Dry Procedure Research Articles

Selective dry cow therapy on dairy farms in Rhineland-Palatinate, Saarland and Hesse, Germany - a survey among farmers

With the Regulation (EC) 6/2019, antibiotic drying off of the entire dairy herd is no longer permissible. Hence, it is necessary to establish selective antibiotic drying off (SDCT: Selective Dry Cow Therapy) in dairy herds. With the publication of the PraeRi study in 2020, systematic data for the implementation of SDCT on farms became available for several German states. For Rhineland-Palatinate, Saarland and Hesse this type of information is only available from individual projects. Therefore, the aim of this survey was to increase the knowledge concerning the implementation of SDCT in dairy farms located in these states. An online questionnaire was sent via newsletters to farmers and was published in the regional farmers' bulletins in the described catchment area. The questionnaire inquired about the saving of antibiotics during drying off, the criteria guiding the farmer's decision (cell count from monthly dairy herd improvement data (DHI), mastitis history, microbiological examination of quarter foremilk samples, California mastitis test), use of teat sealants and the type of dry off procedure (abrupt/gradual). A total of 103 questionnaires were evaluated, making the response rate ~1% for Hesse, ~3% for Saarland, and ~5% for Rhineland-Palatinate based on the number of included farms. Approximately 29% of the farmers dried off one out of four cows, 20% half, 23% three out of four and 13% all cows without using antibiotics. Eighty-nine farm managers based their decision on the somatic cell counts of DHI. Additional criteria influencing the decision were the mastitis history, results of the California Mastitis Test, or a combination of both. In 76 farms cows were dried off abruptly. In 79 farms teat sealers were used. Application of SDCT is established in most of the farms that participated in the survey, even though the proportion varied between farms. Legal requirements are not the only reason farmers need to increasingly deal with SDCT; sustainability programs of the dairies rely on selective drying off as well. Herd veterinarians should be supportive in implementing these measures to achieve good udder health while reducing the use of antimicrobials to a necessary minimum.

Evaluation of water absorption and solubility of digitally and conventionally produced temporary fixed materials

Background/Aim: The study aims to evaluate water sorption and solubility of conventional and digitally produced temporary fixed materials. Material and Methods: A total of 40 disc-shaped specimens were prepared from two conventionally produced temporary fixed materials: bis-acrylic composite resin (Protemp 4-PT) and acrylic resin (Dentalon plus-DP) and two digitally produced [3D printing (MACK4D Temp-MT) and CAD/CAM milling (On Dent-OD)]. The prepared disks were dried in a desiccator until they reached a constant mass. They were then kept in distilled water at 37°C for 1 week and weighed. The weights of the specimens, which were again subjected to conditions similar the initial drying procedure, were measured. Water absorption and solubility values were calculated by formula. The data obtained were analyzed using 1-way analysis of variance (ANOVA) and the Tamhane or Tukey post hoc test (a=.05). Results: Water absorption values of the PT group (24.16±8.1 µg/mm 3) were statistically higher than all other groups (p= 0.001). However, there was no significant difference in the pairwise comparisons of OD, MT, and DP groups (p>0.05). When the water solubility values were analyzed, DP group (0.49±2.01 µg/mm 3) showed no significant difference with the PT group (1.69±2.2 µg/mm 3) (p=0.402), while they were higher than OD (-3.96±0.84 µg/mm 3) and MT (-10.29±1.37 µg/ mm 3) groups. In addition, a significant difference was observed in the water solubility values of CAD/CAM-3D groups (p<0.05). Conclusions: All of test groups were found to be within the values recommended by ISO standards. It can be inferred that the PT material may cause the most staining.

Nanoleakage of apical sealing using a calcium silicate-based sealer according to canal drying methods.

This study investigated the nanoleakage of root canal obturations using calcium silicate-based sealer according to different drying methods. Fifty-two extracted mandibular premolars with a single root canal and straight root were selected for this study. After canal preparation with a nickel-titanium rotary file system, the specimens were randomly divided into 4 groups according to canal drying methods (1: complete drying, 2: blot drying/distilled water, 3: blot drying/NaOCl, 4: aspiration only). The root canals were obturated using a single-cone filling technique with a calcium silicate-based sealer. Nanoleakage was evaluated using a nanoflow device after 24 hours, 1 week, and 1 month. Data were collected twice per second at the nanoscale and measured in nanoliters per second. Data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney U-tests (p < 0.05). The mean flow rate measured after 24 hours showed the highest value among the time periods in all groups. However, the difference in the flow rate between 1 week and 1 month was not significant. The mean flow rate of the complete drying group was the highest at all time points. After 1 month, the mean flow rate in the blot drying group and the aspiration group was not significantly different. Within the limitations of this study, the canal drying method had a significant effect on leakage and sealing ability in root canal obturations using a calcium silicate-based sealer. Thus, a proper drying procedure is critical in endodontic treatment.

Developing ultrasound‐assisted infrared drying technology for bitter melon (Momordica charantia)

AbstractThe design of specific drying equipment requires correct knowledge of kinetic and thermodynamic characteristics of agricultural products. The purpose of this research is to find a suitable mathematical model to describe the experimental drying process, obtain the activation energy to specify the thermodynamic properties and calculate the specificity energy consumption. Bitter melons were dried in an infrared dryer with different temperatures, ultrasonic pretreatment times, and diverse distances from infrared lamps to reach moisture 0.1 kgw.kgd−1. The Midilli's model, best model to describe the drying process of bitter melon was chosen. The effective diffusion coefficient of bitter melon increased from 1.14 × 10−8 to 3.60 × 10−8 m2.s−1 with increasing drying temperature and duration of ultrasound treatment and decreasing the distance from infrared lamps. Also, Specific energy consumption decreased from 161.96 to 303.57 kWh.kg−1 by increasing the temperature and duration of ultrasound pretreatment and reducing the distance of infrared lamps.Practical applicationsReducing moisture through mass and heat transfer is necessary to maintain the quality and shelf life and reduce the waste of medicinal plants and food materials. The controlled and scientific drying of bitter melon is of utmost importance due to the sensitivity of its effective constituents to the application of heat during the drying process. The utilization of mathematical modeling to conduct theoretical research offers a robust and expeditious means of evaluating the phenomena of mass and heat transfer in the context of natural drying conditions. In order to ensure quality control, a thorough investigation of the product's drying procedure and reducing energy consumption is imperative. The findings of this investigation are applicable to the enhancement of drying processes within the medicinal plant drying sector.

Effect of Micronutrient Composition of Fish Feed to the Growth and Nutrient Content of Fishes: Cost-Efficient Production of Nutritious Fishes

Fish is the rich source of good quality protein. Per capita annual fish intake of Bangladesh is 21.90 kg and annual total need of fish is 42.38 lac mt. The current study's objective was to ascertain the nutritional value of various fish farmed in Bangladesh's Biofloc farm and regularly consumed by Bangladeshis by using nutrient rich formulated fish feed. The fish used in the study were tilapia fish (Oreochromis mossambicus) and shorputi fish (Systomus sarana). These fish species were cultured in a Biofloc setting. The edible portion of the samples had its composition closely investigated. The moisture, ash, and protein contents were determined using the AOAC-approved drying, Muffle-furnace, and Macro-Kjeldahl procedures, respectively. The edible proportion of fish in the current study ranged from 46.45 to 58.33%. The value for tilapia was the greatest (58.33%) while the value for shorputi was the lowest (46.45%). For some of the fish samples used in the investigation, the moisture content was found to be between 74.04 and 77.53%. Shorputi's lowest value was discovered to be 74.45%. For several fish samples, the ash concentration was determined to be between 1.04 and 1.31%. Shorputi had the greatest ash concentration (1.31%), while tilapia had the lowest (0.95%). Tilapia had a high protein content (23.77%). The study's most recent findings demonstrate that the farm formulated feed had a beneficial effect on the development and nutritional status of fish raised in biofloc systems. Bioresearch Commu. 10(1): 1453-1461, 2024 (January)

Influence of micro‐sized CaCO3 on hydrates formation of residual calcium aluminate cement in castables during drying

AbstractThe addition of CaCO3 powder in calcium aluminate cement (CAC) is reported to accelerate the hydration of CAC and generate mono‐carbonate C4AC̅H11, which is conducive to shortening the curing time of CAC‐bonded castables at ambient temperatures. Although the hydration of CAC is relatively fast, there is still residual un‐hydrated CAC in castables after curing. The residual CAC would continue to hydrate to produce C3AH6 and AH3 during the subsequent drying procedures in the absence of CaCO3. But it is worth pondering which type of hydrate would be generated in the presence of CaCO3 during the drying at around 110°C. In this study, the effect of micro‐sized CaCO3 addition on the hydrate formation of CAC‐bonded castables during drying at 110°C was investigated. The results indicate that the C4AC̅H11 formed at the curing temperature of 30°C is not decomposed or converted during drying. The CaCO3 remained after curing does not participate in the hydration of residual CAC during drying at 110°C, and thus the residual CAC continues to hydrate to generate C3AH6 rather than C4AC̅H11.

Whey Protein-Pectin Conjugate by Wet-Dry Heating: Optimization using Response Surface Methodology with Box-Behnken Design

The recent progress in glycation of proteins utilizing saccharides through the Maillard reaction has garnered substantial attention, with a specific emphasis on Whey Protein Concentrate (WPC). Conjugation mode is frequently intricate and poses challenges when scaling up for large-scale production. Consequently, this investigation sought to optimize the conditions of the WPC-pectin conjugation process using Response Surface Methodology (RSM) in conjunction with Box-Behnken design (BBD). The experimentation was executed employing a cabinet dryer, incorporating both wet and dry heating procedures to yield a WPC-pectin conjugate exhibiting favorable functional properties. The independent variables investigated encompassed pectin concentration (ranging from 0 to 1%), pH (ranging from 6 to 8), and drying time (ranging from 2 to 6 hours), The measured responses encompassed the emulsion stability index (ESI), emulsifying activity index (EAI), and solubility. Analyzing the experimental data underwent scrutiny for model sufficiency through diagnostic plots, and a second-order polynomial equation was fitted through multi-response regression analysis, resulting in a high coefficient of determination (R 2 ) value. The most effective parameters were identified as a pectin concentration of 0.49%, pH 6.7, and a drying duration of 4.12 hours, yielding a peak ESI of 452.267 minutes, EAI measuring 49.95 m 2 g -1 , and solubility reaching 48.09%. Further experiments were conducted to validate these outcomes, and the presence of the Maillard reaction was confirmed using Fourier Transform Infrared Spectrum (FTIR). The et-dry method demonstrated efficacy in producing WPCpectin conjugates with commendable functional properties.

Effects of different drying methods on the proximate composition, antioxidant activity, and phytochemical content of Hibiscus sabdariffa L. Calyx

The study investigated the impact of freeze drying (FD), cabinet drying (CD), and sun drying (SD) on the proximate composition, phytochemicals, and antioxidant activity of roselle calyx. The proximate composition, phytochemicals, and antioxidant activity of the roselle calyx were determined by the AOAC method and the free radical-scavenging DPPH technique, followed by the spectrophotometric method, respectively. The samples were frozen and condensed at -40 to -60 °C in the FD and then dried at 20 °C for 20–30 h, and in the CD and SD, it was done at approximately 65 °C and 30 °C, respectively. CD retained the least moisture (p < 0.05) and had the highest (p < 0.05) carbohydrate content (38–49 %). There was a substantial difference (p < 0.05) in the ash, protein, and fat content of the provided samples using different drying processes. The TPC of FD, CD, and SD of roselle calyx had 64.70 ± 1.33, 32.23 ± 1.36, and 25.84 ± 1.85 mg GAE/g, respectively. The TFC of FD, CD, and SD dried roselle calyx was 65.41 ± 2.02, 41.64 ± 3.12 and 27.60 ± 1.83 mg QE/g, respectively. The phytochemicals and antioxidant activity of roselle calyces were found to be significantly higher (p < 0.05) in FD compared to CD and SD. Finally, FD should be considered an appropriate drying procedure for retaining excellent qualities.

Support effect of Mn/Na2WO4‐based catalysts in oxidative coupling of methane

AbstractBACKGROUNDIn this work, the supported Mn‐Na2WO4/γ‐Al2O3, Mn‐Na2WO4/γ‐Al2O3‐TiO2 and Mn‐Na2WO4/ γ‐Al2O3‐SiO2 catalysts were prepared using the dry impregnation procedure and tested for suitability to the oxidative coupling of methane (OCM) reaction. The synthesized catalyst was characterized by various techniques such as X‐ray diffraction (XRD), Fourier transform infrared (FTIR), X‐ray photon spectroscopy (XPS), temperature‐programmed reduction (TPR), Brunauer–Emmett–Teller (BET) surface area and field emission scanning electron microscopy (FESEM), and the support effect of the prepared catalysts in the OCM reaction was evaluated.RESULTSThe XPS results showed that the tetrahedral WO42− phase is presented in all prepared catalysts and it is expected that the presence of this phase is correlated with high OCM activity. The XPS results show that the amount of O2− in the treated Mn‐Na2WO4/γ‐Al2O3‐TiO2 catalyst at 800 °C is higher than that in the Mn‐Na2WO4/γ‐Al2O3 and Mn‐Na2WO4/γ‐Al2O3‐SiO2 catalysts, but is reduced with increasing temperature. At 850 °C, the amount of O2− in the treated Mn‐Na2WO4/γ‐Al2O3 catalyst is higher than in the Mn‐Na2WO4/γ‐Al2O3‐TiO2 and Mn‐Na2WO4/γ‐Al2O3‐SiO2catalysts.CONCLUSIONThe results show that the MnSiO3 and MnTiO3 sites may deliver a much easier Mn2+↔Mn3+ cycle than the MnAl2O4 and MnWO4 sites at low temperatures, and may play a principal role in enhancing the catalyst activity in the OCM reaction at 800 °C. © 2023 Society of Chemical Industry (SCI).

Impact of the Drying Procedure and Botanical Origin on the Physico-Chemical and Potentially Bioactive Properties of Honey Powders

This study was aimed at researching the impact of the drying procedure (using the most appropriate honey–maltodextrin concentration for each drying technique) and botanical origin of honey on the physicochemical and potentially bioactive properties of honey powders that were made using maltodextrin as a carrier. The research was carried out with thyme, lavender, vetch and multifloral honey dehydrated using vacuum drying and freeze drying. The analysed parameters were moisture, water activity, colour, glass transition temperature, powder recovery, hygroscopic index and rate, tapped density, solubility, and phenolics as well as antiradical (ABTS•+, ROO•, •OH and O2•−), anti-inflammatory and antimicrobial (against Staphylococcus aureus, Escherichia coli and Listeria monocytogenes) activities. Freeze drying provided the highest recoveries. Powders obtained using freeze drying showed higher moisture and solubility as well as lower glass transition temperature, density and hygroscopicity than those obtained using vacuum drying. Hygroscopicity, glass transition temperature and antimicrobial activity against St. aureus depended on the drying procedure–honey concentration. Colour, anti-O2•− activity and antimicrobial activity against L. monocytogenes depended on the botanical origin of the raw honey. Moisture, solubility, density, total phenolic content, anti-ABTS•+ and anti-ROO• activities as well as anti-inflammatory activity and antimicrobial activity against E. coli depended on the drying procedure–honey concentration and botanical origin.

Flexible, Thermally Stable, and Ultralightweight Polyimide-CNT Aerogel Composite Films for Energy Storage Applications.

Polyimide (PI) aerogels are promising in various fields of application, ranging from thermal insulators to aerospace. However, they are typically in the form of a bulk monolith, which suffers from a lack of conformability and drapability. Moreover, their electrical conductivity is limited, and they mainly display an insulative behavior. These shortcomings can limit the applications of PI aerogels in energy storage systems, which require ultralightweight flexible conductive films, which at the same time offer high thermal stability, ultralow density, and high surface area. To overcome these obstacles, the present study reports the fabrication of PI-carbon nanotube (PI-CNT) aerogel composite films with varying CNT content prepared through a sol-gel preparation method, followed by a supercritical drying procedure. Compared to pristine PI aerogels, which displayed a large shrinkage and density of 18.3% and 0.12 g cm-3, respectively, the incorporation of only 5 wt % CNTs resulted in a significant reduction of both shrinkage and density to only 11.5% and 0.10 g cm-3, respectively. This suggests the importance of CNTs in improving the dimensional stability of aerogels and creating a robust network. Further characterizations showed that incorporation of 5 wt % CNTs also resulted in the highest pore volume (1.25 cm3 g-1), highest surface area (324 m2 g-1), highest real permittivity (80), highest electrical conductivity (3 × 10-1 S m-1), and ultrahigh service temperature (575 °C). It was also shown that the aerogel films can withstand a large degree of bending, can be twisted, and can be fully rolled with no obvious cracks propagated in the structure. The combined outstanding properties of the developed aerogel composite films make them promising potential candidates for supercapacitor electrodes. Therefore, the electrochemical performance of the devices based on aerogel electrodes was further studied. The device demonstrated a high energy density of 2.6 Wh kg-1 at a power density of 303.8 W kg-1. The total capacitance after 5000 cycles was 91.8% of the initial capacitance, which indicated excellent stability and durability of the device. Overall, this work provides a facile yet effective methodology for the development of high-performance aerogel materials for energy storage applications.

Thermal and structural properties of polyzwitterions: Effects of monomer chemistry and salt addition

Thermal and structural properties of polyzwitterions (PZI)s comprising the sulfobetaine moiety were studied as a function of LiCl addition and variations in monomer chemistry. The polyzwitterions chosen for this study are: poly(sulfobetaine methacrylate), PSBMA; poly(sulfobetaine acrylate), PSBA; and, poly(ethyl sulfobetaine methacrylate), PESBMA. When LiCl salt is added, the Li+and Cl− ions disrupt the dipole-dipole electrostatic interaction of the PZI side groups. Fourier transform infrared spectroscopy shows that the vibrational frequencies of the symmetric and asymmetric S=O bonds increase as LiCl content increases. Structural studies by wide angle X-ray scattering show that all the PZIs are amorphous, and the average interatomic spacing, d, increases in the order: dPSBA(= 0.456±0.006nm) < dPSBMA (= 0.474±0.015nm) < dPESBMA (= 0.493±0.011nm). Upon the addition of LiCl, d-spacing for a given PZI decreases as LiCl content increases. Thermogravimetry showed that PZIs had degradation onset temperatures Td ∼ 300°C. As LiCl content increases, the onset temperature of degradation decreases suggesting that the disruption of dipole-dipole crosslinks destabilizes the polymer. All the PZIs are hydrophilic and hygroscopic, and a drying procedure was developed so that well-defined glass-to-liquid transitions could be observed in the dry solid state. PZIs without LiCl have glass transition temperatures, Tg, increasing in the order: Tg,PSBA(= 200±1°C) < Tg,PESBMA (= 204±1°C) < Tg,PSBMA (= 237±1°C). As the LiCl content increases, Tg decreases, and the liquid state heat capacity increases, in all PZIs. The specific heat capacity increment at Tg was studied for PSBA as a function of LiCl content. In PSBA, the heat capacity increment reached a maximum for molar ZI:LiCl content at and above 1:1, and its value agreed well with predictions based on an empirical bead model of polymers. Thermal data on the dry state of PZI-LiCl complexes suggest an analogy between electrostatically crosslinked, fully amorphous PZIs and semicrystalline polymers. The dipolar crosslinks confine the molecular motion of PZIs just as crystal domains confine the molecular motion of the amorphous phase in semicrystalline polymers.

Loadbearing versus non‐loadbearing fire walls

AbstractIn the last decades plenty of fire tests with wall constructions consisting of reinforced AAC elements were executed. Many of the test results have been transferred to European and national technical regulations. Also, theoretical methods to design reinforced AAC elements for fire impact are available. These provide temperature curves for the commonly used dry densities and procedures to calculate and rate the influence of fire stress on the functional capacity of the wall systems.In the last years additional fire tests took place to show the fulfilment of special requirements for buildings with high demands regarding fire safety. For example, tests with six hours of firing were performed which is highly above the definitions and solutions given in standards.Xella's R&amp;D Center meanwhile has its own test stand to execute suitability checks for fire walls and is accredited for performing these tests.In the last years the question about how to rate the performance of fire walls on basis of test results came up, especially regarding load bearing walls. This is the result of different definitions in the relevant national and European standards. Possible approaches for solving this topic shall be presented at the AAC conference.

Research on the drying kinetics for the microwave drying of Y2O3–ZrO2 ceramic powder

Y2O3–ZrO2 ceramic powder has emerged as a vital structural and functional material in ceramic applications owing to its remarkable performance including wear resistance, temperature resistance, and corrosion resistance. Agglomeration during the drying process is the other key issue that needs to be resolved, which improving the quality of zirconia powder becomes crucial in reducing industrial expenses. This study focuses on investigating the influence of modern microwave heating technology on the drying kinetics of Y2O3–ZrO2 ceramic powder. The experimental results revealed that the average drying rate of Y2O3–ZrO2 ceramic powder increased with sample water content, microwave heating power, and sample mass. Four kinetic fitting models, namely Page, Wang and Singh, Quadratic Model, and Modified Page, were employed to analyze the experimental data for Y2O3–ZrO2 ceramic powder with a mass of 20 g, initial water content of 7.5%, and the microwave heating power is 480 W. Among these models, the Modified Page model demonstrated the best fit and effectively described the drying kinetics of Y2O3–ZrO2 ceramic powder. The Modified Page model successfully captured the kinetics across varying masses, microwave heating powers, and initial water content. FT-IR spectroscopy was employed to describe the material before and after microwave drying. The results exhibited a significant reduction in water molecule content in the Y2O3–ZrO2 ceramic powder after microwave drying, thus confirming the high efficiency and rapidity of the microwave drying procedure. This research provides comprehensive experimental data and offers a theoretical foundation for the industrial application of microwave-enhanced drying of Y2O3–ZrO2 ceramic powder.

Microstructure control in printable porous polymer composites

The microstructure of a porous polymer matrix composite, specifically the organization of polymer, particles, and pores, plays a defining role in the physical properties of the material. Developing materials and processes that allow us to control the microstructure gives us a powerful tool to create materials with designed performance. Here, a series of porous polyvinylidene fluoride (PVDF) and alumina (Al2O3) composites produced through evaporation induced phase separation (EIPS) are demonstrated. This process utilizes solution processable inks and achieves porosity via a simple drying procedure. This enabled the materials to be printed using direct ink writing (DIW) techniques. The effects of particle size and loading on the mechanical properties and microstructures of these materials were studied. It was found that these materials remain significantly more ductile and extensible than what is expected from particle reinforcement. In the most extreme case, the use of 300 nm Al2O3 particles were found to only minimally reduce strain at failure, even at high loadings. We believe this behavior is enabled by how the EIPS process alters the microstructure of the material and appears to preferentially locate particles at the polymer-pore interface.

Comprehensive quantification of flavonoids and salicylic acid representative of Salix spp. using microLiquid Chromatography-Triple Quadrupole Mass Spectrometry: the importance of drying procedures and extraction solvent when performing classical solid-liquid extraction

Willow (Salix spp.) is gaining an increasing interest as a fast-growing tree with high biomass yield from low agricultural inputs, which contains potentially bioactive compounds. The present work aimed to develop a high-yield extraction procedure combined with robust, sensitive and fast microLiquid Chromatography-Triple Quadrupole Mass Spectrometry (LC-MS/MS) based method for comprehensively quantifying flavonoids and salicylic acid in the bark of Salix spp. We have investigated the effect of freeze- and oven-drying procedures and five extraction solvents on the yield of individual flavonoid and salicylic acid when performing classical solid-liquid extraction. The freeze-drying was the best drying procedure for preserving monomeric and polymeric flavan-3-ols, whereas other flavonoids were less affected. Salicylic acid was not affected by the drying procedures. The best extraction solvent in terms of the yield of individual flavonoid among the tested solvents in this study was the combination of methanol acidified with 1% hydrochloric acid. LC-MS/MS method has shown a high recovery percentage (≥80%), good precision and overall robustness.

Fully automated radiosynthesis of [18F]mG4P027 for mGluR4 imaging

AbstractBackgroundFluorine‐18 labeled N‐(4‐chloro‐3‐(((fluoro‐18F)methyl‐d2)thio)phenyl)picolinamide, [18F]mG4P027, is a potent positron emission tomography (PET) radiotracer for mGluR4. Our previous in vitro and in vivo evaluations have demonstrated that this tracer is promising for further translational studies. However, automated radiosynthesis process poses significant challenges that need to be addressed.MethodsThe automated radiosynthesis was performed using the TRACERlab FX2N module, which comprises two distinct reactors capable of accommodating the two‐step reactions. Several problem‐solving strategies were employed to overcome challenges during the automation process. This included modifications to the reaction solvents, reaction conditions, use of a scavenger, drying methods, and the handling of the precursor.ResultsThe use of n‐Bu4NN3 for scavenging excess compound 1 along with an efficient drying procedure played a key role in the success of the radiosynthesis. The water was successfully removed by using a different duct to overcome the water sensitivity for the second reaction.ConclusionsSignificant modifications were made to the manual process by carefully examining this process and addressing the root causes of the challenges associated with its automation. We successfully implemented automated radiosynthesis using the TRACERlab FX2N module and consequently, obtained a high‐purity radiolabeled [18F]mG4P027 in high yield, meeting the requirements for future human studies.

Soil moisture content estimation using active infrared thermography technique: An exploratory laboratory study

Small scale laboratory testing was conducted to estimate the moisture content of sandy soils using a non-destructive and non-contact infrared thermography (IRT) technique. Tests were carried out by applying an external halogen lamp light (400 ​W). In this study, the aim was to explore the feasibility of using IRT to assess the moisture content of sandy soil. The laboratory tests conducted included evaluating soil physical characteristics such as grain size distribution. Soil samples were prepared with five different moisture content percentages. The soil moisture content was then evaluated using two different techniques. The first is the gravimetric oven dry method as per (ASTM D2216, 2019). The second is the IRT Technique. During the second procedure the samples were photographed with an ICI IR-Pad 640 ​P Series camera, which had an image resolution of 640 ​× ​480 pixels and a capture rate of 6 frames/minute. The emissivity correction used was 0.98. The soil surface temperature was captured in both the heating and the cooling phase, with the temperature taken from a specific thermal image area called the region of interest (ROI). Moisture content measurements were taken for each sample using the oven-drying method at the initial stage, and at the end of the heating and cooling phases. The procedure produced a good correlation between moisture content and surface temperature in the heating phase. The soil moisture content and surface temperatures were inversely related and formed a linear line with a high degree of accuracy (r2 ​= ​0.9138). A validation check is done at the end for a sample with random moisture content using the IRT technique where the moisture content was found to be 6.81%, this value was confirmed with the oven dry procedure. It was found that IRT successfully estimated soil moisture content.

Amphiphilic polyimide-graphene nanoplatelet aerogel composites with high mechanical stability and enhanced thermal insulation properties for oil sorption applications

This study presents the fabrication of new polyimide (PI) aerogel composites through incorporation of graphene nanoplatelet (GNP) in PI matrix. A series of PI aerogel composites with various GNP concentrations were synthesized in a three-step gel preparation method, followed by a supercritical drying procedure. The role of GNP in tuning and optimizing various properties of aerogel composites including physical, thermal, and mechanical properties was discussed. The fabricated aerogel samples showed a significant reduction of shrinkage from 16% for pristine PI aerogel to only 6% in the presence of 0.5 wt% GNP. Further characterizations showed that incorporation of 0.5 wt% GNP also resulted in the highest pore volume (3.5 cc/g), highest surface area (404.5 m2/g), lowest density (∼ 0.04 g/cm3), and outstanding thermal insulation property (thermal conductivity of only 25.47 mW/m.K). When GNP was incorporated into the solid backbone, it was noticed that even at a very low concentration of 0.1 wt%, the modulus was increased over two times, and the maximum modulus of around 8 MPa was obtained. Such an enhancement in mechanical properties showed that GNP with ultrahigh aspect ratio can not only control and tailor the nanostructured assembly of PI aerogel composites but also due to the better entanglement with polymer chains, a stronger 3D porous network was formed, and thus, GNP can act as a reinforcing filler. Eventually, the sorption capacity and kinetics were determined using various solvents including methanol, acetone, toluene, hexane, and diesel to demonstrate the application of aerogel composites in oil sorption. The results showed that the highest sorption capacity was obtained for PI aerogels with 0.5 wt% GNP, and it could reach 7.3 ± 0.2 g/g for diesel which was significantly higher than the one for pristine PI aerogels. Unlike the previously reported PI aerogel composites where the enhancement of a specific property would often be associated with the deterioration of several other properties, this study showed that various properties of PI aerogel composites can be improved and optimized through the incorporation of GNP and the control of the aerogel synthesis. The proposed materials can therefore be used as high-performance thermally insulating materials and hold great potential for the removal of oil pollutants and organic solvents.

Experimental studies on strength and durability of alkali activated slag and coal bottom ash based geopolymer concrete

This thesis work describes the experimental evaluation of the durability and strength properties of nominally mixed conventional concrete of grade M35, Alkali Activated Slag Based Geopolymer Concrete. Research on Rapid Chloride Permeability Test (RCPT) durability properties has been conducted. Sodium hydroxide (NaOH) and sodium Chloride (NaCl) must be mixed in a 2.5:1 M ratio and at molarities of 12 and 16, respectively, in order to make alkali activators, with dry curing and open-air curing serving as distinct curing regimes. NaOH concentrations of 12 M and 16 M were used to make nine distinct mixes, one of which was designated as the control mix. Then, these mixtures were cured at room temperature in the open air. Prior to the testing day, they were maintained at room temperature after a 24-hour dry curing procedure at 90 °C in a hot air oven. Each of the nine mixes underwent split tensile and flexural strength and durability testing after 90 days. Compressive strength tests are conducted at 28, 56, and 90 days. The results show that tensile strength increases as NaOH solution concentration decreases, but compressive and flexural strength increase as NaOH solution concentration increases. However, it was discovered that the Geopolymer concrete made from Alkali Activated Slag and Coal Bottom Ash (CBA) did not perform well in tests of water fast chloride penetrability because surface cracking predominated. When compared to the results of the control mix, the Alkali Activated Slag and Coal Bottom Ash (CBA)-based geopolymer concrete mix shows a superior improvement in strength measures than standard concrete. At this time, it seems that making geopolymer concrete costs less than regular concrete.