bluuebunny/crossref_metadata_2025_split huggingface dataset:
Signature Investigation of Typical Faults on Francis Turbines
Authors: Støren G K , Dahlhaug O G , Solemslie B W 
Published: August 2020

Abstract
Hydropower is facing new operational strategies as the increasingly competitive power market demands for higher flexibility. Consequently, turbines are forced to handle tougher operation and are prone to more frequent degradation. By implementing a real-time monitoring system, a better understanding of the behavior of components may contribute to detect faults at an earlier stage, reducing potential downtime. This paper will present the work done in the preliminary work of the author’s master thesis. The focus has been to characterize the normal behaviour of a Francis turbine through amplitude and frequency analysis. Steady-state measurements of pressure pulsations have been conducted on the Francis test-rig at the Waterpower laboratory at NTNU. Different hydraulic phenomena and respective frequencies were identified. In addition, the results revealed several unexpected frequencies and suspicious observations, and potential sources of these are discussed. Possible fault detection schemes based on peak-peak and frequency analysis are suggested. Alarm should be raised in case of mismatches in sensor relations, magnitude variations or if new harmonics or frequencies appears.
Uncertainty evaluation of efficiency measurement in laboratory conditions
Authors: Dhakal Prabin , Adhikari Manish , Thapa Biraj Singh , Kayastha Atmaram , Sapkota Prajwal , Dahal Dadi Ram 
Published: August 2020

Abstract
Uncertainty is a parameter associated with the result of a measurement, which characterizes the dispersion of the values that could reasonably be attributed to the measurand. All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by a statement of the associated uncertainty, such as standard deviation or uncertainty band.
The identification of uncertainty of individual sensors and standardization in calibration process is under progress in Turbine Testing Lab (TTL) at Kathmandu University (KU). The lab aims to establish a Francis turbine test rig and procedures that meet the standards set by International Electrotechnical Commission (IEC). This needs a major investment on calibration systems and development of procedures to estimate the uncertainty in measurement more precisely than ever before.
This study aims to identify the sources of uncertainty and their quantification for efficiency measurement systems at laboratory condition. The study is done on the 14 kW Francis turbine project at TTL, KU. Based on different published papers regarding uncertainties, type A and type B uncertainties were evaluated separately and then combined to get combined uncertainty of each components. The uncertainty in efficiency was then calculated using the rules of uncertainty calculation.
In this paper, the standard method is illustrated to evaluate the uncertainties in sensor-based measurement system. The same method is used in investigation of uncertainty to the extent it was possible and feasible in the lab i.e. study could be mainly focused only on torque transducer. The value of efficiency at 1300 rpm is calculated to be 66.7% ± 0.35%, where ± 0.35% represents the uncertainty in efficiency for the same rpm value. The results indicate uncertainty level unforeseen close to meet the IEC standards which could be result of including only parts of uncertainties. All uncertainties should be evaluated for future research papers.
An Overview of Design and Construction practices of Himalayan Hydropower tunnels
Authors: Karki Sujan , Chhushyabaga Bimal , Khadka Shyam Sundar 
Published: August 2020

Abstract
Due to steep terrain and fast flowing rivers in the Himalayan region of Nepal, medium to mega size hydropower projects are constructing day-by-day. Tunnel is one of the best and short routes for water conveyance system for power production. Hundreds of kilometers of tunnels have been constructed and new tunnels are planned in this region. The availability of high head for hydropower generation, the tunnel cross sections are relatively small, up to 6 m diameter in size, and there is high rock cover above the tunnel alignment. This paper focuses on the design and construction practices of hydropower tunnel passes through weak rock mass with high rock cover of the Himalayan region of Nepal. Most of the hydropower tunnels undergo excessive deformation and support failure during the tunnel construction, which delayed the project as well as increases the cost of project. The paper first discusses the available construction practices for tunnel and underground structures. In the second part, the current practice employed during construction in the Himalayas is discussed along with the shortcomings of the methods and how it is addressed in the region.
Tunnel support design in fault zone in hydropower project in the Nepal Himalaya: a case study
Authors: Chhushyabaga Bimal , Karki Sujan , Khadka Shyam Sundar 
Published: August 2020

Abstract
Tunnelling through faulted rock mass is associated with long lasting displacements, stability problems, overburden squeezing, high deformations and dynamic stress conditions. With the dominance of faults in the Nepal Himalaya, determination of behaviour of the rock mass around tunnels and physical parameters for tunnel support is very challenging and demanding. Tunnel support and rock mass stability in tunnel are always dominated by fault. In this paper a hydropower tunnel in the vicinity of a fault has been used as a case study for the design and application of tunnel support. Rock mass is characterized, behaviour of the unsupported rock mass is evaluated, and support is designed. Geological Strength Index (GSI) is used to characterize the rock mass and a methodology has been used to design the support using numerical analysis The system behaviour of the rock mass and the tunnel support are analysed for the various combinations of geomechanical ground conditions. The displacement, stress, yielded elements and plastic region are studied for the influence of the fault and its stress conditions of the designed tunnel supports.
Application of Reverse Engineering method to model eroded Francis runner.
Authors: Sedai Ashish , Thapa Biraj Singh , Thapa Bhola , Kapali Aman , Qian Zhongdong , Guo Zhiwei 
Published: August 2020

Abstract
Damage of runners and other components of hydro turbine by sediment erosion and cavitation erosion is an inevitable problem associated with hydropower established in a region with mountainous topology. The paper attempts to investigate the suitability and sustainability of the reverse engineering method for the design of the eroded Francis runner. This manufacturing technology is in a progressive phase of development in various parts of the world, so research scholars have been constantly working on the concept to increase the speed and efficiency of the method. The case investigation was conducted on Puwa-Khola 1HPP eroded Francis runner. The paper investigates reverse engineering design methodology of the eroded runner and discusses scope and limitation in the utilization of method at Hydropower sector. Also, the paper suggests suitable 3D scanning techniques, reverse engineering tools, and optimization methods for obtaining mathematically sound models without any hydraulic profile deviation between actual and reversed engineered model.
Experimental and CFD study of influence of sediment size on efficiency of hydrocyclone for use as sediment separation device
Authors: Kapali A. , Neopane H.P. , Chitrakar S. , Kayastha A. , Shrestha O. 
Published: August 2020

Abstract
Hydrocyclones are separation devices used in several industrial applications for separation of particles even smaller than 5 μm. However, this paper presents the feasibility of using hydrocyclone as a sediment separation system in hydropower plants, as well as in the development of a non-recirculating type of an erosion test rig. The design of the experimental set up is a part of the erosion test rig that consists of a discrete sediment feed and separation system to conduct erosion related research. Experimental as well as numerical investigation of effect of sediment particles sizes on overall separation efficiency of hydrocyclone geometry is conducted. Hydrocyclone’s overall efficiency is depicted by measuring the particle separation and its variation with sediment particle’s size. The results indicated that under appropriate flow conditions, particles below 200 μm that are responsible for turbine wear can be separated and prevented from entering into the system. Also, it can be concluded that this system can be used to develop non-recirculating type of erosion test rig.
Method of erosion prediction hill diagram to investigate the performance of Francis turbine operated in sediment laden water
Authors: Lama Ram , Gautam Saroj , Chitrakar Sailesh , Neopane Hari Prasad , Thapa Biraj Singh 
Published: August 2020

Abstract
Sediment erosion problem in hydropower plants located under Himalayan regions of Nepal is inevitable. Reliance to the performance curves from model test data in terms of hydraulic efficiency cannot predict the actual performance in context of sediment laden hydropower projects in Nepal. This paper presents novel technique to predict the erosion affecting regions in various operating points in terms of sediment erosion hill diagram. A 2-D representation of erosion rate in several operational points is presented in this paper. This representation is compared with the efficiency characteristics of the same turbine that will be useful for considering the compromise between efficiency and erosion wear for erosion affected hydropower projects. A reference hydropower projects severely affected with sediment erosion is chosen for this study. Using suitable numerical modelling technique, performance of the turbine is calculated in terms of efficiency. Similarly, area averaged erosion rate in the walls of the numerical model was computed at various operating condition. It gives the idea that the turbine can be operated in variable speed operation that in one hand improves the efficiency and minimizes the erosion effects as well.
Green Hydrogen as a Future Multi-disciplinary Research at Kathmandu University
Authors: Thapa Biraj Singh , Thapa Bhola 
Published: August 2020

Abstract
Over 100 million tons of hydrogen are produced every year for a range of industrial purposes. The vast majority of this industrial hydrogen is produced from coal gasification or steam methane reforming, both of which need a lot of energy and generate significant carbon dioxide emissions. A much smaller proportion of hydrogen is produced from the electrolysis of water, which can be a far more sustainable and clean method if the electricity is produced from renewable sources. While the urgency of greenhouse gas emission mitigation has increased, many countries have begun to take action to decarbonize their economies. Nepal is expected to have about a 3000 MW electricity surplus by the Year 2030. It is a time to explore alternative use of electricity to make hydropower projects financially feasible. Hence it is also high time to investigate Hydropower-to-Hydrogen (H2H) technology and transfer the relevant knowledge in the region. Kathmandu University (KU) has been leading to initiate and institutionalize the new academic programs and research avenues to address the future need for this country. KU has played a role model to introduce and establish innovative and unique programs in engineering education in Nepal since it was established in 1994. Since the establishment period, KU carried the vision to establish itself as a research-based university. KU has carried the objective to design its academic programs, courses, and curricula to directly contribute to the research problem the industry or society has been facing. The intuitional realization that Green Hydrogen (GH) is the future academic and research need of this country will be the far-slightness of KU.
Structural change to the persistence of the urban heat island
Authors: Dupuis Debbie J , Trapin Luca 
Published: August 2020

Abstract
The term urban heat island (UHI) is used to describe the effect of urban temperatures rising several degrees above concurrent temperatures in surrounding suburban or rural areas. This is typically assessed through records of daily extreme temperatures. However, on a hot day the temperature can exceed an extreme threshold for several consecutive hours, forming a cluster of extremes. We use the statistical theory of extreme values combined with a model that allows structural breaks to show that there has been a significant upward shift in the length of clusters in New York City. No such shift is found at a Connecticut location where the usual UHI assessment indicates that the two sites are comparable. Our study is the first to highlight this danger of the UHI. Prolonged exposure to extreme temperatures has deleterious effects on both health and the environment.
Momentum-dependence in the infinitesimal Wilsonian renormalization group
Authors: Helias Moritz 
Published: August 2020

Abstract
Wilson’s original formulation of the renormalization group is perturbative in nature. We here present an alternative derivation of the infinitesimal momentum shell renormalization group, akin to the Wegner and Houghton scheme, that is a priori exact. We show that the momentum-dependence of vertices is key to obtain a diagrammatic framework that has the same one-loop structure as the vertex expansion of the Wetterich equation. Momentum dependence leads to a delayed functional differential equation in the cutoff parameter. Approximations are then made at two points: truncation of the vertex expansion and approximating the functional form of the momentum dependence by a momentum-scale expansion. We exemplify the method on the scalar φ
4-theory, computing analytically the Wilson–Fisher fixed point, its anomalous dimension η(d) and the critical exponent ν(d) non-perturbatively in d ∈ [3, 4] dimensions. The results are in reasonable agreement with the known values, despite the simplicity of the method.
TiO2 Synthesis Anatase Phase with The Sol-gel Process at Room Temperature
Authors: Argüelles-Lucho P , Pérez-Cuapio R , Woo-Garcia R M , García-González L , Pacio M. , López-Huerta F 
Published: August 2020

Abstract
Titanium oxide (TiO2) film was deposited on 304 stainless steel substrates using the spin coating technique. The synthesis of the deposited solution was with the sol-gel method at room temperature, using titanium isopropoxide as a precursor. Obtained film was thermally treated at temperatures of 500 °C, 550 °C and 600 °C. The X-ray diffraction (XRD) analysis confirmed the crystallinity of the film in the anatase phase, with the highest intensity at the plane (101). Moreover, the crystallite size increased with the rising temperature of the thermal treatment. The thickness of the deposited film was obtained with profilometry being: 1 µm for the 500 ºC film, 1.2 µm for the 550 ºC film, and 1.5 µm for the 600 ºC film. Raman spectroscopy measurements showed vibrational modes at 144, 399, 519 and 638 cm−1, characteristic of the TiO2 anatase phase. The obtained results showed that these films have a high potential for gas sensor applications due to their surface-to-volume ratio after obtaining the size of nanometric crystallite.
Smart Materials Vis-à-vis Metamaterials
Authors: Qadeer Malik Malik Abdul 
Published: August 2020

Abstract
Smart materials are custom-designed materials that have certain properties that can undergo significant changes as guided through external influence, such as pressure, temperature, pH, electric or magnetic fields. One of the most amazing developments in the smart materials is that of metamaterials. The origin of Meta stems from Greek meaning “beyond”. Metamaterials have rare properties not found in natural occurring materials such that their properties are based on their structure rather than material of their composition. These materials find applications in many fields like public safety, sensors, battlefield communication, ultrasonic devices, solar power equipments, and remote aerospace applications. A synthetic composite material with a structure such that it possesses properties being unusual in natural materials specially a negative refractive index-these materials scatter electromagnetic wave unlike any known material. Thus the shape of the wave emerging from the metamaterials is entirely different from a conventional wave. Besides having a myriad of applications, these materials have the remarkable ability to bend light which can make airplanes, tanks and submarines invisible resulting in the epitome of stealth capability. Metamaterials now find recognition as an enabling technology being the most exciting research area at the crossroads between photonics and nanoscience. Without any exaggeration, the present era is the century of metamaterials. This paper, inter alia, highlights the significance of metamaterials in general and its stealth capabilities for defence sector in particular.
Synthesis and Characterization of Thin TiO2 Films Using the Sol-gel dip Coating Method
Authors: Woo-Garcia R M , García-González L , Argüelles-Lucho P , Guarneros-Aguilar C , Cervantes B , Herrera-May A L , López-Huerta F 
Published: August 2020

Abstract
TiO2 titanium oxide is a material with many applications, due to its electronic and optical properties, the characterization of the nanostructures developed with this material is carried out in order to determine its physical, chemical, and mechanical properties. This article presents the results of TiO2 multilayered thin film deposited in Corning glass substrate with the immersion technique using the Sol-gel dip coating method. The quality of the film strongly depends on the internal forces of the polymeric chains which lead to viscosity, gravitational force, surface tension, and gravity as an efficient form of obtaining TiO2 thin film. The film was submitted to thermal treatment of 400 ºC for 2 hours. The results of the experiment show film with a thickness from 139 to 171 nm that features anatase phase, a crystalline quality that corresponds to the number of deposited layers and have a bandgap close to 3.5 eV. The results show that TiO2 thin film can be used in applications that require high permittivity or high transmittance.
The effect of forced oscillations on the kinetics of wave drift in an inhomogeneous plasma
Authors: EROFEEV V I 
Published: August 2020

Abstract
The kinetics is analyzed of the drift of non-potential plasma waves in spatial positions and wavevectors due to plasma’s spatial inhomogeneity. The analysis is based on highly informative kinetic scenarios of the drift of electromagnetic waves in a cold ionized plasma in the absence of a magnetic field (Erofeev 2015 Phys. Plasmas
22 092302) and the drift of long Langmuir waves in a cold magnetized plasma (Erofeev 2019 J. Plasma Phys.
85 905850104). It is shown that the traditional concept of the wave kinetic equation does not account for the effects of the forced plasma oscillations that are excited when the waves propagate in an inhomogeneous plasma. Terms are highlighted that account for these oscillations in the kinetic equations of the above-mentioned highly informative wave drift scenarios.
Test parameters optimization for constrained spray forming of aluminum alloy based on artificial neural network
Authors: Liu Yingli , Yao Changhui , Yin Jiancheng 
Published: August 2020

Abstract
Spray deposition with following continuous extrusion (SD-CE) forming technique is a novel technology that combines spray forming and continuous extrusion. Optimization of test parameters for spray deposition is an important part of SD-CE. In this study, Al-20Si alloy was produced by spray forming at different melt temperature and gas pressure, and obtained grain diameter of 8 group primary silicon phase. Based on the experimental results, an Artificial Neural Network (ANN) with single hidden layers composing of 10 neurons was employed to simulate optimizing of test parameters for spray deposition. The inputs of the model are melt temperature and gas pressure. The output of the model is grain diameter. Finally, the minimum relative error of grain diameter is 0.09%, the maximum relative error is 8.38%, and error majority concentrate within 3.80%, the average absolute relative error(AARE) is 1.04%, R is 0.097, the error is small. The optimal test parameters for spray deposition are melt temperature(829 °C) and gas pressure(0.2 MPa). The results indicate that the ANN model is an easy and practical method to optimize the test parameters for spray deposition of Al-20Si alloy. Thereby this model is a useful reference for optimizing the test parameters of SD-CE
Waveguide controlled long range surface plasmon-polariton refractive index sensor
Authors: Sharma Vinod K 
Published: August 2020

Abstract
A long range surface plasmon-polariton resonance (LRSPPR) based refractive index sensor (for biomolecular interaction study applications) with ultrahigh sensitivity and extremely narrow resonance dips with very small full width at half maximum (FWHM, w) is proposed. The theoretical analysis of the sensitivity for spectral and angular interrogations is presented. The structure consists of a MgF2 prism and a plasmonic waveguide (consisting of a metal cladded high index dielectric waveguide) separated by a low index dielectric layer. It is shown that both angular and spectral sensitivities increase nonlinearly with increase in analyte index. Angular sensitivity with FWHM = 0.009°, ranges from 340°/RIU to 505°/RIU for analyte index variation from 1.360 to 1.368 and spectral sensitivity with FWHM = 3 nm, ranges from 1.79 × 105 nm RIU−1 to 2.60 × 105 nm RIU−1 for analyte index variation from1.361 00 to 1.361 10. The sensitivities (S) and the figures of Merit of the proposed sensor are the highest obtained so far (to our knowledge).
In-hospital adverse drug reactions in older adults; prevalence, presentation and associated drugs—a systematic review and meta-analysis
Authors: Jennings Emma L M , Murphy Kevin D , Gallagher Paul , O’Mahony Denis 
Published: August 2020

Abstract

Background
the prevalence of adverse drug reactions (ADRs) in hospitalised older patients, their clinical presentations, causative drugs, severity, preventability and measurable outcomes are unclear, ADRs being an increasing challenge to older patient safety.

Methods
we systematically searched PubMed, Embase, EBSCO-CINAHL, the Cochrane Library, ‘rey’ literature and relevant systematic review bibliographies, published from database inception to March 2020. We included any study reporting occurrence of in-hospital ADRs as primary or secondary outcomes in hospitalised older adults (mean age ≥ 65 years). Two authors independently extracted relevant information and appraised studies for bias. Study characteristics, ADR clinical presentations, causative drugs, severity, preventability and clinical outcomes were analysed. Study estimates were pooled using random-effects meta-analytic models.

Results
from 2,399 abstracts, we undertook full-text screening in 286, identifying 27 studies (29 papers). Final analysis yielded a pooled ADR prevalence of 16% (95%CI 12–22%, I2 98%,τ2 0.8585), in a population of 20,153 hospitalised patients aged ≥65 years of whom 2,479 patients experienced ≥ one ADR. ADR ascertainment was highly heterogeneous. Almost 48.3% of all ADRs involved five presentations: fluid/electrolyte disturbances (17.3%), gastrointestinal motility/defaecation disorders (13.3%), renal disorders (8.2%), hypotension/blood pressure dysregulation disorders/shock (5.5%) and delirium (4.1%). Four drug classes accounted for 57.8% of causative medications i.e. diuretics (19.8%), anti-bacterials (14.8%), antithrombotic agents (12.2%) and analgesics (10.9%). Pooled analysis of severity was not feasible. Four studies reported the majority of ADRs as preventable (55–95%).

Conclusions
on average, 16% of hospitalised older patients experience significant ADRs, varying in severity and mostly preventable, with commonly prescribed drug classes accounting for most ADRs.