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Study on K0 consolidation triaxial test of remolded saturated loess
Get PDFExperimental study on K0 consolidation test of remolded saturated loess is carried out by GDS static triaxial apparatus. The deformation characteristics of specimens, under different loading rates, are discussed and the test results are compared and analyzed. The results show that the changing trend of the curve modeling the relation between the axial stress and the axial strain of the sample is consistent even with the change in loading rates. Thus, under this same context, the larger the loading rate is, the greater the axial strain will be, when the axial stress reaches the same value. Moreover, under different loading rates, the trend of the relationship curve between the lateral pressure coefficient K0 and the axial strain of the soil sample is basically consistent. The stability value of the lateral pressure coefficient K0 of the sample varies with the loading rate, but only within a fixed range
Influence of construction technology on the retroreflective performance of two-component traffic marking
Get PDFThe construction technology of traffic marking has a significant influence on its retroreflective performance. To study the effect of different construction processes on the service performance of traffic markings, two-component spraying paint and two different glass beads were chosen to produce traffic markings that were prepared by single-layer or double-layer spraying, as well as once and twice surface spraying of glass beads. The effects of glass bead coating, spraying times of glass beads and paints on the surface morphology and retroreflective performance of traffic markings were investigated, as well as the variation of the retroreflective coefficient (RC) at the early and middle stages. The results indicated that double-layer spraying was more effective than single spraying. The coated glass beads would decrease the initial RC of the markings, but improved their long-term service performance. The TP-21C has the finest overall retroreflective performance and the lower construction complexity
The interface between dental topography and functional appliances accessories
Get PDFDental topography can be defined as the division of receptive fields that we have in the crown of the tooth. It is necessary that we understand this concept very well because it makes all the difference in clinical practice. We need to understand the receptive fields of the tooth, and we must use this knowledge when prescribing accessories for a functional appliance, understanding its function and where these accessories should touch to generate the expected effect. In this paper we will discuss the fundamentals of dental topography and show some accessories used on the therapeutic arsenal of Jaw Functional Orthopedics
Contribution of magnetic resonance imaging in the biomechanical interpretation of the temporomandibular joint. Clinical case report
Get PDFX-rays and tomography, in their different modalities, are used as auxiliary diagnostic elements in temporomandibular joint (TMJ) dysfunction, both in static and dynamic situations; however, because they only allow the observation of bone structures, magnetic resonance imaging (MRI) is the ideal method to analyze, among other structures, the articular disc. Among the internal disorders of the TMJ are the abnormal postural relationships between the disc, mandibular head, fossa and articular tubercle, which can even lead to a musculoskeletal condition causing noise, pain and functional limitation. The clinical evaluation of temporomandibular dysfunctions is complex, especially in asymptomatic patients; the Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), place these entities within the AXIS I protocol, considering that the image is not strictly necessary. However, analyzing the disc situation statically and dynamically, with its surroundings, allows considering the loads that generate dysfunction, leading to the correct diagnosis, and selection of the best treatment. A clinical case is presented, an asymptomatic patient, without functional limitation, who reported a history of occasional mouth opening locking upon awakening. MRI was indicated, finding an abnormal position of the disc, in a static and dynamic situation; finding anterior displacement of the disc in the right and left TMJ in closed mouth position, dynamically anterior displacement without recapture in the right TMJ and with recapture in the left TMJ; Treatment was performed with Jaw Functional Orthopedics (JFO), obtaining changes in the dynamic disc-mandibular head relationship, anterior displacement with recapture of the right TMJ and total recapture of the left TMJ
Functional orthopedic device type Sn20 – a therapeutic resource in the control of chronic temporomandibular dysfunction – case report
Get PDFThe literature indicates that patients with a history of Temporomandibular Disorder (TMD), who experience sudden occlusal changes, may worsen their parafunctional habits and develop TMD again. In this sense, the aim of this study is to present a clinical case of recurrent chronic TMD after oral rehabilitation (increase of vertical dimension in all teeth) using Simões Network 20 (SN20) functional orthopedic appliance as one of the resources therapies. The patient was female, 62 years old, and complained of disabling pain, anxiety symptoms, hypervigilant and history of TMD. The patient reported failure of other treatment modalities, including use of the smooth stabilizer device. The diagnosis was chronic TMD – primary osteoarthritis of the temporomandibular joint and related myofascial pain and orofacial migraine. Treatment included physical measurements, instructions, peripheral and central medication, AOF type SN20 (night use). After three months of therapy, the patient showed significant improvement with complete pain reduction. The use of the AOF SN20 together with conservative measures represents a valuable therapeutic modality for patients with chronic TMD
Influence of barrier effect on barrier sheet pile wharf
Get PDFThis study aims to investigate the barrier effect of front wall-soil-barrier interactions in barrier sheet pile wharf structures. Berth 32 of the Jingtang Port was taken as the prototype structure, and the prototype observation experiment, centrifugal model test, and numerical calculation analysis were performed to study the influence of the length of the barrier pile, the spacing D between wall piles, and the net spacing L of the barrier pile on the barrier effect. The results show that, to maximize the barrier effect, the ratio N of the pile length of the full barrier pile to the depth of the front wall should be between 1.0 and 1.1. To maximize the barrier effect, the top elevation of the semi-barrier pile should not be excessively low. When the bottom elevation is fixed, the ratio of the length of the semi-barrier pile to the depth of the front wall is approximately N= 0.7. The change in the wall pile spacing D has a considerable impact on the barrier effect. Moreover, D has a logarithmic relationship to the horizontal displacement of the front wall. When D exceeds 3 m, the change in the barrier effect can be ignored. The part of the earth pressure shared by the sea and land sides of the barrier pile to the soil between the barrier pile and the barrier pile has a logarithmic relationship to the net spacing L of the barrier pile. The smaller the L, the better the barrier effect. When L exceeds 2 m, the earth pressure shared by the two parts tends to be average, and the barrier effect can be ignored
Optimal design and analysis of inner hole positioning mechanism based on MATLAB
Get PDFTaking the copper conductor vertical barrel as the research object, the process flow principle of the packaging system of the copper conductor vertical barrel is described, the mechanism that meets the positioning of the inner hole is proposed. The transmission and kinematics characteristics of the mechanism under different rod sizes are analyzed. The optimal size of the kinematic parameters of the mechanism is solved using the MATLAB optimization toolbox, the size of each member is determined for further determine the specifications and dimensions of the original moving parts to provide a basis for the selection of the original moving parts
Bio-CCS as a policy measure to achieve climate goals – the pioneering support scheme in Sweden
Get PDFBy 2045, Sweden is to have zero net emissions of greenhouse gases into the atmosphere. After 2045, Sweden should achieve negative emissions. To accomplish this, the use of bioenergy with carbon capture and storage (bio-CCS) will be important. Sweden should aim to capture and store two million tonnes of biogenic carbon dioxide per year by 2030. However, the feasible potential for bio-CCS in Sweden amounts to at least 10 million tonnes of biogenic carbon dioxide per year in a 2045 perspective. To support the development and deployment of CCS the Swedish energy Agency has been given two governmental assignments. 1. The first task/assignment, given in December 2020, was to establish a national centre for CCS. This task entails planning, coordination and promotion of CCS throughout the country. The Swedish Energy Agency will carry out its work in dialogue with both national and international stakeholders: industries, academia, governmental authorities and the Government Offices of Sweden. The present tasks for the centre are to implement a support system for bio-CCS and ensure that it is line with international conventions, such as the UN Convention on Biological Diversity and its moratorium on geo-engineering, and the London Convention and the London Protocol. The centre is also working with questions related to the accounting and reporting of negative carbon dioxide emissions in relation to national and international climate goals as well as following the emergence of a carbon market – voluntary and/or regulated – for negative emissions. 2. The second assignment was to roll-out the support system earlier proposed by the agency. The Swedish Energy Agency has concluded that a reverse action as the most cost-effective support system as well as to be compatible with EU state aid rules. The support system for bio-CCS has a budget framework of 3.6 billion €. A reverse auction means that, for example, a pulp and paper industry or a combined heat and power plant can submit a bid on how much carbon dioxide they can capture and store, and at what cost. The one who can deliver bio-CCS according to the stipulated requirements at the lowest cost, wins the auction. The Swedish Energy Agency hope to launch the first round of auction in 2023 and have the first storage of Swedish captured carbon dioxide taking place in 2026. Other countries can use Sweden’s knowledge and experiences when implementing bio-CCS. Exchanging knowledge, experiences and ideas with other countries are important to achieve large-scale deployment of bio-CCS in the Nordic-Baltic region and net-zero emissions in 2045
New CO2 and Hydrogen storage site marketing: How to make your storage site unique and attractive?
Get PDFToday we met the situation, when our knowledge and expertise are far away from marketing – an ability to sell our knowledge to the end-user (public, policymakers, governments, and small and big enterprises). This study aimed to attract stakeholders by proposing new techno-ecological synergy concept of geological storage of CO2 (CGS) and hydrogen (UHS) in a cost-competitive, self-supporting storage site. The “story of success” of the offshore geological structure E6 in Latvia has started from an invisible point on the European map, oil-bearing but not very promising geological structure to the unique and one of the best cost-competitive, self-supporting, conceptual techno-ecological examples of a possible synergy of storage concepts with renewables energies. Using detailed petrophysical, mineralogical and geochemical analyses of the Cambrian Series 3 Deimena Formation reservoir sandstones in this structure, the CO2 storage capacity was estimated with different levels of reliability from a conservative 158 Mt (106-252 Mt) up to an average optimistic average of 396 Mt (264-631 Mt). The theoretical CO2 storage capacity in the oil-bearing limestones of the Upper Ordovician Saldus Formation was estimated at the end of the Enhanced Oil Recovery cycle using the CO2 (CO2-EOR) as an average of 110 Mt (65-144 Mt). The E6 structure was estimated as the most prospective and the largest for CO2 geological storage in the Baltic Region with a total average CO2 storage capacity of about 500 Mt. Time-lapse numerical seismic modelling was applied to analyze the feasibility of CO2 storage monitoring in the E6. The novelty of this approach was the coupling of the chemically induced petrophysical alteration effect of CO2-hosting rocks, measured in the laboratory during the CO2 injection-like experiment, with time-lapse numerical seismic modelling. According to changes in the amplitude and two-way travel times in the presence of CO2, reflection seismic could detect CO2 injected into the deep aquifer formations even with low CO2 saturation values. Our results showed the effectiveness of the implemented time-lapse rock physics and seismic methods in the monitoring of the CO2 plume evolution and migration in the E6. The new concept of techno-ecological synergy of the CCUS project with different eco-friendly renewable energy recovery technologies, which support circular economy targets, is presented. The concept of the CCUS project includes six innovative elements of techno-ecological synergy: (1) CGS, (2) Geothermal energy recovery during CO2 geological storage (CPG), (3) CO2-EOR, (4) underground hydrogen storage (UHS), (5) solar energy and (6) wind energy recovery. This concept should maximise efficiency, minimize the carbon footprint of the full-chain CCUS process and demonstrate the “winx” situation (where “x” is a number of additional benefits of the project). We demonstrated an example of the project supporting also a win5 global situation (that is, a win-win scenario with a minimum of five potential global outcomes): greenhouse gas emissions (GHGE) reduction, (2) economic profitability, (3) increased CO2 storage capacity, (4) public acceptance and (5) retargeting of oil and gas businesses. Small wind offshore floating plant installed around the rig and solar panels covering free surfaces of the rig and a compact geothermal plant using CO2 (20 times smaller than a conventional plant) will produce renewable energy added to the project electricity net to cover the energy needs of the project. The excess energy will be used by compact hydrogen production plant established directly on the rig. The produced hydrogen could be stored underground and when needed, transported by ship to the port. For the first time, we estimated hydrogen storage capacity in the E6-B, the smaller compartment of the E6 offshore structure as 30 Kt. This scenario is a basis for the new concept of CO2 and hydrogen storage site marketing: how to retarget fossil fuel business (the depleted oil and gas fields) into the storage-targeted and renewable energy business, permitted to achieve the carbon-free energy transition using principles of circular economy and sustainable use of resources and environment
Measurement of natural frequency and mechanical damping of thin brass diaphragm by pulsed laser generated vibrations
Get PDFDamped harmonic oscillator model based fitting of nanosecond pulsed laser induced amplitude variations of clamped vibrating circular plate is used to estimate the mechanical damping and natural frequency of the sample in current work. Laser Pulses of 50 mJ energy, 20 ns duration, and focused at a spot of 4 mm diameter at the center of the circular thin brass sheet of 100 µm thickness is used to generate vibrations in the target. Quadrature Michelson interferometer (QMI) with CW laser focused on the opposite side of the target surface is used to measure the amplitude of vibrations. Variations of fringe frequencies are identified in the frequency domain. Finite element based numerical modal analyses are also performed in ANSYS Workbench for the verification of experimental results for the same geometry and materials. Experimental frequencies of vibrations are found to match nearly 2 percent of FEM modes. Moreover, Elastic parameters are also found using the first two mode frequencies and a reasonable agreement is observed while comparing with the elastic parameter data of brass. Current work in itself is a unique attempt of getting mechanical parameters for the determination of elastic parameters in a single laser pulse impulse excited measurement for thin clamped targets