bluuebunny/crossref_metadata_2025 huggingface dataset:
Distributed fault detection for non‐linear multi‐agent systems: an adjustable dimension observer design method
Authors: Liu Xiuhua , Han Jian , Wei Xinjiang , Zhang Huifeng , Hu Xin
Published: July 2019

This study is devoted to observer‐based fault detection for non‐linear multi‐agent systems. Utilising the output information of the neighbour nodes, an adjustable dimension observer is designed, in which the dimension of the observer can be adjusted within a certain range. Thus, the trade‐off between the detection performance and the detection cost can be obtained. Based on the observers constructed on one node, the fault in its neighbouring nodes can be detected. The disturbance is removed from the residual, which implies that the fault detection result is robust to the disturbance. The region pole constraints are introduced to improve the transient performance of the residual dynamic. Finally, simulation results are provided to indicate the effectiveness of the proposed technique.
Prevalence and subtype distribution of Blastocystis in ethnic minority groups on both sides of the China–Myanmar border, and assessment of risk factors
Authors: Gong Baiyan , Liu Xiaohua , Wu Yanchen , Xu Ning , Xu Meng , Yang Fengkun , Tong Lei , Zhou Kexin , Cao Jianping , Liu Aiqin , Shen Yujuan
Published: July 2019

Blastocystis is one of the most common intestinal parasites in humans worldwide. To understand its prevalence and to explore the risk factors for Blastocystis in humans in developing countries, a molecular epidemiological investigation of Blastocystis was conducted in ethnic minority groups on both sides of the China–Myanmar border. A total of 461 fecal specimens were collected from 289 Yao people in China and 172 Wa people in Myanmar, together with a questionnaire for each participant. Based on sequence analysis of the partial small subunit of ribosomal RNA (SSU rRNA) gene (barcode region or 260 bp region), an average prevalence of 6.29% (29/461) was observed, with 4.50% (13/289) in Yao people and 9.30% (16/172) in Wa people. Twenty-two Blastocystis isolates were successfully subtyped by sequence analysis of the barcode region. Three subtypes were identified: ST1 (n = 7), ST3 (n = 13) and ST4 (n = 2). A statistical difference in the prevalence of Blastocystis was only observed between children (12.37%, 12/97) and adults (4.95%, 16/323), and between not washing hands (11.02%, 14/127) and washing hands (4.76%, 15/315) after using toilets, emphasizing the importance and necessity of health education in people in the investigated areas, especially in children.
Diagnosis of Huntington’s disease via sequential 18F-DOPA and 18F-FDG PET/MRI
Authors: Michler Enrico , Hoberück Sebastian , Martino Filippo , Platzek Ivan , Kotzerke Jörg
Published: July 2019

Introduction

Cases of rare movement disorders like Huntington’s disease (HD) are not easy to diagnose, especially when occurring sporadically, without documented family history. In HD patients, MRI scans commonly feature atrophy of the striatum and reduced volume of white matter. But if morphological findings remain unspecific, functional PET imaging could provide valuable information to further clarify diagnosis. We present a case report of a 56-year-old woman suffering from mild hypokinetic-rigid syndrome and depression, suspicious of Parkinson’s disease, who was referred to 18F-DOPA and 18F-FDG PET/MRI scans at our department.
Acanthopanax senticosus Induces Vasorelaxation via Endothelial Nitric Oxide-Dependent and -Independent Pathways
Authors: Shiokawa Yayoi , Miyauchi-Wakuda Shino , Kagota Satomi , Maruyama-Fumoto Kana , Yamada Shizuo , Shinozuka Kazumasa
Published: July 2019

Although Acanthopanax senticosus root extract (ASRE), a functional food used in Japan, improves peripheral blood circulation and exerts vasorelaxant effects in rats under healthy conditions, the underlying mechanisms currently remain unclear. Therefore, we investigated the mechanisms responsible for ASRE-induced relaxation in isolated thoracic aortas using organ bath techniques and examined whether ASRE affects systemic and peripheral circulation using a photoplethysmographic tail-cuff system and noncontact laser tissue blood flow meter in Wistar rats. Similar to acetylcholine (ACh), ASRE induced dose-dependent relaxation in aortas pre-contracted with phenylephrine; however, in contrast to ACh, ASRE-induced relaxation was partially inhibited by treatments with antagonists of nitric oxide (NO) synthase and soluble guanylyl cyclase as well as by endothelium removal. Contractile responses to phenylephrine or potassium chloride were observed in the presence of ASRE. The oral administration of ASRE (900 mg/kg/d for 1 wk) decreased systolic blood pressure in rats 3 h after the treatment and did not affect heart rate, tail blood flow, mass, or velocity; this decreasing effect was not observed on day 2. A 1-wk treatment with ASRE did not affect vasorelaxation in response to ASRE. These results demonstrate that ASRE induces vasorelaxation via endothelial NO production and an NO-independent pathway in rats. Based on these findings, positive impacts of ASRE on blood pressure and peripheral blood circulation cannot be expected under healthy conditions as the systemic effects of ASRE are temporary. Instead, caution is needed to prevent the occurrence of side effects (i.e., orthostatic dizziness) at the beginning of ASRE dosing.
A Prospective Analysis of Derangement of Coagulation Profile in Adult and Pediatric Age Group in Moderate-to-Severe Traumatic Brain Injury
Authors: Gandhi Swarup Sohan , Mann Manish , Jain Shashikant , Meena Ugan Singh , Sinha Virendra Deo
Published: July 2019

Background and Aim of Study Coagulopathy is a common occurrence following traumatic brain injury (TBI). Various studies have reported the incidence and risk factors of coagulopathy and their correlation with poor outcome in adult as well as pediatric age group. In our study, we aim to analyze trauma-induced coagulopathy in adult and pediatric patients.

Methods Adult (> 18 years) and pediatric (< 18 years) patients of TBI admitted in the intensive care unit of a trauma center of a tertiary care center had been studied from August 2015 to March 2018. Patients were further subdivided into moderate and severe TBI based on Glasgow Coma Scale (GCS) of 9 to 12 and < 9, respectively. Coagulation profile (prothrombin time [PT], activated partial thromboplastin time [APTT], thrombin time, fibrinogen, and D-dimer) and arterial blood gas (ABG) analysis were done on day of admission and on days 3 and 7. Coagulation profiles were analyzed in both the age groups, and risk factors were studied and correlated with the mortality and morbidity based on the Glasgow outcome score.

Results Two hundred patients including 143 adults and 57 pediatric patients were included. Mean age among the adult and pediatric population was 31.51 ± 16.83 and 11.5 ± 5.90 years, respectively. In adults, 96 (83.62%) out of 116 in severe TBI group and 20 (74.07%) out of 27 in moderate TBI group developed coagulopathy, and in pediatric age group, 14 (70%) out of 20 in moderate TBI and 30 (81.08%) out of 37 in severe TBI developed coagulopathy. Midline shift was significantly associated with coagulopathy in both the age groups (p value < 0.039). Mortality was not significantly different in patients with coagulopathy between the age groups, but improved status as per the Glasgow outcome score was more in pediatric age group.

Conclusion The development of coagulopathy is a frequent complication in patients with moderate to severe TBI in both age groups. Even though it is not closely associated with death in this study, it may be regarded as a marker of injury severity.
Empiema del Muñón Ureteral: Secretos Para un Buen Diagnóstico
Authors: Díaz Telli Federico , Mendes Eduardo Nicolás , Trentacoste Juan Francisco , Rosenvasser Jonathan , Padin Carlos Juan , Perotti Juan Pablo
Published: July 2019

El muñón ureteral es el segmento de uréter remanente posterior a una nefrectomía, que puede, ocasionalmente, dar origen a un cuadro sintomático infeccioso poco frecuente, conocido como empiema del muñón ureteral (EMU). El mismo suele atribuirse a otra patología por desconocimiento médico y no es reconocido hasta que el cuadro clínico avanza significativamente o se realiza la exploración quirúrgica.

Los muñones ureterales que se encontraban sanos en la cirugía inicial no suelen desarrollar patología. Por el contrario, los uréteres obstruidos, crónicamente infectados o asociados a litiasis o reflujo distal, son los que se encuentran en riesgo de desarrollar complicaciones futuras.

En esta revisión, se repasa la literatura y se presentan casos de pacientes con antecedentes de nefrectomía que por diferentes causas transcurrieron con empiema en el muñón ureteral, con el fin de analizar las posibles causas y factores predisponentes de la patología, describir los hallazgos radiológicos en los diferentes métodos diagnósticos y poder reconocer las posibles complicaciones para su correcto manejo terapéutico.

Las infecciones urinarias a repetición son útiles para sospechar la presencia de EMU. Ellas se deben al reflujo urinario o disfunción en el vaciamiento del uréter remanente, con estasis e infección del mismo. Por lo tanto, en pacientes con antecedentes de nefrectomía que presentan dolor abdominal difuso, fiebre y antecedentes de infecciones urinarias a repetición, es necesario sospechar empiema del muñón ureteral para poder realizar un correcto análisis imagenológico y posterior tratamiento.
Orbital Schwannoma: Case Report and Review
Authors: Caramanti Ricardo Lourenço , Goes Mário José , Chaddad Feres , Meguins Lucas Crociati , Moraes Dionei Freitas de , Aprígio Raysa Moreira , Calzolari Sérgio Ivo , Rocha Carlos Eduardo , Silva Sebastião Carlos da
Published: July 2019

Orbital schwannomas are rare, presenting a rate of incidence between 1 and 5% of all orbital lesions. Their most common clinical symptoms are promoted by mass effect, such as orbital pain and proptosis. The best complementary exam is the magnetic resonance imaging (MRI), which shows low signal in T1, high signal in T2, and heterogeneous contrast enhancement. The treatment of choice is surgical, with adjuvant radiotherapy if complete resection is not possible. We report the case of a 24-year-old male patient with orbital pain and proptosis, without previous history of disease. The MRI showed a superior orbital lesion compatible with schwannoma, which was confirmed by biopsy after complete resection using a fronto-orbital approach.
Penetrating Injury Due to Bicycle Brake Handle Causing Middle Cerebral Artery Infarct
Authors: Sasidharan Gopalakrishnan Madhavan , Chauhan Abhishek
Published: July 2019

An 8-year-old boy was brought to the emergency room with history of fall from a bicycle he was riding. On examination, he had a swelling in the left orbit with a small laceration under the medial aspect of the left eyebrow. The Glasgow coma scale was E2M5V2. An emergency computed tomographic (CT) scan showed infarct causing mass effect in the territory of the left middle cerebral artery. CT angiogram showed that a branch of the middle cerebral artery was occluded at the end of track traversed by the bicycle brake handle. The patient underwent decompressive craniectomy. Initial methylmethacrylate cranioplasty had to be removed due to infection. Later, the patient underwent titanium cranioplasty. At last follow-up, he was going to school. Hemiparesis persisted. Children are vulnerable to penetrating injury by the relatively sharp brake handle when they fall from an adult bicycle. Previous reports include fatal injury by similar mechanism. In this case, it caused injury to the middle cerebral artery without causing bleed. Bicycle manufacturers could be advised to make the vehicle safer for children by twisting the end of the brake handle.
Ducting of upper-hybrid waves by density depletions in a magnetoplasma with weak spatial dispersion
Authors: Starodubtsev Mikhail , Korobkov Sergey , Gushchin Mikhail , Grach Savely , Nazarov Vladimir
Published: July 2019

The effects of wave trapping and ducting inside a plasma density depletion are studied in a large laboratory magnetoplasma in the upper-hybrid (UH) range of frequencies. A field-aligned density depletion is generated via localized rf plasma heating and subsequent plasma thermal diffusion. Test UH waves are emitted and detected by small-size electric monopole antennas. For a given set of experimental parameters, propagation of UH waves can be considered as collisionless. At the same time, wave surface topology in the UH range is determined by weak spatial dispersion, which is conditioned by the thermal motion of electrons and the ambient magnetic field. For various density depletion depths and diameters, ducting of UH waves belonging to different characteristic parts of the “dumbbell-shaped” wave surface can be observed. Particularly, quasiparallel Langmuir (L-mode) waves and oblique resonance cone (X-mode) waves can be ducted in different regimes. A qualitative explanation of ducting regimes is given based on ray tracing analysis.
Bond dissociation energies of FeB, CoB, NiB, RuB, RhB, OsB, IrB, and PtB
Authors: Merriles Dakota M. , Tieu Erick , Morse Michael D.
Published: July 2019

The bond dissociation energies (BDEs) of the diatomic late transition metal borides (MB, M = Fe, Co, Ni, Ru, Rh, Os, Ir, and Pt) have been assigned from the measurement of a predissociation threshold using resonant two-photon ionization (R2PI) spectroscopy. The open d-shell configurations of the transition metal constituents in the molecules studied here lead to large ML degeneracies, resulting in a dense manifold of states near the ground separated atom limit. This high density of states causes prompt predissociation to occur as soon as the ground separated atom limit is exceeded, allowing a precise assignment of the BDE of the molecule. The measured predissociation thresholds give BDEs of D0(FeB) = 2.43(2) eV, D0(CoB) = 2.954(3) eV, D0(NiB) = 3.431(4) eV, D0(RuB) = 4.815(3) eV, D0(RhB) = 5.252(3) eV, D0(OsB) = 4.378(3) eV, D0(IrB) = 4.928(10) eV, and D0(PtB) = 5.235(3) eV. The gaseous enthalpies of formation at 0 K for these molecules have been derived using a thermochemical cycle that relates atomic enthalpies of formation and the BDE of the molecule, giving ΔfH0K°(g) (FeB) = 733.6(12.2) kJ mol−1, ΔfH0K°(g) (CoB) = 695.1(12.2) kJ mol−1, ΔfH0K°(g) (NiB) = 652.1(14.7) kJ mol−1, ΔfH0K°(g) (RuB) = 740.2(12.7) kJ mol−1, ΔfH0K°(g) (RhB) = 600.1(12.7) kJ mol−1, ΔfH0K°(g) (OsB) = 921.7(13.6) kJ mol−1, ΔfH0K°(g) (IrB) = 748.0(13.6) kJ mol−1, and ΔfH0K°(g) (PtB) = 613.9(12.2) kJ mol−1. This work reports the first experimental measurements of the BDEs of FeB, CoB, NiB, and OsB. Periodic trends are discussed.
Feeding experiment using uniformly 13C-labeled α-linolenic acid supports the involvement of the decarboxylation mechanism to produce cis-jasmone in Lasiodiplodia theobromae
Authors: Matsui Ryo , Takiguchi Kisumi , Matsuda Kazuhiko , Takahashi Kosaku , Matsuura Hideyuki
Published: July 2019

In our previous report, it was found that Lasiodiplodia theobromae produced cis-jasmone via partially utilizing the biosynthetic pathway of JA. A feeding experiment using uniformly 13C-labeled α-linolenic acid, which was added to the culture media of the fungus, strongly supported that the fungus produced CJ via the decarboxylation step of the biosynthetic pathway.
Active vibration control of planetary gears by pole placement
Authors: Olanipekun K A , Rustighi E , Ferguson N S
Published: July 2019

This numerical study focuses on the assignment of poles to a planetary gear train to avoid resonance, which can cause the failure of the system. The control strategy is output feedback, which involves feeding back the displacement and velocity to achieve active stiffness and damping respectively. The reverse process was considered. This occurs when the predicted control gains were assigned by the actuators, which were placed on the translational directions of either the carrier or the sun gear bearing mounted on the shaft. In addition, the closed-loop poles were assigned in the case whereby the actuators were positioned in the translational directions of either the carrier or the sun gear. The active control was considered using both the fixed and rotating frames of reference at a carrier speed of 100 rpm. Numerical examples are presented using both reference frames with the sensors and actuators collocated. The results show that the poles of the modes with lower frequencies, which are predominantly translational modes, can be shifted while the poles of the higher modes, which are predominantly rotational remain unchanged.
Joint state/input estimation with a Fourier dictionary for the input representation: effect of spectral leakage
Authors: Kirchner M , Croes J , Desmet W
Published: July 2019

The compressive sensing-moving horizon estimator (CS-MHE) is an approach for joint state/input estimation. It integrates compressive sensing principles into a moving horizon estimator, enabling to exploit shape functions to model an input, resulting in better observability and wider input bandwidth in comparison to other input models. With the final aim of using the CS-MHE for the estimation of forces and torques in rotating machinery which exhibit some form of periodicity, the authors have recently investigated Fourier shape functions. A first experimental validation showed very accurate estimation under the hypothesis of no spectral leakage, i.e., the MHE window, the sampling rate and the Fourier dictionary match a known input periodicity, with the input consisting of few sinusoidal components. This paper discusses the problem of spectral leakage that can result if the MHE window does not match the signal periodicity. In particular, we show how to remove the link between the MHE window and a Fourier dictionary, we discuss how the autocorrelation can be employed to detect the periodicity and we list further possible alternatives to enhance a sparse solution. The discussion is supported by numerical and experimental investigations.
The dynamics of a cylinder on a vibrating plane with friction
Authors: Vinogradova O A
Published: July 2019

In this work the motion of a cylinder undergoing harmonic forcing is presented. The interaction between the cylinder and the base is governed by Coulomb’s law for sliding and rolling friction. The research aims at finding periodic motions of the system. The obtained motions are categorised and the characteristics of these motions are presented.
Static and Random Vibration Analyses of a University CubeSat Project
Authors: Barsoum George I. , Ibrahim Hesham H. , Fawzy Mina A.
Published: July 2019

This work presents hands on experience of the configuration process and strength analyses of a student’s CubeSat project at the German University in Cairo. The static and dynamic performance of the primary structure, during launching phase, are investigated and checked against the strength requirements in addition to making sure that stiffness constraints imposed by the P-POD and the candidate launchers are met. The static response of the primary structure is performed using ANSYS Finite Element Software by exposing the structure to the maximum quasi static launch load in each of three flight directions separately. Modal analysis results are presented in order to check the compliance of the longitudinal and lateral natural frequencies, of the proposed model, with the launchers requirements. In addition, random vibration response is performed using frequency domain analysis, assuming that the structure will be subjected to launch random vibration loads in all directions. Finally, fatigue life analysis is presented in order to ensure that primary structure will safely survive the launching mechanical environments.
A probabilistic framework for online structural health monitoring: active learning from machining data streams
Authors: Bull L A , Worden K , Rogers T J , Wickramarachchi C , Cross E J , McLeay T , Leahy W , Dervilis N
Published: July 2019

A critical issue for data-based engineering is a lack of descriptive labels for the measured data. For many engineering systems, these labels are costly and/or impractical to obtain, and as a result, conventional supervised learning is not feasible. This paper suggests a probabilistic framework for the investigation and labelling of engineering datasets; specifically, acoustic emission data streams recorded online from a turning machine. Two alternative probabilistic measures are suggested to select the most informative observations. During machining operations, these data would then be investigated and annotated by an engineer, in order to maximise the classification performance of a statistical model used to predict tool wear.
Optimal design of inerter-integrated vibration absorbers for seismic retrofitting of a high-rise building in Colombia
Authors: Li Yuan , Lombardi Luca , Luca Flavia De , Farbiarz Yosef , Blandon John Jairo , Lara Luis Augusto , Rendon Juan Felipe , Jiang Jason Zheng , Neild Simon
Published: July 2019

Retrofitting of existing buildings with seismic protection devices is an important approach which is commonly adopted by the civil engineering community. This paper investigates the potential of inerter-integrated seismic vibration absorber for building structures. A real case study of a high-rise building in Colombia is considered herein to demonstrate the effectiveness of the proposed device. An inerter generates a force proportional to the relative acceleration between its two terminals and it fundamentally enlarges the range of realisable passive mechanical impedances. In this work, an interter-integrated device is modelled into the open-source structural engineering software OpenSees and implemented into a simplified two-dimensional (2D) version of the Colombian test-bed structure. The performances of the structure retrofitted with the proposed absorber are compared to those of the same structure retrofitted with a traditional damper device, a more classical retrofitting. This preliminary work demonstrates the effectiveness of the inerter-integrated retrofitting strategies considering the non-structural damage caused by a moderate earthquake. It has been found that with an optimal inerter-integrated device, the maximum inter-storey drift of the building will be reduced by 45.64% comparing with the structure without any retrofitting, which is 20.8% further reduction comparing with the structure retrofitted with an optimal damper.
Random error propagation and uncertainty analysis in the dynamic characterization of Tilting Pad Journal Bearings
Authors: Barsanti M , Ciulli E , Forte P
Published: July 2019

In this work a new statistical method for the determination of the dynamic coefficients of Tilting Pad Journal Bearings is described. The method is applied to the results obtained testing a 5 pads tilting pad journal bearing with 280 mm diameter. Tests were performed on an advanced experimental apparatus specifically realized for investigations on large size high performance bearings for turbomachinery. The linear coefficient identification procedure is based on the dynamic measurement of forces, accelerations and relative displacements of rotor and bearing, as function of excitation frequency for different operating conditions. The postprocessing of the dynamic data is performed in the frequency domain using the Fast Fourier Transform. Along with a description of the experimental test and identification procedure, this paper presents a least-square minimization technique for determining the dynamic coefficients and a bootstrap statistical technique for estimating their confidence intervals.
An adaptive MOR method for vibro-acoustic analysis of dynamic systems with viscoelastic damping
Authors: Xie Xiang , Zheng Hui , Jonckheere Stijn , Desmet Wim
Published: July 2019

Viscoelastic materials have the capability of dissipating vibrational energy which makes them very effective in the passive control of structural vibration and noise radiation. Efficient modeling-and simulation strategies for vibro-acoustic systems with these frequency-dependent damping materials are necessary. One way of doing that is to utilize the finite element (FE) method supported by a damping model that describes the frequency-dependency of the complex elastic modulus. However, in many applications, very large-scale FE models are required to obtain reliable predictions, which makes full-order system evaluation often intractable. Model order reduction (MOR), however, cannot be directly applied to models including viscoelastic materials due to the frequency-dependent property which exactly makes that the equations of motion are not of a standard second-order form as that for regular FE models. In this paper, a transformation technique based on Taylor’s theorem is introduced to treat the non-standard form of the equations of motion. After transforming the problem into a second-order system equation with an associated remainder term, an adaptive MOR procedure is applied to reduce the computational complexity of the vibro-acoustic systems. A numerical example is provided to demonstrate the simplicity and efficiency of the proposed approach.
Structural Damping by Layers of Fibrous Media Applied to a Periodically-Constrained Vibrating Panel
Authors: Xue Yutong , Stuart Bolton J. , Herdtle Thomas , Lee Seungkyu , Gerdes Ronald W.
Published: July 2019

It has recently been demonstrated that layers of fibrous, “acoustical” material can effectively damp structural vibration in the sub-critical frequency range. In that frequency range, the acoustical near-field of a panel consists of oscillatory flow oriented primarily parallel with the panel surface. When a fibrous layer occupies that region, energy is dissipated by the viscous interaction of the near-field and the fibrous medium, and the result is a damping of the panel motion. Previously, the damping effect has been demonstrated to occur for line-driven, infinite panels and panels with isolated constraints. In this article, the focus is instead on periodically-constrained panels driven into motion by a convective pressure distribution. The constraints are allowed to have translational and rotational inertias and stiffnesses. This arrangement is intended to represent a very simple model of an aircraft fuselage structure. By considering the power flows in this system, it is possible to compute an equivalent loss factor, and then to identify the fibrous layer macroscopic parameters that result in optimal damping at a given mass per unit area. Finally, given that information, it is possible to identify the microstructural details, e.g., fiber size, that would be required to achieve that damping in practice.
Modelling the vibrational field of a single-layered ground containing a buried object
Authors: Duval G , Laulagnet B
Published: July 2019

Better understanding and accurate representation of the vibrational field propagated through the ground is a major challenge in the industrial field. In particular, interactions between vibrating surface objects and elements buried in the soil are poorly understood. This article presents an analytical model of the vibrational field of a single-layered soil solicited at its surface by an non deformable piston and containing a passive flat plate. It offers an original approach to the problem, using coupling between plates and ground to investigate how the surface velocity field is modified by the presence of an object in the soil. Examples of numerical simulations are provided, and possible extensions to the model are briefly discussed to underline its versatility and its use in potential future studies.
A novel approach to solve eigenvalue and forced response problems in waveguide theory by means of bi-orthogonality relations
Authors: Ledet L S , Sorokin S V
Published: July 2019

In this paper recent advances on solving challenging problems in dynamics of multimodal symmetric waveguides (having identical properties of positive/negative going waves) using bi-orthogonality are summarised. It has already been shown by the authors that bi-orthogonality, valid for arbitrarily complicated unbounded symmetric waveguides, greatly facilitates analysis of their forced response in any excitation conditions. Recent findings have shown that bi-orthogonality is a powerful tool also for bounded waveguides and by direct use it resolves the classical Boundary Integral Equations (BIE) into a set of individual relations between modal amplitudes at the boundaries. Moreover, bi-orthogonality permits to uniquely identify special sets of boundary conditions for which the eigenfrequency spectra may be found directly from the dispersion diagrams. These solutions are available simply by drawing horizontal lines specifying an inverse of the wave length of interest in the (Ω, k)-dispersion diagram and so the eigenfrequency spectrum may be read directly as intersections of these lines with dispersion curves. This paper therefore serves to promote this method, discuss applications, new possibilities, physical interpretation and its generalisation to a broader class of waveguide problems.
A new method utilizing smart meter data for identifying the existence of air conditioning in residential homes
Authors: Chen Mo , Sanders Kelly T , Ban-Weiss George A
Published: July 2019

Climate change, urbanization, and economic growth are expected to drive increases in the installation of new air conditioners, as well as increases in utilization of existing air conditioning (AC) units, in the coming decades. This growth will provide challenges for a diversity of stakeholders, from grid operators charged with maintaining a reliable and cost-effective power system, to low-income communities that may struggle to afford increased electricity costs. Despite the importance of building a quantitative understanding of trends in existing and future AC usage, methods to estimate AC penetration with high spatial and temporal resolution are lacking. In this study we develop a new classification method to characterize AC penetration patterns with unprecedented spatiotemporal resolution (i.e. at the census tract level), using the Greater Los Angeles Area as a case study. The method utilizes smart meter data records from 180 476 households over two years, along with local ambient temperature records. When spatially aggregated, the overall AC penetration rate of the Greater Los Angeles Area is 69%, which is similar to values reported by previous studies. We believe this method can be applied to other regions of the world where household smart meter data are available.
B2C cross-border e-commerce export logistics mode selection
Authors: wenying Chen
Published: July 2019

With the development of economic globalization and the proposal of the “One Belt, One Road” policy, cross-border e-commerce has ushered in development opportunities and developed rapidly. However, the lag of cross-border logistics service level and high logistics cost hinder the further development of cross-border e-commerce and become a bottleneck for the development of cross-border e-commerce enterprises. Therefore, in order to improve the cross-border e-commerce logistics level, cross-border e-commerce enterprises need to make reasonable choices about logistics mode to achieve the effect of reducing costs, improving service level and customer satisfaction. This paper divides the current cross-border logistics mode into express parcels and overseas warehousing and introduces them separately. It analyzes the macro influencing factors and micro influencing factors of the choice of logistics mode. By constructing the profit maximization function, it makes a selection of logistics modes and further studies the decision of self-operating or outsourcing in overseas warehouses. Finally, the corresponding suggestions are put forward according to the actual problems.
Typical Fault Analysis of the Key Metal Parts in GIS
Authors: Xie Yi , Duan Mingcai , Qiao Yaxia , Zhang Hao , Luo Hongjian
Published: July 2019

Leakage and cracking of GIS metal parts will directly affect the insulation and conductivity, which will lead to grid equipment failure. The three main typical faults of GIS metal parts were analyzed, ie. air leakage, short-circuit row breakage, and conductor weld crack. Based on the above analysis, suggestion of strengthening the metal supervision in the aterial procurement, infrastructure and transportation inspection stages have been proposed to avoid major safety incidents caused by the failure of GIS metal parts.
Study on effects of mudsill and infilled wallboard on response of steel frame under curvature surface deformation
Authors: Xie Wei , Xia Junwu , Zheng Yuying , Wang Qiufen , Chang Hongfei , Yang Shangtong
Published: July 2019

The structural performance of steel frames with novel lightweight composite infilled wallboard is experimentally and numerically investigated under the curvature surface deformation. This study compares the mechanical behavior for the open-frame, the closed-frame with mudsill and the closed-frame with infilled wallboard, through experiment and finite element analysis, under the positive and negative curvature surface deformations respectively. The structural responses such as basement counterforce, additional strains at different key locations and the effects of mudsill and infilled wallboard are evaluated. It has been found that the steel frames with the new composite infilled wallboard can considerably increase the stiffness of the structures in resisting surface deformation and re-distribute the loads amongst the beam and column members in the frame. The force transmission effect of the mudsill accelerated the changes in the additional strain at column bottom. Frame beam is the main component that bears the curvature surface deformation. Mudsill has a consistent stress pattern with the frame beam and can significantly influence additional strain of the frame beam due to its stress sharing effect. The infilled wallboard is connected with the column-beam members and thereby influences the additional strain of the frame column significantly.
Influence of complex Foundation Pit excavation on adjacent buildings
Authors: Sun Xiaolong , Liu Yan , Wang Guangxiang
Published: July 2019

In order to deeply study the influence of complex foundation pit group excavation on surrounding buildings, this paper takes concrete engineering as an example, using finite element software MIDAS GTS/NX to set up a three-dimensional deep foundation pit model for a piece of land project in a certain city, and carries out numerical simulation and analysis. This paper introduces the general situation of the project, the process of establishing the model, and the value of the deformation of the building and the supporting structure. The results show that the horizontal displacement of the same point increases gradually with the increase of the excavation depth of the foundation pit. The increase of excavation depth will also result in the maximum horizontal displacement moving gradually from the top of the slope to the middle and lower part of the deep foundation pit. In this paper, the three-dimensional numerical simulation analysis of the engineering is carried out according to the site construction procedure, in order to provide technical reference for the support selection and construction of similar projects.
Analysis of Specific Operation of Circulating Water System in a Power Station
Authors: Wan Zhong-hai , Chen Wen , Lu Jin , Liu Zhuan , Cai Wen , Yan Tao
Published: July 2019

Affected by the continuous decline of the water level and the reform of the condenser, the actual operating conditions of a company’s circulating water pump seriously deviated from the design conditions. Especially in the double pump condition, only one pump can be maintained in normal operation, the other’s current is obviously low and the pump body vibrates greatly, and the double pump cannot be maintained in parallel operation. After several field tests and analysis, it was found that when the running head was between the two pump-inflection points of the parallel running, due to the difference in performance between the pump bodies, one of the circulating water pumps runs normally, while the other pump has a sudden current drop and an increase in pump vibration; at the same time, the two pumps have been running for more than ten years, the performance of the equipment is aging, and the head is insufficient, which is one of the main reasons.
Construction Thinking of Concrete Pouring Technology in Building Construction
Authors: Bao-qiang Yue
Published: July 2019

The rapid development of the construction field in the new era has had a positive impact on the effective construction of construction projects. In practice, in order to increase the technical content of construction, optimize its structural performance, and extend the service life of buildings, it is necessary to consider the application of concrete pouring technology, effectively carry out research work in this area, thereby reducing the incidence of structural problems in construction. Based on this, this paper will systematically expound the application of concrete pouring technology in building construction.
Application Research on Construction Management of Urban Underground Utility Tunnel Based on BIM
Authors: Li Yan , Yang Jie , Shen Xiaowei , Ma Yingying
Published: July 2019

The urban underground utility tunnel is a new mode of municipal engineering planning and construction. By summarizing the problems existing in the construction of municipal tunnel in China, we discussed the application of BIM technology in the construction of municipal tunnel. In addition, we analyzed the advantages of BIM software in the construction of municipal tunnel by using its functions of collaborative design, comprehensive design of pipelines, construction schedule and process simulation. The results showed that the application of BIM technology in the construction of municipal tunnel would improve the construction quality and project management level, and maximize the benefits in the construction stage, which would also provide ideas and technical support for the utility tunnel project planning.
Study on Geological Modeling of Heidimiao and Fuyang Oil Layer in Da’an North Area
Authors: Wei Xiaolong , Li Tao , Yuan Yaofeng
Published: July 2019

In this paper, through the study of reservoir geological modeling, the reservoir modeling software is used to establish the reservoir 3D geological model; combined with the sedimentary microfacies research results, the reservoir sedimentary microfacies model is established; using geostatistics and stochastic simulation methods, the small layer performs stochastic modeling of porosity, permeability and oil saturation properties, and establishes a three-dimensional model of the properties under the control of reservoir sedimentary facies.
Research on Simulation Algorithm of Mechanical and Thermal Indices of Ultrasonic Field Based on LabVIEW
Authors: Jiang Junjie , Li Weiwei , Gao Yuan , Liu Mengjun
Published: July 2019

This paper is suitable for the calculation of mechanical and thermal indices in distributed measurement system of ultrasonic field.The cavitation and thermal effect produced by ultrasonic signal acting on human body and the calculation method of mechanical and thermal indices for evaluating these two effects are described.The measurement of acoustic output index of ultrasonic diagnostic equipment can be realized by scanning ultrasonic field.The algorithm is developed based on LabVIEW software and the simulation results can be verified.
Research on Pipeline Design of Solar Heating System Based on Oil-water Graded Heat Conduction
Authors: Liu Denghua , Zhang Peng , Liu Xuetao
Published: July 2019

With the development of society, more non-renewable resources such as coal have been consumed, leading to energy shortage and environmental pollution. In winter, a large amount of coal is burnt for heating in the north, causing heavier smog nationwide, which is a great threat to people’s health. In recent years, some towns in the north also tried to provide heat for the buildings by burning natural gas to achieve boiler water circulation. However, that also caused environmental pollution to some extent. Research leads us to the invention of a solar heating system based on oil-water grading heat conduction and the design of pipelines and oil-water circulation in order to improve energy efficiency and improve heating quality in the north.
Calculation and Analysis of Energy Consumption Index of Environmental Protection Facilities in Coal-fired Power Plant
Authors: Li Chao , Jiang Chong , Qu Li-tao , Yu Hong-Hai , Qi Xiao-hui , De-xin Wang , Du Jia
Published: July 2019

Energy consumption of environmental protection facilities in coal-fired power plants is an important part of energy consumption of generating units. Taking 2 x 600 MW generating unit as an example, in this paper discusses the Energy Consumption Index Composition and Calculation Method of Environmental Protection Facilities. The results show that the energy consumption index for removal of unit quality pollutants can better reflect the energy consumption level of environmental protection facilities. The fan electricity consumption caused by resistance of environmental protection facilities is an important part of energy consumption. The calculation results can provide basic data and basis for energy consumption management and energy efficiency improvement of environmental protection facilities of coal-fired units.
Soil macrofauna in Oil palm plantation of Sei Liput
Authors: Jhon Arlen Hanel , Rauf Abdul , Sabrina T , Akoeb Erwin Nyak
Published: July 2019

Oil palm plantation of PT. Socfindo within area of Sei Liput has been planting oil palm since 1909, with recent status consisted of generation V (± 108 years), IV (± 92 years), III (± 49 years) and II (± 32 years). The different interval of utilization and management of plantation in each generation determine both the species, density, relative density and presence frequency of soil macrofauna. Soil macrofauna are known to maintain the balance of soil ecosystem. The study was conducted at Sei Liput oil palm plantation area on February 2017 until April 2018. Determination of sampling points used purpossive random sampling while sampling of soil macrofauna using quadratic and hand sorting methods. The study found 25 species of soil macrofauna grouped into 2 phyla, 6 classes, 12 orders, 20 families and 25 species. The highest density value in the Generation II plantation area was 217.46 ind / m2 and the lowest density value in the Generation III garden area was 125.38 ind / m2. The three most frequent species of soil macrofauna in the four generations plantations were Pontoscolex corethrurus, Odontoponera denticulata, and Vostax apicedentatus.
Phytoplankton diversity of Situmurun village, Toba Samosir regency, North Sumatera
Authors: Purba Ika Rosenta , Barus Ternala Alexander , Mulya Miswar Budi , Ilyas Syafruddin
Published: July 2019

Lake Toba is the largest lake in Indonesia located in Toba Samosir regency, North Sumatera. The lake is currently facing serious habitat exploitation due to anthropogenic activities in surrounding area. Effort to identify and assess the quality of freshwater bodies are conducted through assessment upon phytoplankton diversity. The aim of study was to identify the phytoplankton diversity at Situmurun village. The village is one of rural area in Toba Samosir regency, known as tourism spot for its Binangalom waterfall. The freshwater area of this village is still considered natural and free of human activities. List of phytoplankton taxa is presented. The study found 5 classes of phytoplankton grouped into 28 families with 33 species. Our result will be compared with overall phytoplankton diversity for assessing biological-based water quality in Lake Toba.
Potential of Capsicum annuum rhizosphere bacteria in inhibiting the growth of Fusarium oxysporum in-vitro
Authors: Sinulingga S , Munir E , Nurtjahja K
Published: July 2019

The rhizosphere has been known to contain rich microbial community which is directly influenced by secretions of roots. Rhizosphere microbes are known to have various benefits such as protection of plant from pathogens and toxic compounds, producing plant growth hormone, nitrogen fixation, and solubilizing phosphate. The objective of this study was to obtain rhizosphere bacteria capable of inhibiting the growth Fusarium oxysporum which is common pathogen attaching Capsicum annum. Bacteria were isolated from rhizosphere C. annum of local farm in Kabanjahe North Sumatra. Nine isolates based on morphological performance and biochemical analyses were obtained. Antagonistic test showed that two isolates BR6 and BR9 inhibited the growth of F. oxysporum with inhibition rate of 60% and 52%, respectively after 7 days incubation. These isolates also exhibited the activity to solubilize phosphate in Pikovskaya media with solubility index of 3.04 and 2.77, respectively. The other isolate BR5 even showed higher phosphate solubility index (3.42). These results suggest these isolates may have important role to support the growth of C. annum by providing protection from pathogens and phosphate ion. Then, study on the control of F. oxysporum attack on C. annum seedlings using these potential isolates is in process in our laboratory, as well as their molecular identification based on 16S rRNA.
Tree Species Diversity, Richness and Similarity in Disturbed and Undisturbed Forest of Ketambe Research Station, Southeast Aceh regency
Authors: Akram Habibul , Pasaribu Nursahara , Siregar Etti Sartina
Published: July 2019

Tree species richness in disturbed and undisturbed site of Ketambe Research Station Ketambe, Southeast Aceh regency, Indonesia has been studied from March to May 2018. Research sites were determined using purpossive sampling method. Tree samples were recorded within a plot measuring 400 m2 for each sites with a total of 40 plots. Ecological parameters measured in this study were: Density (D), Relative density (RD), Frequency (F), Relative frequency (RF), Dominance (Do), Relative dominance (RDo), Importance Value Index (IVI), Shannon’s diversity index (H’), Margalefs index (R1), and Evenness (E). Estimation of biomass (B) carbon stock (CS) was conducted using allometric equation. Physico-chemical characteristics measured were: air temperature (°C), soil acidity (pH), light intensity (lx), air humidity (%), total organic N (%), and phosphate quantity (ppm) as secondary data. Our study found 79 tree species belonging to 30 families, 61 species in undisturbed site and 47 species in disturbed site. An important species with the highest Importance Value Index (IVI) was Dysoxylum sp.3 in undisturbed site and Macaranga tanarius in disturbed site. The biodiversity was more diverse in undisturbed site (H’ = 3.70; R1 = 10.93) than disturbed site on the whole study area (H’ = 3.47; R1 = 9.10). The values of evenness (E) varied between 0.66–0.68 among sites. Estimation of tree biomass and carbon stock followed the similar trend with a total of B = 971.299 Mg/ha and CS = 485.649 Mg/ha on the whole study area. The present study revealed that some vital tree species exist in forest area of Ketambe Research Station as carbon sinks along with their high biodiversities from both disturbed and undisturbed regions. The information on tree species diversity may provide a baseline information for conservation of the biodiversity in this area.