Overview of the Development of 3D-Printing Concrete: A Review

3D-printing concrete technology has attracted more and more attention for smart construction due to its advantages of digitization, automation, and high degree of intelligence. This article introduces the basic principles and related processes of concrete 3D-printing technology, and reviews the development from the following four fields: the material properties, preparation technology, printing parameters, and evaluation criteria of 3D-printing concrete technology. Then the existing difficulties, development direction and key technologies of 3D-printing concrete are described. Finally, we look forward to the development prospects of 3D-printing concrete from the aspects of printing materials, software and hardware cooperation, printing technology, etc. All the researches will provide the useful references for the later development and research

Experiment Study on Yield Stress Using Curve Extension Method and Vane Method

The yield stress is a key rheological parameter of thick paste and critical design parameter of the high pressure pipeline system. Take coal slurry as an example, whether using vane method or curve extension method, the yield stress both exponentially increase with concentration increasing, but the data of yield stress in two methods is different. For pipes with different diameters, the yield stress showed in pipeline transportation varies during the extension of rheology curves. By contrasting the results of curve extension method and vane method using pipelines with different diameters, it comes that with a certain concentration and a certain range of diameter, yield stress with vane is bigger than that with curve extension, due to the effect of wall slip in pipe flow test

Analysis of Vibration of Roadheader Rotary Table Based on Finite Element Method and Data from Underground Coalmine

The intense vibration of a roadheader rotary table damages the cutting system of the roadheader and reduces the efficiency. This paper analyzes the vibration of a rotary table by combining the finite element model with tested data from an underground coalmine. First, the force of the rotary table during the cutting procedure was analyzed, and the finite element model was built using Pro/E and ADAMS. The tested data were then imported into the model after selection, procession, and combination were conducted. Next, the six lowest-order parameters of the rotary table were calculated. A vibration analysis of the rotary table under certain working conditions was conducted, and the results were compared with those from a modal experiment using a single-point excitation method. According to the comparison between the simulation result and experiments, it is clear that this method is both reasonable and feasible. And it could supplement the theoretical foundation of the analysis of other roadheader components, providing reference for the improvement of the structure and dynamic properties of a roadheader. In addition, other vibration components of a roadheader such as the cutting head and the cutting arm could also be analyzed through the proposed method, with very reliable precision

Research of impact of two kinds of check valve on vibration characteristics of long pipeline

In order to study implementation effect of different check valves, vibration test was conducted in testing systems equipped with spring-loaded passive check valve and hydraulic active check valve respectively. Laws of time domain signal and frequency domain signal of the pipeline were studied, and impacts of two kinds of working check valve on vibration intensity of the pipeline were compared. The test results show that the hydraulic active check valve can reduce vibration strength more obviously. The conclusion provides reference for determining reasonable pipeline transportation parameters

Vibration characteristics analysis of high-pressure long-distance dense paste pipeline transporting with hydraulic active check valve

The pumping pressure required for long-distance pipeline transporting of dense paste is very high, the pumping system vibrates strongly, and the pipeline system is seriously damaged. In order to study the causes of vibration and the effect of hydraulic active check valves, pressure shock and pipeline vibration tests were conducted on the transporting pipeline in the field. The paper compared the data of sensors at each measurement point and analyzed the relationship between the action logic of each actuator of the transporting system and pressure shock and pipeline vibration. The first three orders of resonance bands of the pipeline system were obtained and radial vibration of the pump outlet pipeline was found to be greater than axial vibration. The S-pipe valve commutation was the direct cause of the pressure shock when the S-pipe valve took precedence over the piston commutation. Pressure shock increases with pumping volume. The opening of the check valve caused a large axial transient vibration and a small radial transient vibration on both sides of the valve. The above study of field data provides a reference for the selection of dense paste transporting pipeline parameters, the design of pipeline system and the research on the method of reducing the pipeline impact vibration

Estimation of Reversed Flow in Long Pipeline Based on Axial Vibration Model of Dense Paste

Intense axial vibration of the paste and the reversed flow make damage to the transportation system and lag the transport progress. This paper analyzed the axial vibration of the paste by building the vibration model according to the working situations of the system. The amount of the reversed flow share is then estimated based on the formed axial vibration model. The estimation of the reversed flow is carried out by counting the amount of the decompressed paste in certain time, which is being relative to the displacement in a single process of the vibration in numerical. The estimation of the reversed flow share of coal slime paste under certain transportation conditions was given and compared with the result based on the wave velocity method. It is evident that the introduction of axial vibration model into the study of the pipeline transportation system is feasible and reasonable, which also supplements the theoretical foundation for the analysis of dense paste vibrations in pipeline transportation system and its impacts on the system

Fatty Acid Synthase Mutations Predict Favorable Immune Checkpoint Inhibitor Outcome and Response in Melanoma and Non-Small Cell Lung Cancer Patients

Fatty acid synthase (FASN) acts as the central member in fatty acid synthesis and metabolism processes, which regulate oncogenic signals and tumor immunogenicity. To date, no studies have reported the connection of FASN mutations with ICI efficacy. In this study, from 631 melanoma and 109 NSCLC patients who received ICI treatments, we retrospectively curated multiomics profiles and ICI treatment data. We also explored the potential molecular biological mechanisms behind FASN alterations. In melanoma patients, FASN mutations were observed to associate with a preferable immunotherapeutic prognosis and response rate (both p p FASN mutations. This work confirms the clinical immunotherapy implications of FASN mutation-mediated fatty acid metabolism and provides a possible indicator for immunotherapy prognosis prediction

<i>HSPG2</i> Mutation Association with Immune Checkpoint Inhibitor Outcome in Melanoma and Non-Small Cell Lung Cancer

Immune checkpoint inhibitors (ICIs) markedly promote the survival outcome of advanced melanoma and non-small cell lung cancer (NSCLC). Clinically, favorable ICI treatment efficacy is noticed only in a smaller proportion of patients. Heparan sulfate proteoglycan 2 (HSPG2) frequently mutates in both tumors. Herein, we aim to investigate the immunotherapeutic and immunological roles of HSPG2 mutations in melanoma and NSCLC. A total of 631 melanoma samples and 109 NSCLC samples with both somatic mutational profiles and clinical immunotherapy data were curated. In addition, by using The Cancer Genome Atlas data, genomic and immunological traits behind HSPG2 mutations were elucidated. Melanoma patients with HSPG2 mutations had a markedly extended ICI outcome than other patients. An association between HSPG2 mutations and the improved outcome was further confirmed in NSCLC. In addition, an elevated ICI response rate was presented in HSPG2-mutated NSCLC patients (81.8% vs. 29.7%, p = 0.002). Subsequent analyses revealed that HSPG2-mutated patients had a favorable abundance of response immunocytes, an inferior abundance of suppression immunocytes, enhanced mutational burden, and interferon response-relevant signaling pathways. We uncovered that HSPG2 mutations were predictive of a better ICI response and associated with preferable immunogenicity, which may be considered as a genomic determinant to customize biotherapy strategies