Effect Of Compression Research Articles

Effect of clayey sediment compression on fluoride enrichment in the Quaternary groundwater system of Cangzhou Plain, China

The effect of clay layer compression on the enrichment of groundwater fluoride remains unknown. Quaternary groundwater with high fluoride levels at the Cangzhou Plain, which has a long history of land subsidence caused by clay layer compression, poses a potential health risk. The spatial distribution and enrichment mechanisms of groundwater fluoride are identified by sample collection, hydrochemical analysis, and geochemical inverse modeling. The results revealed that fluoride concentrations in 82 % of the 122 groundwater samples above the limit in drinking water as 1.0 mg/L in China. Fluoride in shallow groundwater (depth <20 m, ∼average = 2.08 mg/L) was mainly originated from fluorite dissolution and influenced by groundwater HCO3−, pH, and cation exchange levels. Below ∼200 m, the main source of groundwater fluoride (∼average = 3.12 mg/L) was the compression−release of clay pore water with high F− concentration, which was generated by complex water-rock interaction. Based on hydrochemical inverse simulation and end-member mixing models, the pore water released from clayey sediments supplied 53 %−56 % of deep groundwater (>200 m) and contributed 2.07 −2.87 mg/L to F− concentration. The findings of this study provide a theoretical basis for future research on prevention of high fluoride groundwater induced by clayey sediment compression.

Numerical simulation of unsteady cloud cavitation in an orifice nozzle by a compressible gas-vapor/liquid mixture cavitation model

Abstract Focused on the behaviour of unsteady cloud cavitation in a submerged orifice nozzle, this work presents a numerical investigation by using a compressible gas-vapor/liquid mixture cavitation model. The mean flow of the two-phase mixture is calculated by URANS for compressible fluid and the intensity of cavitation is evaluated by the gas volumetric void fraction considering the effect of fluid compressibility varying with phase change. Water jets issuing from a submerged orifice nozzle are investigated under different cavitation conditions. Computation results are compared with experiment data and the validity of computation is confirmed. The periodical shedding of cavitation clouds is captured reliably. Numerical simulations reveal that a leading cloud principally split by the shear flow and a subsequent cloud detached by the re-entrant jet are successively shed downstream, and they coalesce over the range of approximately x/d ≈ 2∼3. This process is repeated and the flow rate coefficient pulsates periodically under the effect of cavitation clouds.

Cloud–Cloud Collision: Formation of Hub-filament Systems and Associated Gas Kinematics. Mass-collecting Cone—A New Signature of Cloud–Cloud Collision

Massive star-forming regions (MSFRs) are commonly associated with hub-filament systems (HFSs) and sites of cloud–cloud collision (CCC). Recent observational studies of some MSFRs suggest a possible connection between CCC and the formation of HFSs. To understand this connection, we analyzed the magnetohydrodynamic simulation data from Inoue et al. This simulation involves the collision of a spherical turbulent molecular cloud with a plane-parallel sea of dense molecular gas at a relative velocity of about 10 km s−1. Following the collision, the turbulent and nonuniform cloud undergoes shock compression, rapidly developing filamentary structures within the compressed layer. We found that CCC can lead to the formation of HFSs, which is the combined effect of turbulence, shock compression, magnetic field, and gravity. The collision between the cloud components shapes the filaments into a cone and drives inward flows among them. These inward flows merge at the vertex of the cone, rapidly accumulating high-density gas, which can lead to the formation of massive star(s). The cone acts as a mass-collecting machine, involving a nongravitational early process of filament formation, followed by gravitational gas attraction to finalize the HFS. The gas distribution in the position–velocity (PV) and position–position spaces highlights the challenges in detecting two cloud components and confirming their complementary distribution if the colliding clouds have a large size difference. However, such CCC events can be confirmed by the PV diagrams presenting gas flow toward the vertex of the cone, which hosts gravitationally collapsing high-density objects, and by the magnetic field morphology curved toward the direction of the collision.

Mixing enhancement assisted by dual plate cavity in supersonic flow

Fast and efficient mixing of high-speed shear flow formed by fuel and oxidizer is of great importance for the improvement of rocket-based combined cycle engine performance. Nevertheless, the existence of compressibility effects of high-speed flow significantly inhibits the growth process of a mixing layer. Moreover, a finite-length combustor of the engine calls for more effective enhanced-mixing strategies to complete mixing in a shorter streamwise distance. To this end, in present paper, the strategy called dual plate cavity (DPC) is proposed to promote mixing. Three cases including the benchmark, front-DPC and back-DPC cases are selected to perform the comparative study. By means of high-order direct numerical simulations, the structure evolution characteristics and turbulence intensity distributions are researched. The index of velocity thickness is utilized to assess the mixing layer growth. The results indicate that with the introduction of DPC, the mixing process is dramatically promoted. The penetration behavior of newly found T-shaped structures into the upper main stream can engulf more fluid into the mixing region. Specifically, in the back-DPC case, the coexistence of both large-scale and small-scale structures in the far flow field can improve the turbulence intensity. The spatial correlation analysis results show that with the influence of DPC, the structure sizes are much larger than that of the benchmark case in the same streamwise position. Meanwhile, the contour line equal to 0.5 possesses property of distortion for the back-DPC case. The drastic pulsation of a mixing layer edge can obviously promote the mixing process. Through exploration of the enhanced-mixing mechanisms, this work indicates that the proposed DPC strategy is a good candidate for efficient mixing, and in the future, more detailed work including three-dimensional simulations concerning the strategy optimization is suggested to be performed.

Experimental study on the formation and evolution of unconfined counter-helicity spheromaks merging using magnetized coaxial plasma gun

The formation and evolution of unconfined counter-helicity spheromaks merging have been experimentally investigated by using a magnetized coaxial plasma gun. By comparing the time-dependent photodiode signals and plasma radiation images of counter-helicity spheromaks merging and plasma jets merging, it is found that the field-reversed configuration (FRC) plasma formed by counter-helicity spheromaks merging has a distinct contour and a long maintenance time. For plasma jets merging, the resulting plasma has no discernible contours and a shorter lifetime. In addition, it is inferred from these data that stagnation heating and magnetic reconnection events occur during the counter-helicity spheromaks merging, causing a rapid rise in plasma pressure at the merging midplane and sharp kinks in the field lines near the merger region. By changing different operating parameters and observing the impact on the merger characteristics, it is suggested that the qualitative dynamics of the FRC plasma depends on the balance between the plasma pressure and the magnetic pressure. The high discharge voltage breaks the equilibrium in the merged body, while the large gas-puffed mass just weakens the compression effect of the merged body. These results give us an intuitive understanding of the counter-helicity spheromak merger process and its dependence on discharge parameters, and also provide a distinct perspective for the optimal design of FRC.

Matrix Compression and Pore Heterogeneity in the Coal-Measure Shale Reservoirs of the Qinshui Basin: A Multifractal Analysis

The application of high-pressure fluid induces the closure of isolated pores inside the matrix and promotes the generation of new fractures, resulting in a compressive effect on the matrix. To examine the compressibility of coal-measure shale samples, the compression of the coal–shale matrix in the high-pressure stage was analyzed by a low-pressure nitrogen gas adsorption and mercury intrusion porosimetry experiment. The quantitative parameters describing the heterogeneity of the pore-size distribution of coal-measure shale are obtained using multifractal theory. The results indicate that the samples exhibit compressibility values ranging from 0.154 × 10−5 MPa−1 to 4.74 × 10−5 MPa−1 across a pressure range of 12–413 MPa. The presence of pliable clay minerals enhances the matrix compressibility, whereas inflexible brittle minerals exhibit resistance to matrix compression. There is a reduction in local fluctuations of pore volume across different pore sizes, an improvement in the autocorrelation of PSD, and a mitigation of nonuniformity after correction. Singular and dimension spectra have advantages in multifractal characterization. The left and right spectral width parameters of the singular spectrum emphasize the local differences between the high- and low-value pore volume areas, respectively, whereas the dimensional spectrum width is more suitable for reflecting the overall heterogeneity of the PSD.

Pseudocysts of the Adrenal Gland: A Systematic Review of Existing Scientific Literature From 2000 to 2023.

Adrenal masses are abnormal growths in the adrenal gland, comprising entities such as pheochromocytomas, adrenal adenomas, adrenocortical carcinomas, and adrenal cysts. Pseudocysts are predominant among adrenal cysts. Due to its infrequent presentation, there are no specific guidelines present in the current literature to steer its management. In such circumstances, a systematic review of the existing literature is imperative to develop comprehensive insights and evidence-based protocols. We aimed to comprehensively analyze the clinico-radiological characteristics and management outcomesof adrenal gland pseudocysts. Human adrenal gland pseudocysts identified through imaging and histopathology, as retrieved from the PubMed search engine, were included in the study. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Joanna Briggs Institute (JBI) CriticalAppraisal Checklist were used to stratify searched studies published between 2000 and 2023. A total of 39 studies were finally included, of which 36 were case reports and three case series, containing 45 patients in total. Data for clinical, radiological, histopathological, and outcome variables were collected, and descriptive analysis was carried out. All cases presented were adults with a clear female predominance of 66.67%. About 26.67% presented with no palpable mass or clinical symptoms, while 28.89% presented with vague abdominal pain. The most prevalent computed tomography (CT) finding was a cystic lesion with calcification and/or hemorrhage and/or necrosis, occurring in 17.78% of cases. Following this, a cystic lesion with only calcification was observed in 13.33% of cases, and a well-defined cystic mass/lesion was found in 11.11% of cases. The most important indication for surgery was compression effect in 44.44%, increasing size in 20.00%, and suspicion of malignancyin another 20.00% of cases. About 64.44% underwent open surgery, while 35.55% underwent minimally invasive surgery. Most patients, 95.55% of the total, had an uneventful postoperative course without any complications. Adrenal gland pseudocyst, though rare and incidental, warrants consideration in differential diagnosis as it presents with vague symptomsand sometimes no symptoms at all. Our review of existing literature highlights the importance of surgical intervention for symptomatic or potentially malignant cysts, with en bloc adrenalectomy being the preferred approach.

Effectiveness of Aloe Vera and Cabbage Leaf Compress on Breast Swelling Pain in Post-Partners in Bogor Barat District, Bogor City

ASEAN data in 2022 stated that 76,543 postpartum mothers experienced breast engorgement. 17.2 million postpartum mothers worldwide experience breast pain problems while breastfeeding. In Indonesia, the incidence of breastfeeding mothers experiencing breast engorgement reached the highest figure of 37.2% and 16% of working breastfeeding mothers experienced breast engorgement. Breast engorgement is interpreted as increased venous and lymph flow in the breasts to prepare for lactation. This is due to overdistension of the lactation ducts, causing breast swelling pain, and breast engorgement accompanied by an increase in body temperature. The study used a quasi-experimental design with a pretest-posttest two-group design. The sample consisted of 30 postpartum mothers who experienced breast engorgement pain and were divided into 2 intervention groups, namely aloe vera compresses and cabbage compresses, the intervention was carried out for 14 days. The instrument used was the Visual Analogue Scale (VAS). Data were analyzed using the Paired T-Test and Independent T-Test. In the Independent Sample T-Test, the p-value of the VAS scale for the aloe vera group was 0.019 &lt;0.05 with an average score of 2.0 and the VAS scale for the cabbage group was 0.037 &lt;0.05 with an average score of 1.87.

Generation of short microwave pulse trains based on a hybrid mode-locked optoelectronic oscillator.

A novel approach, to the best of our knowledge, for generating short microwave pulse trains based on a hybrid mode-locked optoelectronic oscillator (HML-OEO) is proposed and demonstrated. In the proposed scheme, a saturable absorber (SA) device is inserted into the active mode-locked OEO (AML-OEO) to compress the pulse width of the microwave pulse trains. Numerical simulations and experimental results show that the HML-OEO generates a short microwave pulse train with a repetition rate of 98.994 kHz through fundamental frequency mode locking, and its pulse width is compressed by about 50% compared to the AML-OEO. Additionally, in the experiment, microwave pulse trains with different repetition rates are generated by second-, third-, fourth-, and fifth-order harmonic mode locking, respectively. Compared to the AML-OEO, the HML-OEO achieves pulse compression effects of 49.3%, 49.8%, 49.4%, and 49.9%, respectively. Notably, compared to the AML-OEO, the proposed scheme also exhibits outstanding performance in frequency stability.

PENGARUH PEMBERIAN KOMPRES HANGAT PADA PUNGUNG BAWAH IBU INPARTU KALA 1 FASE AKTIF TERHADAP TINGKAT NYERI DI RUANG BERSALIN RUMAH SAKIT ISLAM JOMBANG

There are two methods of dealing with labor pain, namely medical and non-medical. One of the non-medical actions is the provision of warm compresses given to the lower back area. Giving warm compresses can improve blood circulation, provide a feeling of warmth, prevent muscle spasms and reduce pain. This research is based on the results of observations made at the Jombang Islamic Hospital that the methods used to treat pain in laboring mothers are back massage and providing emotional support, while warm compresses have never been applied. This study aims to determine the effect of warm compresses on the level of active phase I labor pain in the Delivery Room of Jombang Islamic Hospital in 2023. The design of this study used the Quasi Experiment method (pseudo-experiment), with a one group pretest posttest design. The sample of this study was 15 women giving birth normally at the Jombang Islamic Hospital in July 2023. The results of the study were that most (66.7%) of respondents had severe pain before being given warm compresses and almost all (80%) of respondents had moderate pain levels after being given warm compresses. The results of the Wilcoxon statistical test obtained a p value of 0.001 (?&lt;0.05) so it can be concluded that there is an effect of warm compresses on the level of labor pain in the Delivery Room of the Jombang Islamic Hospital. Provision of warm compresses can be applied in the Delivery Room of Jombang Islamic Hospital to help reduce labor pain, provide a sense of comfort and relaxation for mothers in labor.

The interplay of shape and catalyst distribution in the yield of compressible flow microreactors.

We develop a semi-analytical model for transport in structured catalytic microreactors, where both reactant and product are compressible fluids. Using lubrication and Fick-Jacobs approximations, we reduce the three-dimensional governing equations to an effective one-dimensional set of equations. Our model captures the effect of compressibility, corrugations in the shape of the reactor, and an inhomogeneous catalytic coating of the reactor walls. We show that in the weakly compressible limit (e.g., liquid-phase reactors), the distribution of catalyst does not influence the reactor yield, which we verify experimentally. Beyond this limit, we show that introducing inhomogeneities in the catalytic coating and corrugations to the reactor walls can improve the yield.

Spindown of Pulsars Interacting with Companion Winds: The Impact of Magnetospheric Compression

Pulsars in binary systems with strong companion winds can have the magnetopause separating their magnetosphere from the wind located well within their light cylinder. This bow-like enclosure effectively creates a waveguide that confines the pulsar’s electromagnetic fields and can significantly alter its spindown. In this paper, we study the spindown of compressed pulsar magnetospheres in such systems. We parameterize the confinement as the ratio between the equatorial position of the magnetopause (or standoff distance) R m and the pulsar’s light cylinder R LC. Using particle-in-cell simulations, we quantify the pulsar spindown for a range of compressions, R m/R LC = 1/3–1, and inclination angles, χ = 0°…90°, between magnetic and rotation axes. Our strongly confined models (R m/R LC = 1/3) show two distinct limits. For χ = 0°, the spindown of a compressed pulsar magnetosphere is enhanced by approximately a factor of three compared to an isolated pulsar due to the increased number of open magnetic field lines. Conversely, for χ = 90°, the compressed pulsar spins down at less than 40% of the rate of an isolated reference pulsar due to the mismatch between the pulsar wind stripe wavelength and the waveguide size. We apply our analysis to the 2.77 s oblique rotator (χ = 60°) in the double-pulsar system PSR J0737-3039. With the numerically derived spindown estimate, we constrain its surface magnetic field to B * ≈ (7.3 ± 0.2) × 1011 G. We discuss the time modulation of its period derivative, the effects of compression on its braking index, and implications for the radio eclipse in PSR J0737-3039.

The Effects of Contact By the Catalyst Layer and the Gas Diffusion Layer Interface on the Performance of a PEFC with Marimo-like Carbon

When assembling a proton exchange membrane fuel cell (PEMFC), a clamping pressure is applied to all the components. The catalyst layer (CL) and gas diffusion layer (GDL) are compressed to the gasket thickness by the clamping during assembly. This compression increases the conductivity of the protons and electrons while reduces the size of the pores, which are the removal channels for the generated water and the diffusion channels for the fuel and air gases. We evaluated the effect of the CL compression prepared with the Marimo-like carbon (MC) regarding the I-V performance. The MC is a higher order structure of carbon fibers. The maximum power density was the highest (237 mW cm-2) at the 22% compression ratio. The excessive compression was suggested to have a higher effect on blocking the diffusion channels of the fuel and air gases than on improving the conductivity.

Analytical models for predicting the moment‒rotation relationships of steel hub joints with bolted steel side plates in single-layer wood reticulated domes

A very popular and efficient pattern of joints adopted for wood reticulated domes is steel hub joints featuring end-bearing and bolt-connected wood members (EBBC joints). This type of joint shows clear semi-rigidity, which affects the rigidity and overall stability of the structures. This study developed analytical models for predicting the moment‒rotation curves of EBBC joints, considering the effect of axial compression. Specifically, two models termed the WR and WEP models, were developed assuming rigid and elastic-plastic constitutive behaviour, respectively, of the wood in the compression zone of the joint. A tri-linear model for the lateral force-slip relationship of bolt connections was derived. A formula for calculating the deformation modulus and predicting the shear failure of wood members under local compression was proposed and verified. The moment–rotation relationship of the joint was established with equilibrium and compatibility conditions. The accuracy of the analytical models was verified by comparison with a series of experimental results as well as the parametric study results obtained using a refined finite element model. It was revealed that both the WR and the WEP models can predict the moment–rotation relationships accurately for joints without axial compression, whereas for the case of non-negligible axial compression loads, the WEP model offers more accurate predictions. The analytical WEP model proposed in the current paper provides a versatile tool for general design practice to predict moment–rotation curves for traditional or novel EBBC joints.

Generation of 1 MHz 15 fs pulses in the near-infrared with high energy and their application to time-resolved spectroscopy

Ultrashort pulses with a duration of ∼10 fs are crucial to fully resolve nuclear motions in molecules and materials. Here, we employ nonlinear pulse compression using photonic crystal fiber in the near-infrared region to generate ultrashort pulses at a high repetition rate with significant pulse energy. Femtosecond pulses centered around 1200 nm from a cavity-dumped optical parametric oscillator are compressed to a duration of 15 fs. The pulse energy reaches several tens of nanojoules, sufficient for wavelength conversion via nonlinear processes. Second harmonic generation produces clean 13 fs pulses at around 600 nm with pulse energy of 4 nJ. The effectiveness of nonlinear pulse compression using photonic crystal fiber for ultrafast time-resolved spectroscopy is demonstrated through time-resolved fluorescence (photoluminescence) and transient absorption apparatus, utilizing the second harmonic as pump pulses. Specifically, a time resolution of ∼20 fs is achieved in a time-resolved fluorescence experiment, enabling the recording of nuclear wave packets over 1200 cm−1 by spontaneous fluorescence. The high repetition rate at the megahertz level significantly improved the signal quality.

Analysis of dynamic characteristics and influencing factors of CO2 low-permeability coal reservoir sequestration

ABSTRACT Abandoned coal seams can be an important carrier for CO2 geological storage. Considering the gas seepage-diffusion and physical adsorption coupling characteristics in the process of CO2 adsorption and storage in coal and rock, a two-dimensional model of coupled flow-solidity for geological storage of CO2 in low-permeability reservoir with double voids was established by introducing the Zhang Hongbin model algorithm and adding the Klinkenberg effect and the compression effect of the rock skeleton in coal reservoirs in the controlling equation for rock deformation. The coupled flow-solid model was solved by using the PDE equation of COMSOL Multiphics program, and the simulation results difference between the new model and the traditional model in terms of sequestration dynamics were compared. The dynamic characteristic of reservoir gas pressure, formation stress, permeability and sequestration density in the process of CO2 geologic sequestration and injection were analyzed, and the influences of injection pressure and injection well diameter on the amount of CO2 sequestration were explored. The results show that the new model is more reasonable for calculating reservoir gas pressure and permeability compared with the Palmer-Mansoori model (PM model), and can simulate the free-state seepage movement of CO2 in the fracture system as well as its physical adsorption process compared with the single-heavy pore medium model. With continuous CO2 injection, the maximum sequestration density was raised to a limit value of about 1000 kg/m3 after 1 year. The date of reaching the limit of the sequestration volume was advanced by about 45 d when the positive pressure of the injected gas was increased from 10 kPa to 50 kPa. This model can reproduce the main parameters including, when affecting the effect, and realize the calculation of parameters such as CO2 density reaching the limit value, sealing limit day, sealing limit amount, which can provide a theoretical basis for further deep understanding of CO2 geological sealing law and scientific development of gas injection scheme.

Wavelength tunable single-frequency ring cavity fiber laser utilizing external injection locking signal

The ring cavity fiber laser with saturable absorption fibers is a simple and practical technical way of achieving single-frequency laser output. However, this structure cannot obtain wavelength-tunable laser output. In this work, an external injection locking signal launched by tunable LD is used to optimize the tunability in single-frequency ring cavity fiber lasers. By aligning the external injection signal, tunable laser output ranging from 1544.13 to 1546.51 nm is achieved. The maximum output is 16.5 mW and the linewidth is less than 6.15 kHz. The operation process and the linewidth compression effect of external Injection signals are investigated. The results indicate that there is a correlation between the output signal-to-noise ratio and the output linewidth, and this wavelength-tuning structure has the potential for rapid tuning. This work provides a technical solution for achieving a tunable single-frequency laser in the ring cavity structure.

Influence of Anisotropic Consolidation on the Instability of Loose Granular Soils Under Undrained and Drained Loading

Previous studies, mostly experimental, have reported conflicting observations on the effect of the initial anisotropic consolidation stress ratio (η&lt;sub&gt;0&lt;/sub&gt;) on the stress ratio at the onset of instability (η&lt;sub&gt;f&lt;/sub&gt;) for drained and undrained loading that involve static liquefaction. They indicate that as η&lt;sub&gt;0&lt;/sub&gt; increases, η&lt;sub&gt;f&lt;/sub&gt; could decrease, increase, or remain invariant, albeit without providing potential mechanistic factors. In this study, the anisotropic critical state theory (ACST) is used to investigate potential factors, including compressibility, state, and fabric anisotropy, that can explain the influence of η&lt;sub&gt;0&lt;/sub&gt; on η&lt;sub&gt;f&lt;/sub&gt; under undrained and drained loading. The assessments consider numerical simulations with the ACST-based SANISAND-F model, insights from SANISAND-F based instability criteria, the instability surface concept, and available experimental observations. Our findings show that compressibility and fabric anisotropy (and its evolution) are key factors in explaining the influence of η&lt;sub&gt;0&lt;/sub&gt; on η&lt;sub&gt;f&lt;/sub&gt;. In particular, the results show that if fabric evolution is not substantial, an increase in η&lt;sub&gt;0&lt;/sub&gt; decreases η&lt;sub&gt;f&lt;/sub&gt; for materials with significant compressibility, whereas the effect of η&lt;sub&gt;0&lt;/sub&gt; in low compressibility materials is minimal. On the other hand, for materials that promote fabric evolution, the results suggest that the effect of fabric changes counteract compressibility effects, potentially increasing η&lt;sub&gt;f&lt;/sub&gt;.

Comparative Performance of Autoencoders and Traditional Machine Learning Algorithms in Clinical Data Analysis for Predicting Post-Staged GKRS Tumor Dynamics.

Introduction: Accurate prediction of tumor dynamics following Gamma Knife radiosurgery (GKRS) is critical for optimizing treatment strategies for patients with brain metastases (BMs). Traditional machine learning (ML) algorithms have been widely used for this purpose; however, recent advancements in deep learning, such as autoencoders, offer the potential to enhance predictive accuracy. This study aims to evaluate the efficacy of autoencoders compared to traditional ML models in predicting tumor progression or regression after GKRS. Objectives: The primary objective of this study is to assess whether integrating autoencoder-derived features into traditional ML models can improve their performance in predicting tumor dynamics three months post-GKRS in patients with brain metastases. Methods: This retrospective analysis utilized clinical data from 77 patients treated at the "Prof. Dr. Nicolae Oblu" Emergency Clinic Hospital-Iasi. Twelve variables, including socio-demographic, clinical, treatment, and radiosurgery-related factors, were considered. Tumor progression or regression within three months post-GKRS was the primary outcome, with 71 cases of regression and 6 cases of progression. Traditional ML models, such as Logistic Regression, Support Vector Machine (SVM), K-Nearest Neighbors (KNN), Extra Trees, Random Forest, and XGBoost, were trained and evaluated. The study further explored the impact of incorporating features derived from autoencoders, particularly focusing on the effect of compression in the bottleneck layer on model performance. Results: Traditional ML models achieved accuracy rates ranging from 0.91 (KNN) to 1.00 (Extra Trees). Integrating autoencoder-derived features generally enhanced model performance. Logistic Regression saw an accuracy increase from 0.91 to 0.94, and SVM improved from 0.85 to 0.96. XGBoost maintained consistent performance with an accuracy of 0.94 and an AUC of 0.98, regardless of the feature set used. These results demonstrate that hybrid models combining deep learning and traditional ML techniques can improve predictive accuracy. Conclusion: The study highlights the potential of hybrid models incorporating autoencoder-derived features to enhance the predictive accuracy and robustness of traditional ML models in forecasting tumor dynamics post-GKRS. These advancements could significantly contribute to personalized medicine, enabling more precise and individualized treatment planning based on refined predictive insights, ultimately improving patient outcomes.

The Effect of Warm Compress on the Intensity of Back Pain in Pregnant Women in the Third Trimester: Scoping Review

Background: Pregnancy is a natural process. During pregnancy, a mother experiences discomfort, one of which is back pain, there are several treatments to treat back pain, namely pharmacological and non-pharmacological therapies. One of the nonpharmacological therapies that can be done is with warm compresses because it is safer, cheaper, effective, cheap and without adverse effects.Purpose : This article aims to identify literature related to the effect of warm compresses on the intensity of back pain in pregnant women in the third trimester.Methods: The method used is scoping review which consists of 5 phases, namely identifying scoping review questions using the PICO framework; identifying relevant articles; searching for articles using relevant databases, namely PubMed, Wiley, and Google Scholar; creating PRISMA flowcharts; conducting critical appraisals to assess the quality of articles; charting data; compiling, summarizing and reporting results.Results: The results of the review of 15 selected articles obtained 8 articles with grade A, 7 articles grade B, 11 articles using quasi experiment, and 4 articles pre experiment. Two themes that emerged based on the results of the Scoping Review are the concept of back pain, and the concept of warm compresses.Conclusion: Warm compresses are effective in reducing back pain in pregnant women in the third trimester, so they can be recommended as complementary therapy to reduce the intensity of back pain.