South African Journal of Chemical Engineering最新文献

Study of sol-gel derived silver nanoparticle (AgNPs): X-ray computed crystal growth mechanism and thermal analysis 溶胶-凝胶衍生纳米银颗粒（AgNPs）的研究：x射线计算晶体生长机制和热分析

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-28 DOI: 10.1016/j.sajce.2026.100839

Md. Ashraful Alam , Raton Kumar Bishwas , Sabrina Mostofa , Shanawaz Ahmed , Fariha Zannat , Shirin Akter Jahan

Highly crystalline (57.96 %) and thermally stable silver nanoparticles (AgNPs) are incorporated through a unique, simple route involving precursor breakdown which is facilitated by the chelating agent trisodium citrate dihydrate, a key novelty of this research. XRD confirms the prominent 83 % crystalline phase with a cubic FCC unit cell [lattice parameter, a=b=c= 4.0902 Å; α=β=γ= 90 °]. The predominant crystal planes (111), (200), (220), (311), (222) where the lattice volume of 68.427 Å³ and crystal strain of 0.34 % were identified. The crystal structural symmetry observed in the (111) plane exhibits the preferred orientation revealed in the VESTA software. The average crystallite size is 31.56 nm and UV–visible spectroscopy shows the absorption peak of AgNPs going towards the short wavelength of 423.0 nm for the nano size which TEM reveals in average size in nanometers 26.67. Thermal analysis study (TGA and DSC) results showed that the materials are thermally stable up to 130 °C, a glass transition at 195 °C, the melting temperature of the cubic AgNPs is at 960 °C and a melting enthalpy of 29.56 kJ/g was calculated for their outstanding thermal stability and high crystallinity. The synthesized AgNPs calibrated activation energy calculated in TGA-DSC at 15.02 kJ/mole that signify the performance of NPs. Among the four media, ethanol media showed excellent stability, offering the highest zeta potential 103.50 to -58.25 mV. TEM conforms to the particle size 18.17 nm and the phase predominant revealed that (111), (200), (220) planes are uniformly in crystal growth at (111) [0.23552 nm] by SAED. EDS confirmed the purity of AgNPs at 93.0 %.

高结晶性（57.96%）和热稳定性的银纳米粒子（AgNPs）是通过一种独特的、简单的途径结合在一起的，包括前体分解，这是由螯合剂三钠柠檬酸二水合物促进的，这是本研究的一个关键新颖之处。XRD证实了立方FCC单元胞中83%的晶相[晶格参数，a=b=c= 4.0902 Å；α=β=γ= 90°]。主要晶面为（111）、（200）、（220）、（311）、（222），晶格体积为68.427 Å³，晶体应变为0.34%。在（111）平面上观察到的晶体结构对称呈现VESTA软件显示的优选取向。AgNPs的平均晶粒尺寸为31.56 nm，紫外可见光谱显示AgNPs的吸收峰向423.0 nm的短波长方向移动，而TEM显示AgNPs的平均晶粒尺寸为26.67 nm。热分析（TGA和DSC）结果表明，材料在130°C时热稳定，在195°C时发生玻璃化转变，立方AgNPs的熔融温度为960°C，熔融焓为29.56 kJ/g，具有良好的热稳定性和高结晶度。经TGA-DSC计算，合成的AgNPs标定活化能为15.02 kJ/mol，表明其性能良好。四种培养基中，乙醇培养基稳定性较好，zeta电位最高，为103.50 ~ -58.25 mV。透射电镜显示，（111）、（200）、（220）面在（111）[0.23552 nm]处均匀生长。能谱分析证实AgNPs的纯度为93.0%。

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引用次数: 0

Hot-season rise of reflux drum temperature in an atmospheric crude distillation unit: Field impacts on overhead corrosion, flare loading, and loss prevention 常压原油蒸馏装置热季回流鼓温度升高：对架空腐蚀、火炬负荷和防损的现场影响

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-20 DOI: 10.1016/j.sajce.2026.100836

Ahmed Qasim , Thamer Malik , Ghassan Addai , Shahd Ammar Hatem , Hameed Hussein Alwan

This field study quantifies how reflux drum temperature governs the overhead risk posture of an atmospheric crude distillation unit during hot-season operation, with explicit attention to corrosion, flare loading, and economic loss. During a single summer campaign at Al-Diwaniyah Refinery, the drum temperature was stepped from 50 to 70 °C and, at each set point, off gas, light naphtha, and boot water were sampled under steady operation. Hotter drum operation reduced partial condenser driving force and shifted the overhead phase split toward vapor, increasing header pressure from 0.57 to 0.82 barg and standard off gas flows from 320 to 360 and from 35 to 50 Nm³/h to the furnace and the flare, respectively. Concomitantly, off gas became heavier: C₁–C₃ fraction contracted from 56.71 to 41.41 mol %, whereas C₄ rose from 25.53 to 36.72 mol % and C₅₊ increased from 5.71 to 15.94 mol %. From a loss prevention perspective, this C4–C5+ enrichment, together with the higher flare rate, indicates increased diversion of gasoline-range material to the gas header and flare (avoidable hydrocarbon loss) and higher propensity for flare smoke if assist is not adjusted. Light naphtha specification drifted unfavorably (IBP from 32 to 40 °C; EP from 120 to 140 °C) with a modest increase in sulfur (from 300 to 312 ppm), tightening blending margins and risking reprocessing. Overhead corrosion risk increased, as boot water chemistry degraded (pH from 6.4 to 6.0; chloride from 10 to 14 ppm; dissolved iron from 0.15 to 0.44 ppm). These field resolved trends define a practical operating window that favors cooler drum targets (approximately 55–60 °C), recovery of condenser effectiveness, and temperature-compensated neutralizer control to stabilize aqueous chemistry while minimizing avoidable flaring. The results provide actionable guidance for balancing product quality, energy use, environmental performance, and corrosion risk in hot-climate refining.

本现场研究量化了回流鼓温度在热季运行期间如何控制常压原油蒸馏装置的顶空风险状态，并明确关注腐蚀、火炬负荷和经济损失。在Al-Diwaniyah炼油厂的一个夏季作业中，将鼓温从50°C调至70°C，在每个设定点，在稳定运行的情况下对废气、轻石脑油和引导水进行取样。更热的转鼓操作降低了部分冷凝器驱动力，并将顶部相分裂转向蒸汽，将集箱压力从0.57巴增加到0.82巴，将标准气体流量从320到360，从35到50 Nm3/h分别增加到炉子和火炬。与此同时，废气质量也有所提高，C1-C3组分从56.71 mol %下降到41.41 mol %， C4组分从25.53 mol %上升到36.72 mol %， C5+组分从5.71 mol %上升到15.94 mol %。从防止损失的角度来看，这种C4-C5 +富集，加上更高的火炬率，表明汽油范围内的物质向燃气集管和火炬（可避免的碳氢化合物损失）的转移增加，如果不调整辅助，火炬烟雾的倾向更高。轻石脑油规格变化不利（IBP从32°C到40°C； EP从120°C到140°C），硫适度增加（从300 ppm到312 ppm），增加了混合边际并增加了再加工的风险。随着地下水化学性质的降低（pH从6.4降至6.0，氯化物从10降至14 ppm，溶解铁从0.15降至0.44 ppm），架空腐蚀风险增加。这些现场解决的趋势定义了一个实际的操作窗口，有利于冷却器目标（约55-60°C），冷凝器效率的恢复和温度补偿中和剂控制，以稳定水化学，同时最大限度地减少可避免的燃烧。研究结果为热气候炼油中平衡产品质量、能源使用、环境性能和腐蚀风险提供了可操作的指导。

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引用次数: 0

Optimization of cassava starch acetate synthesis using response surface methodology and microstructural evaluation for enhanced hydrophobic properties 响应面法优化木薯淀粉醋酸酯合成及微结构评价增强疏水性

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-20 DOI: 10.1016/j.sajce.2026.100837

Nanik Hendrawati, Uka Nawanti Islamiyah, Bramantyo Airlangga, Sumarno Sumarno

Cassava starch was successfully acetylated via a simplified and scalable process to enhance its hydrophobicity, targeting applications in biodegradable food packaging. Process optimization was carried out using single-factor experiments in combination with Response Surface Methodology (RSM), focusing on the effects of the acetic anhydride-to-starch (AAD/S) ratio, NaOH concentration, and acetic acid-to-acetic anhydride (AA/AAD) ratio. The optimized process yielded a high degree of substitution (DS = 1.69) at an AAD/S ratio of 3.73, an AA/AAD ratio of 0.455, and a NaOH concentration of 0.193 mL/g starch. Structural and functional characterization through FTIR, SEM, XRD, and TGA confirmed successful acetylation and indicated substantial modifications in morphology, crystallinity, and thermal behavior. The cassava starch acetate (CSA) obtained in this study has been proved to be a suitable base material for TPS films. The prepared TPS films exhibited smooth and even surfaces. The hydrophobic character increased, with water contact angles >100°. The material had high flexibility, stretching at break from 10% to 500%, that depended on degree of substitution. These findings verify that the acetylation increased molecular mobility and compatibility in the starch matrix, thereby producing flexible and moisture-resistant films for biodegradable packaging items. Therefore, the optimized conditions of acetylation are an ecologic and high effective method for preparing cassava starch acetate with great potential in sustainable/biodegradable packaging material.

通过简化和可扩展的工艺成功地将木薯淀粉乙酰化，以提高其疏水性，目标是在生物可降解食品包装中的应用。采用单因素实验结合响应面法（RSM）对工艺进行优化，重点考察了乙酸酐与淀粉（AAD/S）比、NaOH浓度和乙酸与乙酸酐（AA/AAD）比的影响。优化后的AAD/S比为3.73，AA/AAD比为0.455，NaOH浓度为0.193 mL/g淀粉，取代度高（DS = 1.69）。通过FTIR、SEM、XRD和TGA进行的结构和功能表征证实了乙酰化的成功，并表明在形态、结晶度和热行为上有了实质性的改变。本研究得到的木薯淀粉醋酸酯（CSA）已被证明是一种合适的TPS薄膜基材。制备的TPS薄膜表面光滑均匀。疏水性增强，与水的接触角达到100°。该材料具有很高的柔韧性，断裂拉伸从10%到500%，这取决于替代程度。这些发现证实了乙酰化提高了淀粉基质中的分子迁移率和相容性，从而为可生物降解的包装物品生产了柔性和防潮的薄膜。因此，优化乙酰化条件是一种生态高效的制备木薯淀粉醋酸酯的方法，在可持续/可生物降解包装材料中具有很大的潜力。

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引用次数: 0

Innovative side rectifier integration in distillation columns for improved ethanol extractive dehydration: performance and energy optimization 创新侧整流器集成在精馏塔改善乙醇提取脱水：性能和能源优化

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-15 DOI: 10.1016/j.sajce.2026.01.005

Adel Beig Babaei , Sahar Zokaeiyan , Arash Dara , Kiarash Beig Babaei

This study presents a novel integration of a side rectifier in an extractive distillation process for ethanol dehydration, aiming to enhance both separation efficiency and energy performance. The new configuration, combining a distillation column with a side rectifier, is compared to the traditional two-column system, focusing on ethanol purity, energy consumption, and operational efficiency. The process uses two solvents: glycerol and Glycellin, a newly developed low-transition-temperature solvent. Simulation results, based on Aspen Plus with NRTL thermodynamic modeling, highlight the impact of key variables such as reflux ratio, solvent/feed ratio, and side-draw position on system performance. Sensitivity analysis revealed that the reflux ratio significantly influences energy efficiency, with optimal conditions yielding higher purity and reduced energy consumption in the new configuration. Notably, the system incorporating Glycellin showed superior performance, reducing energy consumption by 10–20% compared to the traditional two-column system. The energy consumption for the proposed configuration with Glycellin was 2931 kW, compared to 3450 kW for the conventional system. Additionally, the new design lowered the reboiler duty, offering a more sustainable and cost-effective solution for ethanol dehydration. The results underscore the potential of the side rectifier configuration, particularly with Glycellin, in advancing ethanol production processes by offering improved separation, reduced energy demands, and lower operational costs.

本研究提出了一种在乙醇脱水萃取精馏过程中集成侧整流器的新方法，旨在提高分离效率和能源性能。新的配置，结合了蒸馏塔和侧整流器，与传统的双塔系统进行了比较，重点是乙醇纯度，能耗和操作效率。该工艺使用两种溶剂：甘油和新开发的低转变温度溶剂甘油。基于Aspen Plus和NRTL热力学建模的仿真结果突出了回流比、溶剂/进料比和侧抽位置等关键变量对系统性能的影响。敏感性分析表明，回流比对能量效率有显著影响，在新配置中，最佳条件可获得更高的纯度和更低的能耗。值得注意的是，与传统的双柱系统相比，含有Glycellin的系统表现出优越的性能，降低了10-20%的能耗。与传统系统的3450千瓦相比，使用Glycellin的拟议配置的能耗为2931千瓦。此外，新设计降低了再沸器的负荷，为乙醇脱水提供了更具可持续性和成本效益的解决方案。结果强调了侧整流器配置的潜力，特别是Glycellin，通过提供改进的分离，减少能源需求和降低操作成本，在推进乙醇生产过程中。

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引用次数: 0

Metabolite profiling reveals the degradation pathways of Methylene Blue by Co-cultures of Pseudomonas aeruginosa and Daedalea dickinsii 代谢物分析揭示了铜绿假单胞菌和代达利菌共同培养亚甲基蓝的降解途径

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-14 DOI: 10.1016/j.sajce.2026.100835

Adi Setyo Purnomo , Badzlin Nabilah , Oppie Wahyu Wulandari , Hamdan Dwi Rizqi , Surya Rosa Putra , Alya Awinatul Rohmah , Ichiro Kamei

Methylene Blue (MB) is a thiazine-based synthetic dye widely used in industrial applications and is recognized for its high stability and potential toxicity to human health. Biological treatment using fungi has attracted attention as an environmentally friendly approach for dye removal; however, single-microorganism systems often exhibit limited biodecolorization efficiency. Previous studies have shown that the brown-rot fungus (BRF) Daedalea dickinsii is capable of MB biodecolorization and biodegradation, although its performance still requires improvement. In this study, the effect of Pseudomonas aeruginosa addition on MB biodecolorization by D. dickinsii was investigated in a Potato Dextrose Broth (PDB) medium under static conditions at 30 °C for 7 days. The results demonstrated that the addition of P. aeruginosa significantly enhanced MB biodecolorization, with the highest removal efficiency of 62.3% obtained at 10 mL bacterial inoculum, compared to only 16.5% achieved by the single fungal culture. Furthermore, several MB degradation metabolites were identified, including C₈H₁₂N₂ (m/z = 137), Azure B (m/z = 270), C₈H₁₁N (m/z = 120), C₂₀H₂₅N₃O₅S₂⁺ (m/z = 418), C₆H₈N₂O₃S (m/z = 188), and C₈H₁₄N₂O₄S (m/z = 217), enabling the proposal of a possible MB biodegradation pathway. The novelty of this study lies in the integration of a fungal–bacterial co-culture system with metabolite-based analysis to provide mechanistic insight into MB biodegradation beyond color removal. These findings highlight the potential of fungal–bacterial synergism as an environmentally friendly approach for dye-contaminated wastewater treatment.

亚甲基蓝（MB）是一种以噻嗪为基础的合成染料，因其高稳定性和对人体健康的潜在毒性而广泛应用于工业领域。利用真菌进行生物处理作为一种环境友好的染料去除方法已引起人们的关注；然而，单微生物系统往往表现出有限的生物脱色效率。已有研究表明褐腐菌（BRF） Daedalea dickinsii能够对MB进行生物脱色和生物降解，但其性能仍有待提高。本研究在马铃薯葡萄糖肉汤（PDB）培养基中，在30℃的静态条件下，研究了铜绿假单胞菌（Pseudomonas aeruginosa）对D. dickinsii对MB生物脱色的影响。结果表明，P. aeruginosa的添加显著增强了MB的生物脱色，在10 mL细菌接种量下，去除率最高，达到62.3%，而单一真菌培养的去除率仅为16.5%。此外，还确定了几种MB降解代谢物，包括C₈H₁₂N₂（m/z = 137）、Azure B （m/z = 270）、C₈H₁₁N （m/z = 120）、C₀H₂₅N₃O₅S 2⁺（m/z = 418）、C₆H₈N₂O₃S （m/z = 188）和C₈H₁₄N₂O₄S (m/z = 217)，从而提出了可能的MB生物降解途径。该研究的新颖之处在于将真菌-细菌共培养系统与基于代谢物的分析相结合，以提供除颜色去除外MB生物降解的机制见解。这些发现突出了真菌-细菌协同作用作为染料污染废水处理的环境友好方法的潜力。

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引用次数: 0

Experimental design and optimization of process parameters for nanocellulose extraction from pineapple leaves using central composite design 采用中心复合设计对菠萝叶纳米纤维素提取工艺参数进行了实验设计与优化

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-13 DOI: 10.1016/j.sajce.2026.01.007

Ebise Getacho Bacha , Abeba Negawo Tadesse , Martha Zemedu Assefa

The yield of nanocellulose is affected by different parameters, including acid concentration, reaction time, temperature, and the acid-to-fiber ratio. This work aims to extract nanocellulose from pineapple leaves and optimize the process parameters using a central composite design. The chemical composition of pineapple leaf waste was determined using standard methods, and the obtained results were 66.36±0.31 %, 19.84±0.13 %, 7.8 ± 0.14 %, and 13.23±0.4 % for cellulose, hemicellulose, lignin, and extractives, respectively. The extraction was done by alkali treatment, delignification, and hydrochloric acid hydrolysis. The time, temperature, acid concentration, and the ratio of acid to feedstock were studied by response surface methodology. The optimum yield was 76.2 % at 42.5 min, 60.5 ℃, 4 M, and 1 to 20 g/ml for reaction time, temperature, acid concentration, and feedstock to acid solution ratio, respectively. The functional group, particle size distribution, crystallinity, and thermal stability were determined using Fourier-Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), and Thermogravimetry Analysis (TGA), respectively. The average particle size was found to be 23.87 nm with a polydispersity index of 0.7. The FTIR results confirm the significant reduction or complete removal of lignin, hemicellulose, and other amorphous parts found in pineapple leaf. The Crystallinity Index (CI) of pineapple leaf is 40.6 %, cellulose is 60.7 %, and nanocellulose is 80.4 %, respectively. The thermogravimetry analysis shows that the thermal stability of the nanocellulose is better than that of the pineapple leaf.

酸浓度、反应时间、温度、酸纤维比等参数对纳米纤维素的收率有影响。本研究旨在从菠萝叶中提取纳米纤维素，并采用中心复合设计优化工艺参数。采用标准方法测定菠萝叶废弃物的化学成分，纤维素、半纤维素、木质素和提取物的含量分别为66.36±0.31%、19.84±0.13%、7.8±0.14%和13.23±0.4%。通过碱处理、脱木质素和盐酸水解进行提取。采用响应面法对时间、温度、酸浓度、酸料比等因素进行了研究。反应时间、温度、酸浓度、料液比分别为42.5 min、60.5℃、4 M、1 ~ 20 g/ml，产率为76.2%。采用傅里叶变换红外光谱（FTIR）、动态光散射（DLS）、x射线衍射（XRD）和热重分析（TGA）分别测定了其官能团、粒度分布、结晶度和热稳定性。平均粒径为23.87 nm，多分散性指数为0.7。FTIR结果证实了菠萝叶中木质素、半纤维素和其他无定形部分的显著减少或完全去除。菠萝叶结晶度指数（CI）为40.6%，纤维素为60.7%，纳米纤维素为80.4%。热重分析表明，纳米纤维素的热稳定性优于菠萝叶。

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引用次数: 0

Zeolite pellet fabrication for biogas purification: Characterization and CO2 adsorption performance 用于沼气净化的沸石颗粒制备：表征和CO2吸附性能

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-08 DOI: 10.1016/j.sajce.2026.01.004

Bambang Trisakti , Rivaldi Sidabutar , Irvan Irvan , Farida Hanum , Mhd. Rivaldi Syahputra , Hani Suhastifa Rambe , Noersukma Dwi Gusty , Muhammad Syaifan , Michael Michael , Thiodorus Marvin Tjandra , Sheylin Wimora Lumban Tobing , Peer Mohamed Abdul

The escalating urgency for renewable energy solutions and sustainable waste management strategies has intensified research into biogas purification technologies, particularly addressing the critical need for efficient CO₂ removal to enhance methane concentration. This study optimized zeolite pellet fabrication and evaluated their CO₂ adsorption performance for biogas purification. Zeolite samples were systematically processed through pelletization and calcination procedures, with experimental parameters encompassing particle sizes (50-140 mesh), calcination temperatures (200-400^○C), and durations (2-4 hours). The pelletization process achieved optimal yield performance of 75.97±0.70% under conditions of 50 mesh particle size, 200^○C calcination temperature, and 2-hour duration, corresponding to maximum pellet density of 1.94±0.03 g/cm³. Water adsorption capacity reached its peak at 3.35±0.11% utilizing 140 mesh zeolite calcined at 400^○C for 4 hours. Most significantly, CO₂ removal efficiency achieved 92.5±0.75% under optimal conditions of 140 mesh particle size, 400^○C calcination temperature, and 4-hour calcination duration. Comprehensive characterization revealed crystallite size reduction from 53.31 nm to 37.41 nm following activation, while scanning electron microscopy confirmed heterogeneous pore structure with grain-like surface morphology. Energy dispersive X-ray spectroscopy analysis indicated substantial oxygen content increase from 31.31% to 58.30% post-CO₂ adsorption, accompanied by carbon content decrease from 30.59% to 5.54%. N₂ adsorption quantified surface area, pore volume, and pore diameter as 283.01 m²/g, 0.292 cc/g, and 2.569 Å, respectively. These findings establish zeolite pellets as highly effective CO₂ adsorbents with substantial potential for industrial-scale biogas purification implementation.

对可再生能源解决方案和可持续废物管理战略的日益迫切需要加强了对沼气净化技术的研究，特别是解决了有效去除二氧化碳以提高甲烷浓度的迫切需要。本研究优化了沸石颗粒的制备工艺，并对其吸附CO2净化沼气的性能进行了评价。沸石样品通过制球和煅烧程序进行系统处理，实验参数包括粒度（50-140目），煅烧温度（200-400ºC）和持续时间（2-4小时）。在粒径为50目、焙烧温度为200℃、焙烧时间为2 h的条件下，制球工艺的最佳产率为75.97±0.70%，最大制球密度为1.94±0.03 g/cm3。140目沸石在400℃下煅烧4小时，吸附量达到3.35±0.11%。最显著的是，在粒径为140目、煅烧温度为400℃、煅烧时间为4 h的最佳条件下，CO2去除率达到92.5±0.75%。综合表征表明，活化后的晶体尺寸从53.31 nm减小到37.41 nm，扫描电镜证实了非均质孔隙结构，表面形貌呈颗粒状。能量色散x射线能谱分析表明，co2吸附后氧含量从31.31%上升到58.30%，碳含量从30.59%下降到5.54%。N2吸附测定的比表面积、孔体积和孔径分别为283.01 m2/g、0.292 cc/g和2.569 Å。这些研究结果表明，沸石颗粒是一种高效的二氧化碳吸附剂，在工业规模的沼气净化实施中具有巨大的潜力。

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引用次数: 0

Polynomial regression analysis on electromagnetohydrodynamic hybrid nanofluid flow over a rotating disk: Applications in next-generation thermal systems 旋转圆盘上电磁流体动力混合纳米流体流动的多项式回归分析：在下一代热系统中的应用

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-01 DOI: 10.1016/j.sajce.2025.12.010

Gunisetty Ramasekhar , P.D. Selvi , Hijaz Ahmad , Waleed Mohammed Abdelfattah

Thermal systems need effective cooling and heating processes, therefore thermal transfer innovation is critical in modern times, playing an important role in the manufacturing, aerospace, and electronic equipment sectors, in addition to automobiles and other modes of transportation. This study investigates the heat transfer properties of an electromagnetohydrodynamic mixed nanofluid across a porous spinning disk. The primary goal is to develop and validate an efficient engine oil/Cu-CuO hybrid framework that integrates traditional numerical approaches with polynomial regression analysis to accurately predict the flow and thermal features of complex nanofluid systems. The conversion of PDEs into ODEs is achieved by utilizing similarity variables. Thereafter, for graphical purposes, the study employed the bvp4c numerical method. The resultant structure is solved with the bvp4c scheme, and polynomial regression analysis is created to train the solution data for accurate estimation across different parameter (Q, Ec, Rd) settings. The suggested polynomial regression analysis has regression coefficients are 0.98, 0.87, 0.97, indicating high predicted accuracy and effectiveness. The influence of different parameters participating in the mathematical modeling is shown in various graphs and tables. In the result section the investigation noticed the velocity outlines increased, and on the other hand, there was a decreasing tendency in the energy outline for enlarging electric field parameter values. The heat generation and eckert number parameter values are increased, resulting in an improved energy profile. The results of this simulation have the potential to contribute significantly to more advanced study and research in the fields of bioengineering and bio-nanofluid dynamics.

热系统需要有效的冷却和加热过程，因此热传递创新在现代至关重要，除了汽车和其他运输方式外，在制造业，航空航天和电子设备领域也发挥着重要作用。本文研究了电磁流体混合纳米流体在多孔旋转盘上的传热特性。主要目标是开发和验证一种高效的发动机油/Cu-CuO混合框架，该框架将传统的数值方法与多项式回归分析相结合，以准确预测复杂纳米流体系统的流动和热特征。利用相似性变量实现了偏微分方程到偏微分方程的转换。此后，为了图解的目的，本研究采用了bvp4c数值方法。用bvp4c方案求解得到的结构，并创建多项式回归分析来训练解数据，以便在不同参数（Q, Ec, Rd）设置下进行准确估计。建议的多项式回归分析的回归系数分别为0.98、0.87、0.97，表明预测精度和有效性较高。参与数学建模的不同参数的影响以各种图形和表格的形式显示。结果段速度轮廓增大，电场参数值增大时能量轮廓减小。热量产生和埃克特数参数值增加，从而改善了能量剖面。该模拟的结果有可能为生物工程和生物纳米流体动力学领域的更高级研究做出重大贡献。

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引用次数: 0

Manipulating calcination temperature on crystal structure and optical properties tuning of CuO nanostructures 控制煅烧温度对CuO纳米结构晶体结构和光学性质的影响

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-01 DOI: 10.1016/j.sajce.2026.01.002

Arrak Klinbumrung , Reungruthai Sirirak , Samor Boonphan , Atit Wannawek , Yanee Keereeta

The research investigated the influence of calcination temperature on the properties of CuO nanostructures synthesized through a chemical precipitation method. Calcination at different temperatures (200, 400, and 600°C) significantly affected the crystal structure, morphology, and optical characteristics of the CuO nanostructures. Various characterization techniques were employed, including thermogravimetric analysis (TG), X–ray diffractometers (XRD), Fourier transform infrared spectrometers (FT–IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). TG analysis revealed thermal behavior and phase transitions, while XRD results confirmed a monoclinic structure of CuO at 200°C with the calculation of the texture coefficient, crystallite size, lattice constants, strain, and other physical properties. SEM images showed a transition from nanorods to plate structures with increasing calcination temperature. TEM images demonstrated the highly crystalline characteristics of CuO samples. The BET analysis depicted surface area reduction, and CuO nanostructures exhibited energy band gaps ranging from 2.23 to 2.78 eV. Calculating optical terms as a function of photon energy also examined optical behaviors. Photoluminescence spectra revealed oxygen and copper vacancy defects, which sublevels affected energy bandgap change. The 400CuO sample exhibited the strongest PL emission signal, indicating the highest crystallinity and the lowest degree of defects. The findings underscored the significant impact of calcination temperature on the morphology and optical properties of CuO nanostructures, providing insights into their structural characteristics and emerging defects. The study supports opto-electronic applications and contributes to the global goal of pollution control and clean water.

研究了煅烧温度对化学沉淀法合成的氧化铜纳米结构性能的影响。不同温度（200℃、400℃和600℃）的煅烧对CuO纳米结构的晶体结构、形貌和光学特性有显著影响。采用了各种表征技术，包括热重分析（TG）、x射线衍射（XRD）、傅里叶变换红外光谱仪（FT-IR）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）。TG分析揭示了CuO的热行为和相变，XRD结果通过计算织构系数、晶粒尺寸、晶格常数、应变等物理性质，证实了CuO在200℃时为单斜晶结构。SEM图像显示，随着煅烧温度的升高，纳米棒结构向板状结构转变。TEM图像显示CuO样品具有高度结晶性。BET分析显示CuO纳米结构的表面积减小，其能带隙在2.23 ~ 2.78 eV之间。计算光学项作为光子能量的函数也检查了光学行为。光致发光光谱显示出氧和铜空位缺陷，这些空位缺陷亚能级影响能隙的变化。400CuO样品的PL发射信号最强，表明结晶度最高，缺陷程度最低。这些发现强调了煅烧温度对CuO纳米结构的形貌和光学性质的重要影响，为其结构特征和新出现的缺陷提供了见解。该研究支持光电应用，有助于实现污染控制和清洁水的全球目标。

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引用次数: 0

Development and analysis of PVC glass slides for urine microstructure studies 尿液微结构研究用PVC玻片的研制与分析

Q1 Social Sciences

South African Journal of Chemical Engineering

Pub Date : 2026-01-01 DOI: 10.1016/j.sajce.2025.12.018

Mohammed Alwan Farhan, Luma Salman Abd, Zaid H. Mahmoud

The long-term maintenance of urine precipitation microstructures stays a main restriction in medical laboratory education and routine urinalysis, as traditional glass sides typically permit sample stability for only 1–3 h. In this work, a novel polyvinyl chloride (PVC)-coated glass slide system was advanced to capable long-term stabilization and microscopic conception of urine precipitation components. PVC films were functionalized with p-chlorobenzamidine (L) as photostabilizer to inhibit photodegradation induced via elongate exposure to UV light and microscope. The films photostability were systematically investigated employing FTIR, viscosity measurements, UV–Vis and FESEM analysis. At 365 nm, after 125 h of UV irradiation, the carbonyl index (Ico) for PVC+L films were increased to 0.13, compared with 0.18 of PVC, suggesting an essential reduction in oxidative degradation. The constant rate of photodegradation (kd) was reduced from 0.0021 s^-1 for pristine PVC to 0.0014 s^-1 for PVC+L sample, while the quantum yield of main-chain scission (Φcs) was decreased from 373×10¹³ to 884×10¹². Moreover, the PVC+L films preserved a higher viscosity-average molecular weight (Mv 260,000) contracted with the pristine PVC film after protracted irradiation, suggesting efficient inhibition of PVC chain scission. Functionally, at 295 nm, the PVC+L films appeared high (90 % transmittance) and cement clear microscopic conception of urine precipitation components. Cystine crystals, uric acid, calcium oxalate and triple phosphate, as well as amorphous materials, epithelial cells, kept optically distinguishable and morphologically intact for up to one year. These finds illustrate, for the first time, that photostabilized films can use as transparent, durable and chemically stable substrates for urine precipitation preservation, giving a low-cost and practical platform for routine microscopy, medical laboratory training and educational characteristics.

尿沉淀微观结构的长期维持一直是医学实验室教育和常规尿液分析的主要限制，因为传统的玻璃侧通常只允许样品稳定1-3小时。在这项工作中，一种新型聚氯乙烯（PVC）涂层玻璃载玻片系统被推进到能够长期稳定和尿液沉淀成分的微观概念。以对氯苯脒(L)为光稳定剂，对聚氯乙烯（PVC）薄膜进行了长时间紫外曝光和显微镜曝光，抑制了聚氯乙烯薄膜的光降解。采用红外光谱（FTIR）、粘度测试、紫外可见光谱（UV-Vis）和FESEM分析等方法对膜的光稳定性进行了系统的研究。在365 nm处，经过125 h的紫外照射，PVC+L薄膜的羰基指数（Ico）增加到0.13，而PVC的为0.18，表明氧化降解明显减少。恒定光降解速率（kd）从原始PVC的0.0021 s-1降低到PVC+L样品的0.0014 s-1，而主链断裂量子产率（Φcs）从373×1013降低到884×1012。此外，PVC+L膜在长时间辐照后保持了较高的粘度-平均分子量（Mv 26万）与原始PVC膜相比，表明有效抑制了PVC链断裂。在功能上，在295 nm处，PVC+L膜表现出较高的透光率（90%），并且水泥清晰的尿液沉淀成分的微观概念。胱氨酸晶体，尿酸，草酸钙和三磷酸，以及无定形材料，上皮细胞，保持光学可区分和形态完整长达一年。这些发现首次表明，光稳定膜可以作为透明、耐用和化学稳定的基底来保存尿液沉淀，为常规显微镜、医学实验室培训和教育提供了一个低成本和实用的平台。

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引用次数: 0