Effective Reduction of Horizontal Error in Laser Scanning Information by Strip‐Wise Least Squares Adjustments

Though the airborne laser scanning (ALS) technique is becoming more popular in many applications, horizontal accuracy of points scanned by the ALS is not yet satisfactory when compared with the accuracy achieved for vertical positions. One of the major reasons is the drift that occurs in the inertial measurement unit (IMU) during the scanning. This paper presents an algorithm that adjusts for the error that is introduced mainly by the drift of the IMU that renders systematic differences between strips on the same area. For this, we set up an observation equation for strip‐wise adjustments and completed it with tie point and control point coordinates derived from the scanned strips and information from aerial photos. To effectively capture the tie points, we developed a set of procedures that constructs a digital surface model (DSM) with breaklines and then performed feature‐based matching on strips resulting in a set of reliable tie points. Solving the observation equations by the least squares method produced a set of affine transformation equations with 6 parameters that we used to transform the strips for adjusting the horizontal error. Experimental results after evaluation of the accuracy showed a root mean squared error (RMSE) of the adjusted strip points of 0.27 m, which is significant considering the RMSE before adjustment was 0.77 m.     

Sorption of copper ions by granulated chitosan

The features of sorption of Cu²⁺ ions from aqueous solutions of CuSO₄ by granulated chitosan sorbent in static conditions and the different contribution of surface and bulk amino groups in the sorbent to complexation are discussed. Sorption with freshly formed swollen and maximally amorphized granules with accessible bulk amino groups can be described by Langmuir’s equation; it attains 5.6 mmole/g of dry sorbent, which is close to the sorption calculated from the equimolar composition of the amino-copper complex. Sorption of initially dry granules with less accessible bulk amino groups does not obey Langmuir’s equation due to precipitation of copper hydroxide and hydrosulfate on the surface of the sorbent. __________ Translated from Khimicheskie Volokna, No. 2, pp. 11–14, March–April, 2006.     

Synthesis and characterization of novel aromatic condensation polymers containing rigid benzoxazole pendent groups

A new aromatic diamine monomer containing benzoxazole substituents was prepared by a multistep synthesis starting from 1,4‐dibromo‐2,5‐difluorobenzene. The diamine was polymerized with commercial aromatic dianhydride or dicarboxylic acid chloride monomers to provide several different poly(amic acid)s and polyamides with their inherent viscosities in the range of 0.24–0.46 dL/g. Thermal properties of these polymers including thermal imidization of poly(amic acid)s into polyimides were investigated by using FTIR, DSC, and TGA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 178–185, 2004     

Rheological properties of hyperbranched polymer/poly(ethylene terephthalate) reactive blends

The rheological properties in solution, in shear and in uniaxial elongation of poly(ethylene terephthalate) (PET) reacted together with hyperbranched polymers (HBPs) were investigated. Two different PET grades, of low and high molecular weights, were compounded with sub‐ to over‐stoichiometric concentrations of HBPs of second and fourth pseudo‐generation, and subsequently subjected to a solid‐state polycondensation (SSP). The formation of microgels, which occurs at high HBP concentration, gave rise to a large increase in melt elasticity and a related decrease in melt strength. At low HBP concentrations, the complex viscosity of the unreacted HBP/PET was considerably reduced, thus demonstrating a lubrication effect of the HBP molecules. During SSP, the intrinsic and shear viscosities exhibited a gradual increase, which was similar for both PET and HBP/PET blends, and was correlated to an increase in molecular weight, through linear‐chain extension and branching reactions. The elongational viscosity of the reactive blends was also increased as a function of reaction time, and this increase was much larger in the case of the HBP/PET blends. A 400% increase in melt strength of the PET was obtained by combining SSP and trace amounts of an HBP of second generation, without any decrease in drawability.     

Intricate CSTR dynamics

Various dynamical characters of continuous stirred tank reaclors (CSTR) are introduced with respect to the effects of reaction types, extra thermal capacitance, periodic forcing, and coupling of CSTRs. The subject includes the classical dynamics of two-dimensional model and the variety of complex dynamics in three or higher dimensional systems such as periodic bifurcations to torus or chaos, aperiodic oscillations on invariant torus, and universal dynamics of alternating periodic-chaotic sequences with k.2^v-cycles for every natural number k. Particularly this review intends to bring about the problems that the engineers must be prepared to encounter in solving various physical systems including chemically reacting systems.     

Intrinsic Elastic, Dielectric, and Piezoelectric Losses in Lead Zirconate Titanate Ceramics Determined by an Immittance-Fitting Method

The material coefficients of "soft" and "hard" lead zirconate titanate (PZT) ceramics were determined as complex values by the nonlinear least-squares-fitting of immittance data measured for length-extensional bar resonators. The piezoelectric d -constant should be a complex value to obtain a best fitting between observed and calculated results. Because the elastic, dielectric, and piezoelectric losses determined in this process were not "intrinsic" losses, a calculation process to evaluate the "intrinsic" losses was proposed. It was confirmed that the intrinsic losses were smaller than the corresponding extrinsic losses. The intrinsic piezoelectric loss existed in both soft and hard PZTs; ∼50% of the loss of piezoelectric d -constant was derived from the elastic and dielectric losses. The most notable difference between the soft and hard PZTs was observed in their elastic losses.     

Manufacture of Granulated Chitosan

Conditions for dry-wet spinning of spherical chitosan granules 0.5–2.0 mm in diameter into a two-layer spinning bath consisting of immiscible liquids are proposed, where an organic liquid, decane in particular, is the upper layer of the bath while a solution of ammonium hydroxide is the lower layer. The possibility of obtaining chitosan microgranules from 2 to 30 µm in diameter by emulsification of a solution of chitosan in decane or a solution of an anion-active surfactant — sodium dodecyl sulfate — is demonstrated. The effect of the molecular weight and concentration of the solutions on the granule-forming power of chitosan is established. A 6% solution of chitosan with a molecular weight of 200 kD is recommended for further studies.__________Translated from Khimicheskie Volokna, No. 5, pp. 26–29, January–February, 2005.     

Thermal runaway prevention in catalytic packed bed reactor by solid temperature measurement and Control

Magnetic crystallite thermometry has been used to measure the average nickel crystallite temperature in packed bed reactors during ethane hydrogenolysis, an exothermic reaction. The technique is based on the temperature dependence of the magnetic moment of dispersed nickel catalysts. Measurement of the average catalyst temperature is very useful for reactor control because of its shorter time constant compared with exit fluid temperature. Bed temperature control based on the exit fluid temperature, which has often been used as a control variable, is too slow to protect thermal runaway of the bed. The advantage of short time constant by measuring the average catalyst temperature has been incorporated with enhanced feedback control system to control the bed temperature and prevent the thermal runaway of the catalyst bed. An enhanced feedback control structure with supervisory action performed better than the classical proportional-integral control in runaway prevention when the two control schemes were compared with each other on the basis of the trippoint (incipient thermal runaway).     

A study of tailored blank welding between mild steel sheet and zn-coated steel sheet by CO2 laser beam

Research was conducted on tailored blank welding between mild steel sheet and Zn-coated steel sheet using CO₂ laser beam. The materials used in this study were low carbon steel sheets with a thickness of 1.2 mm and Zn-coated steel sheet with the same thickness and 6.3 μm Zn coating. Experiments were conducted by applying the Taguchi method to obtain optimum conditions for the application of this tailored blank laser welding method in practical manufacturing processes. Optical microscopy, XRD, SEM and TEM analysis were performed to observe the microstructures and to determine the structures of welded zone. In addition, mechanical properties were measured by the microhardness test, tensile test and Erichsen test to evaluate the formability of the welded specimen. There was no trapped Zn in the fusion zone, and the phases of this region consisted of polygonal ferrite, quasi-polygonal ferrite, banitic ferrite and martensite. The elongation value of welded specimen was more than 80% of the value in substrate metal, and the LDH value was more than 90% of the value in substrate metal.     

A timing controller embedded driver IC with 3.24‐Gbps eDP interface for chip‐on‐glass TFT‐LCD applications

This paper presents a timing controller embedded driver (TED) IC with 3.24‐Gbps embedded display port (eDP), which is implemented using a 45‐nm high‐voltage CMOS process for the chip‐on‐glass (COG) TFT‐LCD applications. The proposed TED‐IC employs the input offset calibration scheme, the zero‐adjustable equalizer, and the phase locked loop‐based bang‐bang clock and data recovery to enhance the maximum data rate. Also, the proposed TED‐IC provides efficient power management by supporting advanced link power management feature of eDP standard v1.4. Additionally, the smart charge sharing is proposed to reduce the dynamic power consumption of output buffers. Measured result demonstrates the maximum data rate of 3.24 Gbps from a 1.1 V supply voltage with a 7.9‐inch QXGA 60‐Hz COG‐LCD prototype panel and 44% power saving from the display system.