Experimental study on creep wetting of silty clay

To study the wetting of a silty clay subgrade in an expressway, many laboratory tests were carried out. The test results show that the creep deformation of silty clay under water immersion cannot be ignored, but it is different from the deformation caused by wetting. The creep properties of soil mass are affected by many factors. Under different stress conditions, the soil mass will show different properties. In order to study the creep characteristics of silty clay in Chongqing under water wetting and different stress levels, a series of triaxial water wetting creep tests were carried out. The Singh-Mitchell creep equation was introduced to establish the creep model of silty clay drainage in Chongqing, and the parameters of the model were discussed

Planas direct tracks to treat functional crossbites in children: scientific evidence

Introduction: Posterior functional crossbite is a common malocclusion in children, with a prevalence between 7.5-24 %. It has an important impact on facial functions, and may cause asymmetries in craniofacial development. Different interventions have been used to correct this malocclusion but there is a lack of studies with methodological rigor that support these interventions. Planas Direct Tracks (PDT) constitute one of such interventions. They seek to reestablish the functional occlusal balance of children through selective grinding, complementing this adjustment with composites. Objective: To present the level of scientific evidence available on PDT to correct posterior crossbites. Method: A sensitive search was carried out in the main databases: Pubmed, BVS Odontology, Cochrane, SciElo and Google academic. The articles were selected, duplications removed and critical evaluation of the literature performed classifying the studies according to the evidence pyramid. The aim is to point out ways to improve the quality of the studies. Results: 32 studies were included. 30 studies were narrative reviews, case reports or case series and two were controlled trials. All studies had important biases. No randomized controlled trial was found. Conclusion: So far, there are no studies, sufficiently rigorous methodology, on Planas direct tracks to correct functional crossbites

Treatment of vertical problems with jaw functional orthopedics based on scientific evidence. Part 1: anterior open bite

The vertical problems of the stomatognathic system that alter the overbite, either by increasing in the deep bite (DB) or decreasing in the anterior open bite (AOB), are among the great challenges of the dentofacial corrections in the treatment and the retention and stability protocols. It is always good to report that a correct diagnosis is fundamental in the choice of treatment protocol and that skeletal involvement, be it hyper divergence in case of open bite or hypo divergence in case of deep bite, aggravates the problem and as a rule tends to increase treatment and containment time. In this paper the state of art of AOB treatment with Jaw Functional Orthopedics (JFO) will be discussed. It should be emphasized that JFO has a unique diagnostic tool for changes in vertical growth of the face, the Articular Compass, developed by Simões. Studies show that the use of treatment protocols developed by Simões, the SNs (SN2, SN3, SN6) act in the increase of overbite efficiently (P= 0.003) in cases of open bite. This is weak evidence, due to the design of the study, but with promising results, so Randomized Clinical Trials are needed to investigate if these results are replicable

Experimental investigation of bi-modular material coating to enhance damping

Hard coatings can be used to increase damping when applied on the surface of the components of turbomachinery. This can be effective to reduce the resonant vibration level of components working in a high cycle fatigue environment due to the extremely high operational speed. This paper discusses the experimental investigation of a bi-modular material hard coating to enhance damping in structural steel elements. Firstly, a hard coating (Al2O3+MgO) is applied on AISI 304L stainless steel substrate by plasma spraying. After that, a layer of chrome is deposited by chrome plating. Dynamic responses of both coated and uncoated samples are measured. The damping ratio of the test specimen is extracted from the time response by the logarithmic decrement method. Improved damping capacity of the coated steel sample is observed and is mainly attributed to the thin coating of chrome on the steel structure. The natural frequency of coated specimen showed 8 to 10 % improvement, the forced response showed a 30 to 35 % decrement in displacement, the damping ratio showed a 200 % increment, and the time of decaying showed a 20 % decrement. The results of the present study provide new ideas for the development of high-damping structural elements

Techno-economic modelling of the Baltic CCUS onshore scenario

Techno-economic modelling of the Baltic onshore CO2 transport, storage, and utilization scenario included HeidelberCement-owned Kunda Nordic Cement (KNC) plant, the main Estonian cement producer, four Estonian and one Latvian power plant and CO2 mineral carbonation of the oil shale ash, as possible CO2 use option. In 2019 nearly 6.5 Mt of oil shale ash (OSA) was produced in Estonia from energy production. Estonian OSA could be used as an effective sorbent in the proposed CO2-mineralization process, using CO2 from flue gas and producing precipitated CaCO3 (PCC) of high quality. Mineral carbonation of 0.42 Mt CO2 using 3.8 Mt of fresh OSA and about 6.33 Mt CO2 produced annually by five Estonian and one Latvian plant transported by pipeline for storage into the North-Blidene structure in western Latvia are combined in the CCUS scenario. Cambrian Deimena Formation reservoir sandstone is located at the depth of 1035-1150 m in the selected saline aquifer. The average optimistic storage capacity of about 270 Mt allows planning CCUS project for 30 years. The share of the Estonian emissions avoided and stored in Latvia is 86.5 %, including 8.2 % by KNC, while Latvian stored emissions will compose 13.5 %. Annually 6.8 Mt CO2 could be captured, transported and injected, including 6 Mt CO2 avoided using transport and storage and 0.42 Mt CO2 avoided using MC of Estonian OSA. During 30 years nearly 204 Mt CO2 will be captured, used and stored, while 193 Mt CO2 could be avoided. The total average transport and storage (T&S) cost of the scenario is 18.4 €/t CO2 injected. This cost depends on the transport distance, according to the applied methodology, and it is the most expensive for the Eesti Energia PPs. The lowest T&S cost of 5.54 €/t CO2 injected will have Latvenergo TEC-2 PP located at a smaller distance from the storage site. At the price of EEAP (CO2 Emission Allowance Price in EU ETS) of 40 €/t CO2 and 50 €/t PCC, the CCUS scenario could be beneficial for three Eesti Energia and Latvenergo TEC-2 power plants. For the KNC and VKG Energia plants without CO2 use options, the higher EEAP of about 48-50 €/t CO2 is needed to cover all CCUS costs including capture, compression, transport, storage and monitoring. The transport and storage costs are distance-dependent, as pipelines are the most expensive part of the transport, storage and monitoring costs. At the present EEAP of about 90 €/t CO2, all the participating plants will get benefits from the proposed scenario. This study is supported by CLEANKER project, which has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement n. 764816

Potential of CCS at SC Achema

Achema is a leading producer of nitrogen fertilizers and chemical products in Lithuania and the Baltic states. First construction works of the factory date back to 1962, however officially the company was founded on February 9, 1965 after the first tons of synthetic ammonia were produced in a newly launched ammonia unit. Carbon capture and sequestration has been considered as suitable measure of decarbonization during middle term – till year 2030. There is developed technology and logistic chains for on shore and offshore projects. The geographical location of companies plays crucial role because of logistics. SC “Achema” yearly emits more than 2 million tons of CO2. Our advantage is in having 200-300 kilo T of pure CO2 suitable to liquify and transport. Disadvantage of this topic in Lithuania is political attitude and big distances till real wells at North Sea. The deep check of all aspects necessary to estimate real potential of CCS in Lithuania. The company aspires for significant reduction in greenhouse gas emissions and is the winner of ‘Most Environment Friendly Process' nomination for greenhouse gas emission (NO) mitigation in the nitric acid manufacturing process. Company aspires for sustainable and safe production of fertilizers and has also has also developed capabilities to liquify and transport CO2 over long distances. In this conference Achema’s capabilities to liquify 200-300 kilo T of pure CO2 will be highlighted. Potential challenges related to long distance transfer and political challenges will be also be highlighted

Study of torque pulsation control of switched reluctance motor by auto-disturbance rejection control

The switched reluctance motor drives the rotor based on the principle of minimum reluctance, which is structurally simpler, but the doubly salient structure of the stator and rotor leads to severe torque pulsation. This paper briefly introduces the switched reluctance motor and the auto-disturbance rejection controller for suppressing the torque pulsation of the switched reluctance motor. Then, the auto-disturbance rejection controller was simulated in the MATLAB software, and it was compared with the direct torque control strategy. The results showed that the switched reluctance motor installed with the self-reluctance controller reached the set rotational speed faster, with a smoother torque change; when the set speed changed abruptly, it was adjusted to the new rotational speed faster, with a smooth and stable torque change; when the load torque changed abruptly, it was adjusted to the new torque smoother and faster, and the adjustment to the rotational speed was also faster

Effect of acoustic black hole parameters on vibration suppression of rectangular plate

The acoustic black hole has the ability to gather and manipulate the flexural wave in the structure, and can be used to achieve vibration suppression of the structure. A group of FEM models for the vibration analysis of the rectangular plate embedded with acoustic black holes were established in this paper. Four monitoring points on the ABH plate were selected to calculate their vibration velocity response in 100 Hz-3 kHz frequency interval. In order to study the effects of acoustic black hole geometric parameters and damping layer geometric parameters on the vibration response of the ABH plate, 15 combinations of different parameters of the maximum ABH diameter, the truncated thickness of the ABH, the power index of the ABH, and the damping layer thickness, the maximum diameter of the damping layer were selected to calculate the vibration velocity response of the four monitoring points. The calculation result can help us understand the effects of acoustic black hole geometric parameters and damping layer geometric parameters on the vibration suppression of rectangular plate

Genetic engineering – construction of a network of arbitrary dimension with periodic attractor

It is shown, how to construct a system of ordinary differential equations of arbitrary order, which has the periodic attractor and models some genetic network of arbitrary size. The construction is carried out by combining of multiple systems of lower dimensions with known periodic attractors. In our example the six-dimensional system is constructed, using two identical three-dimensional systems, which have stable periodic solutions

Salival biomarkers in inflamatory oro-cranio-cervical inflamatory alterations

During the COVID 19 pandemic, the general population suffered from high degrees of stress, the consequence of which was an increase in myofascial pain syndrome. This inflammatory ailment which affects soft tissues causes pain, muscular rigidity, and modifies posture due to hyperactivity. A state of muscular ischemia leads to structural and chemical changes, and to variations in saliva’s electrical conductivity. The objective of this research was to measure the changes in pH and electrical conductivity of saliva samples, and to use these as biomarkers during therapeutical Maxillary Functional Orthopedics (Planas’ Simple Indirect Tracks and Simões Network 20). All the subjects that took part in the study evidenced changes in the beforementioned biomarkers, as well as clinical improvement of their symptoms