed that Ag and Ag/PS nanocomposite particles were less than 10 and 20 nm in size, which is similar to those observed by TEM. The results of XPS spectra revealed that the microemulsion system can stabilize the silver nanoparticles from aggregation and provided supporting evidence for the polystyrene encapsulated silver nanoparticle structure. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.
Preparation and development of the surface charge density of vanadium phosphate membranes in electrolyte solutions
Authors: Jabeen Fakhra , Rafiuddin  
Published: September 2008

AbstractPolystyrene‐based vanadium phosphate membranes prepared by a sol–gel route process from aqueous solutions were studied. The uni‐univalent electrolytes (KCl, NaCl, and LiCl) were diffused from the feed solution as a carrier through the prepared membranes with saturated calomel electrodes. The Teorell, Meyer, and Sievers equation was used to estimate the membrane potential, surface charge density, distribution coefficient, transport numbers, and other electrochemical parameters to characterize the prepared membranes. The membrane potentials offered by the uni‐univalent electrolytes through prepared membranes were cation selective and found to be in the order LiCl > NaCl > KCl. The membranes prepared at lower pressures had wider pores and an essentially low surface charge density, whereas membranes prepared at higher pressures carried a high surface charge density and narrow surface openings. The order of charge effectiveness of the electrolytes in the membranes depended on the hydration of the solute–solute interaction and ionic radii of the counterions. The experimental results for membrane potential were consistent with the theoretical prediction. The morphology of the membrane surface was studied by scanning electron microscopy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Manipulating the conductivity of carbon‐black‐filled immiscible polymer composites by insulating nanoparticles
Authors: Li Bo , Xu Xiang‐Bin , Li Zhong‐Ming , Song Yin‐Chun 
Published: September 2008

AbstractThe conductivity of an immiscible polymer blend system, microfibrillar conductive poly(ethylene terephthalate) (PET)/polyethylene (PE) composite (MCPC) containing carbon black (CB), was changed by the addition of insulating CaCO3 nanoparticles. In MCPC, the PET forms microfibrils during processing and PE forms the matrix. The CB particles are selectively localized in the PET microfibrils. When the insulating CaCO3 nanoparticles are added, they substitute for some of the conductive CB particles and obstruct the electron paths. As a result, the resistivity of the MCPC can be tailored depending on the insulating filler content. The resistivity‐insulating filler content curve displays a sluggish postpercolation region (the region immediately following the percolation region and in front of the equilibrium flat of the resistivity‐filler content curve), suggesting that the MCPC in the postpercolation region possesses an enhanced manufacturing reproducibility and a widened processing window. These features are of crucial importance in making sensor materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.
A semi‐empirical cell voltage model for polymer electrolyte/methanol systems: Applicability of the group contribution method
Authors: Seong Ji Yun , Bae Young Chan 
Published: September 2008

AbstractA new group contribution model is established to describe the cell voltage of a direct methanol fuel cell as a function of the current density. The model equation is validated with experimental data over a wide range of methanol concentrations and temperatures. The proposed model focuses on very unfavorable conditions for cell operation, that is, low methanol solution concentrations and relatively low cell temperatures. The proposed group contribution method includes a methanol crossover effect that plays a major role in determining the cell voltage of a direct methanol fuel cell. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Differential scanning calorimetry analysis of the thermal treatment of ternary mixtures of ethylene vinyl acetate, polyethylene, and azodicarbonamide
Authors: Reyes‐Labarta J. A. , Marcilla A. 
Published: September 2008

AbstractThe different transitions and reactions involved in the thermal processing of ternary ethylene vinyl acetate (EVA)–polyethylene (PE)–azodicarbonamide (ADC) mixtures with different concentrations of PE and ADC, which was used as a foaming agent, were studied by means of differential scanning calorimetry. The effect of the concentration of PE in the ternary samples was practically linear, which showed an increase in the fusion heat of the PE and the PE domains of the EVA. On the contrary, the mechanism of the thermal decomposition of ADC that the ternary mixtures contained was strongly dependent on its concentration in the sample, which showed clear deviations from linearity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
γ→β Phase transformation induced in poly(vinylidene fluoride) by stretching
Authors: Imamura R. , Silva A. B. , Gregorio R. 
Published: September 2008

AbstractThe purpose of this work was to show in a conclusive way the γ→β phase transformation induced by uniaxial stretching in poly(vinylidene fluoride). Poly(vinylidene fluoride) films were melted and crystallized at 163°C for 36 h. Under these conditions, a mixture of α and γ phases was formed, with a predominance of the latter. These films were uniaxially stretched at 130°C at a draw ratio of 4. Fourier transform infrared and differential scanning calorimetry analyses showed a γ→β phase transition in the solid state, whereas orientation of the α phase without any transition was observed. Optical microscopy analysis permitted the observation of the transformation of spherulitic structures into oriented lamellae during stretching. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and properties of polyaniline nanolayers in the presence of retinol in aqueous ethanol
Authors: Wang Donghong , Qi Shuhua , Wu Youming , An Qunli , Li Chunhua 
Published: September 2008

AbstractPolyaniline (PANI) nanolayers were shown to form spontaneously during the chemical oxidation in the presence of retinol using pure water and aqueous ethanol as reaction media. The effects of the retinol, the volume fraction of ethanol, and the acidity of the polymerization medium on the D.C. conductivity of PANI were investigated through two‐probe method at room temperature. The introduction of 0.2 g retinol improved the D.C. conductivity value of PANI to 3.0 S/cm in pure water and 4.46 S/cm in 50% aqueous ethanol when the H+ concentration was 0.5M. The D.C. conductivity values were 5.1 and 5.49 S/cm when the concentration of H+ was 1.0M in pure water and 2.5M in 50% aqueous ethanol, respectively. The products were also characterized by Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, scanning electron microscope, cyclic voltammetry, and X‐ray diffraction techniques. Moreover, the resulting PANI nanolayers exhibited an unusual electromagnetic loss at the microwave frequency (f = 8.2–12.4 GHz) and it arose from order arrangement of polaron as charge carrier caused by nanolayers morphologies and the materials can be used for the potential application as microwave absorbing materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal bonding of polypropylene films and fibers
Authors: Hegde Raghavendra R. , Bhat Gajanan S. , Campbell R. A. 
Published: September 2008

AbstractThe thermal bonding behavior of different grades of polypropylene was studied in this research. Initial bonding studies were done with polypropylene films of different grades of polymer with varying morphology, and the studies were extended to polypropylene fibers. Polypropylene fibers manufactured with different cross‐sections, deniers, polymer melt‐flow rates, and different processing conditions were bonded under various conditions. The effect of film structure, properties, and bonding conditions on the bonding efficiency was studied by comparing the tensile strength of bonded films. Thermal bonding was carried for a range of temperatures covering poor, optimum, and over bonding. Changes taking place to the polymer in bond point and the original surface were analyzed using the SEM. Higher bond strength was observed in the vicinity of melting temperature and the strength reduced with a further increase in bonding temperature. The frequent failure point was observed at the bond edge crossover points where film undergoes maximum thickness transition. Lower pressure and shorter time were found to be appropriate for bonding. Films with lower orientation formed better bonds. The optimum bond strength and the optimum bonding temperature observed were different for different polymers. Fiber bond strength results were similar to the results observed in the case of films with respect to the bonding temperatures studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Antibacterial poly(vinyl alcohol) film containing silver nanoparticles: Preparation and characterization
Authors: Galya Tsermaa , Sedlařík Vladimír , Kuřitka Ivo , Novotný Radko , Sedlaříková Jana , Sáha Petr 
Published: September 2008

AbstractThe importance of antibacterial materials for biomedical applications is growing nowadays. The presented article deals with the characterization of structural, mechanical and thermal properties and of antibacterial polymeric films based on polyvinyl alcohol (PVA) and silver nitrate, which can find their applicability in wound dressing components and protective coating. The methods of transmission electron microscopy, UV–vis and XRD spectroscopy, optical microscopy, differential scanning calorimetry, stress–strain analysis, and agar diffusion test were used to characterize the polymer films prepared. The results showed strong antibacterial activity against Escherichia coli and Staphylococcus aureus already at the lowest addition level of silver nitrate. An improvement of mechanical properties (Young's modulus) was also noticed due to a modification of PVA with silver nitrate up to 1 wt. % of silver content. Furthermore, the results show a strong effect of the thermal history of the sample preparation on the degree of silver‐ion reduction and formation of nanoparticles. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Structural and photooxidation studies of poly(styrene oxide) prepared with Maghnite‐H+ as cationic catalyst
Authors: Hachemaoui Aïcha , Yahiaoui Ahmed , Belbachir Mohammed 
Published: September 2008

AbstractThe nature of irregularities and end‐groups in poly(styrene oxide) samples prepared using Maghnite‐H+ as a cationic catalyst were studied by 1H‐ and 13C‐NMR at 200 MHz. Head‐to‐head (H‐H) and tail‐to‐tail (T‐T) irregularities are detected in all the samples studied. Secondary hydroxyl terminal groups are identified in polymers prepared with Maghnite‐H+. Poly(styrene oxide) was found to undergo chain scission by aging at 25°C. It was confirmed that oxidation of this type of polymers results from the important sensitivity of the polyether soft segment to oxidative degradation. For this reason, the scissions due to the oxidation of the material lead to notable quantities of low molecular weight photoproducts. Among the various structures produced by the oxidative degradation process, benzoate and secondary hydroxyl groups are identified by MALDI‐TOF‐MS. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008