A Method for Determining the Mechanical Parameters of Solution Pore and Crevice Limestone Based on Porosity

Limestone stratum has great anisotropy, which is distributed from large karst caves, pipelines, and faults to small solution pores, and crevices. In this paper, uniaxial compression tests of solution pore and crevice limestones from Mamaya I hydropower station and Ronglai hydropower station are conducted, and the porosity of these limestones is measured. The results show that there is a good power function relationship between compressive strength and the porosity of the solution pore and crevice limestone. Based on the Hoek–Brown criterion, the method for determining mechanical parameters of the solution pore and crevice limestones is proposed, taking the porosity of the rock into consideration. Then, the relationships between the rock mass parameters mb, s, and a and the porosity n are deduced. Based on the proposed method, the variation laws of the mechanical parameters of the limestones, including uniaxial compressive strength (UCS), tensile strength, deformation modulus, shear strength parameters are analyzed. The proposed method simplifies the complexity of mechanical parameters selection by quantifying GSI, avoids the subjectivity and uncertainty, and has good reliability and suitability in the pore and crevice limestone stratum, which has a certain guiding significance for the construction of similar sites

Cost-effectiveness analysis of toripalimab plus chemotherapy as the first-line treatment in patients with advanced non-small cell lung cancer (NSCLC) without EGFR or ALK driver mutations from the Chinese perspective

Objectives: The results of a CHOICE-1 study demonstrated the superior efficacy of toripalimab (anti-PD-1 antibody) plus chemotherapy for patients with advanced non–small cell lung cancer (NSCLC), with a manageable safety profile. This study was performed to evaluate the economic value of this treatment for this patient population from the Chinese payer’s perspective.Materials and methods: Basic data were derived from the CHOICE-1 study. Markov models were developed to simulate the process of advanced NSCLC, including the progression-free survival (PFS), progressive disease (PD), and death in intention-to-treat (ITT) populations, as well as patients with squamous or non-squamous NSCLC. The cost was obtained from the local institution, and the value of utilities referred to previous studies. Monte Carlo simulations were performed to depict the probabilistic scatter plots of the incremental cost-effectiveness ratio (ICER) and acceptability curves, aiming to address the uncertainty of model inputs.Results: Compared with standard chemotherapy, toripalimab plus chemotherapy yields an ICER of $21,563 per quality-adjusted life year (QALY) in the ITT population. For patients with squamous NSCLC, comparing the combined therapy with chemotherapy led to an ICER of$18,369 per QALY, while the ICER was $24,754 per QALY in patients with non-squamous NSCLC. With the threshold of willingness to pay we set ($37,653 per QALY), toripalimab plus chemotherapy was cost-effective in these patient populations.Conclusion: For patients with advanced NSCLC, toripalimab plus chemotherapy was an optimal choice as first-line treatment, regardless of histology

Study on the mechanism of mechanical property strengthening of Beishan granite under mild temperature condition

Many researches found that mechanical properties of granite were strengthened under the mild temperature range (within 300 °C), which is positive for the long-term safety of the high-level radioactive waste (HLW) geological disposal engineering. To study the thermal strengthening mechanism of granite under elevated temperature by the decay heat of the HLW, a novel experiment was carried out which stress loaded firstly to cause stress damage, then thermal loaded to study the temperature effect on stress damaged granite. Results show: (1) the deformation memory effect and the Kaiser effect existed after stress loaded for non-thermal treated and 120 °C treated on granite, while the deformation memory effect (DME) was significantly faded after 250 °C treated. (2) The volume of pores/cracks in Beishan granite increased after stress loaded, then decreased significantly after 120 °C and 250 °C treated. (3) The deformation behavior, AE activity and pores/cracks closure all showed that the stress induced damage could be healed at elevated temperature, which is positive for the HLW disposal engineering. (4) A viscoelastic frictional sliding model was used to analyze the mechanism of DME fading and the mechanical property strengthening

Unveiling the greenhouse gas emissions of drinking water treatment plant throughout the construction and operation stages based on life cycle assessment

The carbon peaking and carbon neutrality targets proposed by the Chinese government have initiated a green transformation that is full of challenges and opportunities and endowed sustainable development strategy for combating global warming issue. It is essential to execute comprehensive identification and carbon reduction measures across all industries that produce greenhouse gas (GHG) emissions. Water supply system, as an energy-intensive sector, plays a crucial role in GHG reduction. This work conducted a life cycle assessment (LCA) to account the GHG emissions associated with the construction and operation phases of the drinking water treatment plant (DWTP). During the construction phase, the total GHG emissions were 19,525.762 t CO2-eq, with concrete work and rebar project being the dominant contributors (87.712%). The promotion of renewable or recyclable green building materials and low-carbon construction methods, such as the utilization of prefabricated components and on-site assembly, holds significant importance in reducing GHG emissions during the construction phase of DWTP. Regarding the operation stage, the DWTP possessed an average annual GHG emission of 37,660.160 t CO2-eq and an average GHG intensity of 0.202 kg CO2-eq/m3. Most emissions were attributed to electricity consumption (67.388%), chemicals utilization (12.893%), and heat consumption (10.414%). By increasing the use of clean energy and implementing strict control measures in the water supply pumps, energy consumption and GHG emissions can be effectively reduced. This study offers valuable insights into the mapping of GHG emissions in the DWTP, facilitating the identification of key areas for targeted implementation of energy-saving and carbon-reducing measures

Charged Particle (Negative Ion)-Based Cloud Seeding and Rain Enhancement Trial Design and Implementation

China has been suffering from water shortage for a long time. Weather modification and rainfall enhancement via cloud seeding has been proved to be effective to alleviate the problem. Current cloud seeding methods mostly rely on solid carbon dioxide and chemicals such as silver iodide and hygroscopic salts, which may have negative impacts on the environment and are expensive to operate. Lab experiments have proved the efficiency of ion-based cloud seeding compared with traditional methods. Moreover, it is also more environmentally friendly and more economical to operate at a large scale. Thus, it is necessary to carry out a field experiment to further investigate the characteristics and feasibility of the method. This paper provides the design and implementation of the ion-based cloud seeding and rain enhancement trial currently running in Northwest China. It introduces the basic principle of the trial and the devices developed for it, as well as the installation of the bases and the evaluation method design for the trial