Auxiliary Medium Research Articles

A new approach to evaluate the overall heat transfer coefficient of a fluidized bed biomass pyrolyzer

The heat transfer characteristics of non-pretreated rice husk pyrolysis in a fluidized bed with alumina beads (500 μm - 590 μm) as bed material are studied. Assuming instantaneous heating of biomass to the reaction temperature, the effective overall heat transfer coefficient of the system (UA) is initially calculated based on the compositions of the collected products and reaction temperature. UA ranges from 0.82 to 2.95 W/K. This heat transfer coefficient study allows ad hoc product distributions to be predicted from theoretical bases. The effects of the biomass feeding rate (F) and the bed height (H/D) on UA values are also analyzed. Highest UA and specific heat of the pyrolysis reaction of −3.35 MJ/kg are found at F = 5 g/min and H/D = 1.0, where H/D is the largest and F is the lowest in the range studied. Upon feeding of the low thermal conductivity biomass, UA typically decreases. However, if the bed materials are limited, the fed biomass and its produced char act as an auxiliary heating medium to improve the effective heat transfer coefficient. High UA improves the efficiency of the pyrolysis reaction, but it decreases the bio-oil fraction in the product due to secondary decomposition.

Performance improvement of a U-tube heat exchanger based hydrogen storage reactor by phase change materials

Solid-state hydrogen storage technology using metal hydrides as carriers has great application prospects. This study aims to optimize the heat transfer resistance and absorption kinetics issues encountered in practical applications of LaNi5-H2 storage materials in storage reactors. A mathematical model for the hydrogen absorption process in the reactors based on U-tube and straight-tube heat exchangers was built, and the advantages of U-tube structure and the flow characteristics of the heat transfer fluid on its heat transfer and absorption performance were analyzed. To further enhance the U-tube based reactor's performance, phase change materials (PCM) were subsequently introduced as an auxiliary heat transfer medium, while the amount of PCM and the thermal conductivity of the reaction bed were optimized. The results showed that the appropriate PCM dosage could overcome the inherent defects of the U-tube heat exchanger and significantly improve heat dissipation and reaction rates of the reactor, and the H2 absorption completion time was shortened by 1.4 times. In addition, the increased thermal conductivity of reaction beds is equally important for the enhancement of heat transfer and absorption rate. Nevertheless, further increase of PCM's thermal conductivity has a limited effect on the improvement of the performance.

Application of Augmented Reality Technology in a Custom Car Ride Selection Application (Case Study: Impala Auto Fashion)

The use of augmented reality technology as an auxiliary medium in the wheel selection process is proof of the very rapid development of technology. An effective way to make work easier is by utilizing augmented reality technology, namely combining two-dimensional objects or three-dimensional objects that are applied to the real world. In other words, augmented reality is a combination of two or three-dimensional objects with the real world. A lot of time and energy is simply spent during the process of replacing car rims because the car owner does not feel comfortable with how to disassemble the rims, therefore the augmented reality application is a breakthrough to simplify and speed up the process of selecting rims, the method used is concept, design, assembly, testing, and distribution. The result of the research is an augmented reality application to simplify the process of selecting and replacing car rims on Impala auto fashion.

Training on Making 3D Models of Augmented Reality Based Hydrology Education Tools for Teachers

Augmented reality in its development in Indonesia has Lots used as an auxiliary medium classroom teaching for learning to become more interactive between teacher and student. Students get Study independent with an observed tool developed augmented reality display without need guided. However sadly Still how difficult development augmented reality application, making Not yet how many teachers can develop application based on augmented reality. on the basis problem such, he did activity devotion to public in form training creation of 3D models based on augmented reality followed by representatives from teachers from all over Palopo as many as 15 teachers. Activity training is shared into 3 sessions, ie session First through method lecture, session second guided tutorial methods and sessions final with practice. Result of implementation training This is a capable teacher making augmented reality application for free independent and capable tool display hydrology based on augmented reality that can be used for enrich classroom learning.

Web-based STMIK AKBA Student Attendance Information System by Making QR Codes an Auxiliary Medium

The attendance or attendance system is a recording or provision of information on a person's presence which indicates that the person has provided information about his presence and absence, then it is stated in the form of an attendance report. Along with the development of technology, an attendance recording has also developed, where we used to use paper attendance to fingerprint attendance. In educational institutions such as campuses, attendance has an important role in the process of developing a student. Until now, there are still many campuses that still use conventional attendance to record the presence of students in class, which allows for human error or fraud from both lecturers and students. Therefore, a solution is possible to suppress errors that may occur, namely by creating a website-based attendance or attendance system where the QR Code is used as an auxiliary medium in recording the presence or absence of a student at the STMIK AKBA Makassar Campus.

Mean-field approach for Anderson-type off-diagonal disorder

We report a generalized auxiliary coherent medium theory to settle the longstanding challenge of Anderson-type off-diagonal disorder (AODD) for simulating disordered alloys. The AODD is transformed into a diagonal-like disorder with a weighted discrete distribution in an auxiliary medium. This approach is demonstrated for simulating the phonon spectral in NiFe and NiPt alloys, and it is found that accounting for AODD substantially enhances the phonon linewidth to agree well with the supercell and experimental results, compared to results with averaged-value ODD. This paper provides an effective approach to treat the large fluctuation in ODD in disordered materials, presenting an important progress for mean-field simulations in the embedding framework.

Experimental analysis of fluid‐assisted injection molding of pipe fittings with different angles by short‐shot method

AbstractBased on the self‐assisted injection experimental platform, experimental studies on gas‐assisted injection molding (GAIM), and water‐assisted injection molding (WAIM) of 2 curved pipe fittings by adopting short‐shot method were carried out. UDF model was constructed for numerical simulation analysis. The influence rules of auxiliary medium and bending angle on the terminal morphology, inner wall surface quality at bending angle, medial and lateral residual wall thickness, variation range, and residual wall thickness deviation rate of short‐shot fluid assisted injection molding (SSFAIM) bending samples were compared. Meanwhile, the influence mechanism was investigated. The following experimental findings were obtained. SSFAIM had secondary penetration, while water produced multiple penetrations. There are multiple vacuum shrinkage pores in the unpenetrated area at the end of the SSWAIM sample, as well as serious shrinkage depressions on the surface. The shape of the penetration front of water is arc‐shaped with many penetration holes. The shape of the penetration front of the gas at the end of the SSGAIM sample is “pointy.” Compared with the SSWAIM sample, the residual wall thickness of SSGAIM has a narrow distribution range when the bending angle is 0°. With the increase of the bending angle, the “foaming” phenomenon of the inner wall surface quality at the bending angle of the SSGAIM sample becomes less and less obvious. Moreover, the deviation of the inner and outer residual wall thickness of SSGAIM is more obvious than that of SSWAIM due to the increase of bending angle.

21st CENTURY IN GERMAN LANGUAGE LEARNING : IMPLEMENTATION OF CYBERGOGY CONCEPT

As a place for learning activities, educational institutions must adapt to the times to not be viewed as a threat in the current era of education 4.0. Along with 21st-century learning needs to foster students' creative, innovative and competitive attitudes by implementing technology as an auxiliary medium in the learning process to produce quality students. This research is a descriptive case study to explore the application of the cybergogy concept about facing the challenges of learning in the 21st-century, especially in lecturing German in the courses offered by students. The sample in this study were students in semesters II, IV, and VI of the German Language Education Study Program, with 35 students. The instruments used in this study were questionnaires, interviews, and document review. Data from questionnaires, discussions and document reviews were analyzed using descriptive statistics referring to the Milles and Huberman stages. The results showed that the concept of cybergogy had been applying 30% synchronously and 70% asynchronously. On average, 93-94% of students and lecturers have used technology-based media in the German language learning process because of the availability of teaching materials and supporting facilities for information and communication technology to face 21st-century learning.

ANALISA POTENSI PENINGKATAN KINERJA HHP BOILER BERDASARKAN PRINSIP NERACA PANAS

The boiler is in charge of generating steam. The steam produced can be used for several purposes, among others: as a working fluid to drive steam engines such as turbine engines and compressor piston engines, as a heating medium for heating liquids so that they are always at a set temperature, as an auxiliary medium for processing and so on. . In the context of energy conservation today, energy use is very much taken into account, because energy consumption is closely related to operating costs. In principle, the more energy consumed means higher operating costs. For energy savings, it is expected that fuel consumption in the operation of the HHP Boiler is as optimal as possible, so as to provide the appropriate heat. To find out the above, it is necessary to calculate the performance of the boiler. In this case the compilers use the Heat Loss method with dual fuel (fuel oil and fuel gas). From the evaluation results of the HHP Boiler with a heat balance, the efficiency is 89.53%.

Phonon dispersion of binary alloys with auxiliary coherent potential approximation

We report the auxiliary coherent potential approximation (ACPA) for calculating the phonon dispersion of three-dimensional alloys with both mass and force-constant disorders. To obtain the average spectra function of disordered alloys, the average coherent scattering structure factors are derived from the auxiliary coherent medium in single-site approximation. We provide an analytical proof of the sum rule in the auxiliary coherent medium, which ensures the analyticity of physical properties. To demonstrate the accuracy and applicability of the ACPA method, we apply the ACPA to calculate phonon dispersion of several alloys, including CuPd CuAu, PdFe, and NiPt with different disorder concentrations. We find the ACPA phonon dispersion results agree very well with the itinerant coherent potential approximation calculations and experimental measurements. The approximate separable force-constant model used in the ACPA can very well represent the first-principles disordered force constants, presenting minor or even negligible influence on the phonon dispersion of the alloy. The ACPA model features easy implementation and high computational efficiency, providing an effective method for simulating vibrational properties of realistic alloys.

Auxiliary coherent medium theory for lattice vibrations in random binary alloys with mass and force-constant disorders

The inevitable and random impurities or defects can significantly influence the lattice-vibrational properties of materials and devices. Thus, the capability of effectively treating disorder effects is indispensable for theoretical simulations. In this paper, we report an auxiliary coherent medium theory, in the framework of multiple scattering theory, to simulate disordered vibrational systems containing both mass and force-constant disorders. In this method, the physical Green's function is related to an auxiliary Green's function by introducing a separable force-constant model to describe disordered systems. As an important result, the force-constant disorder can be transformed to a diagonal-like disorder in the auxiliary Hamiltonian while maintaining the important force-constant sum rule. In combination with the single-site and cluster coherent potential approximation, the configurational average over the auxiliary Green's function can be performed to obtain the configuration-averaged physical properties. To demonstrate the effectiveness of this method, we apply it to a one-dimensional harmonic chain with atomic disorders and find our calculations agree very well with the exact results for a wide range of mass and force constants. Moreover, we show that the phonon transport property of disordered devices can be derived based on the auxiliary Green's function formalism in combination with vertex corrections. The auxiliary coherent medium theory features easy implementation and feasible incorporation with diagrammatic technique in many-body perturbation and various cluster approximations, providing an important approach to analyze disorder effects on the vibrational properties. Moreover, it is also straightforward to apply the present formalism to treat the general atomic disorder in electronic systems.

Meeting them halfway: Altering language conventions to facilitate human-robot interaction

This article considers the remaining hindrances for natural language processing technologies in achieving open and natural (human-like) interaction between humans and computers. Although artificially intelligent (AI) systems have been making great strides in this field, particularly with the development of deep learning architectures that carry surface-level statistical methods to greater levels of sophistication, these systems are yet incapable of deep semantic analysis, reliable translation, and generating rich answers to open-ended questions. I consider how the process may be facilitated from our side, first, by altering some of our existing language conventions (which may occur naturally) if we are to proceed with statistical approaches, and secondly, by considering possibilities in using a formalised artificial language as an auxiliary medium, as it may avoid many of the inherent ambiguities and irregularities that make natural language difficult to process using rule-based methods. As current systems have been predominantly English-based, I argue that a formal auxiliary language would not only be a simpler and more reliable medium for computer processing, but may also offer a more neutral, easy-to-learn lingua franca for uniting people from different linguistic backgrounds with none necessarily having the upper hand.

Comparison of CPC driven solar absorption cooling systems with single, double and variable effect absorption chillers

In the solar absorption cooling systems, concentrating collector can be adopted to achieve higher driven temperature and improve the system performance. The Compound Parabolic Concentrator (CPC) is a good option with both concentrating and stationary features. With higher working temperature, solar absorption cooling system with concentrating collector has more choices of absorption chillers than the system with non-concentrating collector. The aim of this paper is to find the better chiller choice for solar absorption cooling systems with CPC. The analyzed LiBr-water absorption chillers include the single effect chiller, the double effect absorption chiller and a novel variable effect chiller built by the author. Simulation is carried out in TRNSYS. Model of the variable effect absorption chiller is first derived from MATLAB artificial neural network (ANN) toolbox based on experimental data, and then built in TRNSYS. Performance of the three systems is calculated under the same condition. Performance of the three systems is compared to get the better choices. The impacts of the solar collector area, cutoff driven temperature and storage tank volume on the solar cooling fraction, auxiliary heat input, average chiller COP and average solar efficiency are analyzed. The variable effect system has high solar cooling fraction, low auxiliary heat input and high solar efficiency. The single effect system has medium solar fraction, high auxiliary heat input and medium solar efficiency. The double effect system has low solar cooling fraction, low auxiliary heat input and low solar efficiency.

CRS theory based on a data-driven homeomorphism

The present article outlines an innovative derivation of the well-known CRS traveltime formula. This is made possible by approximating the isochrones tangent to a small reflecting element embedded in a 3D homogeneous auxiliary medium. The arising paraxial traveltime formula is then parametrised by six attributes, each one characterising geometrically the wavefront of the reference normal-incident ray at the emergence point of the datum plane. For a layered medium, the assignment of the six attributes for each azimuthal direction around describes locally the emerging wavefront and establishes the mapping between reflecting elements of the two media, the auxiliary and the real, which respond, however, with different traveltimes. This 3D homeomorphism provides the time correction that gives rise to the CRS traveltime formula with eight attributes. For time imaging applications, the traveltime profile must be numerically shaped by improving iteratively the value of the eight attributes, so as to intercept, without the need of a velocity model, the largest number of coherent data in the volume of seismic traces gathered in the midpoint-offset domain.

RESEARCH OF THE TECHNOLOGICAL MANUFACTURING OPERATIONS LIMITING THE RELIABILITY (FATIGUE STRENGTH) OF RIBBED TITANIUM PANELS

As it is known, titanium alloys due to a number of features (high specific strength, fatigue resistance, fracture toughness and corrosion resistance) are widely used in aerospace engineering, including ribbed panels. For products of this kind it is necessary to meet high requirements of quality of welded joints and dimensional accuracy of the construction. Fusion welding of titanium alloys results in the formation of inhomogeneities in the connection zone and in the reduction of technological and operational performance. The geometric dimensions of design are distorted due to occurrence of welding stresses, pores and microcracks appear in the weld metal, mechanical properties and other parameters are reduced. These facts require a comprehensive analysis of the manufacturing process of titanium ribbed panels: from the manufacturing of semi-finished products to the final stage of heat treatment of the finished product from the point of detection of the most significant in relation to defects in operations. The blank manufacturing operations, including their preparation for welding, welding and subsequent heat treatment regimes affect the cyclic and static strength of welded ribbed titanium panels depending on the number and total area of welding defects. The article presents the research that allows to predict the properties and reliability of welded structures and to achieve identity of the properties of basic metal and weld metal with the lack of a guarantee of both internal and external defects, depending on the choice of the complex technological measures. It is shown that a certain welding cooling rate in the range of phase transformation temperatures, finish milling, running and cleaning (degreasing and dehydration) of the surface of abutting edges, low annealing after welding in the air and subsequent sand cleaning; GLC in the auxiliary gas medium of nitrogen or argon or the combined GLC blanks and cutting by milling determine correspondence of properties and reliability of the welded joints of base metal of ribbed panels from VT20 alloy.

Passive seismic source localization via common-reflection-surface attributes

The common-reflection-surface (CRS) stack can be viewed as a physically justified extension of the classical common-midpoint (CMP) stack, utilizing redundant information not only in a single, but in several neighboring CMP gathers. The zero-offset CRS moveout is parameterized in terms of kinematic attributes, which utilize reciprocity and raypath symmetries to describe the two-way process of the actual wave propagation in active seismic experiments by the propagation of auxiliary one-way wavefronts. For the diffraction case, only the attributes of a single one-way wavefront, originating from the diffractor are sufficient to explain the traveltime differences observed at the surface. While paraxial ray theory gives rise to a second-order approximation of the CRS traveltime, many higher-order approximations were subsequently introduced either by squaring the second-order expression or by employing principles of optics and geometry. It was recently discovered that all of these higher-order operators can be formulated either for the optical projection or in an auxiliary medium of a constant effective velocity. Utilizing this duality and the one-way nature of the CRS parameters, we present a simple data-driven stacking scheme that allows for the estimation of the a priori unknown excitation time of a passive seismic source. In addition, we demonstrate with a simple data example that the output of the suggested workflow can directly be used for subsequent focusing-based normal-incidence-point (NIP) tomography, leading to a reliable localization in depth.

Fusion bonding of thermosets composite structures with thermoplastic binder co-cure and prepreg interlayer in electrical resistance welding

A new concept combining both thermoplastic binder co-cure and prepreg interlayer is proposed and investigated for fusion bonding of thermosets composite structures. Three different thermoplastic binders were co-cured respectively onto the surface of the carbon fiber reinforced epoxy (CF/Epoxy) composite laminates to form an auxiliary medium for electrical resistance welding. The carbon fiber reinforced binder (CF/Binder) prepreg interlayer, which is compression molded with a single layer of carbon fiber fabric sandwiched between two binder films, was designed as the heating element. Double cantilever beam (DCB) specimens were fabricated by fusion bonding of the CF/Epoxy composite laminates. The influence of the thermoplastic binders and the CF/Binder prepreg interlayers on the mode I interlaminar fracture toughness (GIC) and the morphology of the fracture surface were studied respectively by double cantilever beam test and scanning electron microscope. The results indicate that a maximum average delamination strength GIC of 1879.6J/m2 was obtained in the case of the AX8900 binder welded specimens using twill weave fabric heating element. Three types of failure pattern can be visually and microscopically observed, i.e. interfacial-type failure, cohesive-type failure and interlaminar-type failure.

Research on preparation of poly(1, 4-phenylene-terephthalamide) with in-situ phase transition aided heat transfer and its engineering scale study

Thermal management of the polymerization reaction process is one of key factors influencing polymer quality and success in engineering scale-up. Liquid nitrogen is introduced in PPTA polymerization process in the paper, so as to investigate influence on PPTA polymerization process and polymer performance when the inertia heat transfer medium of liquid nitrogen is adopted as the auxiliary heat transfer medium during polycondensation of traditional cryogenic fluid. It is indicated from results that addition of proper amount of liquid nitrogen during PPTA polymerization process can improve logarithmic viscosity and thermal stability, and improve the surface wettability of PPTA. It will not cause obvious influence on the chemical structure, aggregation structure and liquid crystal pattern of PPTA. The logarithmic viscosities of polymer obtained from the polymerization scale-up experiment of 140, 300 and 1000 L reaction vessels are above 6 dL/g.

Effects of Hydrothermal Pretreatment on the Content and Structure of Lignin Extracted from Corncob

A systematic hydrothermal pretreatment of corncob has been conducted with an aim to trace the content and property of lignin during the pretreatment process. The result showed that the lowest content of lignin was obtained under the following condition: water-solid ratio is 3:1,180 °C for 90min with 0.4g auxiliary medium. TG and FTIR analysis has been conducted to investigate the thermal stability and structure of lignin, and the result indicated that hydrothermal pretreatment influenced the thermal stability and structure of lignin extracted from corncob.

Omnidirectional mirror based on Bragg stacks with a periodic gain-loss modulation

In this work we demonstrate that a Bragg Stack with a periodic gain-loss modulation can function as an Omnidirectional Mirror (OM) with complete reflection at any angle of incidence irrespective of the light polarization. The Bragg Stack is composed by the periodic variation of two layers with the same value of the real part of the refractive index (nr) and a periodic modulation in the imaginary part (ni). The origin of the band gaps is due to the interference of complex waves with propagating and evanescent fields in each layer. It is found that the band gaps are wider as the contrast ni/nr increases. We have found the ambient conditions to obtain an OM considering an auxiliary medium n′ external to the Bragg Stack.