Integral Procedure Research Articles

A Feasible Data-Driven Mining System to Optimize Wastewater Treatment Process Design and Operation

Achieving low costs and high efficiency in wastewater treatment plants (WWTPs) is a common challenge in developing countries, although many optimizing tools on process design and operation have been well established. A data-driven optimal strategy without the prerequisite of expensive instruments and skilled engineers is thus attractive in practice. In this study, a data mining system was implemented to optimize the process design and operation in WWTPs in China, following an integral procedure including data collection and cleaning, data warehouse, data mining, and web user interface. A data warehouse was demonstrated and analyzed using one-year process data in 30 WWTPs in China. Six sludge removal loading rates on water quality indices, such as chemical oxygen demand (COD), total nitrogen (TN), and total phosphorous (TP), were calculated as derived parameters and organized into fact sheets. A searching algorithm was programmed to find out the five records most similar to the target scenario. A web interface was developed for users to input scenarios, view outputs, and update the database. Two case WWTPs were investigated to verify the data mining system. The results indicated that effluent quality of Case-1 WWTP was improved to meet the discharging criteria through optimal operations, and the process design of Case-2 WWTP could be refined in a feedback loop. A discussion on the gaps, potential, and challenges of data mining in practice was provided. The data mining system in this study is a good candidate for engineers to understand and control their processes in WWTPs.

Risk-based optimal inspection strategies for structural systems using dynamic Bayesian networks

In most structural systems, it is neither possible nor optimal to inspect all system components regularly. An optimal inspection-repair strategy controls deterioration in structural systems efficiently with limited cost and acceptable reliability. At present, an integral risk-based optimization procedure for entire structural systems is not available; existing risk-based inspection methods are limited to optimizing inspections component by component. The challenges to an integral approach lie in the large number of optimization parameters in the inspection-repair process of a structural system, and the need to perform probabilistic inference for the entire system at once to address interdependencies among all components. In this paper, we outline a methodology for an integral risk-based optimization of inspections in structural systems, which utilizes a heuristic approach to formulating the optimization problem. It takes basis in a recently developed dynamic Bayesian network (DBN) framework for rapid computation of the system reliability conditional on inspection results. The optimization problem is solved by nesting the DBN inside a Monte-Carlo simulation for computing the expected cost associated with a system-wide inspection strategy. The proposed methodology is applied to a structural system subject to fatigue deterioration and it is demonstrated that it enables an integral risk-based inspection planning for structural systems.

Antilinearity rather than Hermiticity as a guiding principle for quantum theory

Currently there is much interest in Hamiltonians that are not Hermitian but instead possess an antilinear PT symmetry. Here we seek to put such PT symmetric theories into as general a context as possible. After providing a brief overview of the PT symmetry program, we show that having an antilinear symmetry that acts on a well-defined Hilbert space is the most general condition that one can impose on a quantum theory for which one can have a well-defined inner product that is time independent, have a Hamiltonian that is self-adjoint, and have energy eigenvalues that are all real. For each of these properties Hermiticity is only a sufficient condition but not a necessary one, with Hermiticity thus being the special case in which the Hamiltonian has both antilinearity and Hermiticity. As well as being the necessary condition for the reality of energy eigenvalues, antilinearity in addition allows for the physically interesting cases of manifestly non-Hermitian but nonetheless self-adjoint Hamiltonians that have energy eigenvalues that appear in complex conjugate pairs, or that are Jordan block and cannot be diagonalized at all. We show that one can extend these ideas to quantum field theory, with the dual requirements of the existence of time independent inner products and invariance under complex Lorentz transformations forcing the antilinear symmetry to uniquely be CPT. We thus extend the CPT theorem to non-Hermitian Hamiltonians. For theories that are separately charge conjugation invariant, PT symmetry then follows, with the case for the physical relevance of the PT-symmetry program thus being advanced. While CPT symmetry can be defined at the classical level for every classical path in a path integral quantization procedure, in contrast, in such a path integral there is no reference at all to the Hermiticity of the Hamiltonian or the quantum Hilbert space on which it acts, as they are strictly quantum-mechanical concepts that can only be defined after the path integral quantization has been performed and the quantum Hilbert space has been constructed. CPT symmetry thus goes beyond Hermiticity and has primacy over it, with our work raising the question of how Hermiticity ever comes into quantum theory at all. To this end we show that whether or not a CPT-invariant theory has a Hamiltonian that is Hermitian is a property of the solutions to the theory and not of the Hamiltonian itself. Hermiticity thus never needs to be postulated at all.

Modeling of integral cutting tool grooves using envelope theory and numerical methods

A groove is a key component of the structure of end mills, drills, and other integrated cutting tools. Machining a groove is one of the most difficult, time-consuming, and costly manufacturing process; therefore, for the sake of reduction of the machining cost and meeting the environmental regulations, the modeling of a machined groove with known wheel geometry and position is necessary for cutting tool manufacture. In order to reveal the process more clear and precise, the envelope theory and numerical methods are used. First, the basic calculation procedure for groove section points is built using a meshing equation. Accordingly, four universal problems for the simulation of groove manufacturing process are analyzed by four typical examples. Namely, the wheel side surface may interfere the machined tool edge and lead to an incorrect simulation; the wheel revolution surface may overcut the machined tool edge and produce fake points that would disturb the results; the tip point might not be precise enough; and the groove section points might be distributed unevenly and result in an imprecise groove section. The conditions to solve these problems are established by mathematical formulas and calculated by numerical methods. In addition, an integral procedure is built to simulate the machined groove with correct, precise, and even distribution points. Finally, groove simulation software is developed using MATLAB GUI, and the results are verified.

Scattering of an arbitrary order acoustical Bessel beam by a rigid off-axis spheroid.

In this study, the authors use the partial-wave series expansion method in the spherical coordinate system and provide a theoretical formula for the off-axis acoustical scattering by rigid prolate and oblate spheroids illuminated by an arbitrary-order Bessel beam to explore the physical characteristics of the off-axis far-field scattering (the axis of the Bessel beam is parallel to the axis of the spheroids). The proposed method is verified and several three-dimensional far-field directivity patterns of rigid spheroids illuminated by zeroth- and first-order Bessel beams are depicted to explore the off-axis scattering. A special emphasis is placed on the geometry size of the prolate and oblate spheroids, the half-cone angle of the Bessel beam, the order of the Bessel beam, and the offset position. Compared with the on-axis scattering, the derivation and calculation of the off-axis scattering takes into account the spherical harmonic function using a numerical integral procedure. In addition, no symmetry was observed in the patterns of the far-field acoustic scattering form function for the zeroth- and higher-order Bessel beams with the off-axis illumination. This investigation provides a tool for the exploration of the complex scattering problems of underwater non-spherical particles under the illumination of the Bessel beam.

Novel biodegradable and antibacterial edible films based on alginate and chitosan biguanidine hydrochloride

Novel bioactive edible films based on sodium alginate (A) and chitosan biguanidine hydrochloride (CG) with different weight percents were successfully prepared. 13C NMR and 1H NMR confirmed the successful guanidylation of chitosan. Fourier transform infrared confirmed the successful reaction between CG and A. The interaction between CG and A was confirmed through the reduction of the crystalline peaks of both CG and A as detected from their wide-angle X-ray diffraction. Thermogravimetric analysis confirmed that CG enhanced the thermal stability of films as detected from the calculated integral procedure decomposition temperature (IPDT) values. CG incorporation improved the mechanical properties of dry and wet samples. A/CG films exhibited a reduced water vapor permeability and good color properties. The antibacterial study proved that the prepared films showed a remarkable antibacterial killing ability. These results revealed that A/CG films could be an alternative candidate to be used as antibacterial edible films in food industries.

The thermal decomposition behavior and kinetics of epoxy resins cured with a novel phthalide-containing aromatic diamine

The thermal decomposition behaviors and kinetics of diglycidyl ether of bisphenol A (DGEBA) epoxy resin cured by a novel phthalide-containing aromatic diamine (BAPP), were studied by thermal gravimetric analysis (TGA) technique in comparison with these of epoxy systems cured by 4,4′-diaminodiphenylsulfone (DDS) and equimolar mixture of DDS/BAPP, respectively. The initial decomposition temperature (Tinitial) and integral procedure decomposition temperature (IPDT) were used to evaluate the thermal stability of cured epoxy resins. Tinitial values are reduced with increasing BAPP content, while IPDT results show the cured DGEBA/BAPP system has the highest inherent thermal stability. The microstructure morphology of charred products, derived from the thermal decomposition of the cured epoxy networks, were characterized by scanning electron microscope (SEM). The decomposition kinetics was investigated by isoconversional approach and the activation energy (Ea) calculated by Starink equation exhibits different dependence on conversion (α) for three epoxy systems. Truncated Sestak-Berggren model was used to describe the thermal decomposition mechanism, and the result shows a good agreement between the experimental data and the theoretical model.

Dose Transition Pathways: The Missing Link Between Complex Dose-Finding Designs and Simple Decision-Making.

The ever-increasing pace of development of novel therapies mandates efficient methodologies for assessment of their tolerability and activity. Evidence increasingly support the merits of model-based dose-finding designs in identifying the recommended phase II dose compared with conventional rule-based designs such as the 3 + 3 but despite this, their use remains limited. Here, we propose a useful tool, dose transition pathways (DTP), which helps overcome several commonly faced practical and methodologic challenges in the implementation of model-based designs. DTP projects in advance the doses recommended by a model-based design for subsequent patients (stay, escalate, de-escalate, or stop early), using all the accumulated information. After specifying a model with favorable statistical properties, we utilize the DTP to fine-tune the model to tailor it to the trial's specific requirements that reflect important clinical judgments. In particular, it can help to determine how stringent the stopping rules should be if the investigated therapy is too toxic. Its use to design and implement a modified continual reassessment method is illustrated in an acute myeloid leukemia trial. DTP removes the fears of model-based designs as unknown, complex systems and can serve as a handbook, guiding decision-making for each dose update. In the illustrated trial, the seamless, clear transition for each dose recommendation aided the investigators' understanding of the design and facilitated decision-making to enable finer calibration of a tailored model. We advocate the use of the DTP as an integral procedure in the co-development and successful implementation of practical model-based designs by statisticians and investigators. Clin Cancer Res; 23(24); 7440-7. ©2017 AACR.

Biaxial testing of cruciform specimens representing characteristics of a metallic airplane fuselage section

Based on biaxial tests with cruciform specimens, the scenario of fatigue cracks in the upper fuselage section between the wings and the tail unit of a commercial single aisle aircraft has been studied. Two different types of specimen were designed, namely for the scenario of a circumferential crack across a broken stringer and for a longitudinal crack parallel to the stringers. With crack length up to 2a ≈ 610 mm, maximum mode I stress intensity factors of 160 MPa√m were obtained for the commercial aluminum alloys AA2024-T351 and AA5028-H116. All experiments were supported by digital image correlation to obtain the actual deformation fields of the specimens. Based on these data stress intensity factors and J integrals were computed with a line integral procedure. Furthermore, plastic zone and crack closure effects were studied.

A fast boundary integral equation method for point location problem

A numerical method based on the boundary integral equation is proposed for the point location problem. For a bounded domain, the integral value is close to 1.0 if a point is inside the domain, and is close to 0.0 when the point is outside the domain. For convenience of integration, the boundary of the domain can be discretized into boundary integral cells. The idea of isogeometric analysis can be easily coupled with the proposed method, i.e., using the parametric functions in geometric modeling to create the integral cells, which results in a mesh-free procedure for which the geometry can be exactly produced at all stages. Thus, the method can be applied to arbitrary shapes and easily embedded in computer-aided design (CAD) packages. The method is time-consuming if implemented directly; a fast multipole method is coupled with the proposed method to accelerate the integral procedure. Some examples of 2D and 3D cases are tested to show the accuracy and efficiency of the proposed method.

Alumina-graphene hybrid filled epoxy composite: Quantitative validation and enhanced thermal conductivity

Abstract Alumina-graphene hybrid fillers (Gr-Al2O3) were synthesized and added to the epoxy matrix to improve thermal properties of the epoxy composite. The alumina particles were surface modified with silane coupling agents like 3-Aminopropyl triethoxysilane (A-Al2O3). 3-Glycidyloxypropyl trimethoxysilane (GPTMS) was used for the surface modification of the graphene (G-Graphene). These modifications on the filler surface help to develop the interface between the fillers and the epoxy matrix, which might help to form the effective 3D thermal conductive networks. The generation of these 3D networks facilitated in reducing the Kapitza resistance and increases the transportation of phonons in the matrix, Furthermore; it improved the integral procedure decomposition temperature (IPDT) and activation energy (Ea) of the composite. Alumina-graphene hybrid filled epoxy composite (hAG-Epoxy) with 50 vol% of hybrid filler (Gr-Al2O3) expressed the considerable improvement in in-plane thermal conductivity and IPDT by ∼8.4 and ∼3.1 folds in comparison with neat epoxy, respectively. The significant improvement in thermal conductivity was related to the generation of effective 3D thermal conductive pathways formed by 2D graphene and 1D alumina in the composite.

Predicting thermal degradation mechanisms in urea–formaldehyde cellulose composites filled with tin particles

This article reports a study on structural characterization, thermal stability, and prediction of the thermal degradation mechanisms of urea–formaldehyde cellulose (UFC) composites filled with tin particles by condensed phase kinetic approaches. Structural characterization of UFC/Sn composites performed by scanning electron microscopy, X‐ray diffraction, and Fourier‐transform infrared analyses demonstrates that the composites are fairly homogenous, and the interactions between UFC and tin in the composites are physical in nature. Measurements of inherent thermal stabilities, apparent reaction profiles, and thermal degradation kinetics of UFC and UFC/Sn composites have been carried out on the thermoanalytical data of materials. The integral procedure decompositions temperature elucidates the increasing thermal stabilities trend of UFC/Sn composites with the increase in tin contents in UFC matrix. Reaction profiles of UFC and UFC/Sn composites suggest considerably complex thermal degradation pathways of the materials which comprise various competitive/consecutive reactions. Substantial variations in the activation energies of matrix and composites with the advancement of reaction by generalized integral isoconversional method verify their multistep reaction mechanisms. Advanced reaction model determination methodology with the help of a novel kinetic function F(α, T) reveals that the multistep thermal degradation of UFC goes to completion by overall following intricate nucleation/growth mechanisms. A detailed account of the mechanistic information related to thermal degradation of UFC and UFC/Sn composites is also given and discussed in this study. POLYM. COMPOS., 39:4341–4354, 2018. © 2017 Society of Plastics Engineers

Synthesis, vibrational spectrometry and thermal characterizations of coordination polymers derived from divalent metal ions and hydroxyl terminated polyurethane as ligand

A series of novel coordination polyurethanes [HTPU-M, where M=Mn(II) ‘d5’, Ni(II) ‘d8’, and Zn(II) ‘d10’] have been synthesized to investigate the effect of divalent metal ions coordination on structure, thermal and adsorption properties of low molecular weight hydroxyl terminated polyurethane (HTPU). HTPU-M have been synthesized in situ where, OH group of HTPU (synthesized by the condensation polymerization reaction of ethylene glycol (EG) and toluene diisocyanate (TDI) in presence of catalyst) on condensation polymerization with metal acetate in presence of acid catalyst synthesized HTPU-M followed by coordination of metal ions with hetero atoms. The structure, composition and geometry of HTPU-M have been confirmed by vibrational spectrometry (FTIR), 1H NMR, elemental analysis and UV–Visible spectroscopy. Morphological structures of HTPU-M were analyzed by X-Ray Diffraction analysis (XRD), Field Emission Scanning Electron Microscope (FE-SEM) with Energy Dispersive X-ray spectroscopy (EDX) and High Resolution Transmission Electron Microscope (HR-TEM) techniques. The thermal degradation pattern and thermal stability of HTPU-M in comparison to HTPU was investigated by thermal-gravimetric (TG)/differential thermal (DT), analyses along with Integral procedure decomposition temperature (IPDT) by Doyle method. The molecular weight of HTPU was determined by gel permeation chromatography (GPC). The preliminary adsorption/desorption studies of HTPU-M for Congo red (CR) was studied by batch adsorption techniques.The results indicated that HTPU-M have amorphous, layered morphology with higher number of nano-sized grooves in comparison to HTPU. Coordination of metal to HTPU plays a key role in enhancing the thermal stability [HTPU-Ni(II)>HTPU-Mn(II)>HTPU-Zn(II)>HTPU]. The HTPU-M can be utilized for industrial waste water treatment by removing environmental pollutants.

Experimental and Numerical Assessment of the Service Behaviour of an Innovative Long-Span Precast Roof Element

The control of the deformative behaviour of pre-stressed concrete roof elements for a satisfactory service performance is a main issue of their structural design. Slender light-weight wing-shaped roof elements, typical of the European heritage, are particularly sensitive to this problem. The paper presents the results of deformation measurements during storage and of both torsional–flexural and purely flexural load tests carried out on a full-scale 40.5 m long innovative wing-shaped roof element. An element-based simplified integral procedure that de-couples the evolution of the deflection profile with the progressive shortening of the beam is adopted to catch the experimental visco-elastic behaviour of the element and the predictions are compared with normative close-form solutions. A linear 3D fem model is developed to investigate the torsional–flexural behaviour of the member. A mechanical non-linear beam model is used to predict the purely flexural behaviour of the roof member in the pre- and post-cracking phases and to validate the loss prediction of the adopted procedure. Both experimental and numerical results highlight that the adopted analysis method is viable and sound for an accurate simulation of the service behaviour of precast roof elements.

Kinetics of the thermal degradation mechanisms in urea-formaldehyde cellulose composites filled with zinc particles

This paper reports a study on the structural characterization, thermal stability, and thermal degradation kinetics of urea-formaldehyde cellulose (UFC) composites filled with zinc particles. Structural characterization of UFC/Zn composites carried out by SEM, XRD and FTIR analyses reveals that the composites are fairly homogenous, and the interactions between UFC and zinc in the composites are physical in nature. Afterwards, measurements of inherent thermal stabilities, probing reaction complexity, and thermal degradation kinetics of UFC/Zn composites have been carried out. The integral procedure decompositions temperature elucidates significantly higher thermal stabilities of UFC/Zn composites. Isoconversional kinetic analysis suggests multi-step reaction pathways of UFC/Zn composites in terms of the substantial variations in their activation energies with the reaction advancement. Advanced reaction model determination methodology with the help of an innovative kinetic function F(α, T) reveals that the thermal degradation of UFC goes to completion by following complicated multi-step nucleation/growth mechanisms. A detailed account of the mechanistic information regarding to the thermal degradation processes taking place in UFC/Zn composites is given and discussed in the present study.

Selection of non-Saccharomyces yeasts to be used in grape musts with high alcoholic potential: a strategy to obtain wines with reduced ethanol content

Ethanol content of wine has increased over the last decades as consequence of searching phenolic maturity, requiring increased grape maturity. This may result in the production of wines with excessive alcohol levels (sometimes more than 15% (v/v)), sluggish and stuck fermentations and excessive volatile acidity. Many strategies to reduce ethanol in wines are being studied, and microbial methods have some additional advantages. However, because of the broad intra- and interspecies variability, new selection criteria should be included. Therefore, the goal of the present work was to design and evaluate a simple and integral procedure for non-Saccharomyces yeast selection. This strategy allowed selection of yeasts that presented successful implantation in grape must with high alcohol potential and their use in co-cultures could reduce the ethanol in wines. A total of 114 native non-Saccharomyces yeasts were assayed to determine their respiratory, fermentative and physiological characteristics of enological interest. Hanseniaspora uvarum BHu9 and BHu11, H. osmophila BHo51, Starmerella bacillaris BSb55 and Candida membranaefaciens BCm71 were selected as candidates to design co-culture starters.

Recognising small image quality differences for ultrasound probes and the potential of misdiagnosis due to undetected side lobes.

Ultrasonic imaging is an integral and routine procedure in many medical applications. An increased awareness of the need for quality assurance in this field has led to numerous tests being proposed. Due to the complexity of the problem, the tests directly measuring the important parameters of resolution and contrast of low-echoic structures are not unified, often more qualitative than quantitative, and are performed at large periodic intervals. Uniform sensitivity of an array transducer is a necessary but insufficient requirement for imaging quality of an ultrasound probe. Good probe uniformity should in no way be confused with meaning the ultrasound probe is working as it should. In this paper, side lobes in the elevation direction and side and grating lobes in the lateral direction are discussed. Both may provide uniform element response across the scanner, yet result in a loss of resolution and contrast. To resolve problems of these resolution and contrast-relevant parameters being overlooked, a crossed filament phantom is introduced. The cross-filament phantom provides the determination of resolution- and contrast-relevant parameters of a scanner, by directly measuring the main, side and grating-lobes of the beam in 3D. The main lobe 3D-data allows the determination of lateral and elevational resolution at different depths and thus the focal settings. In combination with the side and grating lobe information, the contrast for a small non-echoic object (i.e. a cyst) in an echoic environment may be explained. We argue that regarding system acceptance, system baseline quality assurance and routine quality assurance, the analysis of the beam shape should be part of the comprehensive assessment. Combining the results with void resolution and contrast measurements is recommended.

Thermal degradation of urea‐formaldehyde cellulose composites filled with aluminum particles: Kinetic approach to mechanisms

ABSTRACTThis article reports a study on structural characterization and thermal degradation kinetics of insulating/conducting urea‐formaldehyde cellulose (UFC) composites filled with aluminum particles. Structural characterization of UFC/Al composites carried out by SEM, XRD, and FTIR analyses reveals that composites are fairly homogenous, and the interactions between UFC and aluminum in UFC/Al composites are more probably physical in nature. Measurements of inherent thermal stabilities, probing reaction complexity, and thermal degradation kinetics of UFC and UFC/Al composites have been undertaken by thermogravimetric (TG)/differential thermogravimetric (DTG) analyses under nonisothermal conditions. The integral procedure decompositions temperature (IPDT) elucidates significant thermal stability of UFC, and higher aluminum contents in composites are capable of enhancing the thermal stability of UFC resin. TG/DTG analyses suggest highly complicated thermal degradation profiles of UFC and UFC/Al composites, which consist of various parallel/consecutive reactions. Generalized linear integral isoconversional method has been employed to determine the activation energies of thermal degradation processes. Substantial variations in activation energies of UFC and UFC/Al composites with the advancement of reaction verify their multi‐step reaction pathways. Advanced reaction model determination methodology with the help of a novel kinetic function F(α,T) reveals that the multi‐step thermal degradation of UFC goes to completion by principally following intricate nucleation/growth mechanisms. It is also found that aluminum more likely participates in the thermal degradation of resin and tends to alter its reaction mechanism. Detailed interpretations of the obtained kinetic parameters are given, and their probable physical significances are discussed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44826.

전기방사법에 의해 제조된 폴리우레탄 나노섬유의 수산화알루미늄 내첨에 의한 내염화 특성 향상

본 논문에서는 내산화성 및 난연성이 향상된 폴리우레탄 나노섬유를 전기방사법 및 수산화알루미늄 내첨을 통해 제조하였다. 전기방사 조건은 인가전압: 20 kV, 폴리머 용액 유량: 1.2 ml/h, 롤러 속도: 120 rpm 및 롤러와 주사기 팁의 거리: 15 cm의 공정변수에서 최적의 조건을 확인하였다. 폴리우레탄 섬유의 내산화성 및 난연성을 향상시키기 위하여, 수산화알루미늄을 전기방사 시 내첨하였다. 제조된 샘플의 열적 특성을 평가하기 위하여 열중량분석기(thermogravimetric analysis, Shimadzu, TGA-50H)를 사용하였다. 또한 관련 분석을 통해 고분자 분해 온도(polymer decomposition temperature), 적분열분해 진행온도(integral procedure decomposition temperature), 최종 분해 온도(final decomposition temperature) 및 열분해 후 잔여량 등을 분석하였다. 그리고 분해 반응의 속도론적 고찰을 위해 Horowitz-Metzger 적분식을 통해 활성화 에너지를 해석하였다. 수산화알루미늄의 내첨에 의해, 분해 활성화 에너지가 50% 이상 증가함을 확인하였다. 이는 수산화알루미늄이 <TEX>$300{\sim}500^{\circ}C$</TEX>에서 열분해함에 따라 수화반응에 의해 폴리우레탄 나노섬유의 열분해 저항성이 커지기 때문인 것으로 파악된다. Anti-oxidation and flame resistant polyurethane nanofibers were prepared by electrospinning and aluminum hydroxide addition. Electrospinning was carried out under the following procedure conditions; applied voltage, 20 kV; polymer solution feeding rate, 1.2 ml/h; collector rolling speed, 120 rpm; and tip to collector distance, 15 cm. Aluminum hydroxide was added to the prepared polymer solution for electrospinning to enhance the oxidation and flame resistant properties. The thermal properties were investigated by thermogravimetric analysis to determine the polymer decomposition temperature, integral procedure decomposition temperature, final decomposition temperature, and remaining amount after thermal decomposition. The activated energy for polymer degradation was also investigated using the Horowitz-Metzger equation. The activation energy increased to more than 50%. The thermal properties of the polyurethane nanofibers were improved by a hydration reaction during the thermal decomposition of aluminum hydroxide around <TEX>$300{\sim}500^{\circ}C$</TEX>.

The role of forensic medicine and forensic dentistry in estimating the chronological age of living individuals in Hamburg, Germany.

Age estimation represents one of the primary responsibilities of forensic medicine and forensic dentistry. It is an integral procedure aiming to estimate the chronological age of an individual, whose age is either unknown or doubtful, by means of assessing the stage of dental, skeletal, and physical development. The present publication reviews the methods and procedures used in estimating the age of young living individuals as well as the experiences of the Institute of Legal Medicine in Hamburg-Eppendorf, Germany, during the last 25 years. From 1990 to 2015, 4223 age estimations were carried out in Hamburg. During this time, forensic age estimation was requested by different concerned authorities including courts, the foreigners' registration office (Zentrale Ausländerbehörde), and the state office of education and consultation (Landesbetrieb Erziehung und Beratung). In the context of judicial proceedings, orthopantomograms, as well as X-ray examinations of both the left hand and the medial clavicular epiphyses were carried out in accordance with AGFAD recommendations. For investigations not associated with judicial proceedings, orthopantomogram examinations play a key role in the process of age estimation, due to their high diagnostic value and low radiation exposure. Since 2009, mainly unaccompanied young refugees were examined for age estimation. Orthopantomograms and clinical-physical examinations have been used as essential steps in this context to determine whether an individual is 18years or less. Additional X-ray examinations of the left hand and the medial clavicular epiphyses have been used less frequently.