Pressurized Conditions Research Articles

Aerodynamic Damping Predictions During Compressor Surge: A Numerical Comparison Between a Half and Full Transient Approach

Abstract The prediction of the aerodynamic damping during compressor surge is a challenging task, because the flow is continuously evolving along the four surge cycle phases: pressurization (PR), flow-breakdown (FB), reversed flow (RF), and regeneration (RG), and complex flow conditions such as shocks and separations occur. Damping predictions with current existing methods typically consist of two steps. In the first step, a modified numerical model is used to simulate transient surge cycles. In the second step, damping analyses are performed for multiple timesteps along the surge cycle phases, which are then assumed as quasi-steady. The damping simulation can be performed using nonlinear or linear approaches. If shocks or separations occur, the latter yields inaccuracies in the flow and thus in the damping predictions. A new approach was developed to take into account and improve these inaccuracies. This new method includes the damping prediction within the transient surge simulation. Thus, all surge cycle phases and the continuously evolving flow conditions are considered, and nonlinear simulations are performed to account for shocks and separations. The results of this new method are presented and compared to the former method.

Pressurized liquid extraction of compounds from Stevia leaf: Evaluation of process variables and extract characterization

The extraction of compounds from Stevia rebaudiana leaves under pressurized conditions was investigated. The effect of the ethanol percentage in the extracting solvent, static time, pressure and temperature on global extraction yield (YGE), total phenolic content (TPC) and antioxidant activity (AA) was evaluated. The extract from pressurized liquid extraction (PLE) was characterized and compared to that obtained from Soxhlet and ultrasound-assisted extraction (UAE). It appears that the increase of ethanol concentration in the solvent favored response variables, while the increase in static time and pressure did not affect the extraction. The temperature (125 ºC) provided an increase in YGE and the highest levels of active compounds were obtained after using 70% (v/v) ethanol in the extracting solvent (15 mL g−1) and 30 min. The different techniques evaluated provided similar YGE, while PLE providing greater extraction of TPC and AA, and Soxhlet favored the extraction of steviol glycosides and total flavonoids.

Numerical analysis of the subcooled boiling phenomena in a wire-wrapped annulus

The wire-wrapped tight lattice fuel assembly is one of the options for small modular reactors. To investigate the performance of this assembly, the subcooled boiling characteristics in a wire-wrapped annular have been analyzed in the present work. The Eulerian two-fluid model coupled with the RPI wall boiling model was employed in the simulation. The mathematical models are validated by the subcooled boiling experimental data of the circular channel first, and then the simulation for wire-wrapped annular is carried out. The distributions of fluid temperature, wall temperature, vapor volume fraction, and heat flux partitions under a typical pressurized water reactor condition are gained. In the simulation conditions of the current wire-wrapped annular, the results indicate the non-uniform circumferential heat transfer can be ignored in subcooled boiling conditions, and the maximum vapor volume fraction occurred near the wire surface region. In addition, the increase of wire pitch increases the swirl intensity, at the same time, it also will increase the maximum vapor volume fraction near the rod surface region, which may cause DNB to occur earlier. Therefore, the wire pitch should be chosen carefully when the wire-wrapped assembly is applied to the pressurized water reactors. This work can provide a reference for the design of wire-wrapped tight lattice assembly applied in small modular reactors.

Effect of using laser incising treatment and fire-retardant coating on Larix kaempferi wood to improve fire retardant performance

To improve fire-retardant performance of Japanese larch (Larix kaempferi) wood, this study analyzed the effect of pinholes made by laser incising and fire retardant (FR) coating on the surface of Japanese larch wood. Combustion properties such as peak heat release rate (PHRR) and total heat release (THR) of Japanese larch and Korean red pine (Pinus densiflora) wood without FRs showed similar tendencies. The comparison of the combustion properties on wood injected with an inorganic water-soluble FR under vacuum revealed that the PHRR and the THR of Korean red pine wood decreased by 37 and 62%, respectively. FR was injected into the Japanese larch specimens with pinholes on the surface and additionally coated with 5% sodium silicate and 35% potassium bromide. The results indicated a 16 to 25 and 19% reduction in PHRR and THR, respectively, compared to those without the FR. Despite the pinholes and FR coating, the FR employed in this study did not meet the standards set in Korea (THR of 8 MJ/m2). This study serves as a reference for future studies on the application of pressurized conditions and other surface treatments to improve the FR percent injection and performance of Japanese larch wood.

Influence of Operating Parametres on PEM Based Ecmr for Hydrogen Production in Pressurised Condition

Hydrogen has the potential to promote the development of new, innovative and environmentally friendly solutions for future demands which would help for the smooth energy transition from fossil fuels. Though hydrogen has a high potential to replace fossil fuels, the challenges associated with the hydrogen value chain are in the production, storage, transportation and distribution stages.Electrolysis of water in PEM based system is a single step green hydrogen production process while integrated with renewable energy resources. However, this energy-intensive process makes the hydrogen production cost high and it is pave way for adopting the grey hydrogen or blue hydrogen production route as an intermediate stage for the transition from fossil fuel to hydrogen fuel economy. In this context PEM based Electrochemical Methanol Reformer (ECMR) technology has unique advantages such as low electrical energy consumption than water electrolysis and it can be easily integrated with renewable energy sources. Further, it can be operated at near ambient temperature and doesn’t require any hydrogen purification system, unlike a chemical reformer. Currently, PEM based water electrolyzer is producing pressurized hydrogen, which will eliminate the need for an external hydrogen compressor for its storage. Further, the influence of operating parameters on the operation of PEM water electrolyser under pressurised conditions is studied in the literature. However, this aspect of the study is not well studied and not much literature is available on PEM based ECMR systems. The present work, it is aimed to systematically study the effect of various operating parameters on the performance of ECMR under pressurised operation conditions and the obtained results are discussed. It shows the operation of ECMR under pressurised condition are promising and it will eliminate the need for an external H2 compressor system for hydrogen storage like PEM based water electrolyzer. Keywords: Hydrogen, PEM based Electrochemical reformer, pressurised hydrogen

Characterisation of a 10-Layer SOC Stack Under Pressurised CO2 Electrolysis Operation

One promising way of facing recent challenges to slow down the climate crisis or to reduce dependencies on fossil energy sources, e.g. natural gas, is using renewable methane and other e-fuels for storage and distribution via existing infrastructure. Solid oxide cell (SOC) reactors play an important role in the conversion of sustainable electric power into chemicals as they can be obtained from combined steam and CO2 co-electrolysis for syngas production. The pressurised electrolysis operation is a key factor for increasing the system efficiency of PtX-processes, including balance-of-plant (BoP) components, electrochemical reactors and high pressure downstream processes.In general, the yield of CO2 electrochemical reduction at atmospheric and pressurised conditions in high temperature co-electrolysis is still controversially discussed. Previously, several SOC short stacks were thoroughly analysed in pressurised steam- and co-electrolysis operation in a test-rig environment. These experimental results indicate marginal influence of pressure on the performance of electrolyte supported cells (ESC). In contrast, electrochemical impedance spectroscopy (EIS) suggests that pressurisation of pure CO2 electrolysis significantly reduces the fuel electrode impedance contribution, especially at lower temperatures around 700 °C [1,2].This work aims to experimentally determine the kinetic behaviour of pure CO2 electrolysis by varying operating conditions like pressure, temperature, reactant conversion and feed gas composition. The investigation of kinetic parameters during these experiments could complement the formerly described research. Furthermore, the kinetic expressions can be used when studying co-electrolysis operation to identify the shares of: (i) the reverse water-gas-shift (rWGS) and (ii) the CO2 electrochemical reduction. Polarisation curves were dynamically recorded and different current densities were evaluated in steady-state operation. Additionally, EIS measurements were performed at open circuit voltage (OCV), as well as under different current densities. The kinetic parameters were estimated by curve-fitting analysis of the experimental results. The resulting expressions will be implemented in the in-house modelling framework, TEMPEST, based on [3,4] with the aim to increase the accuracy of modelling high-temperature CO2 electrolysis and co-electrolysis systems. [1]Riedel, M., Heddrich, M. P., & Friedrich, K. A. (2020). Experimental Analysis of the Co-Electrolysis Operation under Pressurized Conditions with a 10 Layer SOC Stack. Journal of The Electrochemical Society, 167(2), 024504, DOI: 10.1149/1945-7111/ab6820.[2]Riedel, M. (2020, October 20–23). Experimental analysis of SOE stacks under pressurized co- and CO2 electrolysis operation [Paper presentation]. 14th European SOFC & SOE Forum, Lucerne, Switzerland.[3] Tomberg, M., Santhanam, S., Heddrich, M. P., Ansar, A., & Friedrich, K. A. (2019). Transient Modelling of Solid Oxide Cell Modules and 50 kW Experimental Validation. ECS Transactions, 91(1), 2089, DOI: 10.1149/09101.2089ecst.[4] Srikanth, S., Heddrich, M. P., Gupta, S., & Friedrich, K. A. (2018). Transient reversiblesolid oxide cell reactor operation–Experimentally validated modeling and analysis. Applied Energy, 232, 473-488, DOI: 10.1016/j.apenergy.2018.09.186.

Numerical Analysis and Experimental Verification on Flow Characteristics of a Pressurized Fluidized Bed System

Abstract The pressurized fluidized bed technology is recently shown to be a most promising technology for energy conversion and carbon capture. In the present work, two-phase flow characteristics of a laboratory-scale bubbling fluidized bed (BFB) system have been examined numerically under pressurized cold flow conditions. The BFB hydrodynamics is presented by axial pressure distributions and radial particle volume fractions. Moreover, the influence of drag models on minimum fluidization and bubble formation is studied using two different drag models, namely Wen-Yu/Ergun and EMMS–Yang, at both atmospheric and elevated pressure conditions. The numerical results are validated with a series of pressure drop and axial pressure measurements conducted at three different pressure conditions. The experimentally observed minimum fluidization velocity results are also compared with the theoretical correlations found in the literature. Good agreement has been found between experiments and numerical predictions.

Characterization of Volatile Organic Compounds in Kiwiberries (Actinidia arguta) Exposed to High Hydrostatic Pressure Processing by HS-SPME/GC-MS.

HS-SPME/GC-MS analysis was carried out to characterize the profile of volatile organic compounds (VOCs) in kiwiberry cultivars (Geneva and Weiki) exposed to high hydrostatic pressure (HHP) (450–550–650/5 and 15 min). The sum of individual VOCs in Geneva (6.493 mg/kg) and Weiki (11.939 mg/kg) samples was found to be significantly reduced after processing, particularly for pressurization conditions of 650 MPa/15 min (decrease of 62%) and 550 MPa/15 min (decrease of 84%), respectively. On the other hand, Geneva and Weiki exposed to 450 MPa/5 min manifested the lowest loss in the sum of the VOCs. Geneva exposure to 450 MPa/5 min led to an increase in the hexanal (r = 0.782) and linalool (r = 0.806) content. Sample pressurization (450 MPa/15 min) promoted the formation of methyl butanoate, ethyl hexanoate, and cis-geraniol, simultaneously increasing the benzaldehyde (r = 0.886) concentration. However, the treatment of Weiki at 450 MPa/5 min favored trans-2-heptenal (r = 0.999) and linalool (r = 0.970) formation, as well as the (-)-terpinen-4-ol (r = 0.848) and geraniol (r = 0.694) content. Ethyl butanoate, hexanal, and 1-octen-3-ol were highly concentrated in the HHP-treated (450 MPa/5 or 15 min) Weiki. Pressurization decreased the terpenoid contribution, but also increased the contribution of alcohols and aldehydes to the overall VOC number in both tested cultivars.

Simulation of the High Temperature Test Facility (HTTF) Core Using the 2D Ring Model with SAM

A two–dimensional ring model is developed with SAM to model the core of the High Temperature Test Facility (HTTF) at the system level. The ring model simplifies the complex structure of the HTTF core by converting the hexagonal rows of heaters and flow channels into layers of concentric annular rings. The ring model is first compared against a three–dimensional (3D)–one–dimensional (1D) model where the solid structures are fully resolved in three dimensions while the fluid structures are modeled as 1D flows. Comparison between the 3D–1D and the ring models shows that the latter can predict major parameters reasonably well under steady–state normal operating conditions, but the heater temperatures are under predicted. Adjustment is made to the effective thermal conductivity of the ceramic core of the ring model to improve the heater temperature predictions. The ring model is also used to simulate a transient pressurized conduction cooldown condition and is benchmarked with the experimental data from the HTTF Test PG–27. Good agreement is obtained between the experimental data and the predictions by the ring model.

Novel active management of compressive pressure on a lithium-ion battery using a phase transition actuator

This study proposes a novel method for managing the compressive pressure imposed on a lithium-ion battery (LIB) using a phase transition actuator under constrained conditions considering the influence of compressive pressure on the performance and lifespan of LIBs. Specifically, an active pressure management strategy is proposed to maintain the optimal pressure and reduce the equivalent impedance during operation. A closed-loop control scheme is used to maintain compressive pressure via a phase transition actuator considering the dynamic characteristics of the actuator. This configuration allows managing both reversible pressure due to phase transitions at lithium intercalation/deintercalation and irreversible pressure evolution due to solid–electrolyte interface formation and growth. The analysis on experiments indicates that the equivalent impedance and capacity can be managed through active pressure management under stationary and stochastic operational conditions, demonstrating the effectiveness of the proposed method. Specifically, the accumulated stress in an LIB caused by pressure variation is reduced by 56.17% under a stochastic load condition when activating the proposed pressure management strategy, resulting in a 1.47% increase in discharge capacity immediately after operation compared to that under a passive pressurized condition. The proposed method is simple, effective, and economically feasible for battery management systems in terms of compression pressure control.

Particulate matter formation mechanism in pressurized fluidized bed combustion of various solid fuels

Pressurized fluidized bed combustion (PFBC) is an advanced clean coal technology, and co-combustion of coal and biomass can effectively reduce pollutant and greenhouse gas emission during power generation. However, studies concerning the particulate matter formation during coal and biomass co-firing in PFBC are very rare. In this work, experiments on combustion of different solid fuels (two lignites, one bituminous coal, rice husk) and co-combustion of coal and biomass were carried out at 10 kW pressurized fluidized bed with system pressure of 0.5 MPa. Despite the different fuel types, pressurized combustion produces PM1 with higher content of easily vaporized elements (Na, K, and S), while super-micron particles are mainly composed of refractory elements (Ca and Si). For the cases of cofiring coal with biomass, it was found that the mineral interaction can reduce the yield of submicron particles, such as PM0.4 formation in Zhundong lignite/rice husks and Xiaolongtan lignite/rice husks were reduced by 28% and 47%, while the reduction is 61% and 64% for PM1, and 80% and 75% for PM2.5. Overall, this work provides the insight on particulate matter formation during the combustion of various solid fuels in pressurized combustion conditions, which hopefully can help the development of PFBC technology.

Experimental study and modelling of pressurized oxy-coal combustion: Effect of devolatilization conditions on the physical structure and combustion characteristics of char particles

Pressurized oxy-coal combustion has been regarded as a promising carbon capture and storage (CCS) technology, and the combustion characteristics of char particles under pressurized oxy-fuel combustion conditions have been extensively investigated. However, most previous studies used the char samples prepared under the atmospheric N2 condition rather than under the pressurized CO2 condition, which may lead to the misunderstanding of the combustion characteristics. In this study, the effects of devolatilization atmosphere and pressure on the physical structure of char particles were experimentally investigated. The char particles produced under different devolatilization conditions were then used for the oxy-char combustion experiments conducted in a fluidized bed with the operating pressure between 0.1 and 0.5 MPa. In view of the limitations of the experiment, an experimental verified particle-scale char combustion model was further used for predicting the char particle’s combustion reactivity and temperature, and the influence of physical structure on the combustion characteristics was analyzed. The results obtained from the experiments demonstrated that higher devolatilization pressure led to larger mean pore sizes and specific surface areas of char particles. The char particles obtained with CO2 atmosphere had larger specific surface areas but smaller mean pore sizes than those obtained with N2 atmosphere. Besides, increasing devolatilization pressure resulted in shorter burnout times of char particles. The simulation results showed that using the char samples prepared under the atmospheric N2 condition for the pressurized oxy-fuel combustion experiments led to the underestimations of char combustion reactivity and peak temperature.

Wideband Acoustic Absorbance in Otosclerosis: Does Stapedotomy Restore Normal Tympanic Cavity Function?

Introduction Otosclerosis is characterized by the fixation of the stapes to the oval window, thereby impairing acoustic signal absorbance. A commonly used surgical technique for improving hearing in cases of otosclerosis is stapedotomy. However, it is unclear whether this surgery restores all the physical characteristics of the tympano-ossicular system. Objective To evaluate the tympano-ossicular system in individuals with fenestral otosclerosis pre and poststapedotomy using wideband tympanometry. Method A total of 47 individuals and 71 ears were assessed. The subjects were divided into three groups: presurgery otosclerosis; postsurgery; and a control group of normal-hearing adults. A handheld tympanometer with a wideband module (226-8,000 Hz) was used to take measurements at ambient pressure and under pressurized conditions. The level of statistical significance adopted was p ≤ 0.05. Results Acoustic absorbance at 226 Hz was low for all groups. At frequencies in the range 630 to 5,040 Hz, each group had a characteristic absorbance curve, allowing them to be distinguished from one another. In the presurgery group, absorbance values were below normal levels, with energy absorbance below 10%. Low energy absorbance was most evident at 1,000 Hz in the presurgery group, but this was not observed in the postsurgery group. Although there was an improvement in hearing, the surgery failed to restore the tympano-ossicular system to normal. Conclusion Wideband acoustic absorbance proved able to differentiate normal ears and otosclerotic ears pre and postsurgery, under both ambient pressure and pressurized conditions.

Abstract 3809: Adaptation of prostate cancer cell lines to tumor microenvironment culture conditions induces expression of androgen receptor splice variant 7 and contributes to drug resistance

Abstract The tumor microenvironment (TME) has several characteristics that distinguish it from normal tissue, including elevated interstitial fluid pressures and hypoxic environments. Both pressurized and hypoxic culture conditions can influence gene and protein expression of tumor cells which can result in tumor metastasis and drug resistance. Enzalutamide is effective in treating metastatic castration-resistant prostate cancer (mCRPC), but majority of patients eventually develop resistance to enzalutamide. One of the biomarkers of enzalutamide resistance is the expression of androgen receptor splice variant 7 (AR-V7), but the mechanism of how AR-V7 expression is upregulated in prostate cancer is unclear. To investigate the influence of TME culture conditions on prostate cancer cell lines, 22Rv1 and LNCaP cell lines were incubated under pressurized and hypoxic culture conditions (2 PSI + 1%O2) for a minimum of 7 days. We compared cell growth, morphology changes, gene expression profiles and drug response to enzalutamide treatment. The growth of 22Rv1 and LNCaP cells was markedly inhibited under TME culture conditions, accompanied by distinct changes in cell morphology. 22Rv1 and LNCaP cells cultured under TME conditions exhibited increased resistance to enzalutamide treatment. Higher levels of AR-V7 expression were detected in 22Rv1 and LNCaP cell lines maintained for 7 days in TME culture conditions. RNA-seq data identified 700+ genes that were differentially expressed in 22Rv1 and LNCaP cell lines adapted to TME culture conditions. GSEA analysis identified signaling pathways associated with hypoxia, glycolysis and epithelial-mesenchymal transition were upregulated under TME culture conditions, and the pathways of xenobiotic metabolism and oxidative phosphorylation were downregulated by TME culture conditions. In summary, adaptation to TME culture conditions can promote the expression of AR-V7 in prostate cancer cell lines and can contribute to enzalutamide drug resistance. Adaptation of cell lines to TME culture conditions can provide meaningful insights into mechanisms of drug resistance while providing a novel approach to identify targets and biomarkers of drug resistance. Citation Format: Yunmin Li, Albert Wong, Ann Lu, James Lim. Adaptation of prostate cancer cell lines to tumor microenvironment culture conditions induces expression of androgen receptor splice variant 7 and contributes to drug resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3809.

Abstract 2763: Adaptation of therapeutic NK cell line to tumor microenvironment culture conditions increases potency and reduces cellular exhaustion

Abstract NK-92 is a well-characterized human NK cell line that has demonstrated promising anti-cancer activities in clinical trials. However, the immunosuppressive solid tumor microenvironment (TME) can inhibit NK-92 function thereby limiting its cytolytic properties against tumor cells. To address this limitation, we serially passaged and maintained NK-92 cell lines under tumor microenvironment culture conditions (2.0 PSI + 1% O2) for a minimum of 5+ weeks. This adaptation period was used to precondition and expand NK cells with lower oxygen dependency, enriching for subset of cells that have metabolically adapted to pressurized and hypoxic culture conditions. NK cells maintained and expanded under TME culture conditions gradually reduced their cell-doubling times to reach parity with parental lines maintained under ambient oxygen (21% O2) culture conditions. This adaptation period coincided with improved tumor killing properties for TME-Adapted NK cells (TANK) against the non-small cell lung cancer cell line, A549. Enhanced cytolytic activity of TANK cells was two-fold greater than their non-TME adapted counterparts, with sustained potency observed in both ambient and TME screening conditions. Furthermore, serial exhaustion studies where TANK cells were repeatedly stimulated with tumor cells show sustained cytolytic activity, in contrast to non-TME adapted NK92 counterparts. TANK cells also exhibit higher levels of granzyme B and perforin as assessed by flow cytometry, while exhibiting distinct gene expression signatures as profiled with RNAseq. This initial study supports the hypothesis that immune cells can both react and adapt to different microenvironments. TME-adaptation strategies during cell expansion can enhance potency and efficacy of cell therapies designed to work in a solid tumor microenvironment. Citation Format: Ann Lu, Yunmin Li, Albert Wong, James Lim. Adaptation of therapeutic NK cell line to tumor microenvironment culture conditions increases potency and reduces cellular exhaustion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2763.

Ethanol and dimethyl carbonate as solvents under pressurized conditions to obtain oil and active compounds from crambe seeds

This work investigated the efficiency of pressurized liquid extraction (PLE) to obtain oil and active compounds from crambe seeds, using dimethyl carbonate (DMC) and ethanol as solvents. The Box-Behnken experimental design was used to evaluate the influence of experimental conditions (addition of ethanol to DMC, pressure and temperature) on extraction mass yield (EMY) and yield of phytosterols (PY) and γ-tocopherol (TY). In the condition that provided the maximum value of the evaluated response variables, the effect of the solvent to seed ratio and solvent was determined, as well as the comparison with the data from the application of conventional extraction by Soxhlet. From the results obtained, it was found that the temperature and the addition of ethanol to the DMC had a high influence on the removal and quality of the oil. The addition of 50% ethanol to the DMC, low pressure (50 bar) and high temperature (150 °C) allowed obtaining the highest values for the response variables and the validation of the model was verified by high correlation between the predicted (EMY: 36.43%; PY: 925.44 mg per kg of seeds; TY: 536.66 mg per kg of seeds) and experiments (EMY: 39.35%; PY: 914.57 mg per kg of seeds; TY: 533.29 mg per kg of seeds) values. PLE resulted in EMY higher than that obtained in the Soxhlet extraction, and for the different solvents tested, EMY followed the order DMC + ethanol > ethanol > DMC. The use of ethanol in PLE provided a high content of active compounds compared to the use of the solvent mixture, however, it presented greater extraction of non-lipid compounds. The main fatty acids present in crambe oil were erucic and oleic, the iodine value and the fatty acid composition were similar for the different solvents/extraction technique. In general, the presence of natural antioxidants and the high oxidative stability of the oil showed that it has the potential to be applied in the synthesis of biodiesel.

Sequential process to obtain fatty acid esters from crambe oil using a mixture of acyl acceptors under pressurized conditions

In this study, the use of a mixture of acyl acceptors (dimethyl carbonate, methanol and ethanol) under pressurized conditions to obtain fatty acid esters (FAEs) was investigated. The influence of varying the proportions of acyl acceptors and the temperature applied in the reaction was evaluated using commercial oil. For the proportions that resulted in the maximum FAE yield (YFAE), the crambe oil was extracted using pressurized liquid extraction (PLE) and characterized. The extraction product (oil + acyl acceptors) was then subjected to the reaction step. The addition of alcohols to dimethyl carbonate favored the YFAE, a higher proportion of ethanol made the reaction product less susceptible to thermal decomposition and it was possible to obtain ~86 % of YFAE at 275 ºC. The oil obtained in the PLE had higher contents of phytosterols and γ-tocopherol. Thus, the extraction product had greater stability and YFAE of ~94 % was obtained without thermal decomposition.

Low- and High-Density Unknown Waters at Ice-Water Interfaces.

Experimental confirmation of liquid polymorphs of water, high-density liquid (HDL) and low-density liquid (LDL), is desired for understanding not only the liquid state of matter but also the origin of the mysterious properties of water. However, this remains challenging because the liquid-liquid critical point of water lies in experimentally inaccessible supercooling conditions known as "no man's land". Here, we show by in situ optical microscopy that droplets and layers of low- and high-density unknown waters (LDUW and HDUW) appear macroscopically depending upon ice polymorphs at non-equilibrium interfaces between water and ices under experimentally accessible (de)pressurization conditions. These unknown waters were found to have characteristic velocities (about 20 and 100 m/s for LDUW and HDUW, respectively) different from water (about 40 m/s) and quasi-liquid layers (QLLs) (about 2 and 0.2 m/s for droplet and layer forms of QLLs, respectively). Our discoveries provide insight on liquid polymorphism of water.

Synthesis and Characterization of Edible Films from Garlic<em>(Allium sativum)</em> Husk Components

Garlic husks are waste biomass and unutilized sources of essential compounds like lignin, pectin, cellulose, hemicellulose, lignocellulose and dietary fibre. Pectin was extracted from garlic husk using ammonium oxalate solution. Lignin is a complex biopolymer consisting of p-coumaryl alcohol, sinapyl alcohol, and coniferyl alcohol. Lignin was extracted from garlic husk using alkali pulping method; the sample was subjected to 10% (w/w) NaOH solution in a pressurized condition at high temperature. The extracted lignin was characterized using Fourier Transform Infrared Spectroscopy (FTIR). Transmittance ratios in FTIR Spectra of extracted lignin were similar to those of the commercial lignin. The edible film was prepared by solution casting method where the film was casted from the solution of pectin and lignin. The physical and chemical properties of the film like moisture content, color, solubility of the film, antimicrobial activity, water vapour transmission rate, pectin and lignin were characterized. The lowest water vapour permeability of the film is 17.48 ± 0.12 g/h m 2 . Whiteness index and 'L' value of film decreased from film 1 to film 4. An inhibition zone was formed against the Bacillus cereus proving the antimicrobial activity of the lignin extracted from garlic husk.

Sugarcane bagasse valorization to xylitol: Techno‐economic and life cycle assessment

AbstractA detailed techno‐economic analysis and life cycle assessment (LCA) of a novel bio‐refinery that produces xylitol from sugarcane bagasse are provided. The proposed process includes dilute acid pretreatment in pressurized conditions followed by fermentation (upstream section). The fermentation broth is then sent for separation and purification to the downstream section. Calculations are performed for a plant with 4 t/h of dry bagasse throughput. With a fermentation yield of 0.54 g xylitol per g of xylose, the plant produced 437.4 kg/h of xylitol. Upstream data are adapted from experimental studies, while ASPEN PLUS® flowsheet simulation is used to obtain data for the downstream section. The xylitol production facility is assumed to be annexed to an existing sugar mill in India. The total utility requirement in the process is reduced using heat integration strategies. Cradle‐to‐gate scope is considered for the LCA and 1 kg of xylitol is taken as the functional unit. The product cost of xylitol is calculated to be 230 INR/kg (US$3.17/kg). For a 4 year payback period, the selling price of xylitol must be 450 INR/kg (US$6.2/kg). The fermentation and pretreatment sections are the major components of the product cost. The LCA results show that the life cycle greenhouse gas emissions are 2.759 kg CO2 eq. per kg xylitol. The electricity requirement within the plant is identified as the major source of greenhouse gas emissions, and reduction of fermentation duration is identified as a key factor. The results identify opportunities to improve the process from an economic as well as an environmental standpoint. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.