Centrifugal Process Research Articles

An artificial neural network (ANN) modelling approach for evaluating turbidity properties of paper recycling wastewater

A pre-treatment process was evaluated in this work for wastewater from paper recycling using microwave technology followed by rapid precipitation of contaminants through centrifugation. Artificial neural networks (ANNs) were used to analyze and optimize the turbidity values. Thirty experimental runs were utilized including microwave (MW) power, duration, centrifuge time, and centrifuge speed as input variables, generated by the Central Composite Full Design (CCFD) approach. The experimental turbidity ranged from 8.1 to 19.7 NTU, while predicted values ranged from 8.4 to 19.7 NTU by ANN. The ANN model showed a robust prediction performance with low mean squared error values during training and testing. Moreover, high R2 values showed a remarkable agreement between the experimental observations and ANN predictions. The results obtained from the input values (A:150.00, B:60.00, C:15.00, D:30.00) of sample 2, which gave the lowest turbidity value, showed the most removal of pollution. The results obtained from the input values (A:250.00, B:60.00, C:7.00, D:20.00) of sample 30, which gave the highest turbidity value, showed the least removal of pollution. The results showed that increasing RPM and time of the centrifugation process significantly affected the removal of pollution in wastewater.

CENTRIFUGATION OF NANOMETRIC SILICON CARBIDE POWDER FOR GRANULOMETRIC CLASSIFICATION

In this study, researchers focused on improving the quality of SiC particles, considering their different sizes and shapes. To ensure a high-quality end product, the particles were separated into distinct granulometric fractions, with a focus on the nanometer range. The efficiency of this classification process played a crucial role in determining the quality of the final product. SiC holds significant market value, reaching US$3.3 billion in 2022. Brazil stands as one of the main producers of raw SiC, but it still relies on imports for finer granulometries needed in various industrial applications. The main objective of the research was to develop a highly efficient technique for the nanometric fractionation of silicon carbide powders. After conducting experiments, the researchers successfully obtained SiC with a diameter below 2 μm. To achieve this, multiple chemical dispersants were explored for the centrifugation process, aiming to disaggregate the solution and improve the overall yield, with sodium carbonate emerging as the most promising among the tested dispersants. By presenting these findings, the researchers contribute to advancing SiC production and its applications, especially in industries that require nanometer-sized SiC particles. The study not only enhances the quality of the final product but also reduces the country's dependence on imported carbide for industrial purposes.

Recyclable Palladium-Catalyzed Carbonylative Coupling of Aryl Halides and Organoaluminum Compounds with tert-Butyl Iso­cyanide as CO Equivalent Leading to 1,2-Diketones

AbstractAn efficient heterogeneous palladium-catalyzed carbonylative coupling of aryl halides and organoaluminum compounds has been developed using tert-butyl isocyanide as CO equivalent. The carbonylation reaction proceeds smoothly in toluene with KOtBu as a base at 100 °C by using 10 mol% of an SBA-15-anchored bidentate phosphine palladium(0) complex [2P-SBA-15-Pd(0)] as the catalyst and provides a general and practical approach for the assembly of 1,2-diketones in good to excellent yields. This heterogenized palladium catalyst can be readily separated and recovered via a simple centrifugation process and reused for more than seven cycles with almost consistent catalytic efficiency.

β-Lactoglobulin-based aerogels: Facile preparation and sustainable removal of organic contaminants from water

Economically and efficiently removing organic pollutants from water is still a challenge in wastewater treatment. Utilizing environmentally friendly and readily available protein-based natural polymers to develop aerogels with effective removal performance and sustainable regeneration capability is a promising strategy for adsorbent design. Here, a robust and cost-effective method using inexpensive β-lactoglobulin (BLG) as raw material was proposed to fabricate BLG-based aerogels. Firstly, photocurable BLG-based polymers were synthesized by grafting glycidyl methacrylate. Then, a cross-linking reaction, including photo-crosslinking and salting-out treatment, was applied to prepared BLG-based hydrogels. Finally, the BLG-based aerogels with high porosity and ultralight weight were obtained after freeze-drying. The outcomes revealed that the biocompatible BLG-based aerogels exhibited effective removal performance for a variety of organic pollutants under perfectly quiescent conditions, and could be regenerated and reused many times via a simple and rapid process of acid washing and centrifugation. Overall, this work not only demonstrates that BLG-based aerogels are promising adsorbents for water purification but also provides a potential way for the sustainable utilization of BLG.

Physicochemical Properties of Cellulose Nanocrystals Extracted from Postconsumer Polyester/Cotton-Blended Fabrics and Their Effects on PVA Composite Films.

The utilisation of cotton waste as precursors in the synthesis of nanocrystalline cellulose has gained significant attention. This approach suggests a sustainable solution to address the growing concern of textile waste accumulation while simultaneously producing a valuable material. The main aim of this study is to examine the properties of cellulose nanocrystals (CNCs) obtained from postconsumer polyester-cotton waste and assess the effect of different fabric structures on the extraction and these properties. To acquire nanocellulose, a thorough decolourisation pretreatment process was utilised, which involved the treatment of polyester-cotton waste with sodium dithionite and hydrogen peroxide. Consequently, the postconsumer material was then treated with an acid hydrolysis method employing a 64% (v/v) sulphuric acid solution at 50 °C for 75 min, resulting in the formation of CNCs with average yield percentages ranging from 38.1% to 69.9%. Separation of the acid from the CNC was facilitated by a centrifugation process followed by dialysis against deionised water. Uniform dispersion was then achieved using ultrasonication. A variety of analytical techniques were employed to investigate the morphological, chemical, thermal, and physical properties of the isolated CNCs. Among these techniques, attenuated total reflection-Fourier-transform infrared spectroscopy (ATR-FTIR), energy-filtered transmission electron microscopy (EF-TEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) were utilised to analyse the CNCs. The findings indicated that the separated CNCs exhibited a rod-shaped morphology, measuring between 78 and 358 nm in length and 5 and 16 nm in diameter, and also exhibited high crystallinity (75-89%) and good thermal stability. The extracted CNCs were mixed with polyvinyl alcohol (PVA) and glycerol to assess their reinforcing effect on plastic films. The prepared composite film exhibited improved mechanical properties and thermal stability. Incorporating CNCs led to a 31.9% increase in the tensile strength and a 42.33% rise in the modulus of elasticity. The results from this research proved that CNCs can be extracted from postconsumer mixed fabrics as a potential solution to effectively address the mounting concerns surrounding waste management in the textile industry and also provide avenues for enhancing the qualities of eco-friendly composite films.

Comprehensive thermodynamic and economic analysis of an LNG cold energy recovery system using organic Rankine cycle and freezing-centrifugal desalination for power and water cogeneration

In this study, the LNG cold energy recovery combined with a freezing-centrifugal desalination system is proposed. The thermodynamic and economic analysis is also carried out of the proposed system. To verify the results of sea ice centrifugation process, experimental analysis of sea ice centrifugal desalination is presented based on different types of sea ice: slurry and solid, which are prepared by the method of suspension crystallization method and progressive freezing method, respectively. The experimental outcomes demonstrated that higher rotation speeds and longer centrifugal times enhanced the desalination rate but resulted in decreased freshwater yield in both slurry and solid ice. For the slurry sea ice, achieving a rotation speed of 5000 rpm and a centrifugal time exceeding 3.0 min resulted in melted water with a salinity level below 0.05%, satisfying the standards of drinking water. Moreover, the unit product cost, payback period, and unit cost of CO2 emission reduction for the proposed system are 0.49 $/t, 3.25 years and 18.92 kg/$, respectively. While the unit product cost, payback period, and unit cost of CO2 emission reduction for the conventional system are about 0.84 $/t, 4.80 years, and 15.66 kg/$, respectively. Hence, the proposed system shows higher economic and environmental performance.

Parametric investigation of thermal additive centrifugal abrasive flow machining process for enhancing productivity

Thermal additive centrifugal abrasive flow machining hybrid of abrasive flow machining caters to low material removal issues which enhances the acceptability of the process. The present investigation investigates the different centrifugal force-generating electrode geometry performances in the thermal additive centrifugal abrasive flow machining process. The L27 orthogonal array is used for optimizing the process parameters (electrode type, current supply, and the duty cycle) and their effect on material removal and percentage improvement in surface finish (%Δ Ra) are analyzed. Based on the percentage contribution obtained from Taguchi analysis, electrode type is the prominent parameter for material removal (88.27%) and %Δ Ra (78.54%) followed by current (7.43% for material removal and 13.92% for %Δ Ra) and duty cycle (3.95% for material removal and 6.42% for %Δ Ra). The spline electrode with a curved blade is found optimum with 10 A current and 0.76 duty cycle. The average experimental value based on the design of the experiment and the predicted value for material removal is 10.373 and 10.881 mg, respectively. The average experimental value and the predicted value for percentage improvement in the surface are 42.24% and 43.71%, respectively. The percentage error between the predicted and experimental values for material removal and %Δ Ra is 4.66% and 3.15%, respectively.

Autologous platelet-rich plasma as a potential new approach in the endometrial response during in vitro fertilization cycle: A pilot study

Objectives: Infertility is a global health concern, affecting ~13% of couples. Despite assisted reproductive technology (ART) attempts, implantation failure occurs due to inadequate growth of the endometrium. Increasing endometrial thickness (ET) can be increased to improve the rate of pregnancy; implantation necessitates a minimum thickness of 7 mm. Platelet-rich plasma (PRP) is a recommended treatment approach for endometrium and ovarian infertility. This approach minimizes the potential of immunogenic reactions and disease transmission because PRP comes from an autologous source. The purpose of this study was to evaluate the efficacy of PRP intrauterine infusions during the in vitro fertilization (IVF) cycle in patients with thin endometrium. Material and Methods: Ten patients with primary infertility (age: 28–40 years) were chosen for intrauterine PRP infusion at the RiSSA IVF Center, Delhi. This study was carried out between June 2020 and January 2022 over a span of 18-month period. Intrauterine infusion of PRP was an additional procedure to hormone replacement therapy (HRT) treatment cycle. PRP was prepared by centrifugation process from autologous blood. On the 10th day of HRT cycle, 2 mL of PRP was infused into the uterine cavity. In each cycle, PRP infusion was administered 1–3 times if there was no increase in ET 72 hours later. Out of ten patients, four patients received a single infusion, two patients received two infusions, and four patients received three infusions. The embryos were transferred when the ET reached ≥7 mm. ET was measured at the uterine longitudinal axis at the thickest point. To determine ET, three measurements were made, and the average of those measures was noted. The primary outcome measure was ET, determined by transvaginal sonography, and the secondary outcome measure was clinical pregnancy following embryo transfer. Results: The mean increase in ET was 1.8–2.25 mm. In 8 (80%) patients, there was an increase of 7–7.5 mm in ET. ET thickness did not improve in 2 patients (20%), and it was <6 mm after three infusions of PRP. Further, of the eight patients who had embryo transfer and became pregnant, six patients had a clinical pregnancy with visible cardiac activity at 6 weeks, while two patients had a missed abortion in the first trimester. Six patients had a successful delivery. Conclusion: This study revealed that PRP could support endometrial growth, improving pregnancy outcomes in patients who have thin endometrium. PRP is a novel treatment option for endometrial thinning and poor response to IVF. The findings of the current pilot study support the need for large-scale, randomized, controlled trials in this field.

Effects of blood-processing protocols on cell-free DNA fragmentomics in plasma: Comparisons of one- and two-step centrifugations

BackgroundCell-free DNA (cfDNA) fragmentomic characteristics are promising analytes with abundant physiological signals for non-invasive disease diagnosis and monitoring. Previous studies on plasma cfDNA fragmentomics commonly employed a two-step centrifugation process for removing cell debris, involving a low-speed centrifugation followed by a high-speed centrifugation. However, the effects of centrifugation conditions on the analysis of cfDNA fragmentome remain uncertain. MethodsWe collected blood samples from 10 healthy individuals and divided each sample into two aliquots for plasma preparation with one- and two-step centrifugation processes. We performed whole genome sequencing (WGS) of the plasma cfDNA in the two groups and comprehensively compared the cfDNA fragmentomic features. Additionally, we reanalyzed the fragmentomic features of cfDNA from 16 healthy individuals and 16 COVID-19 patients, processed through one- and two-step centrifugation in our previous study, to investigate the impact of centrifugation on disease signals. ResultsOur results showed that there were no significant differences observed in the characteristics of nuclear cfDNA, including size, motif diversity score (MDS) of end motifs, and genome distribution, between plasma samples treated with one- and two-step centrifugation. The cfDNA size shortening in COVID-19 patients was observed in plasma samples with one- and two-step centrifugation methods. However, we observed a significantly higher relative abundance and longer size of cell-free mitochondrial DNA (mtDNA) in the one-step samples compared to the two-step samples. This difference in mtDNA caused by the one- and two-step centrifugation methods surpasses the pathological difference between COVID-19 patients and healthy individuals. ConclusionsOur findings indicate that one-step low-speed centrifugation is a simple and potentially suitable method for analyzing nuclear cfDNA fragmentation characteristics. These results offer valuable guidance for cfDNA research in various clinical scenarios.

Mathematical Model of Vibration-Centrifugal Processing of Parts Using Loose Abrasive

The article presents some new theoretical and experimental solution of a scientific and applied problem of technological support for vibratory centrifugal processing of complex-profiled parts in a bulk abrasive environment. This solution aims to increase productivity while ensuring the desired quality of the processed surfaces. The authors have developed a mathematical model that describes the action of abrasive particles on the surface of the parts, taking into account the parameters of the granular abrasive medium based on Voigt’s law. This allows the description of dynamic processes in the processing environment for a wide range of material types. The natural frequencies of oscillations of the processed medium layer have been determined, which depend on the amplitude of its vibrations for different densities of soft and hard materials of the processed medium and the medium with linear-elastic properties. The methodology includes the use of test equipment to conduct experimental research on the process, which involves determining changes in specific metal removal rates and surface roughness using the frequency converter Altivar 71 with the PowerSuite v.2.5.0 software.

Resolved Simulation for the Prediction of Classification in Decanter Centrifuges

Solid–liquid separation plays a decisive role in various industrial applications particularly in the treatment and purification of suspensions. Solid bowl centrifuges, such as the decanter centrifuge, are commonly employed in these processes as they operate continuously and enable high throughputs with short processing times. However, predicting the separation performance of solid bowl centrifuges proves to be challenging due to dynamic phenomena within the apparatus, such as particle settling, sediment build-up, consolidation and sediment transport. In practice, design considerations and the dimensioning of the apparatus rely on analytical models and the manufacturer’s expertise. Computational Fluid Dynamics (CFD) offers a way to deepen our understanding of these devices by allowing detailed examination of flow phenomena and their influence on the separation processes. This study utilizes the open-source software OpenFOAM to simulate multiphase flow in a laboratory-scale decanter centrifuge, solving individual transport equations for each particle size class. The basis is the characterization of the material through targeted laboratory experiments to derive material functions that describe the hindered settling and the sediment consolidation. Furthermore, experiments on a laboratory decanter served as validation. The results demonstrate the solver’s capability to replicate clarification and classification within the apparatus. Furthermore, the solver supports the definition of geometries tailored to specific separation tasks. This research demonstrates the potential of CFD for a better understanding of complex centrifuge processes and for optimizing their design to improve performance.

A Comparative Study of B Cell Blast Isolation Methods from Bone Marrow Aspirates of Pediatric Leukemia Patients.

Density gradient centrifugation is a conventional technique widely utilized to isolate bone marrow mononuclear cells (BM-MNC) from bone marrow (BM) aspirates obtained from pediatric B-cell acute lymphoblastic leukemia (B-ALL) patients. Nevertheless, this technique achieves incomplete recovery of mononuclear cells and is relatively time-consuming and expensive. Given that B-ALL is the most common childhood malignancy, alternative methods for processing B-ALL samples may be more cost-effective. In this pilot study, we use several readouts, including immune phenotype, cell viability, and leukemia-initiating capacity in immune-deficient mice, to directly compare the density gradient centrifugation and buffy coat processing methods. Our findings indicate that buffy coat isolation yields comparable BM-MNC product in terms of both immune and leukemia cell content and could provide a viable, lower cost alternative for biobanks processing pediatric leukemia samples.

Effect of Three Layered Centrifugal Casting on Tribological and Microstructural Characteristics of Mg Based Functionally Graded Material Alloy

Objectives: The aim of this study is to examine the tribological properties and microstructural of functionally graded material (FGM) composites based on magnesium (Mg) base material. Magnesium alloys are commonly employed in the development of biomaterials for implant applications owing to their favorable corrosion properties. The research objective is to produce Zn/Mo reinforced functionally graded magnesium composites using the centrifugal casting. Methods: A centrifugal process was employed to fabricate a functionally graded material (FGM) consisting of three layers with a cylindrical shape. The base material used for this FGM was Magnesium, which was alloyed with 10% of Zn and 10% of Mo. The developed FGMs have been analyzed for their mechanical and microstructural characteristics. The microstructure of the samples were analyzed via the Optical Microscope (OM). It is identified that denser particle molybdenum (Mo) have influenced the mechanical and microstructural characteristics of the FGM composites. Findings: Results recommend that, all the three layered testing’s, Mg (80%) +Zn (10%) + Mo (10%) composite exhibited favorable mechanical and microstructural properties. It is identified that denser particle of Mo which is influenced the microstructural characteristics. The alteration in micro hardness in the direction of centrifugal force is observed, and it is observed that the minimum wear loss for sliding wear samples A, B & C of Mg based FGM alloy were found to be 0.0018 g, 0.028 g and 0.031 g respectively, while the maximum wear loss for sliding wear samples A, B & C of FGM alloy were found to be 0.0021 g, 0.41 g and 0.31 g respectively. Novelty: In this study, a novel three-layered centrifugal casting technique was devised. Owing to its rapid degradability, the anticipated duration of the implants within the human body would be significantly shorter in comparison to alternative biomaterials such as Titanium and Stainless steel. Furthermore, the findings from the conducted tests strongly advocate for the utilization of this technique in biomedical implantations. Keywords: Functionally graded material (FGM), Centrifugal casting, Tribological characteristics, microstructural behavior, and bio­implants

Results of experimental research of the process of forming reinforced concrete products by the centrifugation method

The method of conducting an experimental study of the process of forming reinforced concrete products is disclosed. The key factors influencing the quality indicators of the product being formed are defined and considered. On the basis of the conducted active, factorial experiment, a regression equation was compiled, graphical dependences of the influence of these factors on the process were obtained, rational parameters of the centrifugation process were determined, which are decisive in the manufacture of reinforced concrete products by the centrifugation method. Based on the results of laboratory experiment data processing, recommendations were developed for optimizing the operating parameters of industrial equipment for forming reinforced concrete products by the centrifugation method. Problem. When forming reinforced concrete products by the centrifugation method, some problems may arise, uneven distribution of the mixture in the mold body and of reinforcement, formation of voids or cracks, insufficient compaction of the mixture. If the parameters of the centrifugation process are not properly controlled, the quality of the products may vary, which may lead to deviations from specifications and standards. Problems with the deformation of the molds after forming the product can lead to damage to the product or difficulties in its removal. Goal. Based on the results of the conducted factorial experiment, recommendations are developed regarding the rational parameters of the process of forming columns of reinforced concrete supports for power transmission lines by the centrifugation method in the conditions of an operating technological line. Methodology. The basis of the research is the method of conducting a planned factorial experiment with further statistical processing of the obtained results using a computer program. Results. Based on the processing of the obtained results of the conducted factorial experiment, the following recommendations are suggested regarding the rational parameters of the process of forming reinforced concrete pillars for power lines by the centrifugation method in the conditions of an operating technological line.

Advancement in Tympanic Membrane Repair: Exploring the Potential of Platelet Rich Fibrin.

To assess the effectiveness of the autologous plasma-rich fibrin plug technique for repairing small tympanic membrane perforations. Platelet rich fibrin (PRF) is also called second generation platelet rich plasma due to its high amount of growth factors which could be used in tympanic perforation closure. Being autologous, it is readily available with no immunogenic reactions. PRF membrane has a strong elastin fibrin structure containing growth factors and hence can be considered as an ideal sealing material or an adjuvant to the graft in repairing tympanic membrane perforations. Ours is a prospective study. A total of 52 patients with dry small tympanic membrane perforation were included in the study. In this technique, 10ml of blood is withdrawn from the patient, processed in a centrifuge machine, and platelet-rich fibrin (PRF) is separated from the mixture for use in the repair of small tympanic membrane defects. Out of the 52 patients, 42 experienced successful repair (full closure) of the tympanic membrane. The mean time of closure of the perforation was around 2weeks. However, five of them encountered failure. Although the size of the perforation decreased compared to the preoperative size. Additionally, two patients developed granulations on the tympanic membrane. No major side effects were noted. Autologous PRF is a product derived from whole blood through the process of centrifugation. It is safe and effective in promoting the natural process of wound healing by incorporating a high concentration of platelet-derived growth factors as well as fibrin into the graft mixture. This facilitates the rapid healing of tympanic membrane perforation.

Quantitative Assessment of Receptors of Advanced Glycation End Products Expression in Tissue Samples from Patients with oral Submucous Fibrosis, Leukoplakia, and Oral Squamous Cell Carcinoma.

Oxidative stress markers have been firmly established as elevated in oral squamous cell carcinomas (OSCCs). These markers play a crucial role in the pathogenic mechanism underlying the accumulation of advanced glycation end products (AGEs) and their respective receptors. The primary objective of this study is to discern and compare the levels of receptors of AGEs (RAGEs) within tissue samples from patients diagnosed with oral submucous fibrosis (OSMF) at varying stages, oral leukoplakia at various stages, and OSCC. A cross-sectional investigation was conducted, enrolling a total of 49 patients, distributed across three distinct groups. Tissue samples were meticulously collected from the aforementioned patient groups. Subsequently, these samples underwent a process of homogenization and centrifugation. The supernatant obtained was subjected to enzyme-linked immunosorbent assay analysis to precisely determine the concentration of RAGE. The concentration of RAGEs was found to be significantly higher at various stages of OSMF when compared to the reference group of OSCC (P < 0.05). This difference was statistically significant, indicating a substantial association. In contrast, the levels of RAGE in patients with hyperkeratosis accompanied by epithelial dysplasia at various stages were observed to be lower than those in the OSCC group, with the difference in concentration being statistically insignificant (P > 0.05). This comprehensive study has provided compelling evidence demonstrating the heightened levels of RAGE in OSMF when compared to OSCC. These findings collectively suggest the potential utility of anti-RAGE interventions as a promising avenue for novel therapeutic strategies in potentially malignant disorders such as OSMF.

Study on the Effect of Residual Polymer Superplasticizer on the Properties of Graphene-Cement Composites.

Graphene, renowned for its exceptional mechanical, thermal, and electrical properties, is being explored as a cement nanofiller in the construction field. However, the limited water dispersibility of graphene requires the use of polymer superplasticizers, such as polycarboxylate ether (PCE). Previous studies have investigated the mechanisms by which PCE facilitates the dispersion of graphene within cement nanocomposites. However, such studies have made minimal progress, indicating a lack of understanding of the effect of residual PCE (rPCE) remaining in aqueous solution without binding to graphene. In this study, the effects of rPCE on the dispersion of graphene and the mechanical properties of graphene-cement composites (GCCs) were systematically analyzed. For this purpose, the content of rPCE was accurately measured through the centrifugation process and thermal analysis of graphene dispersion with PCE, and the result was 78.0 wt.% compared to graphene. The optical microscopy, particle size analysis, and contact angle measurement of the graphene dispersions with and without rPCE confirmed that rPCE is crucial for the dispersion of graphene and the enhancement of the interfacial affinity between graphene and cement. Additionally, the compressive strength of GCC with rPCE exhibited a substantial enhancement of approximately 10% (68.36 MPa) compared to plain cement (62.33 MPa). The effectiveness of rPCE in enhancing compressive strength correlated with the uniform dispersion of graphene within GCC and the promotion of cement hydration, as evidenced by field emission scanning electron microscopy and X-ray diffraction, respectively.

Abstract 3188: Chitosan-glycerol injectable gel for intratumoral retention of immunotherapeutics

Abstract A novel, injectable chitosan-glycerol hydrogel was developed and characterized. Upon injection with co-formulated therapeutics, the gel vastly improved molecule retention at the injection site, as compared to molecule delivery in less viscous media. Methods. The hydrogel was formed through a centrifugation process. 70% deacetylated, medium viscosity chitosan was dissolved in 0.1M HCl. Glycerol was then added, followed by vortexing. Next, 1x PBS and 1M NaOH were added to neutralize the mixture, which induced gelation. After hydrogel centrifugation at 10,000 rpm for 5 minutes, a hydrogel was separated from precipitate. Several formulation parameters were tested, including chitosan:glycerol volume ratio, chitosan concentration, chitosan degree of deacetylation, and chitosan molecular weight. The retention of model therapeutics, formulated in hydrogel or saline vehicles, following injection in agar-based tumor phantoms was quantified via absorbance and fluorescence readings. To assess biocompatibility, a non-contact cell viability assay was performed utilizing 3T3 fibroblasts seeded in the bottom of transmembrane wells with hydrogels added to the upper chamber. After 48 hours, cells were collected and counted utilizing trypan blue. New Data. A hydrogel for intratumoral therapeutic delivery was constructed with several desirable qualities, including biocompatibility and injectability through a 25-gauge needle. Different relative glycerol to chitosan volumes, from 5 to 95 w/v % glycerol, were tested to determine a range of gelation conditions. Glycerol volume most significantly impacted gelation conditions independent of chitosan concentration, with gelation occurring between 70-85% relative volume glycerol. Increasing chitosan solution concentration and chitosan molecular weight increased the range of chitosan:glycerol ratios resulting in gelation. The hydrogel improved load retention at the agar tumor phantom injection site for various sizes of model therapeutics compared to less viscous solutions. Cytotoxicity testing of the hydrogel showed a statistically insignificant difference between the live:dead cell ratios of the experimental and negative control groups. Conclusion. An injectable, biocompatible hydrogel was created through the neutralization and centrifugation of a chitosan-glycerol solution. The hydrogel displays physiological pH, injectability through a 25-gauge needle, biocompatibility, and vastly improved therapeutic load retention at the injection site compared to less-viscous delivery media. Chitosan-glycerol hydrogels may be useful for intratumoral delivery and retention of immunomodulators within the tumor microenvironment. Citation Format: Robert L. Kobrin, Siena M. Mantooth, David A. Zaharoff. Chitosan-glycerol injectable gel for intratumoral retention of immunotherapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3188.

Modelling the centrifugal mixing process of minced meat to optimise the production of chopped meat semi-finished products

One of the most important problems in ensuring the quality of mincemeat preparation in the production of sausages is the effective structuring of components and mixing of their ingredients. To solve this problem, researchers added a multifunctional admixture based on whey protein in the process of centrifugal mixing of the components, which determined the composition of the factor space of the investigated process. Based on the results of the research, the effective content of whey protein, sodium alginate, and soy fiber in the developed recipe was proven, which showed high characteristics in terms of fat-retaining and moisture-retaining ability, digestibility, pH level – activity, and other parameters. The developed formulation made it possible to improve the general indicator of the balance of amino acids in the product and increase the functional-technological and quality parameters of the developed products. The physical and mechanical characteristics of the obtained meat product were evaluated based on the results of physical and mathematical modelling. Modelling was carried out using Federman-on-Buckingham's second similarity theory and the "dimension theory" method, which allows the processing of the obtained experimental data in the form of a criterion equation, which was compiled using Froude, Euler, and Sherwood criteria. The purpose of this study was to obtain dependencies between such process factors as product density, the coefficient of dynamic viscosity of the technological medium, the ultimate shear stress, the change in the concentration of the main impurities of lactic acid in the raw material, the value of the diffusion coefficient and the coefficient of mass transfer in the loading mass, the weight of one load of products, the angular frequency of rotation of the screws of the minced meat mixer, the radius of the rotating working bodies, the characteristic size of the products after grinding. Using the complex criterion equation and the developed program, we find a recommended set of operating mode parameters for preparing minced meat under the conditions of centrifugal influence on the mixing process and the action of the specified factors.

Development of the replacement skin of the IV arm simulator to meet customer requirements

The IV arm simulator trains IV catheter insertion in nursing education. Repeated practical training on IV catheter insertion can increase the confidence of new nurses or nursing students. All IV arm simulators in Thailand are imported from overseas and are expensive. The replacement skin of the existing IV arm simulators is not durable and is easily broken. Then, the objective of the study was to develop the replacement skin of the IV arm simulator from natural rubber, which was encouraged by the Thai government to advance the processing of natural rubber into higher value products.It was done in 4 phases. First, it was to explore the user requirements and problems of the existing IV arm simulator. The questionnaire was used to interview the requirements and problems of five nursing experts and lecturers and translate them into product characteristics. Second, it was to make a new replacement skin for the IV Arm Simulator from natural rubber. The plaster mould and centrifugal casting processes were selected and integrated to make the new replacement skin. Third, it was to test and compare the material properties of the new replacement skin with the existing replacement skin. The durability and adhesion testing were selected to test the material properties. Fourth, it was to explore user satisfaction after using the new replacement skin. The questionnaire was used to interview nurses and nurse’s lecturers again to explore user satisfaction on physical and usability.Results show that the new replacement skin is more durable than the existing one. It can attach the transpore tape and micropore tape. It can replace and fit with the existing IV arm simulator.The study was a comparative study focusing on Thai nurse requirements. The new replacement skin was developed from the existing IV arm simulator based on the size and texture of Western people. Further studies should be conducted to develop an IV arm simulator that is suitable for Asian people.The new replacement skin from natural rubber can decrease import products, enhance Thai product value, and promote employment in the rubber industry.The new replacement skin can be made from natural rubber as raw material. It was designed based on user requirements and problems. It has durability and adhesion properties are better than the existing replacement skin.