Stochastic model predictive braking control for heavy-duty commercial vehicles during uncertain brake pressure and road profile conditions

When heavy-duty commercial vehicles (HDCVs) must engage in emergency braking, uncertain conditions such as the brake pressure and road profile variations will inevitably affect braking control. To minimize these uncertainties, we propose a combined longitudinal and lateral controller method based on stochastic model predictive control (SMPC) that is achieved via Chebyshev–Cantelli inequality. In our method, SMPC calculates braking control inputs based on a finite time prediction that is achieved by solving stochastic programming elements, including chance constraints. To accomplish this, SMPC explicitly describes the probabilistic uncertainties to be used when designing a robust control strategy. The main contribution of this paper is the proposal of a braking control formulation that is robust against probabilistic friction circle uncertainty effects. More specifically, the use of Chebyshev–Cantelli inequality suppresses road profile influences, which have characteristics that are different from the Gaussian distribution, thereby improving both braking robustness and control performance against statistical disturbances.Additionally, since theKalman filtering (KF) algorithm is used to obtain the expectation and covariance used for calculating deterministic transformed chance constraints, the SMPC is reformulated as a KF embedded deterministic MPC. Herein, the effectiveness of our proposed method is verified via a MATLAB/Simulink and TruckSim co-simulation.     

Role of Metabolism in Bone Development and Homeostasis

Carbohydrates, fats, and proteins are the underlying energy sources for animals and are catabolized through specific biochemical cascades involving numerous enzymes. The catabolites and metabolites in these metabolic pathways are crucial for many cellular functions; therefore, an imbalance and/or dysregulation of these pathways causes cellular dysfunction, resulting in various metabolic diseases. Bone, a highly mineralized organ that serves as a skeleton of the body, undergoes continuous active turnover, which is required for the maintenance of healthy bony components through the deposition and resorption of bone matrix and minerals. This highly coordinated event is regulated throughout life by bone cells such as osteoblasts, osteoclasts, and osteocytes, and requires synchronized activities from different metabolic pathways. Here, we aim to provide a comprehensive review of the cellular metabolism involved in bone development and homeostasis, as revealed by mouse genetic studies.     

Nitric Oxide and Reactive Oxygen Species in the Pathogenesis of Preeclampsia

Preeclampsia (PE) is characterized by disturbed extravillous trophoblast migration toward uterine spiral arteries leading to increased uteroplacental vascular resistance and by vascular dysfunction resulting in reduced systemic vasodilatory properties. Its pathogenesis is mediated by an altered bioavailability of nitric oxide (NO) and tissue damage caused by increased levels of reactive oxygen species (ROS). Furthermore, superoxide (O₂⁻) rapidly inactivates NO and forms peroxynitrite (ONOO⁻). It is known that ONOO⁻ accumulates in the placental tissues and injures the placental function in PE. In addition, ROS could stimulate platelet adhesion and aggregation leading to intravascular coagulopathy. ROS-induced coagulopathy causes placental infarction and impairs the uteroplacental blood flow in PE. The disorders could lead to the reduction of oxygen and nutrients required for normal fetal development resulting in fetal growth restriction. On the other hand, several antioxidants scavenge ROS and protect tissues against oxidative damage. Placental antioxidants including catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx) protect the vasculature from ROS and maintain the vascular function. However, placental ischemia in PE decreases the antioxidant activity resulting in further elevated oxidative stress, which leads to the appearance of the pathological conditions of PE including hypertension and proteinuria. Oxidative stress is defined as an imbalance between ROS and antioxidant activity. This review provides new insights about roles of oxidative stress in the pathophysiology of PE.     

Structurally Diverse Polyamines: Solid‐Phase Synthesis and Interaction with DNA

A versatile solid‐phase approach based on peptide chemistry was used to construct four classes of structurally diverse polyamines with modified backbones: linear, partially constrained, branched, and cyclic. Their effects on DNA duplex stability and structure were examined. The polyamines showed distinct activities, thus highlighting the importance of polyamine backbone structure. Interestingly, the rank order of polyamine ability for DNA compaction was different to that for their effects on circular dichroism and melting temperature, thus indicating that these polyamines have distinct effects on secondary and higher‐order structures of DNA.     

CuI and H2O2 Inactivate and FeII Inhibits [Fe]‐Hydrogenase at Very Low Concentrations

[Fe]‐Hydrogenase (Hmd) catalyzes reversible hydride transfer from H₂. It harbors an iron‐guanylylpyridinol as a cofactor with an Fe^II that is ligated to one thiolate, two COs, one acyl‐C, one pyridinol‐N, and solvent. Here, we report that Cu^I and H₂O₂ inactivate Hmd (half‐maximal rates at 1 μM Cu^I and 20 μM H₂O₂) and that Fe^II inhibits the enzyme with very high affinity (K_i=40 nM ). Infrared and EPR studies together with competitive inhibition studies with isocyanide indicated that Cu^I exerts its inhibitory effect most probably by binding to the active site iron‐thiolate ligand. Using the same methods, it was found that H₂O₂ binds to the active‐site iron at the solvent‐binding site and oxidizes Fe^II to Fe^III. Also it was shown that Fe^II reversibly binds away from the active site iron, with binding being competitive to the organic hydride acceptor; this inhibition is specific for Fe^II and is reminiscent of that for the [FeFe]‐hydrogenase second iron, which specifically interacts with H₂.     

First nuclear transmutation of 237Np and 241Am by accelerator-driven system at Kyoto University Critical Assembly

This study demonstrates, for the first time, the principle of nuclear transmutation of minor actinide (MA) by the accelerator-driven system (ADS) through the injection of high-energy neutrons into the subcritical core at the Kyoto University Critical Assembly. The main objective of the experiments is to confirm fission reactions of neptunium-237 (²³⁷Np) and americium-241 (²⁴¹Am), and capture reactions of ²³⁷Np. Subcritical irradiation of ²³⁷Np and ²⁴¹Am foils is conducted in a hard spectrum core with the use of the back-to-back fission chamber that obtains simultaneously two signals from specially installed test (²³⁷Np or ²⁴¹Am) and reference (uranium-235) foils. The first nuclear transmutation of ²³⁷Np and ²⁴¹Am by ADS soundly implemented by combining the subcritical core and the 100 MeV proton accelerator, and the use of a lead-bismuth target, is conclusively demonstrated through the experimental results of fission and capture reaction events.     

Application results of a prototype ultrasonic liquid film sensor to a 7 MPa steam–water two-phase flow experiment

A prototype ultrasonic liquid film sensor was applied to a high-temperature steam–water two-phase flow experiment. The liquid film sensor was vertically installed in a loop which was connected to HUSTLE, a multi-purpose steam source test facility. The hydraulic diameter of the measurement section was 9.4 mm. The output waveforms of the sensor were acquired with a digital oscilloscope. The fluid temperature and system pressure were kept at 288 °C and 7.2 MPa, respectively, during the experiment. The pulse-echo method was used to calculate the liquid film thickness. The cross-correlation calculation was utilized to determine the time difference between the pulse reflected at the sensor surface and the pulse reflected at the liquid film surface. The time-averaged liquid film thicknesses were less than 0.055 mm in the annular flow condition. The increase of the time-averaged thickness was small with the change of the gas momentum flux. The film thicknesses measured with the sensor were compared with the past experimental results; the former were smaller than one-fourth of the thickness estimated as the mean film thickness. The comparison results suggested that the continuous liquid sublayer thickness was measured with the liquid film sensor.     

Chiral selection in supercoiling and wrapping of DNA

This paper gives an account of our recent studies on the mechanisms for chiral selection in super-coiling and wrapping of DNA. We first present a compact model of double-stranded DNA (Model 1), which consists of two elastic chains that mutually intertwine in a right-handed manner to form a double-stranded helix. Numerical analysis of this model suggests an intrinsic propensity of DNA to writhe in the left direction upon bending. Based on this asymmetric elasticity of DNA, we present a further simplified model of DNA (Model 2), which is a single-chained homopolymer with the propensity to writhe in the left direction upon bending. This simplified model is incorporated into a Langevin dynamics study to explore the origin of the uniform left-handed wrapping of DNA around a nucleosome core particle in nature. We finally show that the propensity of DNA to writhe in the left direction upon bending gives rise to the selective left-handed wrapping, provided that the size of the core particle is appropriate. This result suggests the fundamental significance of the asymmetric elasticity of helical biopolymers in their structural dynamics and functions.     

Stabilization of a Power System Including Inverter‐Type Distributed Generators by a Virtual Synchronous Generator

The capacity of distributed generators (DGs) connected to the grid by inverters is growing year after year. The inverters are generally controlled by a phase locked loop (PLL) in order to achieve synchronization with the power system frequency. Power systems may become unstable as the capacity of the inverter‐type DGs continues to increase, because the inverter frequency is controlled just to follow the frequency determined by other synchronous generators. It has been suggested that inverters be controlled to behave like a synchronous generator. This concept is referred to as the virtual synchronous generator (VSG). In this paper, a control scheme for a VSG is presented, and the design method for the required energy storage and the capacity for grid stabilization control by a VSG is investigated by computer simulations.