Self-made Device Research Articles

Effect of Vertical Pressure on Temperature Field Distribution of Bulk Paddy Grain Pile

Grain storage pressure is an important factor affecting grain pile temperature, and its influencing mechanism needs to be studied further. The distribution and variation of the temperature field of a bulk grain pile under different vertical pressures and a temperature difference of 25 °C are studied by a model test and numerical simulation. Initially, the temperature change and heat transfer law at different points in the bulk grain pile space are studied under different vertical pressures using a self-made test device. Thereafter, a multi-field coupling software platform COMSOL is used to simulate and study the distribution law of the temperature field in the bulk grain pile under different vertical pressures. The influence mechanism of vertical pressure on the temperature field of the grain pile is discussed based on the micro-airflow velocity field obtained by numerical simulation. The results show that the numerical simulation and experimental results are in good agreement. With the increase in vertical pressure, the heat transfer rate of the grain pile increases gradually, the convective heat transfer in the grain pile is hindered, and the temperature distribution gradually attains uniformity. When the vertical pressure increases from 50 kPa to 200 kPa, the temperature of the grain pile decreases by approximately 0.6–2.7 °C, and the rate of change of the temperature gradient reaches 7.4%. Under different vertical pressures, the proportion of the high-temperature area decreases linearly with the storage duration. The micro-airflow velocity field affects the temperature transfer in the bulk grain pile, resulting in the temperature at the top of the storage structure being higher than that at the bottom. The research methods and conclusions in this study can provide theoretical support and reference for the multi-field coupling research on bulk grain pile storage.

Investigation of a Complex Reaction Pathway Network of Isobutane/2-Butene Alkylation by CGC-FID and CGC-MS-DS.

The mechanism of reaction in isobutane/2-butene alkylation systems is extremely complicated, accompanied by numerous side reactions. Therefore, a comprehensive understanding of the reaction pathways in this system is essential for an in-depth discussion of the reaction mechanism and for improving the selectivity of the major products (clean fuel blend components). The alkylation of isobutane/2-butene was studied using a self-made intermittent reaction device with a metering, cooling, reaction, vacuum and analysis system. The alkylates were qualitatively and quantitatively analyzed using a capillary gas chromatography-mass spectrometry-data system (CGC-MS-DS) and capillary gas chromatography with flame ionization detection (CCGC-FID), respectively, and the precision and recovery of the quantitative analytical methods were verified. The results showed that the relative standard deviation (RSD) of the standard sample was below 0.78%, and the recoveries were from 98.53% to 102.85%. Under the specified reaction conditions, 79 volatile substances were identified from the alkylates, and the selectivity of C8 and trimethylpentanes (TMPs) reached 63.63% and 53.81%, respectively. The changes of the main chemical components in the alkylation reaction with time were tracked and analyzed, based on which reaction pathways were determined, and a complex reaction network containing the main products’ and the by-products’ generation pathway was constructed.

Preclinical evaluation of a veno-venous bypass device for liver transplantation based on the principle of magnetic levitation drive

Objective: To explore the performance of a self-made venous-venous bypass (VVB) device for liver transplantation based on the principle of magnetic levitation drive. Methods: Experimental study was conducted from August 2020 to January 2022. Eight Bama minipigs underwent VVB of hepatic portal vein-femoral vein-internal jugular vein after occlusion of hepatic portal vein and inferior vena cava. The animals were divided into two groups according to the VVB devices used during VVB. A self-made VVB device was used in group A(n=5),and an imported VVB device was used in group B(n=3). The hemodynamic changes of the two groups of animals were compared at 6 time points including before vascular occlusion, during vascular occlusion, 30 minutes, 60 minutes, 90 minutes after the start of VVB, and 30 minutes after vascular opening. In addition,the changes of blood compatibility indexes,intestinal injury indexes,kidney injury indexes and internal environment indexes of the two groups of animals at each time point were compared. The independent samples t test was used for the quantitative data between the two groups with non-repeated measures,and the repeated measures analysis of variance was used for the quantitative data between the two groups with repeated measures. Results: During the VVB of the two devices,the venous drainage was sufficient,and the main manifestations were that the color of the intestine of the Bama miniature pig was ruddy, the peristalsis was normal, and the urine output was normal. There were no significant differences in hemodynamics,blood injure indexes,intestinal injury indexes,kidney injury indexes,neutropil gelatinase-associated lipocalin,and internal environment indexes(all P>0.05).The indexes at 30 minutes after vascular opening in the group A and the group B were as follows:mean arterial pressure were (71.0±7.7)mmHg(1 mmHg=0.133 kPa) and (74.0±8.7)mmHg,central venous pressure were (7.0±1.4)cmH2O(1 cmH2O=0.098 kPa) and (7.7±0.6)cmH2O,heart rate were (131±10) beats/minutes and (132±8)beats/minutes; red blood cell count were (6.43±0.89)×1012/L and (6.32±0.58)×1012/L,hemoglobin were (108.4±5.9)g/L and (110.0±3.5)g/L,free hemoglobin were (78.28±3.96)mg/L and (78.08±4.54)mg/L; intestinal fatty acid binding protein were (2.27±0.49)μg/L and (2.40±0.78)μg/L;creatinine were (68.30±9.77)μmol/L and (79.90±26.91)μmol/L,blood urea nitrogen were (3.94±1.39)mmol/L and (3.45±0.65)mmol/L;neutropil gelatinase-associated lipocalin were (4.02±0.53) μg/L and (3.86±0.23)μg/L;pH value were 7.27±0.04 and 7.23±0.03,lactic acid were (6.18±2.62)mmol/L and (4.30±0.50)mmol/L,concentrations of Na+ were (136.3±3.0)mmol/L and (137.6±1.6) mmol/L,concentrations of K+ were (3.89±0.42) mmol/L and (3.98±0.17)mmol/L,concentrations of Ca2+ were (1.40±0.03)mmol/L and(1.40±0.04)mmol/L;all indexes in the two group had no differences(all P>0.05). Conclusion: The self-made venous bypass device can be safely and effectively applied to VVB of Bama minipigs,and achieves the same performance as the imported venous bypass device.

Single incision laparoscopic totally preperitoneal hernioplasty (SIL-TPP): Lessons learned from 102 procedures and initial experience.

Background:The abdominal wall in groin area is conventionally considered that it was comprised by 9 layers. Single incision laparoscopy totally extraperitoneal hernioplasty (SIL-TEP) reported before were operated through the front of the posterior rectus sheath.Method:102 SIL-TPP were conducted from October 2018 to October 2020 at The Affiliated Hospital of Medical School of Ningbo University using a self-made single-port device and standard laparoscopic instruments. Clinical data, demographic and intraoperative findings, and short-term postoperative outcomes were analyzed.Results:Of the 102 hernias treated, 46 were right inguinal hernias, 33 were left inguinal hernias and 23 were double-side inguinal hernias. All patients received the SIL-TPP and no conversion happened. The mean left-side and right-side hernia operative time was almost same. The left-side and right-side operative time were 75.48 ± 26.95 and 76.24 ± 26.09 minutes, respectively. The mean operative time was 75.92 ± 26.45 (range, 29–170 minutes) in unilateral inguinal hernia. Mean operative time was 104.17 ± 28.58 minutes (range, 67–180 minutes) in double-side inguinal hernia. The intraoperative complications rate was 21.57 (22/102) and all the complications were Peritoneum or sac tearing. Postoperative complications occurred in 3 cases (1 case wound seroma, 1 case urinary retension and 1 case upper respiratory infection) and were successfully treated conservatively. The mean hospital stay was 2.8646 ± 1.38 days. The 24 hours Visual analogue scale score was 2.28 ± 0.77. During follow-up to June 2022, no recurrence case occurred.Conclusion:SIL-TPP is safe and feasible. SIL-TPP has its unique skills and advantages to treat inguinal hernia. Large-scale randomized controlled trials comparing SIL-TPP inguinal hernia repair with conventional single port and conventional three port laparoscopic totally extraperitoneal hernioplasty with short-term outcome and long-term recurrence rate are needed to confirm these results.

Inhalation of 4% and 67% hydrogen ameliorates oxidative stress, inflammation, apoptosis, and necroptosis in a rat model of glycerol-induced acute kidney injury

Acute kidney injury (AKI) is the major complication of rhabdomyolysis (RM) clinically, which is usually mimicked by glycerol injection in basic research. Oxidative stress, inflammatory response and apoptosis are recognized to play important roles in development of this disease. Recently, numerous studies have reported the therapeutic effects of molecular hydrogen (H2) on oxidative stress and inflammation-related diseases. Here, the effects of H2 against glycerol-induced AKI and the underlying mechanisms were explored in rats. Low (4%) and high (67%) concentrations of H2 were prepared using a self-made device to investigate the dose-response. After 72 hours of glycerol injection (8 mL/kg), we found that glycerol triggered oxidative stress, inflammatory reactions, and apoptotic events. These caused subsequent renal damage, evidenced by a significant reduction of antioxidases and up-regulation of the relevant damaged biomarkers. H2 inhalation reversed the above alterations and exerted renoprotective effects. Interestingly, for RM/AKI-related factors, no consistent dose-response benefits of H2 were observed. However, higher concentration of H2 inhalation improved histological and morphological changes better. This study suggests that H2 is a potential alternative therapy to prevent or minimize RM induced AKI possibly via its antioxidant, anti-inflammatory, anti-apoptotic and anti-necroptotic properties.

A simple focusing device for macrophotography at higher magnifications

This short note describes a simple, self-made focusing device for macrophotography at higher magnifications.

Electrochemical sensor based on micromotor technology for detection of Ox-LDL in whole blood

Detecting the concentration of oxidized low-density lipoprotein (Ox-LDL) in whole blood is of great significance for monitoring the development of atherosclerosis. In order to simplify the complex processing steps of blood sample before the detection, an electrochemical sensor based on micromotor technology was designed, which was called magnesium (Mg)–Fe3O4@ prussian blue (PB)@ antibody of Ox-LDL (Ab)@ bovine serum albumin (BSA). The active capture of Ox-LDL in whole blood can be realized by the help of the movement of Mg microsphere with the driving force of H2. Then the captured Ox-LDL was collected on the surface of the magnetic glassy carbon electrode (MGCE) by self-made funnel device, and the content of Ox-LDL was detected by electrochemical workstation in the way of chronoamperometry (i-t). Due to the application of micromotor, the electrochemical sensor proposed in this study had good detection efficiency for Ox-LDL in whole blood with range from 1 × 10−2 μg/mL to 10 μg/mL, and the limit of detection (LOD) towards Ox-LDL was 9.80 × 10−4 μg/mL. The electrochemical sensor based on micromotor technology provides a rapid, effective, and sensitive method for the detection of Ox-LDL in whole blood.

Coda Wave Interferometry for Monitoring Bridges with Embedded Ultrasonic Transducers – Lessons Learned at the Gänstorbrücke Bridge Ulm, Germany

Ultrasonic Coda Wave interferometry has the potential to detect minute changes in scattering materials like concrete. By permanently installing ultrasonic transducers in concrete, DFG Research unit CoDA aims to develop methods for concrete damage assessment in Germany's ageing infrastructure. To test the methods developed in simulations and laboratory experiments on a large scale, we have implemented several ultrasonic transducers, both embedded and externally attached at the Gänstorbrücke Ulm, one of Germany's most monitored road bridges. Since fall 2020 we are monitoring parts of the centre of the Bridge, as well as an abutment, and compare the results to the commercial monitoring system. All data is recorded with a self-made data collection device, the so-called W-Box, and analyzed with different coda wave-based algorithms to detect signal and volumetric velocity changes for several transducer combinations. The long-term measurements show that the influence of temperature changes on strains and therefore ultrasound velocity changes calculated with coda waves can be monitored. Maps of velocity change show that parts of the bridge react differently to environmental heating or cooling which indicates material property differences comparing those areas. The capabilities and limitations of the coda wave-based monitoring system are tested in a controlled experiment. Static loading using a truck with varying load at several positions allows the calibration of the system to improve the detectability of possibly damaging loads and changes induced by this loading versus the influence of the environment.

Study on High Temperature Pyrolysis Light Cycle Oil to Acetylene and Carbon Black

The reaction performance of producing acetylene by light cycle oil (LCO) high temperature pyrolysis was investigated with a self-made electromagnetic induction heating device. The results showed that the reaction temperature and residence time were the main factors restricting the production of acetylene during LCO high temperature cracking. When the reaction temperature was 1800 °C and the residence time was 8.24 ms, the yield of acetylene reached 7.90%. At the same time, the comparative study of different raw materials shows that Yangzhou heavy cycle oil (YZHCO) with a higher content of chain alkanes, cycloalkanes, and tetrahydro-naphthalene aromatics was beneficial to the formation of acetylene, and the highest yield of acetylene reached to 12.7%. The preliminary characterization of byproduct carbon black showed it had a good structure and could be used for lithium electron conductive agent.

Experimental study on compression mechanical characteristics of filled rock joints after multiple pre-impacts

The prefabricated artificial filled jointed rock specimens are impacted by a self-made drop hammer impact device for many times, and the specimens with different degrees of cumulative damage characteristics are obtained. Then, the static and dynamic compression mechanical properties are studied by using universal testing machine and SHPB device. Through the static compression test, the strength and deformation characteristics of jointed rock specimens after multiple impacts are obtained, and the influence of the damage degree of jointed rock specimens characterized by wave velocity on the compressive strength of filled joints is analysed. Based on the results of SHPB impact test, the dynamic strength and deformation evolution, wave propagation law and energy dissipation law of filled joints after multiple impacts are analysed. During the SHPB test, the impact failure process of rock specimens is recorded by a high-speed camera. The experimental results show that the damage degree of jointed rock samples increases nonlinearly after multiple impacts. The attenuation laws of static strength and dynamic strength of rock samples under the same damage evolution conditions are different. With the increase of impact times, the failure mode of jointed rock samples after damage is simpler and tends to compression failure.

Experimental research on spontaneous combustion of coal oxidized by ultraviolet photocatalysis

To study the effect of ultraviolet light on the spontaneous combustion characteristics of coal, Lijiahao long-flame coal was selected for irradiation treatment with a self-made ultraviolet light irradiation device. After irradiation for 0, 1, 2, 4, and 8 h, thermogravimetric experiments and Fourier transform infrared spectroscopy experiments were carried out. Compared with the raw coal, the dry cracking temperature, the ignition point temperature, and the maximum weight loss rate temperature of coal samples irradiated for 2 h by ultraviolet light were advanced to different degrees. The ignition activation energy was 0.62, 0.56, 0.59, and 0.91 times that of the raw coal after 1, 2, 4, and 8 h of ultraviolet light irradiation. The ultraviolet light irradiation accelerated the oxidation of –CH3, –CH2−, and –OH, resulting in enhanced coal activity. It shows that ultraviolet light irradiation has a promoting effect on the spontaneous combustion of coal, and the best promotion effect is observed when ultraviolet light is irradiated for 2 h. After 2 h of ultraviolet light irradiation, compared with the raw coal, the content of ether group in the coal structure decreased by 6.79%, the content of methyl and methylene in the benzene ring decreased by 8.68%, the content of C=O and carboxylic acid increased by 30.21%, the content of hydroxy ether and hydroxyl π hydrogen bond decreased by 14.94%, and the content of self-associating hydroxyl hydrogen bonds increased by 16.59%. It shows that ultraviolet light can destroy aromatic hydrocarbons in coal, catalyze the hydrolysis reaction of esters and ethers in coal to generate –OH and –COOH, and promote the oxidative spontaneous combustion of coal.

Evaluating the Influence of Fracture Roughness and Tortuosity on Fluid Seepage Based on Fluid Seepage Experiments

The roughness and tortuosity of fractures are essential parameters affecting the fluid flow in a jointed rock mass. This paper investigates the influence of fracture roughness and tortuosity on fluid seepage behavior. A rough fracture surface was characterized by means of three-dimensional scanning and three-reconstruction technology, and the roughness and tortuosity of rock fractures were calculated. Hydraulic tests were conducted on deformed sandstone fractures with a self-made fracture seepage device, and the variation in the seepage flow was analyzed in rough fractures. The experimental results showed that the seepage flow of fluid decreased non-linearly with the increase in fracture roughness. Under different normal pressures, the friction resistance coefficient and tortuous resistance coefficient decreased with the increase in the Reynolds number. The friction resistance coefficient model and tortuous resistance coefficient model were used to quantitatively analyze the influence of fracture tortuosity and roughness on fluid flow, respectively. A modified model of the frictional resistance coefficient, considering fracture tortuosity and roughness, was established, which clearly expresses the law that with the increase in fracture tortuosity and roughness, the seepage flow of fluid decreases, and the head loss increases. The results of this research can provide a theoretical and experimental basis for studying fluid seepage behavior in deformed sandstone fractures.

Experimental Analysis on the Dependence of the Capacitance of Magnetorheological Fluids on Frequency

The capacitance characteristics of magnetorheological fluids (MRFs) were studied experimentally based on simulation analysis. The nonlinear relationship between the capacitance of MRFs and electric field frequency was measured by the self-made circuit device. The effects of magnetic induction intensity and particle volume fraction on the capacitance characteristics of MRFs were investigated. The results show that the nonlinear dependence of the capacitance of an MRF on frequency induced by the effect of tunnel current decreases with the increase in frequency. The capacitance of an MRF is directly related to the particle structures. The capacitance of the MRF with a chain particle structure is greater than that of the MRF with a random particle distribution. The smaller the clearance between the adjacent particles, the greater the capacitance of the MRF. The network particle structure and particle contact will reduce the capacitance of an MRF. The capacitance of an MRF increases with the increment of external magnetic field. The capacitance of an MRF with higher particle volume fraction is smaller than that of an MRF with lower particle volume fraction.

Improvement of macrolactins production by the genetic adaptation of Bacillus siamensis A72 to saline stress via adaptive laboratory evolution

BackgroundMacrolactins, a type of macrolide antibiotic, are toxic to the producer strains. As such, its level is usually maintained below the lethal concentration during the fermentation process. To improve the production of macrolactins, we applied adaptive laboratory evolution technology to engineer a saline-resistant mutant strain. The hypothesis that strains with saline resistance show improved macrolactins production was investigated.ResultsUsing saline stress as a selective pressure, we engineered a mutant strain with saline resistance coupled with enhanced macrolactins production within 60 days using a self-made device. As compared with the parental strain, the evolved strain produced macrolactins with 11.93% improvement in non-saline stress fermentation medium containing 50 g/L glucose, when the glucose concentration increased to 70 g/L, the evolved strain produced macrolactins with 71.04% improvement. RNA sequencing and metabolomics results revealed that amino acid metabolism was involved in the production of macrolactins in the evolved strain. Furthermore, genome sequencing of the evolved strain revealed a candidate mutation, hisDD41Y, that was causal for the improved MLNs production, it was 3.42 times higher than the control in the overexpression hisDD41Y strain. Results revealed that saline resistance protected the producer strain from feedback inhibition of end-product (macrolide antibiotic), resulting in enhanced MLNs production.ConclusionsIn the present work, we successfully engineered a mutant strain with enhanced macrolactins production by adaptive laboratory evolution using saline stress as a selective pressure. Based on physiological, transcriptomic and genetic analysis, amino acid metabolism was found to benefit macrolactins production improvement. Our strategy might be applicable to improve the production of other kinds of macrolide antibiotics and other toxic compounds. The identification of the hisD mutation will allow for the deduction of metabolic engineering strategies in future research.

Theoretical analysis and experimental research on characteristics of the lubricating gas film of a planar restrictor in the orifice-throttling effect

When a restrictor is coupled with groove microstructures, the analysis on the flow-field status of the restrictor’s lubricating gas film becomes more difficult, especially in theoretical calculation. In this study, a single-orifice planar restrictor with double-ring-grooves was researched. First, the theoretical mathematical analysis and calculation of the pressure and temperature distributions of the lubricating gas film, were conducted based on the proposed analysis method of proportional assignation and resynthesis (PAR) along with the finite difference method. Then, the computational fluid dynamics (CFD) simulations based on the simple model were conducted, the results of which show the agreement with the theoretical analysis. Finally and more importantly, experiments were carried out well by using a self-made micro-flow field parameter measurement device (MFFPMD), which verifies the theoretical calculation and the CFD simulation results. The PAR method can be applied in other structures of restrictors, and the experimental study could facilitate the research of the stability of the lubricating gas film.

Insight of the size dependent bioavailability and health risk assessment of arsenic in resuspended fly ash from power plants

Arsenic can obviously be accumulated in fly ash, and can pose serious health exposure to the on-site workers during the process of reuse and treatment via resuspension due to the fine particle size. However, the knowledge about that is very limit for the lack of effective resuspension equipment. In this study, a self-made resuspension device was designed and applied to re-collect fly ash with different sizes (TSP, PM10 and PM2.5). A sequential extraction procedure and in vitro tests (simulated lung fluid and simulated gastrointestinal fluid) were employed to explore the fractions and bioavailability of arsenic in the resuspended fly ash. Arsenic contents in fly ash increased with the decrease of particle size ranging from 15.15 to 67.78 mg kg−1. Five fractions were identified, and their distribution patterns in the particles with different sizes were also characterized. The fraction distribution of arsenic in fly ash was affected by particle size, and the ingestion and inhalation bioavailability of arsenic mainly depended on non-specifically sorbed and specifically-sorbed fractions. The bioavailability factors (BFs) of arsenic increased with the decrease of particle size, exceeding or approaching the high-risk level (BFs > 0.55). Regarding non-carcinogenic health risk via ingestion and inhalation, the HQ (Hazard Quotient) values of arsenic were lower than the safe level (HQ < 1). Notably, ingestion was the dominant contributor to cancer risk with CR values above acceptable threshold and under tolerable risk level (except three plants). The classification of fly ash is conducive to evaluate the health risk of arsenic more accurately in resuspended fly ash.

Agricultural Waste-Derived Nanoporous Carbon As Electrode Material for High-Power Plant Microbial Fuel Cell

Developing environment-friendly and sustainable energy is urgent these days, as it can solve energy shortages and the pollution that come from fossil fuel. Therefore, Plant microbial fuel cells (PMFCs) start to get attention recently. PMFC is a novel technology that can convert chemical energy into electricity by using microbial in the rhizosphere of plants without producing harmful byproducts during the process. However, PMFCs suffer from some practical issues such as low power output and high costs of electrode materials. This gives rise to the progress of electrode material which can improve the power output and reduce the cost. To break through the limits of PMFCs, the agricultural waste-derived carbons were prepared and optimized as the anode material in our self-designed Canna-indica PMFCs in this study. Green carbon materials utilizing agricultural waste as precursors are not only environment-friendly but also a part of circular economy which helps to mitigate bio-waste and improve society sustainability. The biowaste-derived activated carbon materials were characterized by Brunauer-Emmett-Teller (BET) surface area analyzer, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The high surface area, porosity morphology, and good conductivity of the biowaste-derived activated carbon are the promising characteristics of high-performance anode materials of PMFCs. The maximum power density of our self-made PMFC device can reach 61 mW m−2. The average power density was maintained at 23 mW m−2 during the long-term measurement. All of the results in this study demonstrate the potential of using agricultural waste as electrode material for improving the electricity production of PMFCs.

On-site discrimination of biothiols in biological fluids by a novel fluorescent probe and a portable fluorescence detection device

On-site discrimination of the most abundant low-molecular-weight biothiols including Cys, CysGly, Hcy and GSH in biological fluid is extremely valuable for diagnosing and dissecting various diseases. However, this remains a great challenge due to the very similar structure and reactive activity of the four biothiols. Herein, a novel fluorescent probe that is able to concurrently discriminate Cys, CysGly, Hcy and GSH in distinct fluorescence channel based on a new strategy of regulating the nucleophilic ability of amine group in Cys, CysGly, Hcy and GSH under distinct pH condition. Moreover, a portable fluorescence detection device that can on-site accurately quantify the fluorescence intensities in biological fluid has been rationally fabricated. The fluorescent probe in combination with the self-made portable fluorescence detection device has been successfully applied for on-site quantitative discrimination of Cys, CysGly, Hcy and GSH in biological fluids such as plasma and urine, which provides a quick and inexpensive way to screen and diagnose the biothiols related diseases as well as dissect their physiological and pathological processes.

Heat Control Effect of Phase Change Microcapsules upon Cement Slurry Applied to Hydrate-Bearing Sediment

This study aims to develop a novel low-heat cement slurry using phase change microcapsule additives to reduce the decomposition of hydrate-bearing sediments during cementing. Microcapsules were prepared by coating mixed alkanes with polymethyl methacrylate, and lipophilic-modified graphite was incorporated to enhance the thermal conductivity of microcapsules. The effects of microcapsules upon the hydration heat, pore distribution, and compressive strength of the cement slurry/stone were studied through a variety of tests. The results showed that the phase-change temperature, thermal enthalpy, and encapsulation efficiency of the microcapsules were 8.99–16.74 °C, 153.58 Jg−1, and 47.2%, respectively. The introduction of lipophilic-modified graphite reduced the initial phase-change temperature of microcapsules by 0.49 °C, indicating an improvement in their temperature sensitivity. The maximum hydration heat of cement slurry decreased by 41.3% with 7% dosage of microcapsules; the proposed microcapsules outperformed comparable low-heat additives. Moreover, the presence of microcapsules could reduce the number of large pores in (and thereby improve the compressive strength of) cement stone. The innovation of this study is that it comprehensively and intuitively confirms the feasibility of the application of low-heat cement slurry with MPCM as the key in hydrate sediments rather than just focusing on the reduction of hydration heat; furthermore, a self-made cementing device was developed to simulate the cementing process of hydrate deposition. The results show that the thermal regulation of microcapsules inhibited the temperature increase rate of the cement slurry, significantly reducing the damage caused to the hydrate. These findings should improve the safety and quality of cement in offshore oil and gas well applications.

Determination of Pressure Drop Correlation for Air Flow through Packed Bed of Sinter Particles in Terms of Euler Number

In order to clearly understand the air flow resistance characteristics in vertical tanks for sinter waste heat recovery in the steel industry, experimental research on the air flow pressure drop (FPD) performance in a sinter bed layer (BL) was conducted. Based on a self-made experimental device, the measurement values of air FPD for different experimental conditions were determined firstly, and then the concept of Euler number (Eu) in heat exchangers was introduced into the study of air FPD in BL; the change rules of Eu under different particle diameters were analyzed. Finally, the air FPD correlation in sinter BL was obtained and described in the form of Eu, and the error analysis of obtained air FPD correlation was performed. The results show that, the air FPD increases as a second power relationship with the increase in air superficial velocity when the particle diameter is constant. The decrease amplitude of Eu gradually dwindles when increasing the Reynolds number (Re), and the decrease in the Eu shows a reciprocal relationship with the Re. As the bed geometry factor increases, the FPD coefficient, A, decreases as an exponential relationship, while the FPD coefficient, B, increases as a first power relationship. The obtained air FPD correlation in the form of Eu in the experiment is well compatible with the measurement values, and the mean deviation of obtained correlation is 4.67%, showing good originality.