bluuebunny/crossref_metadata_2025 huggingface dataset:
Aircraft altitude estimation method based on multi‐beam pitching sum and difference channels for SAR
Authors: Li Linghao , Yang Wenfu , Zhou Zhichao , Ding Zegang
Published: July 2019

Synthetic aperture radar (SAR) can provide high‐resolution two‐dimensional radar images of the target area. The error of the altitude between aircraft and the target area causes geometrical distortion of the SAR ground image, which is unfavourable for scene matching and target recognition. Existing methods, such as radar altimeters, work in the case of vertical beam irradiation. However, the highly accurate aircraft altitude estimation for SAR (under oblique irradiation) is still a challenge. In this paper, an aircraft altitude estimation method based on multi‐beam pitching sum and difference channels radar echoes is proposed. The pitching sum and difference channels angle measurement principle is used to achieve accurate beam centre distance estimation, and the cyclic multiple beams are used to realise the estimation of the grazing angle deviation. Therefore, this method can realise the accuracy estimation of the aircraft altitude under oblique beam irradiation conditions. Then, the effects of various error sources on the accuracy of altitude estimation are analysed. The results of simulation and real data verify the correctness of the analysis and the validity of the proposed method.
Three‐step ground moving target detection method for bistatic forward‐looking SAR
Authors: Liu Zhutian , Li Zhongyu , Yang Qing , Wu Junjie , Huang Yulin , Yang Jianyu
Published: July 2019

Detecting ground moving target in bistatic forward‐looking synthetic aperture radar (BFSAR) has become increasingly important in military and civil field. Compared with pulse Doppler radar, the long observation time and high resolution of BFSAR will lead to three problems in the received signal: Doppler ambiguity, large range cell migration and Doppler cell migration, which tremendously aggravate the difficulty of ground moving target detection (GMTD). In this study, the authors propose a three‐step ground moving target detection method for BFSAR to solve these problems and achieve good performance on GMTD. First, the bulk‐deramp filtering and Keystone transform are exploited to suppress Doppler ambiguity and correct range cell migration, respectively. Then, time‐division space–time adaptive processing is utilised for clutter suppression, which eliminates the effect of the Doppler cell migration. Finally, modified Wigner–Ville distribution method is applied to further improve the signal to clutter and noise ratio and the moving target can be detected in the integration domain. Simulations are carried out to demonstrate the effectiveness of the proposed method.
Monopulse SAR angle measurement based on total variation and monotonic iterative algorithm
Authors: Hu Bingtao , Li Feng
Published: July 2019

Synthetic aperture radar (SAR) monopulse angle measurement is an adequate method of target angle measurement in low signal‐to‐clutter and noise ratio. However, there is a contradiction between the instantaneous angle measurement and the SAR coherent accumulation. In this study, the authors use the total variation method to solve the above problem, and propose the monotone iterative method to enhance the efficiency of the total variation method, which is verified in the simulation.
Nierenregeneration
Authors: Gohlisch Christopher , Markus van der Giet
Published: July 2019

Die Prävalenz der terminalen Niereninsuffizienz ist progredient. Bisherige Therapien bezogen sich auf die Therapie der Grunderkrankung, eine Nierenersatztherapie oder eine Nierentransplantation. Eine Ergänzung hierzu bietet die aktuelle Forschung zur Nierenregeneration, die auf Erkenntnissen der Embryologie und der Regeneration spezifischer Zellen in den unterschiedlichen Nierensegmenten beruht. Die Regeneration der Niere wird durch verschiedene Mechanismen beeinflusst. Das Immunsystem nimmt dabei eine wichtige Rolle ein und kann therapeutisch beeinflusst werden. Auch Stammzellen können zur regenerativen Therapie genutzt werden und ermöglichen mittlerweile sogar die Bildung von Organoiden.
Outcome Analysis of Upper versus Lower Cervical Spine Injuries
Authors: Singh Deepak Kumar , Chhabra Anuj , Kumar Rakesh , Ahmad Faran , Yadav Kuldeep , Kaif Mohammad
Published: July 2019

Back Ground/Objective Cervical spine injuries are considered to be a major trauma and classified in various types. They are associated with various neurologic deficits and mortality rates. They account for 50 to 75% of all spine injuries. Various studies are associated with outcome of spinal cord injuries. Our aim was to analyze outcome of upper and lower cervical spine injuries.

Study Design It was a retrospective study in all traumatic cervical spine injuries in all age groups at our center during the past 3 years.

Method All cases operated in the past 3 years at our center were taken up for study. Initial hospital records were reviewed. Patients will be divided into two groups on the basis of anatomic level upper (C1 and C2) and lower (C3 or below) cervical spine. Outcomes were analyzed on criteria of demography, mechanism of injury, preoperative neurologic status, involvement of respiratory system, and time of surgery following injury.

Result tatically significant test was applied for analysis of outcome of cervical spine injury based on aforementioned criteria.

Conclusion In this study, survival rates of patients with upper and lower cervical spine injuries were calculated on the basis of mechanism of injury, preoperative neurologic status, respiratory involvement, and time of surgery following injury. Operative treatment of lower cervical injury was better associated with an improved outcome than upper cervical spine injuries. Further prospective study is required for better assessment.
A Prospective Study on Acute Subdural Hematoma in Mild Head Injury Patients: Outcome with Initial Nonoperative Management
Authors: Barooah R. K , Haloi Hriday , Baishya B. K. , Sarma Kishore
Published: July 2019

Introduction Incidence of acute subdural hematoma (SDH) is 21% in head injury patients. Decompressive craniectomy done for acute SDH itself carries a very high morbidity and mortality. The skull bone defect, prolonged hospital stay, the need of a second surgery (cranioplasty), and bone flap infection are other problems associated with decompressive craniectomy. Hence, this study looks into the outcome of conservative management in acute SDH in patients with mild head injury.

Aims and Objectives The main objective of this article is to study the patients included in the study with regard to outcome, morbidity, duration of hospital stay, and hospital cost. This article also studies the efficacy and outcome of lesser aggressive management (burr-hole evacuation) after initial nonoperative management of the patients included in the study.

Materials and Methods This is a prospective study performed in the Department of Neurosurgery, Gauhati Medical College and Hospital. A total of 30 patients arriving in the emergency department during a 6-month period from December 1, 2017 to May 31, 2018 with a diagnosis of acute SDH and with Glasgow coma scale (GCS) 13 to 15 were evaluated. Evaluation was done by history, clinical examination, GCS, computed tomography (CT) (plain) scan brain, and Glasgow outcome score at 6 months follow-up.

Results and Observations Twenty patients showed complete resolution of the clot, and eight patients had liquefaction of clot which was evacuated by burr-hole. One mortality was recorded and one had to undergo decompressive craniectomy. About 93.33% of patients managed by initial nonoperative management showed functionally independent outcome at 6 months follow-up.

Conclusion Conservative management in patients with acute SDH can be a viable alternative in certain cases. Those patients with GCS of 13 and above with CT scan showing midline shift of even ≥5 mm or thickness of 10 mm and more can also be managed conservatively by close monitoring.
Ovarian Sertoli-Leydig Cell Tumors: Epidemiological, Clinical and Prognostic Factors
Authors: Castro Beatriz Guerreiro Ruiz , Souza Cristiano de Pádua , Andrade Carlos Eduardo Mattos da Cunha , Vieira Marcelo de Andrade , Andrade Diocésio Alves Pinto de , Reis Ricardo dos
Published: July 2019

Objective To describe a series of cases of ovarian Sertoli-Leydig cell tumors (SLCTs).

Methods Retrospective review of 12 cases of SLCT treated at the Hospital do Câncer de Barretos, Barretos, state of São Paulo, Brazil, between October 2009 and August 2017.

Results The median age of the patients was 31 years old (15–71 years old). A total of 9 patients (75.0%) presented symptoms: 8 (66.7%) presented with abdominal pain, 5 (41.7%) presented with abdominal enlargement, 2 (16.7%) presented with virilizing signs, 2 (16.7%) presented with abnormal uterine bleeding, 1 (8.3%) presented with dyspareunia, and 1 (8.3%) presented with weight loss. The median preoperative lactate dehydrogenase (LDH) was 504.5 U/L (138–569 U/L), alpha-fetoprotein (AFP) was 2.0 ng/ml (1.1–11.3 ng/ml), human chorionic gonadotropin (β-hCG) was 0.6 mUI/ml (0.0–2.3 mUI/ml), carcinoembryonic antigen (CEA) was 0.9 ng/ml (0.7–3.4 ng/ml), and cancer antigen 125 (CA-125) was 26.0 U/ml (19.1–147.0 U/ml). All of the tumors were unilateral and surgically treated. Lymphadenectomy was performed in 3 (25.0%) patients, but none of the three patients submitted to lymphadenectomy presented lymph node involvement. In the anatomopathological exam, 1 (8.3%) tumor was well-differentiated, 8 (66.7%) were moderately differentiated, and 3 (25.0%) were poorly differentiated. A total of 5 (55.6%) tumors were solid-cystic, 2 (22.2%) were purely cystic, 1 (11.1%) was cystic with vegetations, and 1 (11.1%) was purely solid, but for 3 patients this information was not available. The median lesion size was 14.2 cm (3.2–23.5 cm). All of the tumors were at stage IA of the 2014 classification of the International Federation of Gynecology and Obstetrics (FIGO). A total of 2 (16.7%) patients received adjuvant treatment; 1 of them underwent 3 cycles of paclitaxel and carboplatin every 21 days, and the other underwent 4 cycles of ifosfamide, cisplatin and etoposide every 21 days. None of all of the patients had recurrence, and one death related to complications after surgical staging occurred.

Conclusion Abdominal pain was the most frequent presentation. There was no ultrasonographic pattern. All of the SLCTs were at stage IA, and most of them were moderately differentiated. Relapses did not occur, but one death related to the surgical staging occurred.
Ultrasound Monitoring after Pelvis-Sparing Dismembered Pyeloplasty: High Sensitivity and Low Specificity for the Success of Operation
Authors: Kiblawi Rim , Kuebler Joachim F. , Petersen Claus , Ure Benno M. , Hofmann Alejandro D.
Published: July 2019

Introduction A decrease in the anteroposterior diameter (APD) of the renal pelvis on ultrasound has been postulated to be indicative of sufficient pelvic drainage after pyeloplasty. Traditionally, pyeloplasty is combined with a reduction of the renal pelvis. We have recently demonstrated that resection of the pelvis during pyeloplasty is not necessary. We aimed to evaluate the efficacy of ultrasound APD measurements during follow-up to identify sufficient pelvic drainage in these patients.

Materials and Methods Data from children (0–16 years) who underwent pelvis-sparing pyeloplasty in our institution from 2007 to 2018 were analyzed retrospectively. We included only those patients for whom pre- and postoperative ultrasound and renal scan data were available. Patients with a decrease versus patients with an increase in APD were analyzed with regard to urinary drainage and reoperation.

Results Seventy-three patients who underwent follow-up at a mean of 3 months after operation were included; 61 showed a decrease in APD. Renal scan showed sufficient urinary drainage in 58 of them, with none requiring reoperation. Twelve patients had an increase in APD. Six of these showed free urinary drainage on renal scan; another six showed insufficient drainage, of whom five required reoperation. The positive predictive value of a decrease in APD was 1, and the negative predictive value of increase in APD was 0.42.

Conclusion To our knowledge, this is the first study evaluating the efficacy of ultrasound measurements to identify patients with decompensated urinary drainage during early follow-up after pyeloplasty with pelvis sparing. Post- versus preoperative decrease in renal pelvis diameter appears to be sufficient to rule out recurrence of obstruction. Renal scan seems to be indicated only in cases with post- versus preoperative increase in the APD of the renal pelvis on ultrasound.
On the Einstein-scalar field Lichnerowicz equations on compact Riemannian manifolds
Authors: Benalili Mohammed , Zouaoui Ali
Published: July 2019

In this paper, we investigate the existence of a positive solution to the Einstein-scalar field Lichnerowicz equation on the compact Riemannian manifold; we use a variational method which allows us to derive a new existence result which depends on the spectral properties of an appropriate operator. A Kazdan and Warner type obstruction is also found in the specific case when the initial value for the scalar field is a constant in the standard unit sphere.
Semiconductor–metal transition in GaAs nanowires under high pressure*
Authors: Liang Yi-Lan , Yao Zhen , Yin Xue-Tong , Wang Peng , Li Li-Xia , Pan Dong , Li Hai-Yan , Li Quan-Jun , Liu Bing-Bing , Zhao Jian-Hua
Published: July 2019

We investigate the structural phase transitions and electronic properties of GaAs nanowires under high pressure by using synchrotron x-ray diffraction and infrared reflectance spectroscopy methods up to 26.2 GPa at room temperature. The zinc-blende to orthorhombic phase transition was observed at around 20.0 GPa. In the same pressure range, pressure-induced metallization of GaAs nanowires was confirmed by infrared reflectance spectra. The metallization originates from the zinc-blende to orthorhombic phase transition. Decompression results demonstrated that the phase transition from zinc-blende to orthorhombic and the pressure-induced metallization are reversible. Compared to bulk materials, GaAs nanowires show larger bulk modulus and enhanced transition pressure due to the size effects and high surface energy.
Characteristics of prosthetic vision in rats with subretinal flat and pillar electrode arrays
Authors: Ho Elton , Lei Xin , Flores Thomas , Lorach Henri , Huang Tiffany , Galambos Ludwig , Kamins Theodore , Harris James , Mathieson Keith , Palanker Daniel
Published: July 2019

Objective. Retinal prostheses aim to restore sight by electrically stimulating the surviving retinal neurons. In clinical trials of the current retinal implants, prosthetic visual acuity does not exceed 20/550. However, to provide meaningful restoration of central vision in patients blinded by age-related macular degeneration (AMD), prosthetic acuity should be at least 20/200, necessitating a pixel pitch of about 50 µm or lower. With such small pixels, stimulation thresholds are high due to limited penetration of electric field into tissue. Here, we address this challenge with our latest photovoltaic arrays and evaluate their performance in vivo. Approach. We fabricated photovoltaic arrays with 55 and 40 µm pixels (a) in flat geometry, and (b) with active electrodes on 10 µm tall pillars. The arrays were implanted subretinally into rats with degenerate retina. Stimulation thresholds and grating acuity were evaluated using measurements of the visually evoked potentials (VEP). Main results. With 55 µm pixels, we measured grating acuity of 48  ±  11 µm, which matches the linear pixel pitch of the hexagonal array. This geometrically corresponds to a visual acuity of 20/192 in a human eye, matching the threshold of legal blindness in the US (20/200). With pillar electrodes, the irradiance threshold was nearly halved, and duration threshold reduced by more than three-fold, compared to flat pixels. With 40 µm pixels, VEP was too low for reliable measurements of the grating acuity, even with pillar electrodes. Significance. While being helpful for treating a complete loss of sight, current prosthetic technologies are insufficient for addressing the leading cause of untreatable visual impairment—AMD. Subretinal photovoltaic arrays may provide sufficient visual acuity for restoration of central vision in patients blinded by AMD.
On the use of entangled wire materials in pre-tensioned rocking columns
Authors: Ahmadi E , Kashani M M
Published: July 2019

This research explores potential application of entangled wire materials as intermediate layers between segments of pre-tensioned segmental bridge columns. An ensemble of free-decay vibration tests was conducted on small-scale columns with various configurations of intermediate layers. Wooden blocks were used for segments and the entire system was tightened together using a pre-tensioned steel tendon. Damping and frequency of the columns were determined and compared. It is demonstrated that entangled wire materials substantially increase total damping of the entire system in rocking. This result is very encouraging for future application of entangled wire materials in testing large-scale pre-tensioned segmental bridge columns. However, shear and axial stiffness of the layers require further improvement to reduce their large shear and axial deformations.
Identification of modal parameters in a lightly damped system based on impact vibration testing: Application of exponential window and removal of its effect
Authors: Tajiri Daiki , Matsubara Masami , Kawamura Shozo
Published: July 2019

The experimental environments for impact tests are simple to construct compared to other vibration tests in experimental modal analysis. However, given that sufficient sampling time is necessary for the response to attenuate, the following two problems arise: The first is that work efficiency is lowered. The second is that the measurement time increases, which makes it more susceptible to noise. To solve these problems, it is common to shorten the sampling time and apply an exponential window to reduce the leakage error of the frequency response function (FRF). Although studies on the influence on the FRF exist, identification accuracy for damping characteristic and the influence on the residue have not discussed. In this study, the influence on the modal properties obtained and the accuracy of the results are clarified using numerical examples based on a circle fit and method using simultaneous equations of the real and imaginary parts of the FRF. Finally, the identification results were compared and made sure that the method using simultaneous equations of the real and imaginary parts of FRF can identify modal properties with high accuracy. This method is effective for improving the working efficiency and reducing the influence of noise.
Vibration characteristics of an operating ball mill
Authors: Yoshida T , Kuratani F , Ito T , Taniguchi K
Published: July 2019

A ball mill, which is used to finely grind materials, causes high levels of vibration and sound during grinding operations. The vibration and sound of mills provide significant information about the internal conditions and can be used to estimate the status of the ground material. We developed a simulation model for the vibration of a mill wall to better understand the relationship between the operating conditions and wall vibration characteristics. The discrete element method can be used to predict the motion of the contents, which are grinding balls and material particles, and estimate the collision force between the balls and the mill wall. A finite element method vibration analysis is performed to calculate the time history response of the vibration from the estimated collision force by DEM. Simulations and experiments are performed to evaluate the influence of changing material particle diameter on the vibration characteristics. The results of experiments and simulations show the same tendencies. A decrease in material diameter reduces the vibration velocity of the mill. The developed simulation is useful for understanding the vibration characteristics of the mill because it could obtain information, such as individual particle element velocities, that is not available from the experiments.
Modelling of a train seat with subject exposed to lateral, vertical and roll vibration
Authors: Wu Jun , Qiu Yi
Published: July 2019

Considering the characteristics of ride vibration of a train, a multi-body dynamic model of a double-unit passenger seat exposed to lateral, vertical and roll vibrations was developed and calibrated using measured seat transmissibilities from the acceleration at the floor to the accelerations at both the seat pan and backrest in lateral, vertical and roll directions. With use of an existing seated human model, two coupled models of the double-unit seat with one and two subjects were then developed and calibrated using the corresponding measured seat transmissibilities. The models showed good agreement with the experimental data. Using these models, modal analysis was conducted to find out the modal properties of the human-seat system and facilitate discussions in relation to the resonances in the seat transmissibilities. It was found the primary peak in the vertical transmissibility of the seat pan may arise from the mode of human body. Two vibration modes around 15 and 30 Hz of the seat contributed to the peaks with approximate frequencies in the seat transmissibilities.
Free vibration of spring-mounted beams
Authors: Vijay Kumar S , Sarkar Abhijit , Padmanabhan Chandramouli
Published: July 2019

In the present work, free vibration characteristics of a spring-mounted beam is studied. The objective is to determine the natural frequencies and mode shapes of this beam. Towards this end, a novel semi-analytical method is developed. The methodology is based on Green’s function of Euler-Bernoulli beam together with a Rayleigh-Ritz method. A minimal set of basis functions for the Rayleigh-Ritz method is found, by generating the beam mode shapes for extreme values (zero and infinity) of the connecting spring stiffnesses. Thus, for a beam with n intermediate spring connections, 2
n
beam modes are generated as basis functions. The Green’s function approach is used to extract the beam mode shapes for the extreme values of the connecting spring stiffnesses. The results from the proposed formulation are compared with those from a finite element (FE) simulation. For most cases, the results obtained by the two methods are in excellent agreement. Guidelines for further improvement of the accuracy of the present results have been proposed. Detailed parametric studies on the effect of spring stiffness value and their location have been performed.
Investigation of the inerter-based dynamic vibration absorber for machining chatter suppression
Authors: Dogan Hakan , Sims Neil D , Wagg David J
Published: July 2019

This study proposes a novel approach to increase the chatter stability in machining operations. It shows the potential performance improvement when an inerter-based dynamic vibration absorber is employed in a machining operation. Tuned inerter based devices have been employed to decrease the magnitude of the vibrations in applications such as civil engineering structures and vehicle suspension systems but the nature of chatter in machining is different from these applications. Therefore, it requires a different tuning methodology to obtain the optimal design parameters. In this study, the machining operation is modelled as an undamped single degree of freedom system and different configurations of an inerter, a damper and two springs are used to ensure a stable region of operation. Strategies for the tuning parameters are developed both analytically and numerically. Using these techniques the performance improvement in the chatter stability provided by using inerter based devices instead of a traditional dynamic vibration absorber is demonstrated.
Tuning of Parametric Excitation for Rotor Balancing
Authors: Mendes Ricardo Ugliara , Dohnal Fadi
Published: July 2019

Residual unbalance is the primary source of vibration in rotating machines. In many cases, the time and, consequently, the cost involved in the balancing procedure is high due to the need to accelerate the rotor up to every critical speed to be balanced in every iteration of the traditional influence coefficients method. Recently, a novel method which does not need to accelerate the rotor up to every critical speed to be balanced was proposed. In this method, active magnetic bearings are used to apply a parametric excitation at the combination resonance frequencies inducing an effect similar to transferring kinetic energy from a lower mode to higher modes. Therefore, maximizing the energy transferred is mandatory to obtain a high signal-to-noise ratio and capture the correct responses of the higher modes to successfully balance the rotor. This paper study the sensibility of the kinetic energy transfer between modes to the parameters of the parametric excitation; namely amplitude, frequency, and phase. The analyses are performed via computational simulations of a flexible rotor sustained by two AMBs and with three critical speeds in its operational range.
Analysis of synthesized non-Gaussian excitations for vibration-based fatigue life testing
Authors: Troncossi Marco , Pesaresi Emanuele
Published: July 2019

Certain applications require that some critical components must undergo qualification tests to check their suitability with respect to vibration excitations. Measured field data are commonly considered as reference for the synthesis of random stationary signals used as excitations for shakers. The current procedures usually generate test profiles in terms of PSD, corresponding to random processes with Gaussian probability distribution of values. Such signals may be unrealistic in representing the characteristics of the reference data if the latter are not Gaussian. The Kurtosis parameter is often used to synthetically represent the amount and the amplitude of signal peaks. Its value is 3.0 for Gaussian signals, whereas higher values hold for signals featuring high peaks, e.g. due to micro-shocks. In case of accelerated fatigue life tests, the synthesized signal must induce, in a limited duration, the same fatigue damage which the reference signal cause on the component throughout its expected lifetime. The Fatigue Damage Spectrum (FDS) is generally used to quantify the fatigue damage potential associated with the excitation. The test signal is synthesized targeting the same FDS of the reference profile. This paper presents two kurtosis-control algorithms of signal synthesis in combination with a technique able to match the prescribed FDS.
Efficient parameter identification and model selection in nonlinear dynamical systems via sparse Bayesian learning
Authors: Fuentes R. , Dervilis N. , Worden K. , Cross E.J.
Published: July 2019

Bayesian inference plays a central role in many of today’s system identification algorithms. However, one of its major drawbacks is that it often requires solutions to analytically intractable integrals, and this has led to solutions via Markov Chain Monte Carlo (MCMC). Today, few Bayesian system identification methods can compete with the robustness of the family of MCMC solutions. However, MCMC suffers severely from its computational cost.

Partly fuelled by the field of Compressive Sensing (CS), an interest in the machine learning community has arisen in sparse linear regression. Its value in identification of dynamical systems has also recently started to receive some attention. The idea is to represent the range of possible candidate functional forms that have generated a specific data set using a dictionary, and to then apply standard Lasso regression to select the “best” basis, with sparsity constraints. A major problem in this approach is that Lasso regression (and its derivatives) requires tuning of the regularisation parameter. In this paper, a procedure for selecting the “best basis” (and thus performing both model selection and system identification) is presented through a sparse Bayesian learning approach. Sparsity is induced via a hierarchical Gaussian prior and an approximation to the posterior distribution is sought using an iterative optimisation scheme for finding the optimal hyper-priors that govern prior and hence, the level of sparsity in the solution. The method is applied to five systems of engineering interest, which include a baseline linear system, an additive quadratic damping term, cubic stiffness (Duffing oscillator), Coulomb damping and a Bouc-Wen hysteresis model. The results are shown using numerical simulations. It is shown that this approach can identify not only the correct model parameters, but whether a nonlinearity is present in the system as well its type. With the formulation being Bayesian, it also yields estimates of uncertainty over the selected basis functions and predicted responses.
Identification of a Duffing oscillator using particle Gibbs with ancestor sampling
Authors: Rogers T J , Schön T B , Lindholm A , Worden K , Cross E J
Published: July 2019

The Duffing oscillator remains a key benchmark in nonlinear systems analysis and poses interesting challenges in nonlinear structural identification. The use of particle methods or sequential Monte Carlo (SMC) is becoming a more common approach for tackling these nonlinear dynamical systems, within structural dynamics and beyond. This paper demonstrates the use of a tailored SMC algorithm within a Markov Chain Monte Carlo (MCMC) scheme to allow inference over the latent states and parameters of the Duffing oscillator in a Bayesian manner. This approach to system identification offers a statistically more rigorous treatment of the problem than the common state-augmentation methods where the parameters of the model are included as additional latent states. It is shown how recent advances in particle MCMC methods, namely the particle Gibbs with ancestor sampling (PG-AS) algorithm is capable of performing efficient Bayesian inference, even in cases where little is known about the system parametersa priori. The advantage of this Bayesian approach is the quantification of uncertainty, not only in the system parameters but also in the states of the model (displacement and velocity) even in the presence of measurement noise.
Learning of model discrepancy for structural dynamics applications using Bayesian history matching
Authors: Gardner P , Rogers T J , Lord C , Barthorpe R J
Published: July 2019

Calibration of computer models for structural dynamics is often an important task in creating valid predictions that match observational data. However, calibration alone will lead to biased estimates of system parameters when a mechanism for model discrepancy is not included. The definition of model discrepancy is the mismatch between observational data and the model when the ‘true’ parameters are known. This will occur due to the absence and/or simplification of certain physics in the computer model. Bayesian History Matching (BHM) is a ‘likelihood-free’ method for obtaining calibrated outputs whilst accounting for model discrepancies, typically via an additional variance term. The approach assesses the input space, using an emulator of the complex computer model, and identifies parameter sets that could have plausibly generated the target outputs. In this paper a more informative methodology is outlined where the functional form of the model discrepancy is inferred, improving predictive performance. The algorithm is applied to a case study for a representative five storey building structure with the objective of calibrating outputs of a finite element (FE) model. The results are discussed with appropriate validation metrics that consider the complete distribution.
Pulse shape discrimination performance of a pixelated plastic scintillator (EJ-299-34) for a coded-aperture based dual particle imaging system
Authors: Cieślak M.J. , Gamage K.A.A. , Glover R. , Taylor C.J.
Published: July 2019

The pulse shape discrimination performance of a pixelated organic plastic scintillator has been investigated. The scintillator has been built using 169 plastic scintillator blocks (arranged into a 13 × 13 square array) of 2.8 × 2.8 × 15 mm3each. The scintillator was coupled with a single-channel photomultiplier tube. The scintillator was exposed to a mixed-field environment provided by252Cf and its pulse shape discrimination capabilities are presented in this paper. Initial results revealed that a 150 MS/s digitising system was insufficient to separate neutrons from gamma-ray photons. Therefore, the experiment was repeated with a 500 MS/s system, which provided improved pulse shape discrimination performance. In order to validate the performance of the pixelated plastic scintillator, it was compared to that of a cylindrical plastic sample. Tests were also carried out in moderated neutron and gamma-ray fields of252Cf. The results indicate that acceptable levels of pulse shape discrimination are obtained for the case of a pixelated scintillator, when the higher sampling rate digitiser was used.
The global and regional impacts of climate change under representative concentration pathway forcings and shared socioeconomic pathway socioeconomic scenarios
Authors: Arnell N W , Lowe J A , Bernie D , Nicholls R J , Brown S , Challinor A J , Osborn T J
Published: July 2019

This paper presents an evaluation of the global and regional consequences of climate change for heat extremes, water resources, river and coastal flooding, droughts, agriculture and energy use. It presents change in hazard and resource base under different rates of climate change (representative concentration pathways (RCP)), and socio-economic impacts are estimated for each combination of RCP and shared socioeconomic pathway. Uncertainty in the regional pattern of climate change is characterised by CMIP5 climate model projections. The analysis adopts a novel approach using relationships between level of warming and impact to rapidly estimate impacts under any climate forcing. The projections provided here can be used to inform assessments of the implications of climate change. At the global scale all the consequences of climate change considered here are adverse, with large increases under the highest rates of warming. Under the highest forcing the global average annual chance of a major heatwave increases from 5% now to 97% in 2100, the average proportion of time in drought increases from 7% to 27%, and the average chance of the current 50 year flood increases from 2% to 7%. The socio-economic impacts of these climate changes are determined by socio-economic scenario. There is variability in impact across regions, reflecting variability in projected changes in precipitation and temperature. The range in the estimated impacts can be large, due to uncertainty in future emissions and future socio-economic conditions and scientific uncertainty in how climate changes in response to future emissions. For the temperature-based indicators, the largest source of scientific uncertainty is in the estimated magnitude of equilibrium climate sensitivity, but for the indicators determined by precipitation the largest source is in the estimated spatial and seasonal pattern of changes in precipitation. By 2100, the range across socio-economic scenario is often greater than the range across the forcing levels.
Problems of energy and resource efficiency in heat and power engineering: water treatment
Authors: Bushuev E.N. , Larin B.M. , Karpychev E.A.
Published: July 2019

An analysis is submitted of the main developments in energy and resource efficiency both in currently operating water treatment systems and those being put into service. A big potential for energy efficiency exists in reverse osmosis installations regarding reduced source water consumption and also disposal of concentrate forming in the water treatment system cycle. A promising development in energy saving is reducing the temperature of raw water warming.
Technology for cleaning off-gases from dust in vortex devices with closed water circulation
Authors: Mahotkin A. F. , Mahotkin I. A. , Starkova A. V.
Published: July 2019

Annotation

The results of the development and implementation in the production of highly efficient technology of wet cleaning of waste gases from dust to solve environmental problems of the processes of burning waste of small limestone in rotary kilns. For the first time in industrial conditions is reached: modern sanitary standards of cleaning gases, full utilization of collected slurry and closed-loop water circulation.
About the results of experimental study performed on a “decarbonizer – vacuum deaerator” system
Authors: Orlov M E , Sharapov V I
Published: July 2019

The paper discloses the results obtained in experimental study, implemented at an operating water treatment unit of the thermal power plant. The study was carried out via using the method of a complete factorial experiment. As a result of the experiments, the dependencies between objective functions and a number of controlled parameters have been determined. Regression equations have been derived and cross-sections of the response surfaces have been constructed in a natural scale, that adequately describe the processes of corrosive gases desorption within the “decarbonizer - vacuum deaeratof’ system. The data obtained allows one to assess the minimal technologically acceptable level, when it is possible to lower the temperature of the treated water and, consequently, to reduce the energy costs for its heating, and to specify the conditions when the reduction of the energy costs for supplying air to decarbonizer is possible.
Mathematical calculation of additional cooling methods to achieve the established temperature regime at the reservoir-cooler of Zainskaya state district power plant
Authors: Vinogradov A S , Gribkov A M , Filimonova A A , Chichirova N D , Chichirov A A
Published: July 2019

A natural and technical complex, including the industrial part - the turbine condenser and cooling system, and the natural part - the cooling reservoir with the surrounding atmosphere, is one of the options for the operation of the circulating system technical water supply of thermal power station and nuclear power station. For cooling equipment Zainskaya state district power plant as a pond-cooler is used Zainskoe reservoir. According to the available data on the reservoir-cooler of Zainskaya state district power plant, the average water temperature in comparison with the natural temperature of the water body in summer months exceeds the current requirements, which negatively affects the functioning of the reservoir and the operation of the power plant itself. The mathematical analysis of the reservoir cooling capacity and the technical justification for the introduction of additional methods for achieving the optimum temperature regime at the point of heat exchange water discharge of the Zainskaya state district power plant are carried out in the article. According to the obtained results, the expected water temperature in the hottest month of the year as a result of wastewater discharge will not exceed a critical temperature maximum of 28 ° C.
Integrated use of lake-type basin-coolers for recreational purposes
Authors: Gordeeva M E
Published: July 2019

At present the bulk of all water bodies in the Russian Federation and the Republic of Tatarstan in particular is experiencing significant anthropogenic impact. One of the types of impact is thermal. The article shows the positive effects of thermal contamination on lake-type basin-cooler such as increasing of the concentration of dissolved oxygen in the water in winter, improving the state of bottom sediments as a result of the water circulation, and expanding the possibilities of aquaculture. The possibilities of integrated use of lake-type coolers for recreational purposes are shown (combining the technical use of lake water with recreational purposes through the implementation of sporting events and the creation of a park and observation zone on the lake).
Problems and perspectives of using warm waters of the state district power station in solving the provision of the population with fish
Authors: Govorkova L K , Kalayda M L
Published: July 2019

One of the sources of increasing fish production in Russia is intensive fisheries development of cooling reservoirs of thermal power plants and nuclear power plants. Cooling reservoirs have a unique temperature regime, which differs from natural water bodies by a higher temperature throughout the year. The increased water temperature causes changes in the quantitative and qualitative composition of the forage reserve, the ichthyofauna, the habitat of the hydrobiont and creates favorable opportunities for the introduction of a complex of thermophilic fishes and enhance the fish productivity of water bodies. The rise in water temperature also accelerates chemical and biochemical processes, promotes the intensive decomposition of organic substances, influences the gas regime of the reservoir, as a result, there may be overseas phenomena and the death of fish in cooling reservoirs. Therefore, the growing of aquaculture objects, the most resistant to high temperatures and temperature and gas changes, is becoming topical.
Features of the hydrobiocenosis of the Kuibyshev reservoir in conditions of local pollution
Authors: Khamitova M F , Kalayda M L
Published: July 2019

A complex ecological situation develops in the area of the largest reservoir of the Volga cascade – Kuibyshev, especially in the areas of concentration of population and production. In connection with the development of aquaculture, the problems of conservation and reproduction of sterlet in the Kuibyshev reservoir become actual. Taking into account the tasks of preserving water quality in the upper part of the Volga reach of the Kuibyshev Reservoir as a spawning site of sturgeon in the early 20th century, special attention was paid to the impact of waste water discharges from the Mari Pulp and Paper Mill (JSC “MTSBK”). The hydrochemical and hydrobiological characteristics of section of the Volga reach of the Kuibyshev reservoir and secondary settler of JSC “MTSBK” were studied. The change in the qualitative and quantitative characteristics of the hydrobiocenosis in the conditions of functioning water treatment plant was shown.
Mathematical modeling of surfactant self-organization in water solution in the presence of carbon nanotubes
Authors: Zueva O S , Rukhlov V S , Gazeeva E V , Mongush Y K
Published: July 2019

Based on the experimental results mathematical modeling of surfactant molecules organization in aqueous solutions into nanostructured formations was performed. The effect of the addition of carbon nanotubes on the processes was investigated. Numerical calculations of CTAB micelles dimensionless electrostatic potential were carried out in the framework of two most commonly used approximations: the Poisson-Boltzmann model and the jellium-approximation model for various surfactant concentrations in the presence and without of carbon nanotubes. A calculation procedure was developed that made it possible to determine the region of the most active counterions redistribution. The possibility of the interaction between micelles was noted, as a result of which a common self-consistent electric field appears, leading to spatial ordering in the bulk of solution. It was shown that there is a more rapid decay of the potential for the case of CTAB micelles in the presence of carbon nanotubes, which may indicate a change in the micelles morphology and their transition to a more compact form. It has been suggested that because increasing in the local surfactant concentration is observed near the carbon surface, carbon nanotubes can act as stimulators for the formation and growth of supramolecular structural complexes.
Efficiency of an alternative LED-based grow light system
Authors: Kulikova E.G. , Efremova S.Yu. , Politaeva Natalia , Smyatskaya Y.
Published: July 2019

This article is dedicated to the assessment of the usage influence of LED lights of varying color spectrum on plant growth and development, and determining their usage impact. The research interest is focused on the usage of LED-based light system inside greenhouses for optimization of lighting conditions.

Research methods. The current research focused on the following Green-LP™ LED-based grow lights: GLP-FH-56-B (30/70 % red(660 nm)/blue(445 nm) spectral composition), GLP-FH-56-R (70/30 % red/blue spectral composition) and GLP-FH-56-RB (50/50 % red/blue spectral composition). Examination of the influence of plant lamps on the growth processes was carried out at the laboratory conditions (23 °C during the day and 20 °C at night, humidity from 75 % to 80%, with the varying PAR intensity and the daylight of 16 h (supplementary illumination was provided for 6 to 8 hours)) with lettuce as a subject. Phenological observations and biometric registrations were conducted according to generally accepted techniques. Chlorophyll content was measured using the express method with atLEAF+ device. Results. Based on the results of the conducted experiments the highest germination rate was observed under the lamps with blue and blue-red spectral peaks, salad seedlings had largest shoot fresh weight under grow lights with red and blue-red spectrum peaks (0.235 and 0.250 g, respectively). The shoot weight exceeded that of control group of plants 1.8 to 2.1 times. Additionally, plants grown under the lamp with a blue spectral peak had 17 to 29 % more powerful root system than those grown under red one and 43 to 73 % higher than control group. Highest chlorophyll content was observed in plants grown under the lamps with blue spectral peak (440-450 nm), which exceeded by two times that in plants grown without supplementary illumination and was 1.8 times higher than that of plants grown under a high-pressure sodium arc lamp.

Conclusion. LED lamps with different illumination spectrum can serve as an additional light source for plants grown inside greenhouses, positively affecting both growth and development of plants, and economical efficiency.
Gas-filled thermal insulation use in heat supply
Authors: Krasnova NP , Gorshenin AS , Rakhimova JI
Published: July 2019

The possibility of applying a new type of thermal insulation, which will significantly reduce heat losses during transportation of heat, increase the service life of the pipeline, and reduce the cost of heat insulation work considered. Using multi-layer thermal insulation, which is a system of closed, sealed microvolumes (pores), which are filled with carbon dioxide proposed. As a shell, high-density polyethylene is used. Such a film can be used as a ready-made material for insulation of pipelines. Depending on the temperature of the pipeline, the required number of layers of thermal insulation is applied to the pipeline.
Heat and mass exchange packing with adjustable parameters for absorption and evaporation cooling
Authors: Persidskiy A.V. , Merentsov N.A. , Lebedev V.N. , Golovanchikov A.B.
Published: July 2019

Data of experimental study of hydrodynamics, heat and mass transfer of packing with adjustable parameters and some comparative characteristics of the packed device with packing, which have wide industrial application, are given in the article.
Assessment of transport losses of heat at change of properties of thermal isolation
Authors: Vankov Yu.V. , Bazukova E.R. , Gavrilov A.S.
Published: July 2019

Research is devoted to increase in system effectiveness of transportation of thermal energy. The control system of thermal insulation properties realized in the environment of LabVIEW is developed. Assessment of transport losses of heat taking into account real service conditions of pipelines and heterogeneity of thermal insulation properties is carried out. Influence of extent of aging of thermal isolation on increase in size of density of a thermal stream is shown. Calculation of specific thermal losses of an elevated steam line taking into account thermal destruction of isolation is carried out.