Loading Capability Research Articles

Fastening solutions on composite structures: Progressive damage analysis of a unique bolted joint design for single-lap CFRP laminate

This study tested a unique assembly method using single and multi-body sleeves with carbon fiber-reinforced plastic (CFRP) to improve load-carrying capacity in single-lap joints. Advanced techniques were implemented into FE code to simulate progressive material degradation behavior. Ti6-4 bolt, insert, and washers with AISI 304L sleeve joint were conceptually designed to keep bolt and nut together with less relative motion. Failure indices were reduced by 16–54%, damage initiation force was improved by 8–40%, and inter-plate clamp loss was reduced by 18% compared to the sleeveless design. Lateral load-carrying capability of joint and inter-plate clamp load significantly improved.

Holmium (III)-doped multifunctional nanotheranostic agent for ultra-high-field magnetic resonance imaging-guided chemo-photothermal tumor therapy

Ultra-high-field (UHF) MRI has shown great advantages over low-field magnetic resonance imaging (MRI). Despite being the most commonly used MRI contrast agents, gadolinium chelates perform poorly in high magnetic fields, which significantly weakens their T1 intensity. In comparison, the rare element Holmium (Ho)-based nanoparticles (NPs) have demonstrated great potential as T2-weighted MRI contrast agents in UHF MRI due to their extremely short electron relaxation times (∼ 10−13s). In this study, a multifunctional nanotherapeutic probe was designed for UHF MRI-guided chemotherapy and photothermal therapy. The Ho (III)-doped mesoporous polydopamine (Ho-MPDA, HM) nanosphere was loaded with the chemotherapeutic drug mitoxantrone (MTO) and then coated with 4T1 cell membranes to enhance active targeting delivery to breast cancer. The prepared nanotherapeutic probe MTO@HMM@4T1 (HMM@T) exhibited good biocompatibility, high drug-loading capability and great potential as Ho (III)-based UHF MRI contrast agents. Moreover, the biodegradation of HMM@T in response to the intratumor pH and glutathione (GSH) promotes MTO release. Near-infrared (NIR) light irradiation of HM induced photothermal therapy and further enhanced drug release. Consequently, HMM@T effectively acted as an MRI-guided tumor-targeting chemo-photothermal therapy against 4T1 breast cancer. Statement of significanceUltra-high-field (UHF) MRI has shown great advantages over low-field magnetic resonance imaging (MRI). Although gadolinium chelates are the most commonly used MRI contrast agents in clinical practice, they exhibit a significantly decreased T1 relaxivity at UHF. Holmium exhibits outstanding UHF magnetic resonance capabilities in comparison with gadolinium chelates currently used in clinic. Herein, a theranostic nanodrug (HMM@T) was designed for UHF MRI-guided chemo-photothermal therapy. The nanodrug possessed remarkable UHF T2 MRI properties (r2 = 152.13 mM−1s−1) and high drug loading capability of 18.4 %. The biodegradation of HMM@T NPs under triple stimulations of pH, GSH, and NIR led to an efficient release of MTO in tumor microenvironment. Our results revealed the potential of a novel UHF MRI-guided multifunctional nanosystem in cancer treatment.

Exploring the therapeutic potential of layered double hydroxides and transition metal dichalcogenides through the convergence of rheumatology and nanotechnology using generative adversarial network

Two-dimensional Layered double hydroxides (LDHs) are highly used in the biomedical domain due to their biocompatibility, biodegradability, controlled drug loading and release capabilities, and improved cellular permeability. The interaction of LDHs with biological systems could facilitate targeted drug delivery and make them an attractive option for various biomedical applications. Rheumatoid Arthritis (RA) requires targeted drug delivery for optimum therapeutic outcomes. In this study, stacked double hydroxide nanocomposites with dextran sulphate modification (LDH-DS) were developed while exhibiting both targeting and pH-sensitivity for rheumatological conditions. This research examines the loading, release kinetics, and efficiency of the therapeutics of interest in the LDH-based drug delivery system. The mean size of LDH-DS particles (300.1 ± 8.12 nm) is −12.11 ± 0.4 mV. The encapsulation efficiency was 48.52%, and the loading efficacy was 16.81%. In vitro release tests indicate that the drug's discharge is modified more rapidly in PBS at pH 5.4 compared to pH 5.6, which later reached 7.3, showing the case sensitivity to pH. A generative adversarial network (GAN) is used to analyze the drug delivery system in rheumatology. The GAN model achieved high accuracy and classification rates of 99.3% and 99.0%, respectively, and a validity of 99.5%. The second and third administrations resulted in a significant change with p-values of 0.001 and 0.05, respectively. This investigation unequivocally demonstrated that LDH functions as a biocompatible drug delivery matrix, significantly improving delivery effectiveness.

Smart battery-free and wireless bioelectronic platform based on a nature-skin-derived organohydrogel for chronic wound diagnosis, assessment, and accelerated healing

Using smart electroactive hydrogels with emerging bioelectronics to monitor wound status wirelessly in real-time is a promising approach as an unremitting therapy for refractory chronic wounds. Based on a natural skin-derived organohydrogel (SGC@MA-Gel) triboelectric nanogenerator, a bioresorbable, battery-free, and wireless smart wound treatment bioelectronic system for pharmacological treatment, nanogenerator-driven electrostimulation, and visual wound condition assessment was engineered in this study. The inherent hierarchical architecture and origins of natural skin, in tandem with the substantial loading capabilities of collagen-based biomaterials, endowed SGC@MA-Gel with favorable characteristics. These included mechanical and adhesive robustness, electrical conductivity, antibacterial properties, controlled on-demand drug release capabilities, and human physiological signal monitoring performance. The customizable bioelectronic system, developed in-house, employs a single-electrode triboelectric nanogenerator, which facilitates skin wound healing via electrostimulation. Consequently, the system's biosensors can simultaneously measure glucose, uric acid, and pH at wound sites, thereby enabling accurate wound diagnosis and real-time assessment. This system accelerates cell proliferation and wound healing in vitro and in vivo, which validates its effectiveness in chronic wound treatment. The results demonstrated that the smart wound treatment bioelectronic system could provide a facile therapeutic strategy to assist with integrated wound monitoring, diagnosis, and therapy for hospitalized patients and those recovering at home.

Effects of a 12-week gait retraining program on the Achilles tendon adaptation of habitually shod runners.

This study investigated the effects of a 12-week gait retraining program on the morphological and mechanical properties of the Achilles tendon (AT) during running on the basis of real-time dynamic ultrasound imaging. A total of 30 male recreational runners who were used to wearing cushioned shoes with a rearfoot strike (RFS) pattern were recruited. They were randomized into a retraining group (RG, n = 15) and a control group (CG, n = 15). The RG group was asked to run in five-fingered minimalist shoes with a forefoot strike (FFS) pattern, and the CG group was asked to keep their strike pattern. Three training sessions were performed per week. All the participants in RG uploaded running tracks obtained through a mobile application (.jpg) after each session for training supervision. The ground reaction force, kinematics, and kinetics of the ankle joint at 10 km/h were collected using an instrumented split-belt treadmill and a motion capture system. The morphological (length and cross-sectional area) and mechanical characteristics (force, stress, strain, etc.) of AT invivo were recorded and calculated with a synchronous ultrasonic imaging instrument before and after the intervention. Repeated two-way ANOVA was used to compare the aforementioned parameters. A total of 28 participants completed the training. The strike angle of RG after training was significantly smaller than that before training and significantly smaller than that of CG after training (F (1, 13) = 23.068, p < 0.001, partial η2 = 0.640). The length (F (1, 13) = 10.086, p = 0.007, partial η2 = 0.437) and CSA (F (1, 13) = 7.475, p = 0.017, partial η2 = 0.365) of AT in RG increased after training. A significant main effect for time was observed for the time-to-peak AT force (F (1, 13) = 5.225, p = 0.040, partial η2 = 0.287), average (F (1, 13) = 7.228, p = 0.019, partial η2 = 0.357), and peak AT loading rate (F (1, 13) = 11.687, p = 0.005, partial η2 = 0.473). Preliminary evidence indicated that a 12-week gait retraining program could exert a beneficial effect on AT. 57% (8/14) runners in RG shifted from RFS to FFS pattern. Although not all runners were categorized as FFS pattern after the intervention, their foot strike angle was reduced. Retraining primarily positively promoted AT morphological properties (i.e., CSA and length) to strengthen AT capability for mechanical loading.

Improving the flow and thermal uniformities of transformer disc-type windings using a self-blocking oil circuit

The design of winding oil circuits is of great significance for improving the reliability, lifetime and loading capability of power transformers. Given the limited cooling capacity and local hot spot problems of the traditional oil circuits, a self-blocking oil circuit was introduced in this work. This study focused on exploring the potential advantages of this self-blocking oil circuit over the traditional ones in terms of the flow and thermal performance. To this end, the winding heat losses, flow and temperature were first calculated using a multi-physics coupling numerical model. Subsequently, the flow and heat transfer mechanisms of the winding were studied. Then, the flow and heat transfer performance of the winding with the self-blocking and traditional oil circuits were evaluated and compared. Furthermore, the effects of blocking degrees and oil flow rates on the winding flow and thermal performance were investigated. The results showed that compared with the traditional oil circuits, the self-blocking oil circuit exhibited a significant potential to improve the flow uniformity of transformer disc-type windings. It owned a larger cooling potential and the ability to lower winding hot spot temperature.

A Low Noise Neural Recording Frontend IC With Power Management for Closed-Loop Brain-Machine Interface Application.

Brain-machine Interface (BMI) with implantable bioelectronics systems can provide an alternative way to cure neural diseases, while a power management system plays an important role in providing a stable voltage supply for the implanted chip. a prototype system of power management integrated circuit (PMIC) with heavy load capability supplying artifacts tolerable neural recording integrated circuit (ATNR-IC) is presented in this work. A reverse nested miller compensation (RNMC) low dropout regulator (LDO) with a transient enhancer is proposed for the PMIC. The power consumption is 0.55 mW and 22.5 mW at standby (SB) and full stimulation (ST) load, respectively. For a full load transition, the overshoot and downshoot of the LDO are 110 mV and 71 mV, respectively, which help improve the load transient response during neural stimulation. With the load current peak-to-peak range is about 560 μA supplied by a 4-channel stimulator, the whole PMIC can output a stable 3.3 V supply voltage, which indicates that this PMIC can be extended for more stimulating channels' scenarios. When the ATNR-IC is supplied for presented PMIC through a voltage divider network, it can amplify the signal consisting of 1 mVpp simulated neural signal and 20 mVpp simulated artifact by 28 dB with no saturation.

Targeted Approach to Enhance the Solubility of Weakly Soluble Drugs by Nanocrystal Technology.

About 90% of the newly discovered drugs are poorly soluble in water, to overcome this problem, nanocrystal technology is used. Nanocrystal technology is a modern technique that is specially used to increase the solubility of less soluble drugs. Production of a nanocrystal on a large scale can be done by techniques like homogenization (high-pressure), precipitation, and milling methods. Using this technique, saturation solubility, the adhesiveness of a drug molecule to the surface cell, and the dissolution velocity is enhanced. This technology is better than the traditional method because it provides certain other benefits like increased drug loading capability, fantastic reproducibility of oral retention, further developed proportionality of portion bioavailability and expanded patient compliance. This audit makes sense of the various kinds of techniques for the arrangement of nanocrystals, benefits, drawbacks, a system of solvency improvement, clinical applications, and future imminent. This review article also provides further guidelines for studies about nanocrystal technology.

Mycophenolic Acid-loaded Naïve Macrophage-derived Extracellular Vesicles Rescue Cardiac Myoblast after Inflammatory Injury.

Exosomes are natural endogenous extracellular vesicles with phospholipid-based bilayer membrane structures. Due to their unique protein-decorated membrane properties, exosomes have been regarded as promising drug carriers to deliver small molecules and genes. A number of approaches have been developed for exosome-based drug loading. However, the drug loading capability of exosomes is inconsistent, and the effects of loading methods on the therapeutic efficacy have not been investigated in detail. Herein, we developed anti-inflammatory drug-loaded exosomes as an immunomodulatory nanoplatform. Naïve macrophage-derived exosomes (Mϕ-EVs) were loaded with the anti-inflammatory drug mycophenolic acid (MPA) by three major loading methods. Loading into exosomes significantly enhanced anti-inflammatory and antioxidation effects of MPA in vitro compared to free drugs. These findings provide a scientific basis for developing naïve macrophage-secreted exosomes as drug carriers for immunotherapy.

Multi-physics coupling analysis of test heat pipe reactor KRUSTY based on MOOSE framework

The heat pipe reactor utilizes heat pipes for passive heat transfer, eliminating the need for any moving parts. This feature significantly enhances its safety characteristics. Given the intricate nature of the heat pipe reactor system, a comprehensive multi-physics coupling simulation is necessary to study its safety features. In this study, a high-fidelity multi-physics coupling analysis incorporating a neutronic-thermal–mechanical-heat pipe coupling model is conducted. The work is based on the multi-physics coupling framework MOOSE, which integrates the Monte Carlo code OpenMC for neutronic analysis and built-in modules for 3-dimensional thermal–mechanical analysis. Furthermore, a heat pipe simulation method called the Thermal Resistance Grid Method is implemented within the MOOSE framework and employed in the multi-physics coupling analysis. To facilitate transient analysis, the Point Kinetics method is also integrated into the MOOSE framework to account for the time-varying power factor during reactor transients. The various modules and physical fields are coupled together using either loose or tight coupling strategies. These coupling strategies are applied to assess a test heat pipe reactor known as KRUSTY. Steady-state simulations are conducted for both normal operation and single heat pipe failure conditions, enabling the calculation of fission power distribution, temperature distribution, stress and strain profiles, as well as power and temperature redistribution following a heat pipe failure. Moreover, a load-following transient of KRUSTY is simulated, demonstrating its capability for load following without reactivity control. The aforementioned calculations validate the feasibility of the coupling framework utilized in this study and highlight its ability to accurately capture local phenomena within the reactor core.

Investigating effect of various time varying load models in grid connected microgrid system integrated with renewables and cogeneration units

ABSTRACT The optimal allocation of sources considering voltage-dependent load models is essential as the power consumption of the loads is sensitive to voltage magnitude. In this paper, optimal allocation of microgrid system with cogeneration units, renewable energy sources (RES), shunt capacitors and heat boiler are determined for constant, residential, industrial, commercial and mixed load models. The cost, emission, energy loss, voltage deviation and voltage stability values for each load model is determined using particle swarm optimisation (PSO) integrated fuzzy max–min approach while the uncertainties in RES are taken into account. Results demonstrate that the cost, energy loss and voltage deviation values are maximum for constant power (CP) load model compared with other load models. Furthermore, the system with constant impedance (CZ) load achieves maximum loading capability than with other types of constant loads. The proposed method is validated on 33-bus grid-connected microgrid system with all the load models.

Dual-responsive Drug Delivery System based on PEG-functionalized Pillararenes Containing Disulfide and Amido Bonds for Cancer Theranostics.

The construction of smart drug delivery system based on amphiphilic pillararenes with multiple responsiveness properties has become an important way to improve the efficacy of tumor chemotherapy. Herein, a new PEG-functionalized pillararene (EtP5-SS-PEG) containing disulfide and amido bonds was designed and synthesized, which has been used to construct a novel supramolecular nanocarrier through the host-guest interaction with a perylene diimide derivative (PDI-2NH4) and their supramolecular self-assembly. This nanocarrier showed good drugloading capability, and dual stimuli-responsiveness to enzyme and GSH (glutathione). After loading Doxorubicin (DOX), the prepared nanodrugs displayed efficient DOX release and outstanding cancer theranostics ability.

The cylindrical mechanical metamaterial with high-level thermal-mechanical stabilities and high dynamic stiffness

Mechanical metamaterials with high-level thermal-mechanical stabilities are attracting increasing interest in aerospace. Although numerous configuration designs have been proposed, few of them can satisfy the demands of space explorations, mainly considering the inevitable geometric errors during the assembling process of the metamaterial using a number of parts. To address this issue, the design strategy of cylindrical mechanical metamaterials based on the building block assembly method is proposed here to achieve high-level thermal-mechanical stabilities and high dynamic stiffness. The mechanical and thermal properties of the metamaterial have been systematically studied in terms of theoretical predictions, Finite Element Analysis (i.e., FEA), and experimental measurements. The theoretical model proposed here has accurately predicted the thermal-mechanical behaviors of the metamaterial and demonstrated the capabilities of the metamaterial in achieving combined attributes of the good loading capability (i.e., 2.30 × 106 kN mm/kg for the specific compression modulus, 1.02 × 106 kN mm/kg for the specific shear modulus), the experimentally high thermal-mechanical stabilities (i.e., 0.037 ppm/°C), the high-level dynamic stiffness (i.e., 1013.84 Hz). Notably, the selective electron beam melting and the unique assemble method realize the feasibility of structurally integrated preparation of the metamaterial and achieve the reusability capability even once fabricated.

A 1-A Switching LDO With 40-mV Dropout Voltage and Fast DVS

This brief presents a 1-A fully-integrated switching LDO for digital loads. By using 4-phase 200-MHz pulse-width modulation (PWM), it can significantly reduce the output ripple and allow using a smaller output capacitor. Distinctive from the prior dual-loop structure, we adopt a single feedback loop with a wide bandwidth error amplifier (EA) using a quasi-Type-III compensation to improve the dynamic voltage scaling (DVS) rate and to reduce the transient recovery time. Meanwhile, compared with the prior stacked power transistor architecture, the single-PMOS with auxiliary constant current (ACC) control can reduce by 4-fold the power transistor size, and decreases the driver current by at least 2.5 times. Fabricated in 28-nm bulk CMOS, the proposed LDO measures a 1-A load capability with a 40-mV dropout voltage. Moreover, the measured load regulation is 2.2 mV/A, and the line regulation is 1.8 mV/V. In addition, the regulator obtains a fast DVS speed of 4V/μs and a fast load transient recovery time of <50ns.

Synchrotron X-ray diffraction and radiography - Lattice strain characterization in thin-walled carbon fibre channel structures subjected to buckling

Carbon fibre composites are widely used in low specific stiffness and high strength structures such as airframes. Compressive loading of these assemblies can lead to buckling and localised deformation around defects and imperfections that can hinder performance and lead to overengineering via excessive safety factors. Synchrotron X-Ray Diffraction (SXRD) has recently been shown to be capable of performing lattice strain mapping within carbon fibre composites at the microscale, a previously unprecedented resolution. In this study SXRD and radiography was performed on carbon fibre composite columns produced via two different methods (standard lamination and half square) at a range of different load states: unbuckled, one-third of the buckling load and post buckling. The results provide quantitative insights into the impact of these different production methods on lattice strain and fibre orientation, as well as the influence these factors have on reducing buckling load (by up to 22%). As well as being the first use of SXRD on industrially representative full-size carbon fibre samples, these insights provide invaluable detail into the factors which limit performance and the origins of column failure; crucial factors required to optimise structural design, production and loading capability.

Topology comparative assessment for hybrid medium-voltage AC/DC networks

Recently, there has been significant growth in integrating renewable energy generation and electric vehicles and deploying new technologies into the electrical networks, leading to new challenges for planning, design, operation, control and protection of the distribution grid. In particular, an increasing amount of large-scale DC load and generation is expected to be connected to the distribution system, especially at the MV level. Thus, adoption of new grid topologies is required and among others, hybrid AC/DC networks have emerged as an attractive pathway to meet new grid operational requirements. This paper evaluates future hybrid AC/DC distribution systems at the MV level, considering potential network topologies and new technologies. Steady-state analysis is performed to compare five topologies of hybrid MV AC/DC networks. Key technologies for such hybrid grids such as voltage source converters and fast charging stations are considered. The results provide quantitative comparisons between topologies regarding large-scale DC load and generation integration capability, contingency operation, sensitivity analysis. Several challenges presented to the protection and fault location that are caused by the adoption of new topologies are also identified. The topologies are compared by network losses, voltage and power factor constraints, analysing the different benefits and drawbacks of the hybrid AC/DC topologies.

R.C.C Shell Structure Design of Selected Head Cap Shape

Abstract: A shell structure is a thin structure composed of curved sheets of material, so that Shell structures are inspired from natural element named “SHELL”. A thin curved member or slab usually of reinforced concrete that function as tension member and shell. The waviness plays an important role in the structural behavior realizing a spatial form. Some of natural elements like eggshell, seashell, fruit shells (walnut) etc are showing shell structure properties. The present reinforced concrete shells as a very efficient structure, spanning wide, architectonically beautiful, relevant and valuable structural solution. Shell structures are very attractive lightweight structures, which are especially suited to Architectural building, industrial application, commercial projects etc.. The actual design of shells, involves theories of shells and the use of appropriate codes of practice. Types of curved shell like Parabolic, Hyperbolic or Cylindrical members are often said to act as tension rigidity hence called tensile members. For achieving the optimized load capability and flexural strength of such an element in form of shell covering structure is checked in for M30 grade concrete. Tensile shell members are structural edifice that caries only tension and without buckling or bending. Tensile structures are the most common type of thin-shell structures used worldwide from past decades. The profile and aspect of structure used are unlike for loading conditions, geographical locations and Architecture design differs as such as horizontal, sloping or curved member (dome and shell member). In this research work the tensile shell (plate) structure is designed in the form of beam and as grid shell slab element (plate). After then load has been applied for analysis via software tool i.e. STAAD Pro. The types of load assigned dead and live loads. The Design code specifications for curved shell member in IS: 2210–1994, IS 2204-1962 “Code of practice for construction of reinforced concrete shell roof” [CED 13: Building Construction Practices including Painting, Varnishing and Allied Finishing] and the load case criteria is to be as per IS: 875(2)–2000. RCC design specifications as per IS: 456–2000

Three Dimensional Low-Tortuosity Carbon Fibers Enable High-Areal-Capacity and Long-Durability Battery

Increasing the thickness of lithium-ion battery electrodes enables significant improvement in energy density and reducing the manufacturing cost. However, the existing barriers such as manufacturing challenges, performance issues, and scalability impede the development of fabricating thick electrodes. Here, we demonstrate a three dimension, low-tortuosity, and metal current collector free carbon fiber (CF) electrode which works as an integrated host substrate for LiNi0.5Mn0.3Co0.2O2 (NMC 532) cathode materials, similarly, the paired anode. The low tortuosity (~ 1.7) aligned microchannels of CF provide a good electron conductivity (~ 0.23 S cm-1), low Li+ diffusion resistance (~ 22 Ω), and high reversibility (91% over 500 cycles at C/3) compared to ~ 0.01 S cm-1, ~ 34 Ω, and 50% over 50 cycles for 100 µm slurry-casting graphite electrode with tortuosity of 2.9, respectively. The large porosity (~ 60%) enables CF a high mass loading capability of NMC 532 (> 70 mg cm-2) which provides a theoretical areal capacity ~ 14 mAh cm-2. The practical design of NMC 532/CF versus CF thick cells, with NMC 532 mass loading 32 mg cm-2, and theoretical areal capacity ~ 5.5 mAh cm-2 show an initial discharge areal capacity 4.1 mAh cm-2 at C/3 (1.5 mA cm-2), a capacity retention of 90.4% (500 cycles), 78.1% (1000 cycles), and 65.5% (1500 cycles). Furthermore, the post-analysis of long-term cycled NMC 532 particles, with consistent morphology of pristine particles, demonstrates lessen thermal stress across the electrodes. Our work presents a well-aligned microstructure for thick lithium-ion electrodes with practical level, scalable manufacturing, high areal capacity, and long-term electrochemical durability.

MIMO state feedback control for redundantly-actuated LiBr/H[formula omitted]O absorption heat pumping devices and experimental validation

Absorption heat pumping devices (AHPDs, comprising absorption heat pumps and chillers) use mainly thermal energy instead of electricity as the driving energy to provide resource-efficient heating and cooling when using waste heat or renewable heat sources. Despite this benefit, AHPDs are still not a very common technology due to their complexity. However, better modulation and part-load capability, which can be achieved through advanced control strategies, can simplify the use of AHPDs and help to better integrate them into complex energy systems. Therefore, this paper presents a new, dynamic model-based control approach for single-stage AHPDs that can extend an AHPD’s operating range by employing multi-input-multi-output (MIMO) control methods. The control approach can be used for different AHPD applications and thus control configurations, i.e., different combinations of manipulated and controlled variables, and can also be used for redundantly-actuated configurations with more manipulated than controlled variables. It consists of an observer for the state variables and unknown disturbances, a state feedback controller and, in case of redundantly-actuated configurations, a dynamic control allocation algorithm. The proposed control approach is experimentally validated with a representative AHPD for two different control configurations and compared to two benchmark control approaches – single-input-single-output (SISO) PI control representing the state-of-the-art, and model-predictive control (MPC) as an alternative advanced control concept. The experimental validation shows that the two MIMO control approaches (the proposed state feedback and the MPC approach) allow for a wider operating range and hence better part load capability compared to the SISO PI control approach. While MPC generally results in a comparably high computational effort due to the necessity of continuously solving an optimization problem, the proposed state feedback control approach is mathematically simple enough to be implemented on a conventional programmable logic controller. It is therefore considered a promising new control approach for AHPDs with the ability to extend their operating range and improve their part load capability, which in turn facilitates their implementation and thus the use of sustainable heat sources in heating and cooling systems.

A three-month physical training program improves cardiovascular autonomic function in patients with metabolic syndrome with and without diabetes - a pilot study.

Vascular complications and neuropathy may develop in the presence of metabolic syndrome. The aim of our study was to measure the cardiovascular autonomic function following physical training in patients with metabolic syndrome with and without diabetes. 56 patients with metabolic syndrome (32 men/24 women, 40 non-diabetic patients (NDMetS)/16 diabetic patients (DMetS) [mean ± SD]: age: 50.35 ± 8.03 vs. 56.8 ± 9.30 years, p=0.023; baseline BMI: 32.2 ± 7.03 vs. 32.8 ± 5.94 kg/m2, p=0.739) were involved in our study. All tests and measurements were carried out before and following a 3-month physical training period. Autonomic function was assessed by means of five standard cardiovascular reflex tests. ECG repolarization parameters, including short-term QT variability and stress-ECG were also measured. In the whole population, Valsalva-ratio (VR) and the autonomic score (AS) improved following training (VR: 1.49 ± 0.24 vs. 1.64 ± 0.34, p=0.001; AS: 2.05 ± 1.73 vs. 1.41 ± 1.36, p=0.015) accompanied by the significant decrease of the systolic (150.3 ± 16.12 vs. 134.1 ± 16.67 mmHg, p<0.001) and diastolic (90.64 ± 12.8 vs. 82.79 ± 11.1 mmHg, p<0.001) blood pressure. An improvement in VR was detected in NDMetS patients following training (1.51 ± 0.24 vs. 1.67 ± 0.31, p= 0.002). No significant changes could be detected in autonomic tests' results in the DMetS patient group following training. The applied exercise training program did not lead to significant changes in ECG repolarization. The stress-ECG test in the whole study population yielded a significant increase in the test duration (12.9 ± 3.76 vs. 15.1 ± 2.96min, p<0.001) and in the test load (10.5 ± 2.78 vs. 11.6 ± 2.39 MET, p<0.001). The load capability improved significantly in both subgroups: 11.1 ± 2.04 vs. 12.1 ± 1.82, (p<0.001) and 9.0 ± 3.64 vs. 10.4 ± 3.05, (p=0.033) in subpopulations of NDMetS and DMetS, respectively. The DMetS patients achieved a significantly lower MET score at baseline (p=0.039) and following training (p=0.044) in comparison to the NDMetS patients. The three-month exercise program improved the Valsalva-ratio and the AN score in the MetS patients, that is potentially protective against cardiovascular events. The training had some beneficial effect on blood pressure and the results of the stress-ECG tests in both groups. The absence of significant change in the reflex tests in DMetS group reflects an impaired adaptation compared to the NDMestS group.