An environmentally friendly method was used to synthesize selenium microparticles (SeMPs) by applying Psidium guajava leaf extracts as a reducing agent. In addition, in this study, SeMPs were combined with graphene oxide (Se/GO) via an ex situ method. The results of the phytochemical analysis of the Psidium guajava leaves revealed the presence of flavonoids, polyphenols, triterpenoids, and ascorbic acid. In addition, the results indicated that the SeMPs were spherical and uniformly distributed on graphene oxide (GO) sheets with an average diameter of about 475 nm. Moreover, the antioxidant activity was investigated with two free radical scavenging methods 2-diphenyl-1-picrylhydrazyl and 2,20-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid) with yields of 63.34 and 90.9%, respectively. Additionally, the antibacterial performance of the resulting material, which showed a great inhibition performance against the Gram-positive strains of Staphylococcus aureus, Bacillus subtilis, and Limosilactobacillus fermentum, Gram-negative ones of Escherichia coli and Salmonella enterica, and the fungi strain of Candida albicanas, was investigated. Moreover, the anticancer activity was evaluated towards three cell lines, including liver cancer cells, lung cancer cells, and human embryonic kidney cells. The results revealed that the anticancer performance of the material achieved 90% with a Se/GO concentration of 256 mg mLÿ1. The anti-diabetic ability of the material toward the enzyme a-glucosides also showed high results with an inhibiting percentage of 100%, reaffirming the promising potential of the Se/GO materials in medical applications.

The valorization of shrimp wastes to develop advanced materials brings economic and environmental advantages. This paper presents a facile and eco-friendly synthesis of shrimp chitosan-derived carbon (CCS) and CCS/NiO@Ni(OH)2(CSSN) aerogel nanocomposite for supercapacitor application, in which NiO and Ni(OH)2 nanoparticles were tightly attached to the porous surface of CCS aerogel. As a result, CCSN- 300 aerogel carbonized at 300 0C has high porosity and electrical conductivity and demonstrates its potential as an active electrode material for supercapacitors. The CCSN-300 aerogel material electrode exhibits a high capacitance of 316 mAh.g-1 at 1.0 A.g-1. Furthermore, the CCS//CCSN-300 device had a capacitance of 209 F.g-1 at 1.0 A.g-1 and over 84% remaining after the 10,000 cycles. Moreover, it has a high energy density of 65 Wh.kg-1 at a power density of 1500 W.kg-1. The results demonstrate that chitosan-derived carbon composites hold great promise in high application efficiency for energy storage.

Spent coffee grounds (SCGs), the main by-product in the coffee industry, were proposed as a starting material to fabricate both ultraviolet (UV) shielding material and nanocomposite based on polyvinyl alcohol (PVA). The extract using low SCGs concentration (0.25 wt%) contains a significant amount of UV-absorbing substances. The UV shielding film from 5 wt% PVA solution and SCGs extract (1 g SCGs/200 ml water) could shield most of the radiation in UV-B and UV-C regions and maintain 63% transmittance at 550 nm. The SCGs after washing were ball milled and the ultrasonic liquid processor was applied to synthesize SCGs nanoparticle. The effects of ultrasonic amplitude and hexadecyltrimethylammonium bromide (CTAB) on the particle’s hydrodynamic diameter were investigated. The particle’s size of 148 nm was obtained with 50% ultrasonic amplitude. Fourier-transformed infrared spectroscopy (FTIR) results confirmed the presence of hydroxyl groups (–OH) on the SCGs-based nanoparticle’s surface. The tensile strength of PVA-SCGs nanocomposite was significantly improved. However, the presence of CTAB in the nano solution could not show a better tensile result. The organic compounds contained in the SCGs extract and even in the nano SCGs solution could enhance thermal oxidation stability for both UV shielding films and nanocomposites.

 We present the in situ synthesis of silver nanoparticles (AgNPs) through ionotropic gelation utilizing the biodegradable saccharides lactose (Lac) and alginate (Alg). The lactose reduced silver ions to form AgNPs. The crystallite structure of the nanocomposite AgNPs@Lac/Alg, with a mean size of 4–6 nm, was confirmed by analytical techniques. The nanocomposite exhibited high catalytic performance in degrading the pollutants methyl orange and rhodamine B. The antibacterial activity of the nanocomposite is pH-dependent, related to the alterations in surface properties of the nanocomposite at different pH values. At pH 6, the nanocomposite demonstrated the highest antibacterial activity. These findings suggest that this nanocomposite has the potential to be tailored for specific applications in environmental and medicinal treatments, making it a highly promising material.

In the study, rGO was used as an electron mediator to establish WO3@rGO@AgI (WrGA) ternary heterojunction to apply for degradation of Amoxil upon excitation of visible light. Various characterization methods and technologies, such as XRD, SEM, TEM, UV–Vis and PL, and trapping experiments of active species were applied to determine charge separation as well as degradation mechanism. The achieved data showed that both WO3 and

AgI in the synthesized WrGA had suitable band gap energies to absorb provided visible light for e􀀀 jumping from valence band (VB) to conduction band (CB) leaving h+ at the VB. Then, the rGO effectively acted as e􀀀 mediator to promote Z scheme mechanism for its migration from the WO3 CB to the AgI VB to prevent charge recombination in WO3 as well as AgI. The charge separation via Z scheme mechanism also maintained significant charges

(e􀀀 at AgI CB and h+ at WO3 VB) with high redox potentials for photocatalysis. Therefore, the Amoxil degradation efficiency of the WrGA was 24% higher than that of the WA (without rGO). Finally, the recycling tests showed novel stability and recycling potential of the synthesized WrGA opening new era for its application in practical system for degradation of organic pollutants.

A facial strategy for the synthesis of hierarchical binary core-branch carbon microspheres (CMS)@α-Fe2O3 is presented. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), and Brunauer–Emmett–Teller (BET) were used to characterize the structural and morphological properties of the products. XRD diffraction analysis of CMS@α-Fe2O3 reveals the highly crystalline nature of α-Fe2O3 in the hierarchical binary core-branch CMS@α-Fe2O3 nanocomposite. Morphological analyses show that the α-Fe2O3 shell layer grew onto the surface of CMS to form nanoscale heterointerfaces in the core-branch structure, demonstrating the effectiveness of the synthesized route. More importantly, CMS@α-Fe2O3 demonstrated superior electrochemical behavior to CMS. The enhanced CMS@α-Fe2O3 electrochemical performance can be attributed to its large specific surface area, which allows for the rapid transfer of electrons into the electrode during the redox process. 

 In this work, a novel Ag-incorporated 3D flower-like porous Fe3O4 magnetic microstructure (Fe3O4/Ag-FM) was effectively prepared via a quasi-reverse emulsion soft template approach and reductive deposition of Ag nanoparticles. The synthesized Fe3O4/Ag-FM material was applied for the electrochemical sensing and catalytic reduction of 4-nitrophenol (4-NP). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were used to determine the electrochemical sensing ability of the synthesized material. Results showed that the fabricated Fe3O4/Ag-FM-based electrode detected a low concentration of 4-NP (0.093 μM) and a linear response in the range of 1.0–15 μM. Furthermore, the Fe3O4/Ag-FM material also exhibited excellent reduction ability towards 4-NP with the assistance of NaBH4. This is because a synergistic effect formed between Ag nanoparticles and flower-like Fe3O4 magnetic microstructure enhanced the catalytic activity towards electrochemical detection and reduction of 4-NP. Overall, the current strategy could help design and synthesize future catalysts that can work as sensors and catalysts.

An increasing interest in nanocomposites prepared from agricultural/industrial byproducts has been paid for environmental remediation, especially in water treatment. This study reports the facile preparation of a low-cost magnetic biocomposite of magnetic Fe3O4 nanoparticles (NPs) incorporated with biopolymers extracted from durian husk, called bp-Fe3O4 and examined in the removal of methylene blue (MB) dye. Here, Fe2O3 NPs were first recovered from red mud waste and then converted to magnetic nanostructured Fe3O4 using a one-pot process via carbon combustion. The bp-Fe3O4 inherited the characteristics of each constituent component, while showing slightly higher saturation magnetization than the bare Fe3O4 NPs (19.84 and 18.66 emu/g, respectively), allowing for easy separation from the aqueous solution using a suitable magnet. The MB adsorption on bp-Fe3O4 reached an equilibrium state within 60 min reaction and achieved .90% of removal (at 50 mg/L MB) at an optimal pH range of 6–8. The effective adsorption of MB dye was attributed to both the hydroxylated-Fe3O4 NPs and biopolymers. The material showed excellent reusability tested up to the seventh MB adsorption cycle (decreased by ,2% of adsorption efficiency). Overall, the outstanding magnetic properties and low-cost bp-Fe3O4 rendered them easily manipulated and separated, and reusable for water/wastewater treatment of MB dye.

Low-cost adsorbents derived from agricultural by-products incorporated magnetic nanoparticles (NPs) are promising for wastewater treatment. They are always preferred due to their great performance and easy separation. This study reports cobalt superparamagnetic (CoFe2O4) nanoparticles (NPs) incorporated with triethanolamine (TEA) based surfactants from cashew nut shell liquid, namely TEA-CoFe2O4, for the removal of chromium (VI) ions from aqueous solutions. To have detailed characteristics of the morphology and structural properties, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry (VSM) were employed. The fabricated TEA-CoFe2O4 particles exhibit soft and superparamagnetic properties, which make the nanoparticles easily recycled by using a magnet. Chromate adsorption on the TEA-CoFe2O4 nanomaterials reached an optimal efficiency of 84.3% at pH = 3 with the initial adsorbent dose of 10 g/L and chromium (VI) concentration of 40 mg/L. The TEA-CoFe2O4 nanoparticles can maintain the effective adsorption of chromium (VI) ion (by 29% of efficiency loss) and retain the magnetic separation using a magnet up to three cycles of the regeneration, which promise a high potential of this low-cost adsorbent for long-term treatment of heavy metal ions from polluted waters.

This study presented two approaches to synthesize bio-surfactants using cashew nut shell liquid (CNSL), an abundant natural resource. The different preparation conditions were investigated and optimized to obtain the surfactant products of maximum weight and desired characteristics. The anionic sodium anacardate surfactant was recommended to be synthesized by carrying out the saponification reaction between CNSL and NaOH in a weight ratio of 1 : 2 at 85°C for 1 h. Meanwhile, the amphoteric triethanolamine anacardate surfactant was prepared using the neutralization reaction between CNSL and triethanolamine in a weight ratio of 1 : 1 at 70oC in 3 h. All the surfactant products were examined by Fourier transform infrared spectroscopy to confirm their chemical structure. In addition, characteristic properties of the surfactants including solubility, emulsifying ability and stability, foaming ability and stability, surface tension, and skin irritation were also explored. Both the sodium anacardate and triethanolamine anacardate demonstrated

comparable foaming capacity and surface tension with commercial surfactants. In an attempt, sodium anacardate was utilized to make industrial soap and shoe polish of good sensory quality.

In recent years, essential oils extracted from different plant species have become increasingly popular in the production of pharmaceuticals, cosmetics, and foods. The essential oil from orange (Citrus sinensis) is important in large-scale applications due to its antibacterial, antioxidant activities, and pleasant aroma. In this study, factors affecting the production of orange essential oil on a distillation device with an operating capacity of 50 L/batch, including the ratio of material to water, temperature, and time distillation, have been surveyed. Through the survey, it was found that the raw materials were pureed, the materials: water ratio was 1:3 g/g, the water heating temperature was 130 °C, and the distillation time was 140 min. The yield of the essential oil was 1.8 mL/g with compounds limonene accounting for 98%, α-Pinene (0.655–0.734%), and β-Pinene (1.114 and 1.163%) by the GC-MS method. The review also found that the hydrodistillation equipment was designed to be suitable for the semi-industrial scales of orange essential oil due to its stable yield and volatile compounds contained in the essential oil.

The gray abalone mushroom is a rich source of amino acids and carbohydrate compounds, with some biological activities and antioxidants. Nowadays, the variety of food additives on the market such as sodium glutamate (E621), sodium guanylate (E627), or sodium insonate (E631), could probably cause negative effects for people’s health. This study used gray abalone mushrooms to create naturally derived seasoning products without using flavor enhancers and synthetic compounds. The gray abalone mushroom was pretreated and dried at 60°C until attaining the moisture content of <5%, while the biological activity and antioxidant values were kept optimal. The mixture ingredients, including 5% abalone mushroom powder, 2% baby cornstarch, and other seasoning ingredients, were uniformly ground. The based-gray abalone mushroom powder that was packed in PE with the moisture content below 3% displayed stability in terms of quality throughout 90 days. Gray abalone mushroom seasoning powder contributed to creating safe, natural products as well as improving consumers’ health.

The aim of this study is to investigate the impact of time and temperature of the heat pump drying process of soursop slices at different levels on moisture content and total polyphenol content (TPC). Twelve types of classical kinetic models have been used in this work to describe the suitability of experimental data with models. The conformity is assessed based on statistical values (e.g., coefficient of determination (R2), Chi–square value (X2), etc.). The loss of moisture in the material is described in accordance with Fick’s diffusion law. Value of moisture rate (MR), and effective moisture diffusivities (Deff) have been identified. Experimental results show that MR value depends on the time and drying temperature, Deff increases when increasing the drying temperature from 20–50 °C with values of 1.24 × 10−9, 1.85 × 10−8, 7.69 × 10−8, and 5.54 × 10−7 m/s2. The Singh et al. model is the best option to describe the moisture of the sliced soursop drying process at 30 °C (R2 = 0.97815). The largest TPC decomposition occurs at a temperature of 50 °C. The ability to decompose TPC is proportional to the drying temperature. The TPC decomposition dynamic model follows a first–order reaction when drying at 20 °C with a determinant coefficient R2 = 0.9693.

Using mango purée from overripe mangoes to produce powders helped to solve agricultural product stagnation. The research investigates the effect of thickening additives, convection drying, and heat pump drying on bioactive compounds such as total phenolic content (TPC), total flavonoid content (TFC), color, and solubility of the final product. The obtained results showed that the mixture (gum arabic and maltodextrin in the ratio 50:50 w/w) at a concentration of 15% gave a good quality powder texture when dried by hot air convection at 55°C with TPC (21.24 ± 1.58 mg GAE/g dry weight [DW]) and TFC (0.34 ± 0.02 mg QE/g DW), respectively. In addition, the product has a high solubility of 64.35%, with the highest pass-through point of 17.11.

Polymer-based hydrogels are hydrophilic polymer networks with crosslinks widely applied for drug delivery applications because of their ability to hold large amounts of water and biological fluids and control drug release based on their unique physicochemical properties and biocompatibility. Current trends in the development of hydrogel drug delivery systems involve the release of drugs in response to specific triggers such as pH, temperature, or enzymes for targeted drug delivery and to reduce the potential for systemic toxicity. In addition, developing injectable hydrogel formulations that are easily used and sustain drug release during this extended time is a growing interest. Another emerging trend in hydrogel drug delivery is the synthesis of nano hydrogels and other functional substances for improving targeted drug loading and release efficacy. Following these development trends, advanced hydrogels possessing mechanically improved properties, controlled release rates, and biocompatibility is developing as a focus of the field. More complex drug delivery systems such as multi-drug delivery and combination therapies will be developed based on these advancements. In addition, polymer-based hydrogels are gaining increasing attention in personalized medicine because of their ability to be tailored to a specific patient, for example, drug release rates, drug combinations, target-specific drug delivery, improvement of disease treatment effectiveness, and healthcare cost reduction. Overall, hydrogel application is advancing rapidly, towards more efficient and effective drug delivery systems in the future.

Herein we report a method for the synthesis of 2-arylthiochromenones via a sulfuration of 2’-chlorochalcones. The chalcones could be prepared in advance or in situ obtained from 2’-chloroacetophenones and aromatic aldehydes. The conditions were tolerant of functionalities including chloro, fluoro, methylthio, phenoxy, and trifluoromethyl groups. 2-Heteroaryl thiochromenones could also be obtained in moderate yields. Our method appears to be a simple, general tactic to afford 2-aryl thiochromenones from commercial starting materials

In the study, rGO was used as an electron mediator to establish WO3@rGO@AgI (WrGA) ternary heterojunction to apply for degradation of Amoxil upon excitation of visible light. Various characterization methods and technologies, such as XRD, SEM, TEM, UV–Vis and PL, and trapping experiments of active species were applied to determine charge separation as well as degradation mechanism. The achieved data showed that both WO3 and AgI in the synthesized WrGA had suitable band gap energies to absorb provided visible light for e􀀀 jumping from valence band (VB) to conduction band (CB) leaving h+ at the VB. Then, the rGO effectively acted as e􀀀 mediator to promote Z scheme mechanism for its migration from the WO3 CB to the AgI VB to prevent charge recombination in WO3 as well as AgI. The charge separation via Z scheme mechanism also maintained significant charges (e􀀀 at AgI CB and h+ at WO3 VB) with high redox potentials for photocatalysis. Therefore, the Amoxil degradation efficiency of the WrGA was 24% higher than that of the WA (without rGO). Finally, the recycling tests showed novel stability and recycling potential of the synthesized WrGA opening new era for its application in practical system for degradation of organic pollutants.

In this research, ZnO/GO nanocomposites were successfully synthesized by a simple hydrothermal method using graphene oxide (GO) and zinc acetate dihydrate (Zn(CH3COO)2.2H2O) as the reactants. The effect of the hydrothermal reaction time on the structure and optical property of the ZnO/GO was systematically investigated. The structure, morphology and chemical composition of the samples were measured by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and Raman and Fourier transform infrared (FTIR) spectroscopy, while the optical properties were measured using photoluminescence spectroscopy. The synthesized products consisted of large quantities of one-dimensional (1D) ZnO nanorods (NRs), which were dispersed uniformly on the GO surface. The XRD and Raman results reveal that the ZnO NRs in the fabricated samples had a hexagonal wurtzite structure with high crystalline quality. The FESEM and TEM images reveal that ZnO NRs with an average diameter in the range of ~85–270 nm and length in the range of ~0.3–6 µm were covered with GO sheets. Additionally, it was found that the crystallographic orientation of ZnO NRs was dependent not only on the hydrothermal reaction time but also on the presence of GO in the nanocomposites. However, the addition of GO did not affect the stoichiometric ratio and the crystal structure of ZnO NRs. The room-temperature PL results indicated that, compared to those of pure ZnO, the luminescence of the GO/ZnO nanocomposites was suppressed and shifted towards a higher wavelength (red shift), which was attributed to the incorporation of ZnO NRs within the GO matrix and the formation of a C-O-Zn chemical bond in the nanocomposites. The hydrothermal technique is considered one of the best routes due to its low cost, high growth rates, low-temperature synthesis, controllable crystallographic orientation, particle size, as well as morphology.

In this research, 2D-MoS2/rGO nanocomposites were successfully synthesized by a facile hydrothermal method using graphene oxide (GO), sodium molybdate (Na2MoO4) and thiourea (CH4N2S) as the reactants. The effect of hydrothermal temperature (180–240 °C) on structure and optical properties of the MoS2/rGO have been systematically investigated. The study of chemical composition, structural and morphological properties was performed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS) and Raman spectroscopy, while the optical properties were measured using photoluminescence spectroscopy. The FESEM and HRTEM results revealed that the ultrathin MoS2 nanosheets with thickness in the range of ~6–13 nm (~6–8 layers) and average lateral size of ~130–330 nm were uniformly dispersed on the GO surface. Both the XRD and Raman analyses confirm that the MoS2 sheets in all prepared samples have a hexagonal phase structure (2H-MoS2). By increasing hydrothermal temperature, the characteristic diffraction peak (002) of 2H-MoS2 phase (at 2θ ≈ 14.2–14.5o) becomes sharper and its intensity gradually increases, thereby showing a very strong preferential orientation and better crystal quality. The estimated optical band gap for MoS2/rGO is achieved in the range of ~1.56–2.38 eV and it seems to be controlled by adjusting the synthesis temperature. Our work underscores the principle that controlling hydrothermal reaction temperature may constitute a generic strategy for modifying microstructure and engineering the optical bandgap of these semiconductor 2D nanocrystals, which opens the possibility of its use in electronic applications

Polymer-based hydrogels are hydrophilic polymer networks with crosslinks widely applied for drug delivery applications because of their ability to hold large amounts of water and biological fluids and control drug release based on their unique physicochemical properties and biocompatibility. Current  trends in the development of hydrogel drug delivery systems involve the release of drugs in response to specific triggers such as pH, temperature, or enzymes for targeted drug delivery and to reduce the potential for systemic toxicity. In addition, developing injectable hydrogel formulations that are easily used and sustain drug release during this extended time is a growing interest. Another emerging trend in hydrogel drug delivery is the synthesis of nano hydrogels and other functional substances for improving targeted drug loading and release efficacy. Following these development trends, advanced hydrogels possessing mechanically improved properties, controlled release rates, and biocompatibility is developing as a focus of the field. More complex drug delivery systems such as multi-drug delivery and combination therapies will be developed based on these advancements. In addition, polymer-based hydrogels are gaining increasing attention in personalized medicine because of their ability to be tailored to a specific patient, for example, drug release rates, drug combinations, target-specific drug delivery, improvement of disease treatment effectiveness, and healthcare cost reduction. Overall, hydrogel application is advancing rapidly, towards more efficient and effective drug delivery systems in the future.

A new depsidone, parmoferone A (1), together with three known compounds, parmosidone K (2), albifolione (3), and 4-chloroorcinol (4) were isolated from the lichen Parmotrema cristiferum (Taylor) Hale (Parmeliaceae). The structures of isolated compounds were identified from its spectroscopic data and by comparison with the literature. Compounds 1-4 were evaluated for alpha-glucosidase inhibition. Compound 1 was determined to be a potent non-competitive inhibitor against alpha-glucosidase with an IC50 value of 18.1 μM.

In this work, a novel Ag-incorporated 3D flower-like porous Fe3O4 magnetic microstructure (Fe3O4/Ag-FM) was effectively prepared via a quasi-reverse emulsion soft template approach and reductive deposition of Ag nanoparticles. The synthesized Fe3O4/Ag-FM material was applied for the electrochemical sensing and catalytic reduction of 4-nitrophenol (4-NP). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were used to determine the electrochemical sensing ability of the synthesized material. Results showed that the fabricated Fe3O4/Ag-FM-based electrode detected a low concentration of 4-NP (0.093 μM) and a linear response in the range of 1.0–15 μM. Furthermore, the Fe3O4/Ag-FM material also exhibited excellent reduction ability towards 4-NP with the assistance of NaBH4. This is because a synergistic effect formed between Ag nanoparticles and flower-like Fe3O4 magnetic microstructure enhanced the catalytic activity towards electrochemical detection and reduction of 4-NP. Overall, the current strategy could help design and synthesize future catalysts that can work as sensors and catalysts.

BACKGROUND: The surfactant-assisted extraction of essential oils from Melaleuca alternifolia foliage, also known as tea tree oil (TTO), was systematically studied with the design of experiments (DoE) aiming to improve the extraction of TTO. Specifically, the optimal parameters of hydrodistillation process were obtained with the response surface methodology (RSM) based on a central composite design (CCD). RESULTS: The concept of enhanced TTO extraction with the renewable nonionic Triton CG-110  urfactant was proven. An opti- mal extraction yield of TTO was predicted by the RSM model at 6.71 wt% under the following conditions: (i) 597 mg L−1 Triton CG-110 as liquid extractant, (ii) a ratio of liquid  tractant/desiccated leaf at 25.4 mL g−1, and (iii) 140 min for the extraction time. The presence of 650  g L−1 Triton CG-110 in the extractant could increase the extraction rate of TTO by 17.5%, compared to  hat without surfactant. The forecast of the DPPH antioxidant activity of TTO by RSM was in good accordance  ith the mea- sured values. Various microemulsion formulations of TTO with Triton CG-110 were  eveloped and reported.

Bài báo tập trung đưa ra quy trình tính toán thiết kế thiết bị truyền nhiệt phổ biến (dạng ống xoắn và vỏ bọc) và mô phỏng quá trình tính toán thiết kế trên phần mềm MATLAB. Nhiệt độ dòng nóng (chất tải nhiệt nóng), nhiệt độ dòng lạnh (chất tải nhiệt lạnh), loại chất tải nhiệt, lưu lượng dòng và loại thiết bị truyền nhiệt là những yếu tố quan trọng ảnh hưởng rất lớn đến kết quả tính toán. Mô phỏng tính toán thiết kế thiết bị truyền nhiệt giúp tính toán hàng trăm phép tính khi có sự thay đổi của một thông số bất kỳ

Trong vài năm qua, phương pháp phân tích thành phần chính Kernel - Kernel Principal Component Analysis (KPCA) được ứng dụng trong kiểm soát quá trình trong sản xuất để phát hiện lỗi sản phẩm. Đây là phương pháp có độ tin cậy cao và đang dần được triển khai rộng rãi tìm lỗi cấu trúc sản phẩm. Trong bài báo này, chúng tôi kết hợp đồng thời KPCA và đo khoảng cách Mahalanobis (MD) để xác định các cấu trúc bất thường trên các mẫu đĩa silicon. Độ đồng đều của bề dày đĩa sẽ được phân tích và tìm những vị trí lỗi dựa trên khác biệt độ dày của nó. Thông qua ứng dụng Python, đã phát hiện điểm bất thường  (outlier). Khoảng cách Mahalanobis chỉ ra sự biến đổi không gian mới bằng cách cho chạy KPCA qua các hàm khác nhau như Linear, Polynomial, Radial Basic Function (RBF), Sigmoid… Dữ liệu được tìm thấy, so sánh các MD khi tìm nghiệm qua các hàm này sẽ được kết quả tối ưu.

This study gave a new method to synthesize 2-arylquinoxalines from o-phenylenediamines and aryl methyl ketones. The reaction occurred via molecular iodinepromoted direct C(sp3)-H bond functionalization of aryl methyl ketones under transition metal-free conditions. The utilities of this study are the (1) direct Csp3-H bond functionalization, (2) inexpensive and abundant iodine source, (3) transition metal-catalyst free, and (4) different synthesis of 2-arylquinoxalines from common materials.

Bê tông tro bay hàm lượng cao (HVFC) được nghiên cứu trong những năm gần đây để giải quyết các vấn đề về ô nhiễm tro thải nhiệt điện và các vấn đề môi trường do ngành công nghiệp sản xuất xi măng gây ra. Nghiên cứu này tiến hành tạo mẫu cấp phối bê tông với hàm lượng tro bay 70% thay thế chất kết dính thủy lực xi măng. Sự bổ sung phụ gia vôi và Silica Fume (SF) đã có những cải thiện đáng kể về đặc tính kỹ thuật của sản phẩm so với các mẫu HVFC đã công bố trước đó. Các đặc tính kỹ thuật như cường độ nén, cường độ uốn, cường độ chẻ bửa, độ hút nước được đánh giá theo các tiêu chuẩn Việt Nam (TCVN) đang được áp dụng đối với bê tông thương mại trên thị trường (nhóm bê tông nặng có ρv = 2200 - 2500 kg/m3). Kết quả nghiên cứu của mẫu bê tông tro bay hàm lượng cao cũng được so sánh với sản phẩm đối chứng theo độ tuổi bảo dưỡng 3 ngày, 7 ngày, và 28 ngày.

Nghiên cứu này thực hiện khảo sát các thông số ảnh hưởng tới quá trình trích cao ethanol từ lá trứng cá, các thông số độc lập được tối ưu bằng phương pháp bề mặt đáp ứng gồm có: nhiệt độ, tỷ lệ dung môi và nguyên liệu, thời gian chiết. Kết quả cho thấy hiệu suất chiết cao nhất là 9,77% ở điều kiện nhiệt độ 80 °C, tỷ lệ dung môi/nguyên liệu là 19 mL/g, thời gian 36 phút. Nghiên cứu cũng thực hiện định lượng tổng polyphenol, flavonoid cũng như khả năng khử gốc tự do DPPH trong cao ethanol và các cao phân đoạn. Ở phân đoạn ethyl acetate, tổng hàm lượng flavonoid, polyphenol và khả năng kháng gốc tự do cao hơn các phân đoạn khác, có giá trị lần lượt là: 93,3 (mg/g); 319,0 (mg/g) và IC50 là 6,25 µg/mL.

The simultaneous spectrophotometric determination of copper(II) and cobalt(II) is based  on the  ormation of their complexes with diethyldithiocarbamate (DDTC) in the presence of polysorbate 20 (Tween 20) as a micellar media using partial least squares modeling. The absorption spectra were  ecorded from 290 to 500 nm. The calibration graph was linear in the range of 0.5-4.0 µg.mL-1  for Cu(II) (R2 = 0.9979) and 0.5-3.0 µg.mL-1 for Co(II) (R2 = 0.9976); The root mean squared error of prediction (RMSEP) was 0.160 and correlation coefficient (R2) for copper and cobalt by PLS method were 0.988; 0.954 respectively. The results indicate the probability of the method in the simultaneous determination of copper(II) and cobalt(II).