bluuebunny/crossref_metadata_2025 huggingface dataset:
Reservoir gas losses at UGS facilities in aquifers
Authors: Mikhailovsky Alexander A.
Published: October 2022

Experience shows that in the process of creating and long-term cyclic operation of underground gas storage facilities (UGS) in reservoirs of aquifers, reservoir gas losses can occur. Losses can reach tens of percent of the injected volumes of gas into the reservoir and have a significant impact on the reliability and safety and efficiency of operation of UGS. In this regard, the issues of the organization of field control and methodology for assessing reservoir gas losses at UGS are relevant.

The article proposes the structuring of the gas injected into the reservoir into possible reservoir components, taking into account the state of the gas phase and participation in filtration mass transfer processes. The main factors determining the formation of different reservoir components are given. The basic concepts are considered and the definition of reservoir gas losses at UGS in aquifers is given. The main features of one or another type of reservoir gas losses are shown.

Reservoir losses from free gas currents from an artificial gas deposit, which can occur as a result of vertical leaks from the storage facility and lateral gas escapes through the reservoir beyond the trap, are briefly described. Formation losses associated with gas adsorption by rocks, gas phase transitions and gas saturation of low-permeable sections of reservoirs; gas dissolution in invading reservoir water and its convective-diffusion entrainment by displaced water into the aquifer region of the reservoir are also considered.

Using the example of a UGS created in an aquifer, the system of geological and commercial monitoring of a subsurface area within a mining branch in conditions of vertical interplastic flows of free gas is considered. It is shown that the implemented system of observation and control wells allows for adequate monitoring of the gas storage facility and control of the tightness of UGS throughout the section above the storage facility.

The following components of reservoir gas losses at the storage facility are considered: dissolved gas in residual water within the gas reservoir; gas adsorbed by rocks within the gas reservoir; dissolved gas diffused from the gas reservoir into the contact aquifer region of the reservoir; dissolved and free gas in the control horizons. Using a geological model of the formation, as well as the results of modeling the convective-diffusion transfer of dissolved gas into the aquifer region of the formation, the assessment of the components of reservoir gas losses in a direct way by their locations is given.
Karagaikul gold-porhyric ore occurrence (South Urals): geochemistry and petrogenesis of intrusive rock, composition of minerals of near-ore metasomatites and ores
Authors: Znamensky Sergey E. , Kosarev Alexandr M. , Shafigullina Gulnara T.
Published: October 2022

The petrological and geochemical characteristics of intrusive rocks, sources of magmatic melts, as well as the composition of minerals of near-ore metasomatites and ores of the Karagaikul gold-porphyry ore occurrence located in the Main Ural fault zone in the South Urals have been studied. The content of petrogenic oxides was determined by the silicate method, rare elements – using ICP-MS analysis on a quadrupole mass spectrometer ELAH 9000. The composition of minerals was studied using electron microscopic analysis on a scanning electron microscope REMMA-202M. It was found that gabbro, gabbro-diorite and diorite of the ore-bearing dyke series of the Karagaikul ore occurrence are suprasubduction magmatites of normal alkalinity belonging to the transitional and calc-alkaline petrogenetic series. They were formed from fluid-saturated melts. The main source of melts for intrusive rocks was most likely spinel peridotites of the suprasubduction lithospheric mantle, previously metasomatized by aquatic fluids that arose during the dehydration of rocks of the subducting oceanic plate. The dykes underwent propylitization of the biotite-actinolite facies in a near-ore halo (paragenesis: biotite + actinolite + epidote + orthoclase + albite + quartz + chlorite + pumpelliite), and the host serpentinized ultrabasites – carbonatization (chromogenesis: dolomite + magnesite). According to the chlorite geothermometer, the temperature of propylite formation is 287–317 °С. Sulfide minerals in gold-bearing stockworks are represented by pyrite, chalcopyrite, galena, pentlandite, pyrrhotine, and violarite.
Chromitite deposits of Ufaley ultramafic massif (South Urals)
Authors: Saveliev Dmitry E.
Published: October 2022

Data on the morphology, composition, textural and structural features of chromite deposits of the Ufaley ultramafic massif are presented. The mineralogical and compositional features of the host ultramafic rocks allow us to interpret them as depleted restite from partial melting of mantle peridotites. Relatively wide variations in the composition of ore-forming chromian spinel grains (#Cr 0.6–0.8) and noticeable metamorphism of disseminated ores with replacement of chromite by Cr-magnetite are noted. It is assumed that chromitite bodies were initially formed under the conditions of the upper mantle by a rheomorphic mechanism, and then their structural and geochemical transformation took place in the collisional setting of the upper part of the crust. Flattened bodies of disseminated chromitites have been preserved near competent gabbroid blocks, while other deposits have been transformed into lenses and podiform bodies of densely disseminated and massive ores of smaller size. The “cold tectonics” of the crustal stage led to the disintegration of deposits and the simultaneous local enrichment of deformed chromitite bodies.
Influence of carbon sorbents on the potential ability of soils to self-cleaning from petroleum pollution
Authors: Smirnova Elena V. , Okunev Rodion V. , Giniyatullin Kamil G.
Published: October 2022

In a laboratory experiment, the ability of the soil to self-cleaning under heavy petroleum pollution and the effect of biochars and shungites on the cleaning process were studied. Incubation of contaminated soils for 28 days at a constant humidity and temperature without addition of sorbents led to a decrease in the residual content of petroleum products by only 8%. The addition of biochar and shungite at a dose of 2.5% made it possible to reduce the content of petroleum under constant incubation conditions to 48.8% and 38%, respectively. It was shown that the incubation of oil-contaminated soils in the regime of variable humidity and temperature without the addition of sorbents makes it possible to reduce the content of petroleum by 32% over 28 days of the experiment. In the course of the study, methods were developed for determining substrate-induced respiration (SIR) in various incubation modes. Soil contamination with petroleum led to a significant decrease of SIR in the initial period of incubation from 12.8 C-CO2 µg/g h to 8.6 C-CO2 µg/g h, which returned to normal on the 14th day of the experiment. It has been shown that the introduction of biochars (to a lesser extent schungites) into oil-contaminated soils ensures the maintenance of SIR at the required level and increases the potential capacity of soils for self-purification. The paper discusses the possibilities of increasing the potential capacity of soils for self-cleaning under heavy oil pollution.
Reserves-to-production ratio – on the reliability of estimates
Authors: Sokolov Alexander V. , Shubina Anastasia V.
Published: October 2022

At present, when estimating the state of the resource base and the general forecast for the development of oil production, ones often operate with the reserves-to-production ratio, which reflects, as it is believed, a guaranteed time for involving current recoverable reserves in active development. However, the terms (numbers) differ significantly. In this regard, it seems appropriate to once again discuss the content of the commonly used ratio, the differences in approaches to its estimation and use in Russia and abroad, as well as the possibility of using it when forecasting production and the need for an increase in reserves.
Paleozoic and Mesozoic hydrocarbon foci of generation and assessment of their role in formation oil deposits of the Pre-Jurassic complex of Western Siberia
Authors: Isaev Valery I. , Galieva Margarita F. , Lobova Galina , Kuzmenkov Stanislav G. , Starostenko Vitaly I. , Fomin Alexander N.
Published: October 2022

The following problem is solved by the present research: the probable sources of Paleozoic hydrocarbon deposits are determined on the basis of modeling the hydrocarbon foci of generation Paleozoic-Mesozoic oil source formations (for example, the southeast of Western Siberia, Tomsk Region). The research area is the lands Ostanino field group: the Selveikin area of deep drilling, the Ostaninskoye and Gerasimovskoye oil and gas condensate fields. Pre-Jurassic strata with oil source potential, including the Paleozoic Larinskaya (S1lr), Mirnaya (D13mr), Chuzikskaya (D2cz), Chaginskaya (D3cg) and Kehoregskaya (C1kh) formations, as well as Jurassic Bazhenovskaya (J3bg) and Tyumenskaya (J1-2tm ) formations, and, accordingly, the reservoirs of the weathering crust and bed-rock Paleozoic reservoirs are the objects of study. The subject of analysis was selected in accordance with the concept of the geothermal regime of the subsoil, as a leading factor in the implementation of the generation potential of the parent sediments. The research methods are digital paleotemperature modeling and historical-geological analysis.

The results and conclusions concerning the fundamental problems of “Paleozoic oil” are obtained. 1. Source of the Paleozoic oil deposits can be both the Domanic type rocks of the Paleozoic formations and the Jurassic oil source formations. Thus, both upward vertical interstratal HC migration and downward HC migration can take place. Therefore, the two concepts of “main source” are compatible and should not be considered, as often, orthodoxly alternative. 2. The domanicoid rocks of the Paleozoic formations are most likely the source for Paleozoic gas and gas condensate deposits. 3. Paleozoic formations the roof of the bed-rock Paleozoic (on the Ostankinskaya group of fields – C1kh and D3cg) can be only the source of the «Paleozoic oil» and gas deposits in the Pre-Jurassic oil and gas complex. 4. Bazhenov formation – J3bg may be the “Jurassic” source of oil deposits in the Pre-Jurassic oil and gas complex. The results were obtained and conclusions were drawn concerning the applied (search) aspects of the problem: 1. Results additionally substantiate the author’s search criterion for the oil and gas content of the Paleozoic – these are anomalous geophysical and petrophysical characteristics of the Jurassic section. 2. The absence of hydrocarbon deposits in the Jurassic section is most likely a negative sign of the Paleozoic oil and gas content. 4. The low density of the modern heat flow (less than 40 mW/m2) is most likely a negative sign of oil deposits in the Paleozoic. 3. High paleotemperatures in terms of VR (more than 175oC) are most likely a negative sign of oil and gas deposits in the Paleozoic. 4. Reasons have been obtained to state that oil deposits in the Paleozoic cannot be richer than oil deposits in the Jurassic.
Criteria for the searching for hydrocarbon deposits and polymetal ores using the geofluidic system model
Authors: Gorobets Semen A. , Laptev Nikolay N. , Makarova Irina R. , Goldobin Arkady Ya. , Valiev Farhat F. , Yafyasov Adil M. , Makarov Dmitry K.
Published: October 2022

This work is a continuation of a cycle of studies on the generalization of geochemical information on the content of elements in the composition of rocks and oils in the area of the Ukhta anticline of Southern Timan region. Based on the values of yttrium (Y/Ho) and cerium anomalies (Ce sample/Ce*PAAS) established in modern sedimentary basins, the studied rocks of the Upper Devonian are divided according to the conditions of formation and transformation into predominantly hydrothermal and hydrogenous. It is shown that, depending on these conditions; zones of hydrothermal and hydrogenous mineralization with an increased content of Zn, Cu, Co, V, Mn, and Mo are formed. As a result of a comparative analysis of the content of elements in oils and the values of geochemical ratios U/Th, V/Ba, Th/Ba, As/Ba, three types of oils were identified: Yaregsky, Nizhnechutinsky high-temperature, and Nizhnechutinsky low-temperature. The values of these indicators are considered as search criteria for a certain type of oil.
The North Tambey uplift history study using 3D seismic data
Authors: Zagorovsky Yuri A.
Published: October 2022

Paper shows the information about the geological and geophysical exploration of Tambeyskoye natural gas field located in the north of the Yamal Peninsula. The problems with mapping of natural gas deposits in Cretaceous and Jurassic formations are described. The results of formation thickness analysis are presented in order to explain the reasons for the unprecedented concentration of separate natural gas accumulations and the heterogeneous saturation of massive reservoirs in Cretaceous formations. The method of paleotectonic analysis is briefly described, the initial data are reported. Structural and isopach maps are presented. Structural elements and their evolution in Jurassic and Cretaceous time are presented. It was concluded that different structural elements of the work area transformed quite independently until the end of Cenomanian. The modern shape of North Tambey uplift was forming during the Neogene to Quarter age. Natural gas bearing reservoirs in Jurassic formation with the overpressure were reported. The young age of the North Tambey uplift, the unprecedented concentration of separate natural gas accumulations, the and the heterogeneous saturation of massive reservoirs in Cretaceous formations, overpressure in Jurassic formation – all these facts show that the Tambeyskoye natural gas field is under active gas accumulation. Hydrocarbon gases coming from deep Jurassic formations and it was not enough time for gas accumulations to be distributed over the reservoirs of Cretaceous.
Features of geological structure heavy oil field complicated palaeovalley (P-N)
Authors: Bachkov Albert P. , Bazarevskaya Venera G. , Anoshin Dmitry V.
Published: October 2022

The geological study of reservoirs of heavy oil confined to the deposits of the Sheshma horizon, for further involvement of deposits in pilot production, is an expensive project in itself due to the high viscosity of oil from 200 to 200,000 MPa∙s and changes in the depth of the productive formation from 100 up to 500 m. It’s advisable to exclude all kinds of factors, including geological ones, leading to additional costs in the development of heavy oil deposits in an unstable economic situation.

The purpose is determining of impact palaeovalley on the efficiency of wells using the example of heavy oil deposits. For the analysis authors have applied, materials the estimation of reserves, laboratory researches and macro descriptions of the core, the results of structural and geomorphological studies, and development parameters.

It is viewed heavy oil deposits of the Sheshma horizon, complicated by palevalley, and geological structure. The porosity-permeability properties and characteristics of the bedding are given. The authors’re determined areas of palaeovalley the drilled wells, a macro description of the core and cuttings in the palaeovalley part are given. Zones of deconsolidation of the Upper Permian terrigenous deposits are identified by results of structural and geomorphological studies. A comparison of the map of predictive fracturing with the map of Pliocene formations characterizing the genesis of the palevalley is made. The authors’re comparisoned the operational capabilities of wells with the location of the wellhead in the palaeovalley zone and outside the palaeovalley. Recommendations for the design of horizontal wells complicated by palaeovalleys are determined.
Distribution of fractured reservoirs in the Chayanda field (Eastern Siberia)
Authors: Zhukov Vitaly S. , Motorygin Vladimir V.
Published: October 2022

The results of laboratory studies of nearly 1,300 samples from 50 wells of reservoirs of three productive terrigenous horizons represented by sandstones and siltstones are considered. Intergranular and fractured components mainly make up the porosity structure of reservoirs and their values influence the main parameters of rocks, including filtration-capacitive properties of reservoirs, and determine the processes of hydrocarbon field development. The spatial distribution of the intergranular and fractured components of reservoir porosity affects the development and exploitation of oil and gas reservoirs and determines the relevance of this study. The values of the fracture and intergranular component of porosity were determined by the author’s method using data on open porosity and the rate of elastic wave propagation in rock samples and the mineral skeleton of these samples during the simulation of reservoir conditions.

A mosaic area distribution of fractured porosity values, caused by a long geological and tectonic history of the area development, was revealed. We identified zones of increased fractured porosity up to 0.7–0.8 % (percent absolute porosity) in the north and center of the western part of the field, and zones with minimum fractured porosity values of less than 0.2–0.3 % in the eastern part of the field. Results of laboratory core studies showed the presence of fractured porosity in reservoirs up to 1.26 %. The data on the size and distribution of fractured reservoirs across the Chayanda field area may be used to refine the field development project.
Carbonate reservoir rocks characterization of the Kazanian Stage of the Gorsky ultraviscous oil field by electron paramagnetic resonance method
Authors: Mudarisova Raushania A. , Volkov Yuri V. , Khasanova Nailya M. , Uspensky Boris V.
Published: October 2022

The use of the electron paramagnetic resonance (EPR) method for studying carbonate rocks is widespread. EPR makes it possible to reconstruct lithological and geochemical environments of ancient sedimentation, including redox conditions and paleo-radioactivity of sedimentation basins. The paper considers the heterogeneous structure of carbonate reservoir rocks of the Kazanian Stage of the Gorsky ultraviscous oil field by paramagnetic marks: manganese ions Mn2+, radical ions SO3–, SO2–, РO22-(РO20) in carbonate minerals and radical С600 in the remains of organic matter in the rock. The carbonate reservoirs of the Gorsky structure, tectonically confined to the eastern side of the Melekess Depression, are represented by two main lithotypes: dolomitic boundstones and dolomitic oolitic packstones, which have various post-sedimentary alterations. EPR data were obtained for 28 samples with a step of 0.5-1.5 m along the section. The EPR spectra are characterized by narrow lines that indicate the marine origin of carbonates. Based on the EPR spectra of the ions Mn2+ and its content in carbonate minerals, the lagoonal-marine genesis of the Gorsky structure rocks was revealed. The dominant dolomite mineralization of the section was established. The absence of dolomite radicals and low values of the degree of population of the magnesium and calcium positions of dolomites are due to the secondary nature of carbonates. The distribution of manganese ions, organic and inorganic radicals in the rock along the section is shown simultaneously with its reservoir properties and the conditions for the formation of two dolomite lithotypes.
Moderating Effect Of Bank Size On Nexus Between External Equity Capital And Financial Performance Of Lower-Tier Commercial Banks In Kenya
Authors: Singh Indu , Singh KP
Published: October 2022

The commercial banks in Kenya have been recording declining performance over the recent past, with the lower-tier banks being the hardest hit. As a result, several banks in the lower-tier, such as Chase Bank, Dubai Bank of Kenya, and Imperial Bank, have been put under receivership. The collapse of banks does not give a good reflection of the sustainability of the banking system. Thus, the signals of poor financial performance need to be addressed promptly as the collapse of the banking system could also have a ripple effect on other sectors. The Kenyan banking sector is categorized into tier I, II, and III. The categorization is dependent on the size of the bank. The decline in profitability of the banking sector has affected tier II and III most. Also to note is that Tier one is made up of six giant banks that control close to half (49.9 percent) of the market, which begs the question as to whether the size of the bank has any influence on the performance of the banks. Therefore, this study sought to determine whether external financing influences Tier II and III performance and whether the bank size moderates this influence. Descriptive and explanatory research designs were employed in the study. The study population was 37 commercial banks in Tier II and III of the Central Bank's Lower-tier classification. Secondary data were adapted in the study for the years 2016 to 2020. After data cleaning, 26 banks were retained (70%) for further analysis. Data collected was analyzed by use of both descriptive and inferential analysis. Descriptive statistics included means, standard deviations, skewness, and Kurtosis, while inferential analysis included Multilevel Mixed Model Analysis and Hierarchical Multiple Linear Regression. The model coefficients show that equity has a positive and statistically significant relationship with the performance of lower-tier banks in Kenya measured using net profit margin (β=.229, p-value=.036<0.05). Further, the study found that size moderates the relationship between external equity and performance as an introduction of size in the model change R2 by .035 (p-value = 0.001). The study thus concludes that external equity capital positively influences the performance of lower-tier banks in Kenya, while size moderates the same. The study recommends that a bank evaluate when to use external equity funding, although external equity funding may be costlier. As a recommendation, lower-tier banks are encouraged to use external equity as this will improve their performance. Lower-tier banks are also encouraged to increase their asset base as their size moderates the banks′ performance.
Record On Incidence And Intensity Of Estigmena Chinensis Hope. (Coleoptera: Chrysomelidae) On Natural Bamboo Stand
Authors: Singh Indu , Singh KP
Published: October 2022

Bamboo is a robust, relatively fast-growing, environmentally sustainable material used worldwide for centuries. It has the potential to be an extremely pleasing and a value alternative to more traditional materials like timber, as seen by numerous visually stunning modern structures. Approximately 212 insect pest species have been identified attacking bamboo, causing damage from seed to completed product. For the first time, Estigmena chinensis was seen destroying seven green-standing bamboo species in natural stands, including Gigantochloa manggog, Thyrsostachyus oliver, Bambusa balcooa, Schizostachyum dullooa, Dendrocalamus hamiltoni, Gigantochloa atroviolacea, and Bambusa polymorpha. Maximum attack incidence was observed in T. oliver (56.18%) in 2017 and minimum in G. atroviolacea (20.75%) in 2020. The maximum and minimum intensity of the attack was recorded in B. balcooa (3.16%) in 2018 and T. oliveri (1.08%) in 2017, respectively.
Effects of Dietary Supplementation of Different Levels of Zinc, Manganese and Copper Nanoparticles on Growth Performance and Bioavailability in Commercial Broilers Chicks
Authors: Gowtham B. , Ramesh J. , Karunakaran R. , Karthikeyan N. , Raja P.
Published: October 2022

Background: Nanotechnology is an emerging field and it has shown the great impact in broiler sector for production. Although extensive research is needed to evaluate the safety of nanominerals. Methods: A biological study was carried to evaluate the effect of dietary supplementation of inorganic, organic and nano forms of zinc, manganese and copper trace minerals on growth performance and immune status of commercial broiler chicken out for 35 days with 150 numbers of commercial broiler chicken and randomly distributed in 5 treatment groups viz., T1 (Inorganic 100%), T2 (Organic 100%), T3 (Nano 100%), T4 (Nano 50%) and T5 (Nano 25%) comprising of 30 birds in each group. Result: The results revealed that body weight, cumulative body weight gain and feed intake of broiler chicken increased significantly (p less than 0.01) in the 50 and 100% nano trace mineral supplemented groups when compared to other groups without any significant change in FCR. T3 and T4 exhibited significant (p less than 0.05) improvement in serum superoxide dismutase activity. The mRNA expressions of biomarker gene metallothionein, manganese-superoxide dismutase and ceruloplasmin were upregulated in T3 and T4 groups revealing that the nano trace mineral supplementation had better bioavailability.
Establishing a Framework for Sustainable Community Action Research
Authors: Jones Malcolm , Hoague Danielle , Spriggs Raenita , Catalan Elijah , Adams Naomi , Watkins Timothy , Tripati Aradhna , Norris Keith C.
Published: October 2022

Community-based participatory research/ community-partnered participatory research (CBPR/CPRR) is viewed as a critical ap­proach for improving health and address­ing inequities found in under-resourced communities by pairing community partners and academic partners to address health and environmental concerns. This article aims to amplify the potential of the current CBPR/CPPR models through insights learned from the underserved community of Watts in south central Los Angeles. We discuss our framework that shifts the primary academic focus in the community-academia partner­ship from individual investigators and/or research groups to the academic institution to generate sustainable partnerships. We summarize the Community Action Research Engagement (CARE) Framework as a new set of recommended tenets to expand CBPR/ CPPR. This framework can provide guid­ance for how universities can catalyze: 1) building trust; 2) facilitating knowledge; 3) advancing solutions; and 4) fostering men­torship in the context of leveraging a univer­sity’s position to address the root causes of community inequities and thus create more sustained partnerships that achieve greater impact within their surrounding com­munities.Ethn Dis. 2022;32(4):333-340; doi:10.18865/ed.32.4.333
Modeling and Dynamics Analysis on Pseudo-Rigid-Body for the Swing Vibrator of the Caudal-Fin-Like Valve-Less Pump
Authors: Hu Xiaoqi , Hu Caiqi , Du Hui , Liu Jude
Published: October 2022

A bio-inspired swing vibrator applied in fluid driving has the characteristics of a large deformation and rigid-lexible structure. Currently, there is a shortage of influential theories and methods to analyze its vibration. This research established a dynamic model for studying the bionic rigid-flexible swing vibrator based on pseudo-rigid-body theory. The weak coupling relationship between vibration arm DOF and flexible caudal-fin DOF was proposed by comparing the diagonal elements with the characteristic matrix's anti-diagonal elements. Analysis results showed that the presence of a flexible caudal-fin had minimal impact on the vibration modes of the vibration arm. The flexible caudal-fin vibration could be treated as a dynamic response that uses the vibration arm's end as a foundation. Experimental studies were conducted, and a laser Doppler vibrometer was used to measure the vibrator's vibration modes. The experimental results indicated that whether the vibrator works in water or in air, the presence of a flexible caudal-fin had little impact on the resonance frequency of the vibration arm. Finally, experimental results were discussed based on theoretical analysis and conclusions. This paper provides an academic tool for modeling, optimization, and a working mechanism analysis on the rigid-flexible swing vibrator.
Numerical Investigation of Interaction Between Tubes and Loose Supports Caused by Turbulence-Induced Vibration in Steam Generators
Authors: Guo Kai , Tian Ce , Tan Wei
Published: October 2022

The tubes in heat exchangers are usually loosely supported and are vibrated by fluid. The interaction between tubes and supports caused by the fluid induced vibration (FIV) is influenced by different factors. In this work, a finite element code is established to investigate the interaction between tubes and supports. The comprehensive influence of clearance, tube offset and pre-load is studied by analysis of the contact parameters such as contact forces and displacements. The results show that the change of sliding velocity can affect the normal work rate at different the pre-loads and force ratios. The change law of the contact force and normal work rate caused by preload and force ratio differs in different clearances. The offset can affect the normal contact forces and the sliding velocity, and result in the decrease of normal work rate at offset value of 80%. The results of this work can be helpful in the design and further research of heat exchangers especially steam generators.
Isolation Efficiency of Vehicle Seat Suspension with Three Quasi-Zero Stiffness Models
Authors: Li Shiming , Nguyen Vanliem , Jiao Renqiang , Ni Dengke , Zhou Huaxiang
Published: October 2022

This study proposes three different models of the quasi-zero stiffness (QZS) using the horizontal spring (QZS-HS), air piston (QZS-AP), and roller spring (QZS-RS) for the seat suspension of the vehicle to improve ride comfort. A dynamic model of the two-axle vehicle with the seat suspension added by the different QZS models has been established under the various excitations of the road surface. The design parameters of the different QZS models have been optimized to enhance the isolation efficiency and ride comfort. The indexes of the root mean square of the displacement (z_ws), acceleration (a_ws), and power spectral density acceleration (maximum PSD) of the driver's seat have been chosen to evaluate the vehicle's ride comfort and the isolation efficiency of three different QZS models. The results indicate that the seat suspension equipped with the different QZS models greatly improves the ride comfort in comparison with the seat suspension without the QZS. Also, the isolation efficiency of three different QZS models has been greatly affected by their design parameters. With the design parameters of the different QZS models optimized by the genetic algorithm, the stable value of the dimensionless restoring force of the optimal QZS-AP is lower than that of both the optimal QZS-HS and optimal QZS-RS. Particularly, under the random excitation of the road surface, the z_ws, a_ws, and maximum PSD have been greatly decreased by 41.4%, 73.8%, and 94.4% in comparison with the seat suspension without the QZS, respectively. Therefore, the optimal QZS-AP should be applied to enhance the driver's ride comfort and health.
Experimental and Numerical Study on Flow-Induced Vibration of PWR Steam Generator U-Tubes
Authors: Guangming Xiong , Teng Long , Yong Zhu , Ce Tian , Kai Guo , Wei Tan
Published: October 2022

The flow-induced vibration (FIV) of steam generators (SGs) in pressurized water reactors (PWRs) is a significant problem in the design process. This problem contains issues such as two-phase flow, nonlinear dynamics and fretting wear. In this paper, an experimental setup was established to study the FIV of a newly designed U-tube SG. Numerical simulations, including computational fluid dynamics (CFD) and vibration studies were performed to reveal the detailed mechanisms of FIV. To study the U-bend region of the tube bundles, the experiments were carried out under 23 experimental conditions containing void fractions of 70%, 80%, 90 and 95%. The flow fields of the tested model in each condition were calculated to reveal the causes of the vibration phenomenon, and the vibration results were calculated through structure dynamics. The experimental results showed that the vibration amplitudes of the U-tube increased with increasing inlet velocity, flow rate and bending radius. It decreased with increasing void fraction under the same inlet velocity, while it increased with increasing void fraction under the same flow rate. Along with the out-of-plane vibration, the in-plane vibration also featured high amplitude vibration of the U-tubes due to lack of support by the anti-vibration bars (AVBs). The simulation results show the same variation trends of the vibration responses as the above experiments. The prototype SG can be fluid-elastic stable in given working conditions, and the main vibration mechanism of this model is turbulence buffeting. The experiment and simulation methods and data can be used in the design process of new SGs similar to this prototype.
A Design Method for Vibration and Acoustic Reduction of the Power System in an Underwater Automobile Glider
Authors: Liu Yujun , Liu Jing , Pan Guang , Guo Liming , Huang Qiaogao
Published: October 2022

Underwater automobile gliders (AUGs) are new underwater vehicles, that should have lightweight structures with low vibration and acoustic characteristics due to their working conditions. This paper proposes a design method for vibration and acoustic reduction of the power system in an AUG by using the stand-off layer perforated viscoelastic material (SOL-PVEM) damping treatment with lightweight characteristics. The finite element method is used to calculate the vibration characteristics and modal loss factors of the plates with different SOL-PVEM damping treatments. The influence of the perforation of the damping layer on the modal loss factor is investigated. Then, the structure and acoustic coupling of finite element models of the power system with the SOL-VEM and SOL-PVEM damping treatments are established. The vibration acceleration, sound power, and sound pressure directivity of the power system of the AUG coated with the two proposed damping treatments are analyzed respectively. The results show that the vibration and acoustic responses of the power system can be effectively reduced by using the proposed lightweight SOL-PVEM damping treatment.
Design and Characterization of a Test Bench For Interior Noise Investigations
Authors: Liu Ling , Ripamonti Francesco , Corradi Roberto , Rao Zhushi
Published: October 2022

The increasing demand for acoustic comfort in vehicles has popularized the vibroacoustic analysis using computer-aided engineering (CAE) tools and boosted the development of various noise control measures. Concerning the often-unknown reliability of a CAE tool and the high cost of testing control strategies in a real vehicle, this paper proposes a test bench called Noise-Box, for benchmarking the CAE tools and testing new control measures. The test bench is designed towards a simple plate-cavity system that is easy to model and analyze, so that any vibroacoustic test performed on it can be accurately reproduced by numerical models. Specifically, it is a concrete box with six rigid walls and an opening that can be covered by flexible or soundproofing panels. The complete design is elaborated, including the cavity's shape and dimensions, the panel's installation and the device's overall configuration. Moreover, the acoustic field provided by the test bench is characterized for the typical features that will guide the device's future applications, covering modal property, reverberation time (or sound absorption) and field diffuseness. This work could be informative and instructive not only for the presentation of the novel test bench but also for the utilized methodologies in its design and characterization.
Investigation of Piezoelectric Energy Harvesting From Structural Vibration Induced by Rotating Machinery
Authors: Ucar Hakan
Published: October 2022

Increasing energy consumption has led recent efforts towards energy harvesting technologies. Among them, piezoelectric energy harvesting with piezo-based sensors and energy harvesters have gained significant attention due to their applicability and efficacy for microscale power generation systems. Present study aims to investigate energy harvesting with piezoelectric materials from structural vibration propagating throughout the structure from vibration sources. For this purpose, a use case of a mechanical pump mounted on a steel foundation is chosen. A Finite Element (FE) model of the foundation of the pump with piezoelectric energy harvesters is developed and validated in an experimental setup. Measured frequency response functions (FRFs) show particularly good match with simulation results. Afterwards, a real measured acceleration data from the mechanical pump is applied. Simulations are performed and effectiveness of the piezoelectric energy harvester for two different locations are demonstrated. In this study, piezoceramic (PZT), PVDF polymer, ZnO film and a PMN-PT single crystal composite is considered as harvester material and the effectiveness of each piezoelectric material are compared.
Design of Multi-Mode Low-Frequency Vibration Suppressor Based on Dynamic Vibration Absorption Principle
Authors: Cheng Yipeng , Peng Zilong , Wen Huabing , Song Hao , Cui Zixian
Published: October 2022

Dynamic vibration absorbers (DVA) are commonly studied for their advantage in controlling the low-frequency resonance peaks, but most relevant studies are still at the stage of theoretical innovation such as nonlinearity parameters and active control. Nevertheless, there are few kinds of vibration suppression structures based on dynamic vibration absorption principle. In this paper, therefore, we proposed a novel vibration suppressor inspired by the DVA theory. The vibration of a four-sided simply-supported thin plate attached with the DVAs array was studied by applying the modal superposition method. A preliminary suppressor model was proposed with rubber and steel as its main material, and whose modal frequency is calculated theoretically. Geometric and material parameters of each component were adjusted based on the DVA parameters. The vibration control effect of the suppressors array was verified through simulation and by experiment. Results showed that three resonance peaks were suppressed, and it was obvious after the attachment to the DVAs array or suppressors array. The contact form between the suppressors array and the plate is surface contact, which is different from the point contact between the DVAs array and the plate, therefore the vibration control effect of vibration suppressors array is more obvious.
Investigation of Motorcycle Handle Vibration Attenuation using a Suspended Handlebar with Different Rubber Mount Characteristics
Authors: Usamah Nabil Mohamad , Mazlan Ahmad Zhafran Ahmad , Ripin Zaidi Mohd
Published: October 2022

Motorcycle riders are exposed to prolonged hand-transmitted vibration that can lead to hand numbness and trembling and, in extreme cases, disorders such as the Hand-arm Vibration syndrome (HAVs). The vibration of a motorcycle handle is the result of two major excitation forces, namely the engine vibration and the road-tire vibration. Operating the engine throttle control requires the rider to grip and twist the throttle handle which in turn provides a good vibration transmission path from the handle to the hand. The on-road measurement of hand-arm vibration (HAV) in a rider of an underbone single-cylinder motorcycle show a relatively high value of HAV, with a_hv of 8.28m/s^2. One feasible solution is to attenuate the handlebar vibration transmissibility, by using rubber mounts to create a suspended handlebar. In this study, based on Experimental Modal Analysis (EMA), a hand gripped modal model of the handlebar is developed, and the evaluation is done on the frequency responses of different handlebar designs. The selection criterion is based on the frequency response function (FRF) synthesis index (area under curve) and in this work the area under FRF curve is taken for frequency range of 0 ? 200Hz based on the HAV system. Order analysis of the handle vibration showed higher acceleration level in the z-axis (vertical) compared to the y-axis (horizontal) and for the on-road testing produces, much higher vibration level is determined compared to engine-related vibration due to the tire-road interaction. The suspended handlebar with the best performance is selected for actual on-the-road test, and the result shows a lower a_hv value of 4.08m/s^2 (51% reduction), which significantly increases the vibration exposure limit value (EAV) time from 44 minutes to 3 hours.
Quasi-3D Vibrational Analyses of Laminates and Sandwich Plates Resting on Elastic Foundations
Authors: Zenkour A.M. , Mashat D.S.
Published: October 2022

This article establishes the vibrational response of laminates and sandwich plates inserted in an elastic medium. The quasi-3D elasticity equations are used for this purpose. The two-parameter Pasternak's model is utilized to give the interaction between the elastic foundation and the presented plate. The virtual displacement principle is applied to obtain governing dynamic equations. Many validation examples are displayed to show the accuracy and efficiency of the current model. The effects of various parameters like lamination scheme, material properties, aspect and thickness ratios, number of layers, and elastic foundation parameters on vibrations of laminates and sandwich plates are investigated.
Environmental Noise Harvester Using a Helmholtz Resonator and Piezoelectric Transducer
Authors: Aguilar-Torres Daniel , Jimenez-Ramirez Omar , Flores-Acoltzi Onesimo , Jimenez-Garcia Juan Antonio , Luque-Zuniga Guillermo , Vazquez-Medina Ruben
Published: October 2022

This work represents a guideline for designing, analyzing, and implementing a compact, low-cost, lightweight, and portable system that harvests energy from environmental noise at different locations. Considering that the proposed energy harvesting system (EHS) is based on a piezoelectric transducer (PZT) embedded in a Helmholtz resonator (HR), we first characterize the noise at four different locations selecting the most suitable ones for energy harvesting. Then, we electrically analyze and describe the PZT determining its resonance frequency. Subsequently, by using this frequency, we perform the sizing of the HR. Thus, we analyze the behavior of the implemented EHS under controlled and actual conditions. In controlled conditions, we determine the gain of the implemented EHS using a pure sinusoidal signal at 500 Hz and a pink noise signal. In actual conditions, we measured its gain considering two different locations. We observed that under controlled conditions, the implemented EHS achieved a gain between 168.3% and 200.3%, and under actual conditions, its gain was 159.5% in the traffic zone and 597.7% in the music zone. In addition, for the HR modeling and design, we show that its theoretical gain corresponds to its simulation gain but differs from its experimental gain due to the used material and manufacturing. Finally, we show that the implemented EHS performs similarly or better than other more sophisticated systems or systems with more piezoelectric elements.
Walking on Hot Coals: A Phenomenological Study on Dealing with Temptations in the Seminary
Authors: Naparan Genesis , Canoy Mike R. , Mahinay Foelan Degie , Villaflor Jan Elbe
Published: October 2022

The seminary life for Catholic seminarians includes aspects of their human, spiritual, academic, and pastoral formation. While staying in the seminary, they may encounter different kinds of temptations that can hinder them from pursuing their priestly vocations. This research explored the diverse temptations diocesan priests experienced when they were still seminarians. This study then explored the diverse ways of managing these temptations for the research participants. Using the transcendental phenomenology design, the researchers interviewed ten priests to explore their experiences on how they dealt with their experienced temptations. After the data analysis, six themes surfaced on temptations: family-related temptations, sexuality, deviation from the seminary structure, the temptation to isolate from the community, the envy of life outside the seminary, and doing things inconsistent with the priestly vocation. To cope with their temptation, they employed strategies such as: cultivating self-discipline, prayer, and reflection, being faithful to the mandates of the priestly vocation, living in the seminary formation process, and adjusting to community life. Thus, the research participants completed their seminary formation and were ordained as Roman Catholic priests.
Evaluation of Stories of the Prophets in the Holy Qur'an Based on Existential Therapy
Authors: Torun Harun , Tekke Mustafa
Published: October 2022

This study aimed to examine the stories of 25 prophets mentioned in the Qur'an within the framework of the existential theory. The research has been studied on associating the prophets and their stories in the Qur'an with the concepts of the existential theory. While the life of the prophets was encountered with the existentially positive concepts of the existential theory, no relationship could be established with the negative concepts. Knowing that the prophets mentioned in the holy book of Islam, the Qur'an, can be associated with the concepts of existential theory is important because it can be beneficial in existential therapy studies with Muslims. In addition, the study finding is significant in terms of establishing a bridge between the Qur'an, which is the main element of Islam, and the existence of western philosophers and mental health experts.
The Pattern of School Cooperation with Parents and the Community in Building Student Character at Madrasah Aliyah
Authors: Yuliani  , Hidayatulloh
Published: October 2022

There are three kinds of education, namely education in the family (informal), education in schools (formal), and education in the community (non-formal). Education in the family is the first education for a child and as a child's foundation. The second education includes schools which in the process are systematic and transfer of knowledge. Third, education in the community. The pattern of cooperation between the three is very necessary for the realization of character education. The aims of this study are (1) to analyze the pattern of school cooperation with parents and the surrounding community in shaping the character of students at Madrasah Aliyah Al-Islamy Sedati Mojokerto. (2) Analyzing the factors that support and hinder the pattern of school cooperation with parents and the surrounding community in shaping the character of students at Madrasah Aliyah Al-Islamy Sedati Mojokerto.