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This study focuses on the evaluation of the Notch Stress Intensity Factor (NSIF) as a key parameter for estimating the material's master failure curve in API 5L pipe steel. The research encompasses both experimental investigations and numerical validations to comprehensively assess the applicability of NSIF in predicting failure behavior. Through a series of controlled experiments, various notched specimens were subjected to different loading conditions, allowing the determination of NSIF values. Concurrently, a numerical framework was developed using finite element analysis to simulate the stress distribution near the notches. The experimental results were compared with the numerical simulations to validate the accuracy of the proposed approach. This research contributes to enhancing the understanding of how NSIF can serve as a reliable indicator of failure potential in industrial applications, particularly in the context of pipeline structures. The findings highlight the significance of NSIF-based predictions in ensuring the integrity and safety of materials under varying loading conditions.

In this paper, the similarity criterion and dimensionless conversion method combined with the elasticity condition and Hooke's law are used to derive the functional relationship of the maximum effective value of the vibration velocity between the prototype pump and the model pump. The seawater circulation pump of a nuclear power plant is used as the prototype pump, and the model pump is obtained by performance conversion and choosing the appropriate scale, and the vibration state of the model pump under different flow rates is measured and analyzed. The vibration data of the model pump through the function relationship to find out the vibration parameters of the prototype model pump, and compare with the vibration data of the seawater circulation pump in reality. It can be seen that with the increase of flow rate, the maximum effective value of the vibration velocity of both model and prototype decreases and then increases, and the relative error is small, the maximum value is 7.7757%. Therefore, it can be considered that the functional relationship of model pump converted to prototype pump derived in this paper can be used to analyze the vibration of the actual seawater circulation pump of coastal nuclear power plant.

Natural gas hydrates represents a huge source of energy. At the same time substantial leakages of natural gas from hydrates contributes significantly to climate changes. One of the most important reasons for these natural gas fluxes is leakage of seawater in to the hydrates from seafloor, through fracture systems. Hydrate dissociates if surrounding seawater is less than hydrate stability limit. Another interesting aspect of natural gas hydrates is the potential for safe CO2 storage. These different aspects of hydrates in natural sediments put demands on thermodynamic models. In addition to accurate description of pressure temperature hydrate stability there also a need to describe hydrate dissociation in concentration gradients towards surrounding water or surrounding gas as two examples. In this work we present new experimental data and an extensive thermodynamic model for hydrate. In contrast to conventional thermodynamic models for hydrate the model is consistent since all thermodynamic properties are derived from the Gibbs free energy. In this work we examine mixtures of CH4, C2H6, N2, CO2 from the China Sea and some synthetic mixtures, using this model. Maximum CO2 content in these mixtures are 60 mol% and the rest is dominated by CH4. Agreement between experimental data and model calculations are generally good and average deviations are below 5.5% for all the systems and conditions examined. Another aspect of the model is the ability for incorporation of effects of mineral surfaces. Specifically it is illustrated that adsorption of water on rust dominates liquid water drop out from gas as compared to water dew-point. Production of natural gas with such high CO2 content requires a strategy for CO2 separation and storage. It is proposed that the CH4 is separated from the C2H6, CO2 and N2 and cracked to H2 and CO2 using steam. Thermodynamic analysis indicates a significant potential for safe CO2 storage in natural gas hydrate and H2 as the only export product.

This paper presents data from three experimental campaigns investigating slamming loads on a three-dimensional non-prismatic aluminium wedge, complementing the original research article “Slamming loads and responses on a non-prismatic stiffened aluminium wedge: Part I. Experimental study [1].” The experiments were designed to investigate the effects of slamming loads on structural responses through a series of free-fall drop tests. These tests included wedges with stiffened and unstiffened bottom plates to examine the influence of flexural rigidity on hydroelastic slamming. The experimental setup utilized three accelerometers for vertical acceleration measurement, sixteen pressure sensors for slamming pressure capture, and twenty strain gauges for recording structural responses. Detailed information on wedge geometry, material properties, and test plans is provided. Symmetric impact tests were conducted at drop heights from 25 cm to 200 cm with two different wedge masses. Asymmetric impact tests were carried out at three drop heights with heel angles ranging from 5 to 25°. The dataset includes time histories of sensor records, the geometry of the wedge section, and video footage from various runs. This comprehensive data offers insights into the effects of water impact velocity, deadrise angle, wedge mass, and bending stiffness on hydrodynamic pressures and structural responses on V-shaped sections. The experiments provide a valuable benchmark for future slamming impact research, aiding in the refinement of experiments, validation of numerical methods, and enhancement of mathematical models.

This paper attempts to reveal the freezing temperature and its influencing factors of heavy metal-contaminated loess by adopting two cooling methods: fast and slow grading. As a result, Lanzhou loess was used as an experimental material to make polluted soil with varying heavy metal concentrations and initial water content. The pollutant elements included Zn, Ni, Cu, Cr, Cd, and Pb. The findings demonstrate that: 1) The slow cooling rate causes supercooling, jumping, and a progressive decrease in the temperature of the polluted soil. Different cooling methods have no obvious effect on freezing temperature. Furthermore, the freezing temperature of contaminated soil varies depending on its water content. The impact of increasing water content on freezing temperature is not evident; 2) The freezing temperature of loess decreases with the increase of heavy metal ion content. The freezing temperature of loess polluted by Zn, Ni and Cd ions decreased linearly with the increase of ion content. The influence of cations on the freezing temperature of loess is as follows: Zn2+> Ni2+> Cd2+> Cr3+> Pb2+> Cu2+. The influence order of anions is Cl− > SO42−; 3) The freezing temperature of loess containing heavy metal ions is about equal to the freezing temperature of the corresponding heavy metal solution plus the freezing temperature of loess itself. The freezing temperature of heavy metal-polluted loess follows the temperature superposition principle.

The initial investment for a buried pipe system using soil as a seasonal thermal storage medium is costly and not suitable for small rural buildings. To promote the cost-effective heating in rural areas, this study proposes a novel seasonal thermal storage system utilizing water and soil as thermal storage medium with copper rods to enhance thermal transfer between water tank and the surrounding soil. An experimental platform was established to discuss the temperature variation characteristics and investigate the thermal performance under different operating modes and experimental parameters. The results show that the temperature of the soil without copper rods is linearly related to the depth, while the highest temperature at the end of the copper rods occurs at the middle depth. The soil with short copper rods exhibits the most rapid thermal storage response and a relatively shorter thermal extraction response time. Intermittent operation can significantly enhance the thermal extraction rate and outlet temperature of the thermal storage unit, whereas the energy storage efficiency decreases with the extension of the downtime. The soil contribution rate of the thermal storage unit is influenced by the operational duration, initial temperature of the water tank and outdoor ambient temperature.

Experimental investigations were conducted on an air gap membrane distillation (AGMD) unit to evaluate the impact of heat recovery on system performance. The study utilized a steady-state heat source in conjunction with a spiral air gap membrane module for water desalination. The process was implemented using two configurations aimed to minimize heat loss enhancing productivity, gain output ratio (GOR), and thermal efficiency. The experiments involved feedwater with salt concentrations ranging from 10,000 to 30,000 ppm. The measurements were recorded for inlet and outlet temperatures of the heat source, water productivity, and thermal efficiency at various coolant and water feed flow rates. These configurations effectively addressed critical technical challenges in thermal AGMD systems by optimizing heat recovery. The incorporation of heat recovery resulted in a significant increase in water productivity by 37.07 % compared to systems without heat recovery while maintaining the same initial heat input. The heat recovery in series (HRSS) and parallel (HRPS) configurations resulted in power consumption reductions of approximately 29.7 % and 23.1 %, respectively compared to the conventional configuration (CC) at a flow rate of 12 L/min. The levelized cost of water (LCOW) for the AGMD system was comprehensively evaluated and found to be $ 7.71 per cubic meter. This figure reflected the total cost of water production over the system's operational lifespan including capital expenditures, operating and maintenance costs, and energy consumption. The calculated LCOW provides a clear indicator of the system's economic viability, demonstrating the cost required to produce each cubic meter of water through the AGMD.

Using seawater to make concrete structures saves freshwater resources and reduces transport costs in offshore construction. However, the presence of chloride ions in mortar causes the formation of Friedel’s salt, which changes the microstructure of cement hydration products. As a result, the compressive strength of the mortar significantly deteriorates due to excessive chloride ions. Graphene oxide (GO) is used to overcome chloride ions-induced deterioration in the compressive strength of mortar in this study. The compressive strength of mortar mixed with chloride ions is increased from 38±5.2 MPa to 44.5±0.2 MPa with the addition of GO. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis show the decrease of porosity in mortar with GO and adsorption of chloride ions on GO. Molecular dynamics simulations show that GO yields constraints on the mobility of chloride ions and the improvement of interfacial strength between calcium silicate hydrates.

The compression of coral concrete-filled aluminum alloy tube columns is a novel type of laterally restrained concrete element, with axial compressive load being the primary load type sustained by the laterally restrained concrete elements during their service life. In this study, square intermediate-length columns of coral concrete-filled aluminum alloy tubes were subjected to axial compression tests to investigate the influence of section width-to-thickness ratio (B/t), and aspect ratio of the column (L/B) on the failure mode, ultimate load-carrying capacity, and load-deformation relationship of the specimens. The research findings demonstrate that the intermediate-length columns of coral concrete-filled aluminum alloy tube exhibit good compressive performance, with a significant combined effect between the aluminum alloy tube and the core concrete. With an increase in the section width-to-thickness ratio (B/t), the compressive stiffness, ultimate load-carrying capacity, and deformation ductility of the specimens all decrease. As the aspect ratio of the column (L/B) increases, under the condition that end-zone failure does not occur, the ultimate load-carrying capacity and deformation ductility of the specimens gradually decrease, while the extent of flexural deformation significantly increases.

Background: Stroke is a debilitating condition with high morbidity, disability, and mortality that significantly affects the quality of life of patients. In China, the WenYang FuYuan recipe is widely used to treat ischemic stroke. However, the underlying mechanism remains unknown, so exploring the potential mechanism of action of this formula is of great practical significance for stroke treatment. Objective: This study employed network pharmacology, molecular docking, and in vivo experiments to clarify the active ingredients, potential targets, and molecular mechanisms of the WenYang FuYuan recipe in cerebral ischemia-reperfusion injury, with a view to providing a solid scientific foundation for the subsequent study of this recipe. Materials and methods: Active ingredients of the WenYang FuYuan recipe were screened using the traditional Chinese medicine systems pharmacology database and analysis platform. Network pharmacology approaches were used to explore the potential targets and mechanisms of action of the WenYang FuYuan recipe for the treatment of cerebral ischemia-reperfusion injury. The Middle Cerebral Artery Occlusion/Reperfusion 2 h Sprague Dawley rat model was prepared, and TTC staining and modified neurological severity score were applied to examine the neurological deficits in rats. HE staining and Nissl staining were applied to examine the pathological changes in rats. Immunofluorescence labeling and Elisa assay were applied to examine the expression levels of certain proteins and associated factors, while qRT-PCR and Western blotting were applied to examine the expression levels of linked proteins and mRNAs in disease-related signaling pathways. Results: We identified 62 key active ingredients in the WenYang FuYuan recipe, with 222 highly significant I/R targets, forming 138 pairs of medication components and component-targets, with the top five being Quercetin, Kaempferol, Luteolin, β-sitosterol, and Stigmasterol. The key targets included TP53, RELA, TNF, STAT1, and MAPK14 (p38MAPK). Targets related to cerebral ischemia-reperfusion injury were enriched in chemical responses, enzyme binding, endomembrane system, while enriched pathways included lipid and atherosclerosis, fluid shear stress and atherosclerosis, AGE-RAGE signaling in diabetic complications. In addition, the main five active ingredients and targets in the WenYang FuYuan recipe showed high binding affinity (e.g. Stigmasterol and MAPK14, total energy

This article uses experimental methods to measure the operational performance and pollutant emissions of micro gas turbines in different intake environments, and analyzes the feasibility of replacing mine ventilation fans with micro gas turbines. The results show that when the compressor efficiency is increased from 70 % to 90 %, the total efficiency of the micro combustion engine is increased from 28% to 34 %, with an increase of up to 21.4 %. When the demand power is 25 kW, the fluctuation range of NOx emission concentration is within 5.4 %. When the intake opening is below 50 %, the effect is obvious. When the intake opening is reduced from 50 % to 25 %, the performance of the micro gas turbine decreases by 0.7 %; The influence of intake humidity on various operating parameters of micro gas turbines is generally within 3 %, which can meet the requirements of high humidity environment operation; The intake temperature has the greatest impact, with an increase in intake temperature leading to a decrease in power generation efficiency. After comprehensive analysis, we believe that the application of gas turbines in mines is feasible.

Aim: To determine whether targeting mild hypercapnia (PaCO2 7 kPa) would yield improved cerebral blood flow and metabolism compared to normocapnia (PaCO2 5 kPa) with and without targeted temperature management to 33 °C (TTM33) in a porcine post-cardiac arrest model. Methods: 39 pigs were resuscitated after 10 minutes of cardiac arrest using cardiopulmonary bypass and randomised to TTM33 or no-TTM, and hypercapnia or normocapnia. TTM33 was managed with intravasal cooling. Animals were stabilized for 30 minutes followed by a two-hour intervention period. Hemodynamic parameters were measured continuously, and neuromonitoring included intracranial pressure (ICP), pressure reactivity index, cerebral blood flow, brain-tissue pCO2 and microdialysis. Measurements are reported as proportion of baseline, and areas under the curve during the 120 min intervention period were compared. Results: Hypercapnia increased cerebral flow in both TTM33 and no-TTM groups, but also increased ICP (199% vs. 183% of baseline, p = 0.018) and reduced cerebral perfusion pressure (70% vs. 84% of baseline, p

Interfacial tension (IFT) reduction and wettability alteration of porous media are effective in enhancing oil recovery. However, the impact of these factors on CO2-brine two-phase flow for CO2 geological storage is yet to be directly demonstrated. In this study, experiments were conducted on two Berea sandstone cores with an average length of 120 mm and diameter of 38 mm to assess the effect of surfactant pre-injection on the flow of CO2-brine under reservoir conditions at 10 MPa and 40 °C. It was validated that the experimental system could provide reliable results by comparing the baseline relative permeabilities with those presented in the existing literature. It was consistently demonstrated through repeated experiments that a surfactant solution, even when present in low concentration, could enhance CO2 saturation and relative permeability using identical procedures. Specifically, the CO2 relative permeability was increased by at least 56% from the baseline. Additionally, the experiment on the imbibition process showed that surfactant treatment effectively increases residual CO2 saturation. The results support previous numerical analysis and show that surfactant pre-injection could improve injectivity and contribute to a smaller CO2 footprint such that CO2 is prevented from any leakage pathway.

Background: Prolonged circulatory arrest time is an independent risk factor for postoperative adverse events of type A aortic dissection (TAAD) surgery. Further reduction of the circulatory arrest time is essential to improve surgical outcomes. This study aimed to evaluate the safety and effectiveness of the novel Sutureless Integrated Stented (SIS) graft prosthesis in an animal experiment. Materials and methods: Straight type of the SIS graft prosthesis was implanted into the descending aorta of 10 adult male sheep, and the use of the device was scored on a scale of 1–10. Aortic digital subtraction angiography (DSA) was performed at 4, 14, and 26 weeks to investigate the prostheses. After 26 weeks, the animals were sacrificed for histological analysis. Results: The immediate success rate of the surgery was 100 %, and the overall mean score of the use of the device was 9.65 ± 0.99. Three animals died from non-device-related causes during follow-up. Aortic DSA showed filling defects in 5 animals. Histological analysis revealed that all prostheses were intact. Except for 2 early deaths, the other 8 prostheses were endothelialized with mild inflammation, foreign body reactions, and intimal fibrosis. The mean cross-sectional area of the sutureless region was reduced by 26.4 % (range, 1.3–39.1 %). Conclusions: The safety and effectiveness of the novel SIS graft prosthesis were acceptable, and the delivery system exhibited a promising performance. Using the SIS graft prosthesis in TAAD surgery was expected to simplify the procedures and shorten the circulatory arrest time. Further large-scale clinical trials are required to verify these findings.

Generally, the monostrand anchor, which is made of cast iron and used in the global market, has a rectangular shape. It is commonly used when low concrete stresses are induced and minimum slab thickness is needed. Multiple monostrand anchors can be used adjacent to each other at one or more horizontal levels in slabs to replace a multistrand anchor system, which combines two or more strands in the same anchor. Monostrand anchor has a proper stress distribution, while the multistrand has greater overlap zone stresses in post tension slabs. An experimental study was conducted on round monostrand anchors to investigate anchorage and anchor bearing zones. Concrete blocks were prepared, and tested at different ages. The goal is to evaluate the contribution of the concrete's strength improvement against bursting pressure caused by jacking forces at the edge zone of a flat slab. The blocks were stressed using jacking machine. Strands with two diameter sizes (12.7 mm and 15.7 mm) were used. A rigid steel framework was developed as an abutment that can withstand all jack's response forces on the tested concrete blocks. On the other hand, this framework serves as a fixation for the cables' dead ends. The concrete blocks were attached to this framework. After that, they were stressed up to failure. Hairpin reinforcement were used to strengthen the blocks, and resist the applied stresses. Multiple round monostrands were also placed adjacent to each other to produce stress concentration in the concrete blocks. Numerical models were also constructed using finite element to simulate the experimental tests and validate the obtained results. The results were also compared to ACI provision.

Objectives: Evidence of the impact of chronic stress on sleep is abundant, yet experimental sleep studies with a focus on acute stress are scarce and the results are mixed. Our study aimed to fill this gap by experimentally investigating the effects of pre-sleep social stress on sleep dynamics during the subsequent night, as measured with polysomnography (PSG). Methods: Thirty-four healthy individuals (65% females, Mage = 25.76 years SD = 3.35) underwent a stress-inducing (SC) or neutral control condition (CC) in virtual reality (VR). We used overnight EEG measurements to analyze the basic sleep parameters and power spectral density (PSD) across the sleep cycles, and measured heart rate and its variability (HRV), skin electrodermal activity (EDA), and salivary cortisol to capture physiological arousal during the VR task and the pre-sleep period. Results: Following acute stress (SC), the amount of slow-wave sleep (SWS) was higher and N2 sleep lower relative to CC, specifically in the first sleep cycle. In SC, PSD was elevated in the beta-low (16–24 Hz) and beta-high (25–35 Hz) frequency ranges during both stages N2 and SWS over the entire night. Conclusions: Sleep promoted adaptation to acute social stress by a longer duration of SWS in the subsequent sleep period, especially in early sleep. A similar homeostatic effect towards restorative sleep is well-evidenced in animal model stress studies but has not been previously reported in experimental human studies. Whether the high-frequency PSD activity during stages N2 and SWS also serves in the resolution of transient stress, remains open.

Aim: Compare lung injury and hemodynamic effects in synchronized ventilations (between two chest compressions) vs. unsynchronized ventilations during cardiopulmonary resuscitation (CPR) in a porcine model of cardiac arrest. Methods: Twenty pigs were randomized to either synchronized or unsynchronized group. Ventricular fibrillation was induced electrically and left for 1.5 minutes. Four minutes of basic chest compression:ventilation (30:2) CPR was followed by eight minutes of either synchronized or unsynchronized ventilations (10/min) during continuous compressions before defibrillation was attempted. Aortic, right atrial and intracerebral pressures, carotid and cerebral blood flow and cardiac output were measured. Airway monitoring included capnography and respiratory function monitor. Macro- and microscopic lung injuries were assessed post-mortem. Results: There were no significant differences between groups in any of the measured hemodynamic variables or inspiration time (0.4 vs. 1.0 s, p = 0.05). The synchronized ventilation group had lower median peak inspiratory airway pressure (57 vs. 94 cm H2O, p

Introduction: Despite the relatively low prevalence of metastatic cervical spinal tumor, these entities give rise to more profound complications than thoracic and lumbar spinal tumor. However, it is regrettable that experimental investigation has thus far shown a dearth of attention to metastatic cervical spinal tumor. Research question: What is the conceptualization and realization of quadriparesis resulting from metastatic cervical spinal tumor? Material and methods: Using Fischer 344 rats as the experimental cohort, this study orchestrated the engraftment of tumor cells procured from the 13762 MAT B III cell line (RRID: CVCL_3475), which represents mammary adenocarcinoma. These cells were engrafted into the vertebrae of the cervical spine. A comprehensive inquiry encompassing behavioral assessments, histological evaluations, and microangiographic analyses conducted after the aforementioned cellular transplantation was subsequently pursued. Results: The incidence of cervical paralysis was 61.1%. Notably, the evolution of paralysis was unfurled by two distinctive temporal phases within its natural history. A meticulous histological examination facilitated delineation of the tumor's posterior expansion within the spinal canal. Simultaneously, the tumor exhibited anterior and lateral encroachment on the spinal cord, inducing compression from all sides. Augmented by microangiographic investigations, conspicuous attenuation of stained blood vessels within the affected anterior horn and funiculus of the spinal cord was observed. Discussion and conclusion: The pathological advancement of paralysis stemming from metastatic cervical spinal tumor is now apprehended to unfurl through a biphasic phase. The initial phase is characterized by gradual unfurling spanning several days, juxtaposed against the second phase marked by swift and accelerated progression.

A novel test specimen was designed for experimental investigations of pure and mixed mode fracture. This novel test configuration is called “modified edge notched disc bend” (M-ENDB) specimen. The M-ENDB specimen has a circular disc shape with an edge crack along its diameter that is loaded using asymmetric three-point bending. Different fracture parameters including: stress intensity factors (SIFs), geometry factors, T-stress, biaxiality ratio (BR), and out-of-plane constraint factor (Tz) were determined for the suggested disc bend specimen using the extensive finite element (FE) analyses. According to the obtained results, the proposed specimen can present all combinations of mode mixities, including pure modes I, II, and III as well as mixed-mode I/II, I/III, and I/II/III deformations. Afterwards, a large number of pure and mixed-mode fracture toughness experiments were carried out on polyurethane (PUR) foam to examine the capabilities of the suggested M-ENDB specimen. Fracture path, fracture surface, fracture toughness, work of fracture, and critical T-stress of broken foams under general mixed mode conditions were investigated. Mixed mode I/II/III fracture toughness value was smaller than the pure mode I fracture toughness (KIc) value showing the weakness of brittle materials against multi-axial fracture compared to pure tensile type fracture.

This paper presents a heat recovery system (HRS) that exploits the chimney`s exhaust gasses to heat water. Optimization of a waste HRS called the ''multi tube tank,'' as suggested by Khaled et al., is performed through experimental means. The design is described in detail and constructed, after which it is tested. Investigation of the impact of altering the head shape on the performance of the system is performed by constructing two distinct heads, one cylindrical (Cyl) and one conical (Con). Results indicate that the conical head (ConH) outperforms the cylindrical head (CylH). Specifically, in 275 min, the water temperature increases to a maximum of 59 °C with the CylH, while the ConH can raise the water temperature to 68 °C. Moreover, in 400 min, the ConH system can augment the water temperature up to 80 °C. Furthermore, economic and environmental analyses are performed, which show that the ConH system can save approximately 16 $/month more than the CylH system when the system is exploited 140 times/month for 275 min. Additionally, the payback period for the ConH system is about half that of the CylH system (6 months). Finally, the ConH system can reduce emissions of CO2 gas by 2 tons/year more than the CylH system when utilized 140 times/month.

The main aim of this experiment was to determine the thermal conductivity of two nanofluids, ZrO2/DW and SiC/DW, under different temperatures and concentrations as compared to the base fluid. In this work, zirconium oxide and silicon carbide nanoparticles were obtained, and the nanofluids were prepared using a two-stage method by dispersing the nanoparticles in distilled water (DW) by the ultrasonic processor and a magnetic mixture. Field emission scanning electron microscopy (FESEM), Energy-dispersive x-ray spectrometer (EDX), Transmission Electron Microscope (TEM), and X-ray diffraction (XRD) techniques were used to microstructural and characterize the nanoparticles. Stability of nanofluids were examined by zeta potential test. After that, thermal conductivity was measured using the thermal hot wire method using a KD2-Pro thermal analyzer at temperatures ranging from 20 to 60 °C. Solid volume fractions (φ) of 0.025%, 0.05%, 0.075%, and 0.1% were used. The results showed that the thermal conductivity of the nanofluid was enhanced with increased volume fractions and temperature. The highest recorded thermal conductivity was at the highest temperature 60 °C and solid volume fraction 0.1%. The thermal conductivity enhancement for ZrO2/DW at the volume fraction of 0.1% was 20.455%, and that of SiC/DW was 30.303%. The enhancement was compared to that of the base fluid, distilled water. Finally, based on experimental data, A new mathematical correlations were obtained by curve-fitting. The correlations were used to estimate the thermal conductivity of ZrO2/DW and SiC/DW nanofluids at different solid volume fractions and temperatures. The results obtained were compared to a correlation to determine their accuracy. The deviations from the presented correlations were 1.49% and 1.2% for ZrO2/DW and SiC/DW, respectively. The comparison between experimental results and correlation outputs showed a good agreement which signifies that the results were accurate.

It is becoming very difficult for the industrial and technological sectors to meet the ever-escalating fuel and energy demands of a growing population. Experts and scholars have emphasized studying the feasibility of using renewable energies specifically solar energy. In this regard, huge efforts have been invested lately to study the effects of adding nanofluids in solar-based devices. The hybrid nanofluid in this work is prepared by dispersion of ZrO2-SiC particles in distilled water (DW). The nanofluid is employed into a Flat plate solar collector (FPSC) to identify the performance change of the collector. The study is conducted in solar energy laboratory, Gödöllő, Hungary. Next, various instruments are employed to evaluate the nanofluids’ stability and thermo-physical properties. Consequently, the ASHRAE standard 93–2003 is followed during the evaluation of the efficiency of solar collectors filled with nanofluids at mass flow rate of 0.025, 0.033, and 0.041 kg/s. The outcomes of the experiment revealed that the solar collector system showed greater energy and exergy efficiencies in the presence of a nanofluid as compared to the exergy and energy efficiencies shown by the system-based distilled water. The results indicated that at zero value of [(Ti – Ta)/GT], volume fraction of 0.1 % and mass flow rate of 0.041 kg/s, the collector showed maximum thermal efficiency equalling 75.21 %. Hence, nanofluid addition leads to a 31.64 % enhancement in thermal efficiency. It was found that the solar collector exergetic performance was evaluated which indicated a decline in exergy efficiency at a higher mass flow rate and also indicated a rise in the exergy efficiency at a higher concentration of nanoparticles in the nanofluid. At the concentration of 0.1 %, the system yielded maximum increase of about 28.31 % in the exergy efficiency.

The pipe conveying fluid is a classic fluid structure interaction experiment. First studied for industrial applications such as liners and pipelines, it became a “paradigm” of non-linear dynamics in the same way as the vertical rotating shaft. Hundreds of papers studying different pipe instabilities and different phenomena with various numerical and analytical methods have been published in the last decades. However, many studies lack the comparison with experimental data to validate the analytical models and numerical simulations. Indeed, designing and building a pipe conveying fluid experimental setup can prove to be a long and a burdensome process. This paper presents an easy to build pipe conveying fluid experimental setup built in the LM2 laboratory at Polytechnique Montréal. Fig. 1 presents the global architecture of this experimental rig. This large scale setup uses relatively high speed cameras to track the pipe in three dimensions. It does not require heavy construction or major plumbing and electrical work. Moreover, it is removable and can be modified easily to observe different phenomena with various large scale pipes or boundary conditions. Lastly, it is relatively inexpensive as it costs less than 20 000 US dollars including all the sensors and acquisition systems.

Phase change materials and geometric structure of latent heat storage (LHS) devices constitute crucial factors affecting the performance of phase change thermal energy storage systems. In this study, focusing on the LHS system with a heat source temperature of 150 °C, a rectangular finned-tube latent heat storage device was designed and fabricated. Polyethylene wax (PEW) with a 10% mass fraction of expanded graphite was adopted to prepare the composite phase change material. A series of experiments was conducted to evaluate the thermodynamic performance of the device with varying inlet temperatures and mass flow rates. The experimental results showed that the process of heat storage and release was predominantly governed by thermal conduction due to the high viscosity of PEW. Although the temperature variations in various directions within the LHS device remain nearly consistent, the heat transfer in the non-fin regions on the rectangular LHS device walls and corners was comparatively inferior due to the absence of natural convective heat transfer. In comparison to the mass flow rate, the inlet temperature exerts a more significant impact on accelerating the heat storage/release processes. While an increase in the mass flow rate enhanced the heat transfer capacity, its slightly accelerates the heat transfer duration. Moreover, the heat release ratio of the device exhibits an initial increase followed by a decrease with an increasing mass flow rate. In practical applications, prioritizing an increase in inlet temperature difference proves to be more effective than adjusting mass flow rate to enhance the heat storage performance.

The hybrid indirect evaporative cooling-mechanical vapor compression (IEC-MVC) process is an emerging cooling technology that combines the advantages of IEC and MVC, i.e., effective temperature and humidity control, high energy efficiency, and low water consumption. This paper presents an experimental study of the hybrid IEC-MVC process. A 1-Rton pilot is fabricated by connecting IEC and MVC in series, and its performance is evaluated under different operating conditions (outdoor air temperature and humidity, air flowrate, compressor frequency). Results revealed that the outdoor air temperature and humidity could be lowered to 5–15 °C and 5–10 g/kg, respectively. The IEC handles 35%–50% of the total cooling load, and the energy consumption can be reduced by 15%–35% as compared to standalone MVC. Moreover, the condensate collected from the evaporator can compensate for >70% of water consumption in IEC, making the system applicable in arid regions. Based on the derived results, a simplified empirical model is developed for rapid evaluation of the IEC-MVC process, and the energy-saving potential in major cities of Saudi Arabia is estimated.

Experimental investigations of an air gap membrane distillation (AGMD) unit were carried out to study the energy-saving by heat recovery. The spiral air gap membrane module in the water desalination unit was used. The unit was configured to operate in two novel arrangements and designed to minimize the loss of heat within the drains which maximize the unit productivity as well as the thermal efficiency. Water of salt concentrations 10,000 ppm and 20,000 ppm were used. Measurements of the heat source in the form of inlet and outlet temperatures, water productivity, and thermal efficiency are conducted for different flow rates of coolant and water feeds. The new arrangements are found to save much of the supplied heat, minimize the heat loss, and maximize the unit performance. An enhancement of 38.62% in the water productivity was achieved compared to the conventional AGMD unit. The considered heat recovery system showed water productivity of 155.92 m3/year for the proposed fresh potable water system with a cost of $12.85 per m3.

A unique and novel steam power station has been built using a concentrated solar dish, to generate electricity. The system was built based on recommendations by previous researchers about the possibility of obtaining high temperatures using a solar dish. The steam generated will be used to operate a mini steam station, after making some simple changes to fit the new working mechanism, while retaining the main working principles of large steam power stations. This was achieved by using the main elements found in a Rankine cycle system for steam power plant stations (turbine, generator, condenser and pump) and by adding auxiliary secondary components to facilitate its protection and operation all year round. A small station consisting of a solar dish (solar heater), works as a boiler connected to a turbine, this linked to an electric generator. Outlet working fluid travels to the condenser and is then recycled back to the solar heater by a pump. A prototype of the solar dish was built of diameter 3 m, an aperture area reaching 7.1 m2, and focal length 1.41 m, covered with 2 mm glass/ silver mirrors. Data was gathered in situ in summer and winter, to test its performance under different weather conditions and changes in the amount of solar radiation, temperature and wind speed. The results show that the station was able to generate good quantities of energy, ranging from between 900–2000 W, working at 31%–34% overall efficiency. A statistical analysis of the system was also carried out using a SPSS software the results of high accuracy, the maximum value of the coefficient of determination (R2), 85%–91.3%.

CO2 drilling is a promising underbalance drilling technology with great advantages, such as lower cutting force, intense cooling and excellent lubrication. However, in the underbalance drilling, the mechanism of the coupling CO2 jet and polycrystalline-diamond-compact (PDC) cutter are still unclear. Whereby, we established a coupled smoothed particle hydrodynamics/finite element method (SPH/FEM) model to simulate the composite rock-breaking of high-pressure CO2 jet & PDC cutter. Combined with the experimental research results, the mechanism of composite rock-breaking is studied from the perspectives of rock stress field, cutting force and jet field. The results show that the composite rock-breaking can effectively relieve the influence of vibration and shock on PDC cutter. Meanwhile, the high-pressure CO2 jet has a positive effect on carrying rock debris, which can effectively reduce the temperature rising and the thermal wear of the PDC cutter. In addition, the effects of CO2 jet parameters on composite rock-breaking were studied, such as jet impact velocity, nozzle diameter, jet injection angle and impact distance. The studies show that when the impact velocity of the CO2 jet is greater than 250 m/s, the CO2 jet could quickly break the rock. It is found that the optimal range of nozzle diameter is 1.5–2.5 mm, the best injection angle of CO2 jet is 60°, the optimal impact distance is 10 times the nozzle diameter. The above studies could provide theoretical supports and technical guidance for composite rock-breaking, which is useful for the CO2 underbalance drilling and drill bit design.

In the self-circulating evaporative cooling system for high power rectifier equipment, horizontal and vertical hollow copper bars constitute a complex nonlinear system. The operating characteristics of system may be affected by parallel affect. Then in this paper, experiment setup was established for one bridge according 240 kVA thyristor rectifier. Through experiment got the data of pressure and flow rate as the heat load was gradually increased. When the system work under rated condition, the temperature is lower than 80 °C. The system with composite structure shows great difference with simple structure. Then the operating characteristics was researched through a series of experiments. Meanwhile, the flow resistance of the three flow passages was studied according traditional calculation models. The homogeneous model correlation was chosen for No 1 and No 2 flow passage, and Friedel correlation was chosen for No 3 flow passage here. Results shows that the relative error is less than 25%. The work in this paper can provide guidance for optimal design of system and application in future.

Glued-in perforated steel plate (GIPSP) connections demonstrate significant shear strength and high slip modulus. Consequently, they indicate substantial potential for application in timber–concrete composite (TCC) structures according to the emerging tendencies in high-storey and large-span buildings. However, the application pattern in prefabricated TCC structures and the theoretical analysis of the shear performances of GIPSP connections are highly deficient. This hinders the application of this type of shear connection. In this study, the shear performances of GIPSP connections were evaluated using push-out tests. Ten groups of push-out specimens with different steel plate numbers, steel plate lengths, and concrete slab types were tested. The concrete slab types investigated in the experiments included a prefabricated concrete slab and cast-in-situ concrete slab. The experimental results were discussed in terms of the failure mode, load-carrying capacity, and slip modulus. The theoretical models for the load-carrying capacity related to the associate failure mode were discussed based on an analysis of the failure mechanisms. In addition, design proposals with regard to the load-carrying capacity and slip modulus of the GIPSP connection were presented. The research results can provide design guidance for TCC beams using GIPSP connections and prefabricated concrete slabs.

In order to investigate employees’ needs of the Medical Faculty of the University of Freiburg regarding research data management, the BE-KONFORM study was performed in a two-step approach. First, guideline-based qualitative video interviews with four researchers were performed to identify key constructs of relevance. Second, a standardized online survey was conducted from 1st to 15th of November 2020 based on e-mail invitation by the dean and a faculty newsletter. The questionnaire was provided bilingual (English and German) using a backward-forward translation method, no reminders and incentives were used to increase the response rate. The online survey was programmed in REDCap and was accessible via online link. The target population were members of the Medical Faculty (listed in the newsletter mailing list) regardless of the type of working contract signed. The final dataset contains 236 complete cases (90% German and 10% English). The study includes a randomised module asking for data publication (group A) or not (group B). 113 cases were randomized into group A and 99% of them consented to the publication of the collected research data in anonymized form (n=112). The dataset comprised questions about work-related characteristics (professional status, working experience, scientific field of work), data management-related items (definition of research data management, type of data used, type of storage used for saving data, use of electronic laboratory notebooks), experience and attitudes towards data publication in data repositories, as well as needs and preferences regarding research data management support. The produced data offers the possibility to connect with other data collected in this field in other contexts (faculties or universities).

A novel solar desalination system and experimental studies to the performance are presented in this paper. The open system takes the harvested solar energy to heat brackish water in its solar collection chamber and its integrated chimney is a metal-sheet duct to draw ambient air to the water basin and condenses the moisture when humid air flows out of it vertically relying on buoyance force. The solar collection chamber is covered by thermal insulation glasses, while the chimney is made of highly thermal conductive metal and cooled externally by ambient air. The maximum potential of water production from using the system has been analyzed and expression derived. In the laboratory tests, controlled water heating and ambient air temperature were provided to study the water evaporation and harvest performance. The evaporation of water could utilize as high as 84% of the energy supplied, which showed the fact that the chimney-effect-induced airflow takes the moisture away effectively and thus enhances the evaporation. The latent heat from the harvested water against supplied energy reached to a satisfactory value of 26%, which will be more improved in the future. Whereas the energy-efficient water evaporation has proven the advantages of the technology, the cooling capacity from the metal-sheet chimney can be improved in the future by means of increased height of the chimney, enhancement of heat transfer at inner and outer surface of the chimney, or even active cooling to the chimney.

In order to explore the dynamic mechanical properties of concrete under biaxial compression-compression, a true triaxial instrument was used to conduct an experimental study on the dynamic mechanical properties of plain concrete under biaxial compression-compression. Eight different lateral compressive stresses (0 MPa~14 MPa) and four strain (10−5/s, 10−4/s, 10−3/s and 10−2/s) rate were considered. From this, the effects of lateral compressive stress and loading strain rate on the biaxial compression-compression properties of concrete were compared and analyzed by obtaining the failure modes, principal compressive stress-strain curves and related mechanical characteristic parameters of plain concrete under different loading conditions. The research results show that: with the increase of lateral compressive stress, the failure modes of concrete were developed from columnar failure at low lateral compressive stress to sheet-like failure at high lateral compressive stress. With the increase of lateral stress, the development trend of concrete failure mode decreased gradually under the influence of strain rate. With the increase of lateral compressive stress, the variation range of concrete principal compressive stress decreased first and then tended to be relatively stable under the influence of strain rate. With the increase of strain rate, the increase range of concrete principal compressive stress decreased under the influence of lateral compressive stress. The influence mechanism of lateral compressive stress and strain rate on biaxial compression-compression performance of concrete was analyzed. Meanwhile, based on Kupfer biaxial compression failure criterion, a biaxial compression dynamic failure criterion model considering the effect of loading strain rate on plain concrete was proposed. The research results provided an important theoretical basis for the application and development of concrete engineering.

Glue joints make precast concrete segmental beams with discontinuity, which is the weak link and an important part of the structure and needs to be given special attention in practical engineering. To test the shear behavior of five segmental glue joint beams and one monolithic beam, the test parameters included shear span ratios (1.2, 1.5), prestress levels (4 MPa, 6 MPa, 6.5 MPa), prestress types (unbonded prestress, bonded prestress), and beam types (segmental beam, monolithic beam). The results show that both segmental glue joint beams and monolithic beams exhibited typical brittle failure characteristics in the failure stage. The shear span ratio increased, the shear bearing capacity of the specimen decreased, and the deformation increased. The deformation of the specimen decreased when the prestress level increased. The bonded prestressed screw-thread bar improved the overall strength and stiffness of the segmental glue joint beam. The crack resistance of the monolithic beam was better than the crack resistance of the segmental glue joint beam, but the difference in shear bearing capacity between them was small. The test data were compared with the calculated values of shear bearing capacity of different formulas, and the results show that the calculated values of formulas of the American Association of State Highway and Transportation Officials (AASHTO (2003)) standard were in the best agreement with the test values. Based on the test results, the strain distribution and stress distribution of the specimens were further explored by combining the finite element method. The results show that cracks of different specimens would cross the glue joints. The yield strength of the prestressed screw-thread bar was not reached when the specimen was damaged.

Indonesia has a lot of tidal current energy resources that can be harnessed using a vertical-axis turbine. However, one of the disadvantages of the vertical-axis turbine is its low self-starting capability. Under the actual condition, tidal current velocity is fluctuated and sometimes is very low, making the turbine unable to rotate. The purpose of this study is to investigate and improve the self-starting capability of a vertical-axis turbine. The study was conducted experimentally using a towing tank in Institut Teknologi Sepuluh Nopember (ITS) at Surabaya, Indonesia. The speed of towing carriage was set with the starting condition of 0 up to 0.4 m/s with an increment of 0.1 m/s. The stages of the test are as follows: first, the original vertical-axis turbine, a turbine with three straight-blades, was investigated; second, the modified vertical-axis turbine (inclined-blade) was proposed to increase the self-starting capability. The inclined-blade turbine has smooth self-start characteristics compared with the straight-blade turbine. It can start rotating at 0.2 m/s with a turbine rotation speed of 2.25 rpm. The original vertical-axis turbine with straight blades can start rotating at 0.3 m/s with a turbine rotation speed of 1.93 rpm. Therefore, a vertical-axis turbine modified with inclined-blades has better self-start capability that is suitable to implement in an area with low tidal current velocity.

In this study, an experimental and numerical approach is used in order to evaluate the thermoelectric cooler (TEC) control performance and efficiency. For this purpose, the refrigeration system is designed by using the semi-conductor material operating under Peltier effect, and Arduino device. The efficiency of the system is investigated through the performance coefficient and temperature span for carrier fluid between the hot and cold exchanger by using the prototype developed recently at Medea University. In addition, the proportional-integral-derivative (PID) is used in order to maintain temperature control and heat transfer of the system TEC in a closed-loop through the driving circuit, which is specially designed for the TEC can conveniently adjust the input current, which passes through the refrigerator so as to fully make use of quick cooling power advantages. The main obtained results including, the maximum coefficient of performance registered is 0.73 to 0.1 with a temperature span about of 51 °C, by inputting current of 5 A within a control temperature range 0–30 °C, while targeting a temperature of 5 °C at room temperature for the proposed control system had a control time of 21 s, with only a discrepancy of ±0.1 °C. The experimental results confirm that during the time interval 0–20 min, the inside temperature of thermoelectric refrigerator has been decreased rate of 1.5 °C/min.It was shown through the different simulation results with PID controller by taking kp = 0.9, ki = 0.15, and kd = 0, that the cooling temperature decreases over time to 5 °C, which means that these systems work in time-dependent conditions. The proposed controller is able to reach an error of 0.1 °C with minimal overshoot under than 20 s.

Since the 1970s, commercial-scale thermally-driven seawater desalination plants have been powered by low-grade energy sources, drawn either with low-pressure bled-steam from steam turbines or the solar renewable energy harvested that are supplied at relatively low temperatures. Despite the increasing trend of seawater reverse osmosis plants, the role of thermal desalination methods (such as multi-stage flashing and multi-effect distillation) in GCC countries is still relevant in the Arabian Gulf, arising from higher salinity, the frequent algae blooms of seawater and their ability to utilize low temperature heat sources. Given the urgent need for lowering both the capital and operating costs of all processes within the desalination industry and better thermodynamic adaptation of low-grade heat input from renewable sources, the present paper addresses the abovementioned issues by investigating the direct contact spray evaporation and condensation (DCSEC) method. A DCSEC system comprises only hollow chambers (devoid of membranes or tubes, minimal use of chemical and maintenance) where vapor generation (flashing) utilizes the enthalpy difference between the sprayed feed seawater and the saturated vapor enthalpy of the vessels. Concomitantly, vapor is condensed with spray droplets of cooler water (potable) in adjacent condenser vessels, employing a simple design concept. We present detailed design and real seawater experiments data of a DCSEC system for the first time. The water production cost is calculated as $0.52/m3, which is one of the lowest figures reported compared to commercial processes presented by Global Water Intelligence.

Use of spur dikes by modifying the flow pattern is among the common methods for control of erosion at the river banks and their protection. In this research by construction of a laboratory meandering channel and use of five spur dikes, the effects of permeability and length of a series of spur dikes on the erosion control was investigated. The experiments were performed using three effective lengths, four permeability values and three Froude numbers in the non-submerged state. The results showed that the highest amount of bank retreat was achieved in impermeable spur dikes with a length of 9 cm and the lowest amount of bank retreat in permeable spur dike was 54% and a length of 15 cm. In this research use has been made of two criteria R2 and RMSE for comparing the data obtained from the predicted relationship and the observed data and showed a good compatibility.

Background and Objectives: Repeated checking results in large reductions in metamemory variables (confidence, details, and vividness). It has been suggested that the underlying mechanism is gradual automatization. At the same time, individuals with obsessive-compulsive disorder (OCD) are reluctant to automatize routine processes. The aim was to investigate whether high responsibility for potential harm, typical of OCD, would attenuate the effects of repeated checking on metamemory variables and automatization., Methods: One hundred seventy-five participants were initially provided with a cover story that put the subsequent virtual checking task in a context of potential harm for not checking properly. Participants were randomly allocated to four experimental groups (varying high and low responsibility, relevant and irrelevant checking) and performed a virtual checking task repeatedly, using either identical stimuli (relevant checking) or different stimuli (irrelevant checking) between the first and final checking trial. Metamemory variables were rated on visual analogue scales, and response latencies were assessed to establish automatization., Results: Larger reductions in metamemory variables following relevant checking compared to irrelevant checking replicated previous findings. High responsibility did not affect these results. Large reductions in response latencies across the checking trials (automatization) were also independent of the perceived responsibility., Limitations: We did not include individuals with OCD., Conclusions: Since responsibility did not influence the effects of repeated checking on metamemory variables, findings are consistent with the idea that automatization remains a plausible explanation of the effects of repeated checking on metamemory variables in individuals with OCD., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Due to limited flow capacity and the instability of the asymmetric structure of traditional baffle dropshafts, a novel baffle dropshaft with a symmetric structure, adopting the construction shield well directly, is proposed for large-range flow discharge in deep tunnel drainage systems. In this study, a two-phase flow field of the novel baffle dropshaft with three different baffle spacings was simulated at seven different flow rates with a three-dimensional (3D) numerical model verified with experiments, to study hydraulic characteristics of this novel baffle dropshaft. The results show that the novel baffle dropshaft has a remarkable energy dissipation effect. Baffle spacing of the novel baffle dropshaft has a greater effect on flow patterns and baffle pressure distributions than the comprehensive energy dissipation rate. Flow rate is a critical issue for the selection of baffle spacing in the design. Some guidance on baffle spacing selection and structure optimization for the application of this novel baffle dropshaft in deep tunnel drainage systems is proposed.

In underground engineering, such as geological CO2 sequestration, unconventional oil and gas exploration, and radioactive waste storage, permeability of rock is important to evaluate the potential CO2 storage capacity, improve oil and gas production, and prevent leakage of radioactive waste. In this study, hydrostatic stress tests and triaxial compression tests with gas permeability measurements were carried out on intact and damaged sandstone specimens. Three series of experiment were designed to evaluate the permeability evolution laws of sandstone under different testing conditions. They included triaxial seepage tests on intact specimens under different confining pressures, triaxial seepage tests on damaged specimens with different extents of damage, and hydrostatic seepage tests on damaged specimens under increasing and decreasing gas pressures. Based on the experimental results, the effects of effective confining pressure, extent of damage and increasing and decreasing gas pressure on permeability of sandstone were investigated. It shows that the permeability of the intact sandstone specimens first decreased and then increased, followed by a constant value with increase in axial strain. The permeability of the sandstone specimens was observed to decrease with increase in effective confining pressure. The extent of damage affects the permeability evolution, but does not influence the failure patterns of damaged sandstone. As the gas pressure increased, the permeability of the damaged sandstone specimen increased. Under the same gas pressure condition, the permeability during the decreasing process is generally higher than that during the increasing process. These experiments are expected to enhance our understanding of seepage behavior in underground rock masses.

This paper presents experimental and numerical investigations in the single-lap, single-bolt joints of carbon fiber reinforced bismaleimides (CF/BMI) composites. In order to guide the engineering design, an optimum configuration of composite joints is determined. Effects of stacking sequence and geometry dimensions on composite joints under tensile loading are discussed to select an optimum configuration. The optimum configuration is validated by the experimental method. Quasi-static tensile tests are conducted according to ASTM D5961 to evaluate the joint stiffness, joint strength, and bearing behavior. Finite element (FE) models considering progressive failure and delamination failure are established to investigate the joint stiffness, bearing strength, damage mechanisms, and evolution of delamination damage. Results show that bearing failure accompanied with delamination caused by secondary bending is the main failure mode, indicating an expected non-catastrophic failure mode.

Purpose: The current study was directed to investigate the effectiveness of docosahexaenoic acid (DHA) as a chemopreventive agent on experimentally induced hamster buccal pouch (HBP) carcinogenesis. Material and methods: In this study we used 40 Syrian male hamsters, five weeks old, were divided into 4 groups (GI, GII, GIII, and GIV) of 10 animals in each as follows, GI: Topical application of liquid paraffin alone (thrice a week for 14 weeks), GII: Topical application of 7, 12 dimethyl benz[a]anthracene (DMBA) alone (0.5% in liquid paraffin, thrice a week for 14 weeks), GIII: Topical application of DMBA (0.5% in liquid paraffin, thrice a week for 14 weeks) + Oral administration of DHA (125 mg/kg b.w. in 1 ml distilled water by oral gavage, thrice a week for 14 weeks on alternative days of DMBA application), GIV: Oral administration of DHA alone (125 mg/kg b.w. in 1 ml distilled water by oral gavage, thrice a week for 14 weeks). Results: Gross observations and histopathological findings revealed that, in GI: normal stratified squamous epithelium, in GII: well and moderately differentiated squamous cell carcinoma (SCC), in GIII: variable results ranges from hyperkeratosis, hyperkeratosis and focal hyperplasia, mild dysplasia, and well differentiated SCC with superficial invasion of tumor cells not extended to deeper areas, while in GIV: normal similar to GI. Immunohistochemical results indicated that oral DHA treatment to DMBA treated hamsters restored the normal expression of bcl-2. Conclusion: Our results indicated that DHA has the potential to be a dietary chemopreventive agent due to its capacity to improve carcinogen detoxification and to block/suppress the initiation and promotion stages of experimentally produced HBP carcinogenesis.

In this paper, 8 loading strain rates were configured to carry out experimental research on the compressive dynamic behaviors of plain concrete (PC) and lightweight aggregate concrete (LWAC) by utilizing a hydraulic servo machine. The compressive failure modes and stress-strain curves of PC and LWAC under various loading states were generated from the experiments. The peak stress and peak strain values extracted from the stress-strain curves, as well as the elastic modulus, were comparatively analyzed between the two types of concrete. The experimental findings indicate that the failure mode of PC under the static strain rate mainly manifest as the damage to bonding materials, while the failure under dynamic strain rates involves part of coarse aggregates. For LWAC, the failure modes under both static and dynamic loading mainly manifest as the damage to shale ceramisite. As the strain rate increases, the peak stress and elastic modulus of both PC and LWAC increase significantly. Compared with PC, the strain rate effect on LWAC is more obvious. The peak strain of both PC and LWAC varies insignificantly across different strain rates, even though the changing trend shows a discrete pattern. In addition, on the basis of the experimental results, the relationship equations between the strain rate and the related mechanical parameters were established for both PC and LWAC. It is found that the values of peak stress and elastic modulus and the logarithmic value of the corresponding strain rate after non-dimensional treatment fit a linear relationship. The findings provide theoretical insights into the research and engineering application of LWAC.

During drilling, to maximize future expected production of hydrocarbon resources, the experts commonly adjust the trajectory (geosteer) in response to new insights obtained through real-time measurements. Geosteering workflows are increasingly based on the quantification of subsurface uncertainties during real-time operations. As a consequence, operational decision-making is becoming both better informed and more complex. This paper presents an experimental web-based decision support system, which can be used to both teach expert decisions under uncertainty or further develop decision optimization algorithms in a controlled environment. A user of the system (either human or AI) controls the decisions to steer the well or stop drilling. Whenever a user drills ahead, the system produces simulated measurements along the selected well trajectory which are used to update the uncertainty represented by model realizations using the ensemble Kalman filter. To enable informed decisions the system is equipped with functionality to evaluate the value of the selected trajectory under uncertainty with respect to the objectives of the current experiment.To illustrate the utility of the system as a benchmark, we present the initial experiment, in which we compare the decision skills of geoscientists with those of a recently published automatic decision support algorithm. The experiment and the survey after it showed that most participants were able to use the interface and complete the three test rounds. At the same time, the automated algorithm outperformed 28 out of 29 human participants.Such an experiment is not sufficient to draw conclusions about practical geosteering but is nevertheless useful for geoscience. First, this communication-by-doing made 76% of respondents more curious about and/or confident in the presented technologies. Second, the system can be further used as a benchmark for sequential decisions under uncertainty. This can accelerate development of algorithms and improve the training for decision making.

In present study, the heat transfer and the throughflow losses characteristics of single/triple-row of fan-shaped and cylindrical film cooling holes with a fixed outlet width are studied experimentally with an engine-representative density ratio. The pressure-sensitive paint (PSP) measurement technology is utilized to test the film cooling performance. The film cooling holes with the inclination angle α which ranged from 20° to 30° and the diffusion angle β which ranged from 0° to 15° are considered. The heat transfer and flow resistance characteristics of film cooling holes under the engine-representative density ratio, DR, of 1.52 as well as the blowing ratio, BR, which ranged from 0.3 to 2.0 are studied. The critical blowing ratios of the secondary flow detaches from wall surface of each hole shape and the hole shape parameters which acquire the highest span-wise averaged adiabatic film cooling efficiency are obtained. Moreover, the experimental results indicate that, within the scope of the investigative parameters pondered in present study, the discharge coefficient and the film cooling performance of the cylindrical hole are significantly lower than that of the fan-shaped film cooling holes. The coolant jet which ejects from the fan-shaped holes does not blow off from the wall surface when BR ≤ 1.5. However, when BR = 2.0, a part of coolant jet begins to detach from the wall surface. In addition, when BR ≤ 1.5, the fan-shaped film cooling hole with the hole shape parameters of α = 20°, β = 15° generates the highest film cooling effectiveness. However, when BR > 1.5, the highest film cooling effectiveness is obtained by the fan-shaped hole with hole shape parameters of α = 25°, β = 10°. Importantly, the discharge coefficient does not change monotonously with the variation of the hole shape parameters. In addition, the fan-shaped film cooling holes with the hole shape parameters of α = 25°, β = 13° as well as those with α = 30°, β = 10° offer the highest discharge coefficient. Finally, the correlations for the discharge coefficients of different hole shape parameters are developed.

Underground buildings are one of the most effective old and modern techniques, at the same time to meet the trade-off between thermal comfort and low energy consumption in hot and arid climates, through the soil thermal properties, which can be applied as a heat capacitor for moderating indoor temperatures. This research aims to improve the thermal comfort and energy efficiency of underground buildings compared to aboveground buildings in hot and arid climates based on yearly energy consumption. The experimental measurements of soil temperatures at different depths were compared to the numerical results of the Kasuda equation. Furthermore, TRNSYS software simulation findings were validated by monitoring the temperature of an underground room in Ouargla, Algeria, using digital temperature sensors. The findings revealed that an underground structure with a depth of 2.34 m decreases cooling energy demand considerably during the summer season. Furthermore, with and without state support, the investment return time was predicted from 6.5 to 3.25 years, respectively.

Importance: The field of meniscal root preservation has undergone significant advancement over the past decades; however, the challenge remains to fully understand whether meniscal root repair can ultimately arrest or delay osteoarthritic changes., Objective: To assess longitudinal changes in articular cartilage, subchondral bone, and progression to meniscal extrusion (ME) using high-resolution magnetic resonance imaging (MRI)., Methods: Medial meniscus posterior root tear was surgically induced in 39 New Zealand white rabbits. Animals were randomly assigned into three experimental groups: partial meniscectomy after root tear (PM, n ​= ​13); root tear left in situ (CT, n ​= ​13); and transtibial root repair (RR, n ​= ​13). Contralateral limbs were used as healthy controls. High resolution 4.7 Tesla MRI of the knee joint was performed at baseline, after 2-, and 4-months of post-surgery. Cartilage thickness was calculated in medial and lateral compartments. In addition, the evaluation of ME, subchondral bone edema and healing potential after root repair were assessed too., Results: Progressive cartilage thinning, ME, and subchondral bone edema were evident in all 3 study groups after 4-months of follow-up. The mean cartilage thickness in the PM group was 0.53 ​mm (±0.050), 0.57 ​mm (±0.05) in the CT group, and 0.60 ​mm (±0.08) in the RR group. The PM group exhibited significantly higher cartilage loss when compared to the CT and RR groups (p ​< ​0.001). Moreover, progressive ME and subchondral bone edema were associated with a more severe cartilage loss at the final follow-up., Conclusion: Meniscal root repair did not halt but rather reduced the progression of osteoarthritis (OA). Degenerative changes worsened at a rapid rate in the PM group compared to the RR and CT groups. Early cartilage swelling, persistent subchondral edema, and progressive ME predicted a more severe progression to knee OA in the CT and RR groups., Level of Evidence: II., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

In this research, the application of nanoparticles for cooling in the drilling operation is investigated. In addition, a mathematical model is derived for perdition of temperature profile in drilling zone. A solid cylinder which is equipped by heat pipe is used for evaluation of drill performance. The numerical results of the mathematical model are compared with the experimental data, finally. The studies show that nanofluid injection into the heat pipe has a significant effect on the reducing of temperature profile. Results show that the best ratio for heat pipe diameter to the drill diameter will be about 0.12. The results show that the optimum distance between the tip of the heat pipe and the tip of the drill per drill length is 0.2, approximately. Also, the best cutting length per the drill diameter is 1.2 and the input heat flux is about 0.4 W/m.K. Also, the effect of different greases on temperature profile has been investigated in this research.