Excessive Fluctuations Research Articles

The relationship between glycaemic variability and cardiovascular autonomic dysfunction in patients with type 1 diabetes: A systematic review.

Rigorous glycaemic control-reflected by low HbA1c goals-is of the utmost importance in the prevention and management of complications in patients with type 1 diabetes mellitus (T1DM). However, previous studies suggested that short-term glycaemic variability (GV) is also important to consider as excessive glucose fluctuations may have an additional impact on the development of diabetic complications. The potential relationship between GV and the risk of cardiovascular autonomic neuropathy (CAN), a clinical expression of cardiovascular autonomic dysfunction, is of increasing interest. This systematic review aimed to summarize existing evidence concerning the relationship between GV and cardiovascular autonomic dysfunction in T1DM. An electronic database search of Medline (PubMed), Web of Science and Embase was performed up to October 2019. There were no limits concerning year of publication. Methodological quality was evaluated using the Newcastle Ottawa Scale for observational studies. Six studies (four cross-sectional and two prospective cohorts) were included. Methodological quality of the studies varied from level C to A2. Two studies examined the association between GV and heart rate variability (HRV), and both found significant negative correlations. Regarding cardiovascular autonomic reflex tests (CARTs), two studies did not, while two other studies did find significant associations between GV parameters and CART scores. However, associations were attenuated after adjusting for covariates such as HbA1c, age and disease duration. In conclusion, this systematic review found some preliminary evidence supporting an association between GV and cardiovascular autonomic dysfunction in T1DM. Hence, uncertainty remains whether high GV can independently contribute to the onset or progression of CAN. The heterogeneity in the methodological approach made it difficult to compare different studies. Future studies should therefore use uniformly evaluated continuous glucose monitoring-derived parameters of GV, while standardized assessment of HRV, CARTs and other potential cardiac autonomic function parameters is needed for an unambiguous definition of CAN.

Evaluation of air curtain system orientated to local environmental control of archaeological museum: A case study for the stone armor pit of Emperor Qin’s Mausoleum Museum

Due to the lack of effective environmental control systems, Emperor Qin’s Mausoleum Museum is facing problems of air pollution and excessive environmental fluctuations, which threaten the protection of the unearthed historical relics. Air curtain systems have proven to be a feasible way to improve the preservation environment, and will be applied to Emperor Qin’s Mausoleum Museum. In order to identify the design requirements of the air curtain system, a theoretical model was employed to analyze the isolation efficiency under different scenarios, and the suitable operation parameter range of the air curtain system of the stone armor pit was then proposed. Based on the geometric structure of the stone armor pit, a computational fluid dynamics (CFD) model was established, and the environmental control performance of the air curtain system was investigated in the case where the jet velocity and elevation angle are 6.0 m/s and 5。, respectively. The results show that the air curtain system can effectively isolate the relics preservation area of the stone armor pit from the exhibition hall, ensuring the local environmental control of relics preservation. These results provide a basis for the design and operation of the air curtain system of the stone armor pit. Moreover, they provide an effective solution for the local environmental control of relics in pit structure sites.

Testing for multiple bubbles in the copper price: Periodically collapsing behavior

This study investigates whether multiple bubbles exist in the copper price on the basis of the Generalized Supremum Augmented Dickey-Fuller (GSADF) approach (Phillips et al., 2013). This technique delivers date-stamping strategies for the emergence as well as collapse of explosive bubble episodes and is best suited for practical application to time series. The results reveal that four explosive bubbles are detected over the period of 1980–2019 when copper price deviates from fundamental value. Besides, this finding is in accordance with the asset pricing model (Gürkaynak, 2008), which generally considers both fundamental and bubble components in the presence of asset prices. Based on the empirical results, the multiple emergence and collapse of multiple price bubbles are attributed to speculation, depreciation of the U.S. dollar, an imbalance between supply and demand, and financial crises. Policymakers should actively recognize bubble episodes and monitor their evolution, which could be conducive to achieving the effective stabilization of the international copper price. To reduce excess price fluctuations and explosive copper bubbles, authorities should impose restrictions on excessive speculative behaviors under extreme market conditions.

Excess conductivity investigations of WO3 nanowires added to YBa2Cu3O7-d superconductor

Series of YBa2Cu3O7-d + x wt% WO3 nanowire mixtures where x = 0.0–2.0 wt% were prepared via solid-state reaction method. X-ray diffraction (XRD) patterns show the unaffected orthorhombic structure in various composites. Scanning electron microscopy (SEM) micrographs show the increase in grains size and the filling of voids between grains by WO3 nanowires. The superconducting transition temperatures deduced from electrical resistivity versus temperature (ρ(T)) measurements are almost unchanged by lower WO3 nanowires addition (i.e., x 0.5 wt%). The analysis of excess conductivity fluctuation (∆σ) by means of Aslamazov–Larkin (AL) and Lawrence–Doniach (LD) approaches was investigated. Dimensional fluctuations, coherence lengths, effective layer thickness, zero temperature lower and upper critical magnetic fields (Bc1 (0) and Bc2 (0)), and critical current density at temperature T = 0 K (Jc(0)) were extracted and discussed in relation with the structure and morphology. Improvements in Bc1 (0), Bc2 (0), and Jc(0)) were noticed for samples added with lower WO3 nanowires content, particularly for x = 0.1 wt% composite sample.

Simulation and operation control strategy of ground source thermal energy management system by cold and heat auxiliary technology

To explore the performance of the ground source thermal energy management system under the cold and heat sources, based on the cold and heat auxiliary technology, a ground source thermal energy composite management system is constructed and simulated. The constructed ground source heat pump-refrigeration unit-hybrid heating management system of urban heating networks, as well as the simple system, are analyzed and investigated in terms of power consumption and underground temperature control. The research results show that the constructed ground source heat pump-refrigeration unit-hybrid heating management system of the urban heating network has lower power and energy consumption than a simple system during the same period, which meets the economic requirements and guarantees the system with relatively low energy consumption. For underground temperature control, the constructed system is more stable than a simple system without excessive temperature fluctuations. The operation control strategy of the constructed system is mainly for chiller units, heat pump units, cooling towers, source side, and side circulation water pump modules. In summary, the constructed ground source heat pump-refrigeration unit-hybrid heating management system of an urban heating network based on the ground source heat pump meets the requirements for energy consumption and temperature control and can operate the control strategy normally. The results are significant for subsequent researches on the ground source thermal energy management system based on cold and heat auxiliary technology.

Optimization of Coordinated Control System on Radial Basis Function Neural Network

Coordination control system is an indispensable part of the thermal power unit, which is a multi-input and multi-output, complex structure of the system. The coordinating way of boiler-follower has the ability of high respond to load, but this method will cause excessive fluctuation of steam pressure in the boiler, what worse is that will produce excessive pressure cause explosion if you operate in a wrong way. Above all, this paper show a new method which combines the advantages of neural network and conventional PID control to improve the load response rate of the coordinated control system. According to the characteristics of non-linearity, large inertia and large delay of the system, a 300MW unit model is adopted in this paper. After analyzing its dynamic characteristics, we decide to use PID decoupling controller to eliminate the coupling phenomenon of the system itself. A control approach based on RBF neural network is proposed. The experimental results show that the dynamic response of the system is obviously improved, the system is more stable, the response speed is faster and the satisfactory control effect is achieved.

EXCHANGE RATE CHANNEL OF TRANSMISSION MECHANISM OF THE NBU’S MONETARY POLICY

The essence of exchange rate channel of transmission mechanism of the monetary policy is considered. Pearson’s, Spearman’s, and Kendall’s correlation coefficients were applied to calculate the relationship between variables. It is emphasized that the exchange rate channel of the monetary policy transmission mechanism reflects its impact on output and price level due to changes in the exchange rate of the national currency. It is noted that the hryvnia devaluation has always been observed against the background of economic crises and declining exports. In all three cases of sharp devaluation, the crises were accompanied by a significant drop in exports of goods, which reduced the NBU's reserve assets. In general, the NBU conducted interventions to counteract excessive fluctuations in the national currency exchange rate, selling currency during periods of devaluation and buying it during periods of revaluation. In addition, there is an inverse relationship between the discount rate and the official hryvnia exchange rate from January 2015 to October 2019. In other words, the higher the discount rate, the lower the USD price expressed in UAH is. In addition, the Pearson’s correlation coefficients indicate a strengthening of the relationship between the official hryvnia exchange rate against the U.S dollar and the lagged discount rate. In other words, raising the interest rate in the current month will have a long-term impact on the value of the dollar, expressed in UAH. The strongest link between the discount rate and the official hryvnia exchange rate is in the first leg, with the link loosening in the next. The values of the Kendall correlation coefficients show the same as the previous coefficients. First, the relationship between the official hryvnia exchange rate against the U.S dollar and lag values of discount rate is increasing. Second, similarly, the relationship between the USD/UAH exchange rate and the interbank lending rate is increasing. Third, the link between the CPI lag values and the official hryvnia exchange rate is increasing. Fourth, the relationship between the hryvnia against the US dollar and the NBU's interventions is insignificant. Fifth, there is a link between rising exports and the devaluation of the hryvnia against the US dollar. Keywords : exchange rate, transmission mechanism, monetary policy, exchange rate channel, discount rate.

Mechanisms for the Development of Blood Pressure Variability and the Potential of Antihypertensive Drugs in Their Correction

Blood pressure variability (BPV) is the fluctuations of blood pressure over a certain period of time under the influence of various factors. The issue of increased BPV is of particular clinical importance due to high predictive value of this parameter as a risk factor for fatal and non-fatal cardiovascular, cerebrovascular and renal events. It is proved that in the BPV increasing, the key role is played by impairments in arterial baroreflexes, which, in turn, are mediated by increased vascular stiffness, impact of angiotensin II and the sympathetic nervous system, endothelial dysfunction, nitric oxide deficiency and aging, including the vascular aging. Antihypertensive drugs that targeting largest amount of pathophysiological mechanisms in BPV increasing have a most advantages in correcting excessive pressure fluctuations. In this regard such drugs are perindopril and amlodipine, which can eliminate almost the entire spectrum of increased BPV causes and, therefore, optimally reduce the cardiovascular risk.

Bloom of the potentially toxic cyanobacterium P. rubescens: seasonal distribution and possible drivers of its proliferation in the Vrutci reservoir (Serbia)

Abstract Planktothrix rubescens is a filamentous cyanobacterium with a worldwide distribution in lakes and reservoirs of varying size and morphology. The objective of this study was to identify the population dynamics and the major drivers of P. rubescens blooms. Samples for qualitative and quantitative analysis of phytoplankton were collected every month in 2014 and 2015 from stationary depths, while the main physical parameters were measured in situ along the water column. Samples for chemical analysis were collected below the surface, at mid-depth (metalimnion) and near the bottom. In the periods of thermal stratification, P. rubescens formed the maximum biomass in the metalimnion, however, its volume-weighted biomass reached the maximum value in the winter mixing period (4.40 mm3 l−1). Changes in the P. rubescens population in the reservoir were related to changes in the measured environmental parameters. Significant physical, hydrological, meteorological and chemical parameters were distinguished based on the multivariate analysis. The variable associated with water-level fluctuations showed the highest positive correlation with P. rubescens biomass. We conclude that it is necessary to establish water quality monitoring and prevent excessive water-level fluctuations to ensure a high quality of water supplies from the reservoir.

Capacitor Voltage Fluctuation Minimization for Four-Level Hybrid Clamped Converter Using Improved Common-Mode Voltage Injection

When a four-level hybrid clamped converter (4L-HCC) operates at low frequencies, the high load current causes significant voltage fluctuations among the capacitors in the dc link. A mathematical model is developed to clarify the mechanism of excessive capacitor voltage fluctuations. An improved common-mode voltage injection algorithm is proposed and integrated to the overall control method. With the applied algorithm, the voltage fluctuation minimization of the dc-link capacitors and the dynamic voltage balancing capability are investigated. Both simulation and experimental results validate the effectiveness of the proposed algorithm, with a voltage fluctuation reduction over 50%. The 4L-HCC with the proposed algorithm achieves much faster dynamic response to converge the unbalanced capacitor voltages and the reduced output current harmonics compared with the conventional common-mode voltage injection algorithm.

Order Exposure and Liquidity Coordination: Does Hidden Liquidity Harm Price Efficiency?

We show that the excessive use of hidden orders causes artificial price pressures and abnormal asset returns. Using a simple game-theoretical setting, we demonstrate that this effect naturally arises from mis-coordination in trading schedules between traders, when suppliers of liquidity do not sufficiently disclose their trade intentions. As a result, hidden liquidity can increase trading costs and induce excess price fluctuations unrelated to information. Using NASDAQ order book data, we find strong empirical support and illustrate that hidden liquidity is higher if bid–ask spreads are smaller and relative tick sizes are higher.

Psychological resilience negatively correlates with resting-state brain network flexibility in young healthy adults: a dynamic functional magnetic resonance imaging study.

Psychological resilience is an important personality trait whose decrease is associated with many common psychiatric disorders, but the neural mechanisms underlying it remain largely unclear. In this study, we aimed to explore the neural correlates of psychological resilience in healthy adults by investigating its relationship with functional brain network flexibility, a fundamental dynamic feature of brain network defined by switching frequency of its modular community structures. Resting-state functional magnetic resonance imaging (fMRI) scans were acquired from 41 healthy adults, whose psychological resilience was quantified by the Connor-Davidson Resilience Scale (CD-RISC). Dynamic functional brain network was constructed for each subject, whose flexibility was calculated at all the global, subnetwork and region-of-interest (ROI) levels. After that, the associations between CD-RISC score and brain network flexibility were assessed at all levels by partial correlations controlling for age, sex, education and head motion. Correlation was also tested between the CD-RISC score and modularity of conventional static brain network for comparative purposes. The CD-RISC score was significant negatively correlated with the brain network flexibility at global level (r=-0.533, P=0.001), and with flexibility of the visual subnetwork at subnetwork level (r=-0.576, corrected P=0.002). Moreover, significant (corrected P<0.05) or trends for (corrected P<0.10) negative correlations were found between the CD-RISC score and flexibilities of a number of visual and default-mode areas at ROI level. Meanwhile, the modularity of static brain network did not reveal significant correlation with CD-RISC score (P>0.05). Our results suggest that excessive fluctuations of the functional brain community structures during rest may be indicative of a lower psychological resilience, and the visual and default-mode systems may play crucial roles in such relationship. These findings may provide important implications for improving our understanding of the psychological resilience.

Fluctuation Conductivity and Its Scaling Behavior in BaFe1.9Co0.1As2 Superconductor

Excess fluctuation conductivity of BaFe1.9Co0.1As2 single crystal was studied by measurements of temperature and magnetic field dependence of resistance. The mean field critical temperature Tc (H) is determined by using the criterion of the dR/dT as a function of temperature, where a unique sharp peak appears in the dR/dT curves. By analyzing the excess fluctuation conductivity and the resistance experimental data in the framework of Aslamazov and Larkin theory, different fluctuation regimes such as the three-dimensional (3D), the two-dimensional (2D), the one-dimensional (1D), and short-wave fluctuation (SWF) were identified. In the mean field region, it was also found that the analyses of the resistance experimental data based on the Aslamazov-Larkin theory describes the real measured resistance data very well down to about 0.5 Rn at different regions, which supported the excess fluctuation conductivity results. Based on the lowest Landau level method, both the three-dimensional (3D) and two-dimensional (2D) scaling behaviors were observed in the fluctuation conductivity at magnetic field larger than 5 T and different temperature interval around the mean-field critical temperature Tc.

Identification and Control of Electric Elasticity Limit for Electric-Spring-Based Flexible Loads

By comprehensively analyzing the effective working voltage range of electric springs (ESs), this paper proposes a new control strategy to improve the absorption capacity of ES-based flexible loads for mains voltage fluctuations; thus, enhancing the stability of the microgrid fed by intermittent renewables. Analogous to a mechanical spring, the effective working voltage range of ESs is also restricted by the electric elasticity limit (EEL). In specific circumstances, the ES-based flexible load is incapable of dealing with excessive fluctuations of mains voltage caused by intermittent renewable energy sources. Accordingly, this paper investigates the impact of key parameters on the EEL of ESs, such as the distribution line, the voltage reference, and the loads. Besides, by adjusting the proportion between the critical and the noncritical loads, this paper proposes and implements an EEL controller to regulate the absorption capacity of ES-based flexible loads for mains voltage fluctuations; thus, effectively ensuring the voltage stability of critical loads. Finally, the simulated and experimental results are both given to verify the theoretical analysis for ES-based flexible loads and the feasibility of the proposed EEL controller.

Energy localization and excess fluctuations from long-range interactions in equilibrium molecular dynamics

Molecular dynamics (MD) simulations of standard systems of interacting particles (“atoms”) give excellent agreement with the equipartition theorem for the average energy, but we find that these simulations exhibit finite-size effects in the dynamics that cause local fluctuations in energy to deviate significantly from the analogous energy fluctuation relation (EFR). We have made a detailed analysis of Lennard-Jones atoms to track the origin of such unphysical fluctuations, which must be corrected for an appropriate description of the statistical mechanics of small systems, especially at low temperatures (T). Similar behavior is found in a model of nitromethane at higher T. The main conclusion of our study is that systems separated into nanometer-sized “blocks” inside much larger simulations exhibit excess fluctuations in potential energy (pe) that diverge inversely proportional to T in a manner that is strongly dependent on the range of interaction. Specifically, at low T with long-range interactions pe fluctuations exceed the EFR by at least an order of magnitude, dropping abruptly to below the EFR when interactions include only 1st-neighbor atoms. Thus, excess pe fluctuations cannot be due to simple surface effects from the robustly harmonic 1st-neighbor interactions, nor from any details in the simulations or analysis. A simplistic model that includes 2nd-neighbor interactions matches the excess fluctuations, but only if the 2nd-neighbor energy is not included in Boltzmann’s factor, attributable to anharmonic effects and energy localization. Empirically, adding 2nd-neighbor interactions greatly increases the width of the pe distribution, suggesting that Anderson localization may play a role. Characterizing energy correlations as a function of time and distance reveals that excess pe fluctuations in each block coincide with negative pe correlations between neighboring blocks, whereas reduced pe fluctuations coincide with positive pe correlations. Indeed, anomalous pe fluctuations in small systems can be quantified using a net local energy in Boltzmann’s factor that includes pe from the surrounding shell of similarly small systems, or equivalently an effective local temperature. Our results and analysis elucidate the source of non-Boltzmann fluctuations, and the need to include mesoscopic thermal effects from the local environment for a consistent theoretical description of the equilibrium fluctuations in MD simulations of standard models with long-range interactions.

Spectral Properties of Populations Behind the Coherence in Spitzer Near-infrared and Chandra X-Ray Backgrounds

Abstract We study the coherence of the near-infrared and X-ray background fluctuations and the X-ray spectral properties of the sources producing it. We use data from multiple Spitzer and Chandra surveys, including the UDS/SXDF surveys, the Hubble Deep Field North, the EGS/AEGIS field, the Chandra Deep Field South, and the COSMOS surveys, comprising ∼2275 Spitzer/IRAC hours and ∼16 Ms of Chandra data collected over a total area of ∼1 deg2. We report an overall ∼5σ detection of a cross-power signal on large angular scales &gt;20″ between the 3.6 and 4.5 μm and the X-ray bands, with the IR versus [1–2] keV signal detected at 5.2σ. The [0.5–1] and [2–4] keV bands are correlated with the infrared wavelengths at a ∼1–3σ significance level. The hardest X-ray band ([4–7] keV) alone is not significantly correlated with any infrared wavelengths due to poor photon and sampling statistics. We study the X-ray spectral energy distribution of the cross-power signal. We find that its shape is consistent with a variety of source populations of accreting compact objects, such as local unabsorbed active galactic nuclei or high-z absorbed sources. We cannot exclude that the excess fluctuations are produced by more than one population. Because of poor statistics, the current relatively broad photometric bands employed here do not allow distinguishing the exact nature of these compact objects or if a fraction of the fluctuations have instead a local origin.

Conductivity Fluctuation and Some Parameters of High temperature Superconductor Polycrystalline Y1Ba2Cu3O7−δ doped with Silver Nanoparticles

In this study, we report the effect of Ag nanoparticles doping on the dimensional fluctuations of superconducting order parameters, crystal structure, and some parameters of Y1Ba2Cu3O7−δ + × Ag (x = 0.0, 0.06, 0.1, 0.3, and 0.6 wt%) polycrystalline ceramics. By increasing the content of Ag in YBCO matrix, X-ray diffraction (XRD) with the Rietveld refinement technique revealed that the crystal lattice parameters changed and the orthorhombicity decreased slightly. Also, the increase of Ag wt% caused a decrease of superconducting transition temperatures (Tc) which are determined from the standard four-probe method and dropped abruptly. Aslamazov–Larkin (AL) model was used to analyze excess conductivity fluctuation. Lawerence–Doniach (LD) temperature named TLD which is responsible for the dimensional nature of fluctuation inside the grains is influenced by nano-silver combination in the compound. Crossover temperature from 2D to 3D (TLD) decreased in the mean-field region as a resultant dominance of 3D region by increasing of Ag in YBCO matrix. The decrease in zero-resistance critical temperature (Tc zero), zero-temperature coherence length along the c-axis ξc(0), and super layer length d values implies the degradation of inter-grain weak links, more disorder state of samples and unsettling of the mean free path for the charge carriers respectively with addition of silver nanoparticles. The calculations based on AL and LD model showed the highest anisotropy (γ = 1.34681) for the x = 0.6 sample. The size of the Ag ions, being larger compared to Cu ions, and the number of substitution sites affects the coupling between the CuO2 planes and that results in higher anisotropy. Critical magnetic fields Bc1(0), Bc2(0), and critical current density Jc(0) were indirectly calculated from the Ginzburg–Landau (GL) number and GL equations. By increasing the doping level of silver nanoparticle, these parameters were found to be higher in Ag-added YBCO samples compared to the pure Y123, meaning better intrinsic flux pinning properties of doped Y123. The silver nanoparticle inclusion reduces the grain size and increases the strength and hardness of the parent compound.

Calculations of High-Frequency Noise Spectral Density of Different CdTe Metal–Semiconductor–Metal Schottky Contacts

An analytical approach for the study of high-frequency noise in different CdTe Schottky contacts is proposed. The model takes into account the fluctuations from three primary current sources: the leakage current through the Schottky barrier, the fluctuations of surface charge current, and the excess carrier density produced by light illumination (photocurrent). In particular, the current densities related to the perturbation of the electric field inside the whole structure and the free carrier fluctuations are used to determine the detectivity in the Giga and the Terahertz frequencies. It is shown that the current spectral density exhibits a resonance peak near 109 Hz due to the free carrier concentration. The excess carrier fluctuations show a negligible contribution to the total spectral current density. It was found that the Au-S-Au structure presents a high detectivity due to their low noise level of the leakage current. These findings and the detailed model describing the current fluctuation processes in the detector is crucial for the development of detection technology.

Fluctuation of the background sky in the Hubble Extremely Deep Field (XDF) and its origin

Abstract We performed a fluctuation analysis of the Hubble Extremely Deep Field (XDF) at four optical wavelength bands and found large fluctuations that are significantly brighter than those expected for ordinary galaxies. Good cross-correlations with flat spectra are found down to ${0{^{\prime\prime}_{.}}2}$, indicating the existence of a spatial structure even at the ${0{^{\prime\prime}_{.}}2}$ scale. The detected auto- and cross-correlations provide a lower limit of 24 nW m−2 sr−1 for the absolute sky brightness at 700–900 nm, which is consistent with previous observations. We searched for candidate objects to explain the detected large fluctuation using the catalog of the Hubble Ultra Deep Field (UDF), and found that the surface number density of faint compact objects (FCOs) rapidly increases toward the faint end. Radial profiles of FCOs are indistinguishable from the point spread function (PSF), and the effective radius based on de Vaucouleur’s law is estimated to be smaller than ${0{^{\prime\prime}_{.}}02}$. The spectral energy densities (SEDs) of FCOs follow a power law at optical wavelengths, but show greater emission and structure at $\lambda \gt 1\, \mu$m. Assuming that the FCOs are the cause of the excess brightness and fluctuations, the faint magnitude limit is 34.9 mag for the F775W band, and the surface number density reaches 2.6 × 103 arcsec−2. Recent γ-ray observations require that the redshift of FCOs must be less than 0.1, if FCOs are the origin of the excess optical and infrared background. Assuming that FCOs consist of missing baryons, the mass and luminosity of a single FCO range from 102 to 103 solar units, and the mass-to-luminosity ratio is significantly lower than 1.0 solar unit. The maximum effective radius of an FCO is 4.7 pc. These results and the good correlation between the near-infrared and X-ray background indicate that FCOs could be powered by the gravitational energy associated with black holes.

Experimental Investigation of a Flat-Plate Closed-Loop Pulsating Heat Pipe

The thermal performance and operating modi of a flat-plate closed-loop pulsating heat pipe (PHP) are experimentally observed. The PHP is manufactured through computer numerical controlled milling and vacuum brazing of stainless steel 316 L. Next to a plain closed-loop PHP, also one that promotes fluid circulation through passive Tesla-type valves was developed. Each channel has a 2 × 2 mm2 square cross section, and in total, 12 parallel channels fit within the 50 × 200 mm2 effective area. During the experimental investigation, the power input was increased from 20 W to 100 W, while cooling was performed using a thermo-electric cooler (TEC) and thermostat bath. Three working fluids were assessed: water, methanol, and ammonia. The PHP was charged with a 40% filling ratio. Thermal resistances were obtained for different inclination angles. It was observed that the PHP operates well in vertical evaporator-down orientation but not horizontally. Moreover, experiments show that the minimum operating orientation is between 15 and 30 deg. Two operating modi are observed, namely, the thermosyphon modus, without excessive fluctuations, and the pulsating modus, in which both the temperature and pressure responses oscillate frequently and violently. Overall thermal resistances were determined as low as 0.15 K/W (ammonia) up to 0.28 and 0.48 K/W (water and methanol, respectively) at a power input of 100 W in the vertical evaporator-down orientation. Infrared thermography was used to visualize the working fluid behavior within the PHPs. Infrared observations correlated well with temperature and pressure measurements. The experimental results demonstrated that the developed flat-plate PHP design, suitable for high-volume production, is a promising candidate for electronics cooling applications.