Boiling Research Articles

Water Quality in Puerto Rico after Hurricane Maria: Challenges Associated with Water Quality Assessments and Implications for Resilience

Extreme weather events can adversely impact potable water production and distribution, which could in turn have public health implications. The original study goal was to assess potential water quality hazards (both chemical and microbiological) in the aftermath of Hurricane Maria, which made landfall in Puerto Rico on September 20, 2017. The first sampling campaign surveyed water sources that were contextually relevant to disaster recovery and included government-managed systems, community-managed systems, and unmanaged/improvised (spring) sources. Due to extensive power outages, residents increasingly leveraged community-managed and unmanaged sources to fulfill their needs, and these sources showed a higher prevalence of microbiological hazards. However, an unexpected finding in the first sampling campaign was high concentrations of lead in a subset of samples collected from exterior taps, which instigated three follow-up sampling campaigns. Reflecting on the sampling methodology, we conclude that sampling the exterior taps was an appropriate, conservative approach based on a higher likelihood of lead-based plumbing materials and the contextual use of those taps before and after the hurricane due to extended boil water notices and interrupted service. This conservative sampling approach aligned better with historical data reported to the national database. Although the elevated lead concentrations may not be a direct result of the hurricane, this study explores the challenges of rapid reconnaissance research after disasters.

Evaluation of Long-Term Boiling Water Immersion as Artificial Aging Test of Silicone Rubber Insulators

Our country IRAN have long coastal area with length of more than 1830 km. Utility companies with 30 years of experience in using polymeric insulators in this very heavy polluted area. Operational history in these areas indicates many insulating problems. With the advancement of polymer insulation technology, the utilities want to select the longest life insulators for these areas. Laboratory studies accelerated testing of polymer insulators is the only available method to investigate the trend of insulator degradation during the aging process, because it takes a long time for noticeable changes and signs of aging to appear on insulators in the power grid. Different methods such as salt-fog, UV and boiling water are used to test artificial aging, each method has advantages and disadvantages. In our experience, boiling water is used as a low-cost method in compared to the other methods especially salt fog test. The aim of this research was to determine a shorter method for evaluation of SR insulators. In this paper, the accelerated aging of polymer insulators using salt-fog and boiling water immersion tests are investigated. During and after the aging test, the polymer insulator's electrical quality is analysed using leakage current measurement tools, partial discharge, and hydrophobicity. Surface changes are also analysed by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), Thermo Gravimetrical Analysis (TGA), and Fourier Transform Infrared Spectroscopy (FTIR) both qualitatively and quantitatively.

Tracking the post-disaster evolution of water infrastructure resilience: A study of the 2021 Texas winter storm

In February 2021, severe winter weather in Texas caused widespread electrical blackouts, water outages, and boil water notices. Water systems faced extensive challenges due to cascading failures across multiple interdependent infrastructure systems. Water utilities have since made considerable progress in improving resilience to extreme events, but ongoing challenges remain. Through a qualitative analysis of semi-structured interviews with 20 large water utilities in Texas, this study tracks the evolution of water infrastructure resilience across three phases: the storm and immediate aftermath, the subsequent one-year period, and the “new normal” in the post-disaster environment. We consider five dimensions of resilience—economic, environmental, governance, infrastructure, and social—to identify where solutions have been implemented and where barriers remain. This study contributes to efforts throughout the United States to build more robust water systems by capturing lessons learned from Winter Storm Uri and providing recommendations to improve hazard preparedness, resilience, and public health.

Boiled Eggs: Soft and Hard — Part 1

Boiled Eggs: Soft and Hard — Part 1

The Effect of Giving Avocado Leaf Boiled Water on Lowering Blood Pressure in the Elderly with Hypertension in the Work Area Gambut Health Center

Background: Hypertension is a condition of a person’s blood pressure being at a level above normal, hypertension treatment can be done herbally using avocado leaves. Avocado leaves can lower blood pressure because they contain active substances, namely flavonoids and quercetin. This research was conducted in the working area of the Tilango Health Center. Objective: This study aims to determine the effect of giving boiled water of avocado leaves on reducing blood pres sure in the elderly with hypertension. Methods: Design This study used a two group quasi experimental pretest posttest design. The sample is the elderly who have hypertension, amounting to 125 people with purposive sampling technique. The research instrument used a questionnaire. Results: Statistical test using T-Test on blood pressure before and after the intervention was given a significance value of 0.000 (pvalue < 0.05). Conclusion: This study concludes that there is a significant effect between giving avocado leaf boiled water on reducing blood pressure in the elderly with hypertension in the working area of the Tilango Health Center.

How might climate change impact water safety and boil water advisories in Canada?

A boil water advisory (BWA) informs the public that there is an increased level of risk associated with their water and that they should boil it before consuming. Studies show that small communities in Canada are particularly likely to experience repeat and long-term BWAs. Climate change has led to changes in precipitation and temperature patterns, leading to region-specific impacts such as increased frequency, severity, or variance in floods, forest fires, droughts, freezing rain, and sea water intrusion. Academic and non-academic “grey” literature was reviewed to establish the most likely impacts of climate change on water treatment and infrastructure. Anonymized data from public drinking water systems in Canada was analyzed to determine the most common causes of BWAs between 2005 and 2020. Most BWAs reported were related to breakdowns/malfunctions along the distribution, though inadequate disinfection residual and turbidity or coliforms in the treated water were also common. Furthermore, statistical analysis of the data showed seasonal trends in some of these parameters. The results of this study suggest that increased precipitation, flooding, permafrost degradation, and forest fires are likely to have significant impacts on water safety in Canada. Highlights: Climate change effects are expected to worsen many current water challenges. Climate change will disproportionately impact small, rural, and remote water utilities. Water distribution systems are the main source of water safety risk in Canada. Groundwater-supplied systems experience a disproportionate number of BWAs. Seasonal trends in BWA reasons provide opportunities for targeted mitigation.

Characterization and split-split-plot analysis of steamed factors affecting the swimming crab (Portunus trituberculatus) flavor quality

Swimming crab (Portunus trituberculatus) is a kind of popular crab for being rich in nutrition and intense in flavor. The time and heat exposure cause differences in flavor during steaming, dramatically affecting first impression and acceptability. The quality of P. trituberculatus with different steaming methods (steam with Room Temperature Water, RTW and steam with Boiling Water, BW) was evaluated using consumer acceptability, sensory characterization, and instrumental analysis. The split-split plot analysis was employed to compared the effects of the edible parts, steaming methods and steaming time. The results demonstrated that the hedonic score of crab meat was 1.3 times higher than that of hepatopancreas. Edible parts were the most important factor followed by the steaming method without interaction. The female crab meat (F-M) and male crab meat (M-M) were correlated with positive emotions, while opposite for hepatopancreas. RTW was more likely to evoke positive emotions, while BW followed the opposite trend. Instrumental analysis revealed that the types of volatiles produced with BW were similar to those by RTW, but their contents are generally 1.5–2.5 times higher. In sum, P. trituberculatus which were steamed for 25 min using RTW may be more acceptable.

Drinking water contamination and avoidance behavior: do bottled water sales adequately measure the cost of this behavior?

ABSTRACT This paper examines the impact of anticipated duration for drinking water contamination on avoidance behavior. Differences in anticipated duration are based upon the type of public information provided to water customers: short-term boil water advisories (BWAs) versus long-term public notifications based upon Safe Drinking Water Act (SWDA) health-based violations. Avoidance behavior is measured by weekly bottled water sales at the county level in Kentucky. Our results confirm that BWAs have a much larger impact on bottled water sales than SWDA notifications. Bottled water sales increase by an estimated 3.8% in response to a 10-percentage point increase in population affected by BWAs during the week. This change in bottled water sales, however, represents a fraction of total avoidance behavior costs. Thus, bottled water purchases should be considered a very lower bound estimate for avoidance behavior cost estimates from contamination episodes of drinking water.

Model for determining rupture area in Zircaloy cladding under LOCA conditions

The dispersal of nuclear fuel through a cladding rupture opening during a transient event is the primary safety concern preventing the United States nuclear industry from extending burnup beyond a peak rod average burnup of 62 GWd/tU. The majority of research thus far has prioritized understanding, or at a minimum prioritized quantifying, fuel fragmentation and pulverization as a function of burnup and to a lesser extent onset temperature. Early high burnup loss-of-coolant accident tests performed at the Halden Boiling Water Reactor evaluated the impact of relocation on cladding temperature, whereas historical and recent cladding burst tests focused primarily on generating data related to cladding balloon and burst timing. However, very little effort has been put forth to develop a relationship for determining the rupture opening dimensions for Zircaloy cladding tubes bursting during a simulated light water reactor loss-of-coolant accident. This is significant because high burnup loss-of-coolant accident data suggest dispersal could be limited by the size of the rupture opening or rupture dimensions, thereby minimizing the safety concern. Therefore, the purpose of this research is to build a database composed of all simulated loss-of-coolant accident data to develop an empirical model that conservatively captures the rupture opening dimensions and translates those dimensions to rupture area. Analysis of the experimental data indicates the rupture dimensions are strongly correlated to the peak balloon strain. This relationship is leveraged to develop a rupture length empirical correlation as a function of peak balloon strain and a rupture width empirical correlation as a function of rupture length. Outliers in the experimental data are identified and discussed. Finally, the rupture opening empirical model is presented in such a way for general implementation into high fidelity fuel performance codes or fuel performance codes used for safety analyses.

Back Porch

Back Porch Tom Rankin Click for larger view View full resolution Lumberton, NC, 2016. Photos courtesy of the author. In october 2016, my wife, Jill McCorkle, and I drove our Tacoma pickup filled with cases of bottled water and other essentials to her hometown of Lumberton, North Carolina. Hurricane Matthew had made landfall at McClellanville, South Carolina, just north of Charleston, and then drifted northeasterly into North Carolina. An eight-mile stretch of I-95 went completely underwater, and by October 10, just two days after the hurricane came ashore in South Carolina, the Lumber River rose to over twenty-two feet in Lumberton. Roads, yards, and first floors of many houses were underwater. As Lumberton resident James Robinson told the Raleigh News and Observer, “All that water got to go somewhere.” Where it went was into the homes and businesses throughout Lumberton, over-taking [End Page 142] the city water treatment plant, leaving most residents with either no running water or water too contaminated to drink or use at home. The rains of Hurricane Matthew drenched a Robeson County that is perpetually one of North Carolina’s poorest, with over one-third of the population living in poverty in 2016.1 Click for larger view View full resolution Lumberton, NC, 2016 The irony of driving a truckload of water into a flood zone is all too obvious. We picked our way from Hillsborough in the Piedmont through the Sandhills to avoid flooded roads, arriving in a Lumberton community that held far too much water and yet no potable water, awaiting deliveries such as ours. Excess and scarcity in the same place and time, profound and dire forces perpetrated upon those with the least resources, those living in public housing and on the lowest land most vulnerable to flooding. Throughout covid we saw vividly the realities and challenges of the digital divide as so much school and work moved to virtual platforms. A similar divide, along familiarly recognizable maps, is evident during floods and the all-too-common water crises. We might call it the water divide, a cousin of the digital divide, where drainage can be destiny and neglected infrastructure leads to [End Page 143] unhealthy and undrinkable water. Class and racial divides are visible, too, around impacts from climate change, floods, and lack of clean water. One need look no further than the case of water infrastructure in Jackson, Mississippi. In August 2022, relentless rains caused the Pearl River, which flows through Jackson, to flood. The Pearl River has flooded Jackson before, most notably in 1979, when a historic flood brought massive destruction. The recent 2022 flood damaged a water treatment plant which, combined with a malfunction of pumps at the treatment plant, led to no water in Jackson. Prior to that, there was a boil water requirement for the city. “Unfortunately, what is central to the endgame of the Jackson water crisis is power,” wrote Ralph Eubanks in an eloquent piece for cnn. “Power lies at the core of the politics of identity being played by Mississippi’s Republican politicians. What all the parties involved in getting clean water to Jackson’s citizens should be seeking is knowledge and truth, rooted in a shared meaning of Mississippi’s past, even the ugly parts of it that make us all uncomfortable when we look at them through a deep, dark, truthful mirror. Until Mississippi begins to see the connection between the Jim Crow past in its present—and see it clearly—the Jackson water crisis will never be resolved.”2 Click for larger view View full resolution Estill, MS, 2021 ________ FLOOD STORIES ARE VERY OFTEN TOLD with an emphasis on an aftermath of rebuilding and rebirth, the proverbial theme of newness that runs through so much mythology and folk narrative after the high waters recede. Traditional full-immersion baptism draws much meaning from the symbolism of being buried and reborn, going under water, then rising from a watery grave. In my documentary fieldwork through the years, I have often heard sermons, delivered on the bank of a lake, that beautifully articulate the meaning of baptism as death, burial, and resurrection, the long-held ritual signaling a...

Sanitary sewage overflows, boil water advisories, and emergency room and urgent care visits for gastrointestinal illness: a case-crossover study in South Carolina, USA, 2013-2017.

Sanitary sewage overflows (SSOs) release raw sewage, which may contaminate the drinking water supply. Boil water advisories (BWAs) are issued during low or negative pressure events, alerting customers to potential contamination in the drinking water distribution system. We evaluated the associations between SSOs and BWAs and diagnoses of gastrointestinal (GI) illness in Columbia, South Carolina, and neighboring communities, 2013-2017. A symmetric bi-directional case-crossover study design was used to assess the role of SSOs and BWAs on Emergency Room and Urgent Care visits with a primary diagnosis of GI illness. Cases were considered exposed if an SSO or BWA occurred 0-4 days, 5-9 days, or 10-14 days prior to the diagnosis, within the same residential zip code. Effect modification was explored via stratification on participant-level factors (e.g., sex, race, age) and season (January-March versus April-December). There were 830 SSOs, 423 BWAs, and 25,969 cases of GI illness. Highest numbers of SSOs, BWAs and GI cases were observed in a zip code where >80% of residents identified as Black or African-American. SSOs were associated with a 13% increase in the odds of a diagnosis for GI illness during the 0-4 day hazard period, compared to control periods (Odds Ratio: 1.13, 95% Confidence Interval: 1.09, 1.18), while no associations were observed during the other hazard periods. BWAs were not associated with increased or decreased odds of GI illness during all three hazard periods. However, in stratified analyses BWAs issued between January-March were associated with higher odds of GI illness, compared to advisories issued between April-December, in all three hazard periods. SSOs (all months) and BWAs (January-March) were associated with increased odds of a diagnosis of GI illness. Future research should examine sewage contamination of the drinking water distribution system, and mechanisms of sewage intrusion from SSOs. Sewage contains pathogens, which cause gastrointestinal (GI) illness. In Columbia, South Carolina, USA, between 2013-2017, there were 830 sanitary sewage overflows (SSOs). There were also 423 boil water advisories, which were issued during negative pressure events. Using case-crossover design, SSOs (all months) and boil water advisories (January-March) were associated with increased odds of Emergency Room and Urgent Care diagnoses of GI illness, potentially due to contamination of the drinking water distribution system. Lastly, we identified a community where >80% of residents identified as Black or African-American, which experienced a disproportionate burden of sewage exposure, compared to the rest of Columbia.

Quantification of Deep Neural Network Prediction Uncertainties for VVUQ of Machine Learning Models

Recent performance breakthroughs in artificial intelligence (AI) and machine learning (ML), especially advances in deep learning, the availability of powerful and easy-to-use ML libraries (e.g., scikit-learn, TensorFlow, PyTorch), and increasing computational power, have led to unprecedented interest in AI/ML among nuclear engineers. For physics-based computational models, verification, validation, and uncertainty quantification (VVUQ) processes have been very widely investigated, and many methodologies have been developed. However, VVUQ of ML models has been relatively less studied, especially in nuclear engineering. This work focuses on uncertainty quantification (UQ) of ML models as a preliminary step of ML VVUQ, more specifically Deep Neural Networks (DNNs) because they are the most widely used supervised ML algorithm for both regression and classification tasks. This work aims at quantifying the prediction or approximation uncertainties of DNNs when they are used as surrogate models for expensive physical models. Three techniques for UQ of DNNs are compared, namely, Monte Carlo Dropout (MCD), Deep Ensembles (DE), and Bayesian Neural Networks (BNNs). Two nuclear engineering examples are used to benchmark these methods: (1) time-dependent fission gas release data using the Bison code and (2) void fraction simulation based on the Boiling Water Reactor Full-size Fine-Mesh Bundle Tests (BFBT) benchmark using the TRACE code. It is found that the three methods typically require different DNN architectures and hyperparameters to optimize their performance. The UQ results also depend on the amount of training data available and the nature of the data. Overall, all three methods can provide reasonable estimations of the approximation uncertainties. The uncertainties are generally smaller when the mean predictions are close to the test data while the BNN methods usually produce larger uncertainties than MCD and DE.

Iterative computed tomography reconstruction of void fraction in a fuel bundle on unstructured mesh

The experimental investigation of internal two-phase flow structures in high pressure/high temperature systems is technologically challenging and limited to a few instrumentation techniques. For complex fuel bundle geometries, the use of Computed Tomography (CT) allows for relatively high spatial resolution (0.2 to 1 mm) and non-intrusive measurement of time-averaged void fraction. One of the main issues using standard structured reconstruction mesh is due to the loss of accuracy near the test section boundaries, for instance within the pixels overlapping both the two-phase coolant and the heated rods. In this work, a void fraction reconstruction methodology based on unstructured mesh is developed to accurately bound relevant attenuation regions within the considered test section. This method eliminates any overlapping reconstruction pixels and allows straightforward applications of knowledge-based, low noise, algebraic iterative reconstruction techniques (ART, SIRT, etc.). Within the same consistent framework, CT scan forward projections can be simulated for various selected cases (single-phase, arbitrary-two-phase void fraction distributions, etc.) and reconstructed to assess the performance of both the CT scan setup (e.g., projection data sampling and number of projections) and the reconstruction technique. The method is applied to the void fraction reconstruction of gamma CT data in a 5 × 5 fuel bundle geometry measured at the Westinghouse FRIGG thermal–hydraulic test facility operating under prototypical conditions of Boiling Water Reactor. The unstructured mesh is designed to match the features of the test section (isolation, pressure vessel, water gap, fuel channel, heated rods and coolant) with high-resolution in the domain of interest (coolant) and very low-resolution in all other domains with known attenuation coefficients. As compared to previous void fraction reconstruction attempts for this data set, the new reconstruction methodology allows significant improvements in void fraction resolution and noise reduction.

Measuring moisture damage of hot-mix asphalt (HMA) by digital imaging-assisted modified boiling test (ASTM D3625): Recent advancements and further investigation

Boiling water test (ASTM D3626) has been utilized to investigate the moisture susceptibility of asphalt mixture for decades. It was originally intended to compare the relative moisture resistance of a few mixtures, and the degree of stripping after the boiling was recorded based on visual observations. In recent years, several digital imaging-assisted modified boiling tests have been proposed, which significantly improved the accuracy of test results. This paper reviewed the recent advancements (2009–2022) in different test methods by digital imaging. The limitations and challenges of each method were also discussed and compared to each other. In addition, further experiments were performed to investigate the effect of aging, boiling time and water quality on the coating ratios. The boiling test results of sixty loose mixtures were compared to the tensile strength ratios (TSRs). Based on the results, the boiling water test with enhanced accuracy by image processing can be potentially developed as a measure of field performance. More importantly, the test should be conducted immediately after the mixing of asphalt and aggregate, and the aging of asphalt mixtures could significantly increase the results of coating ratios up to 100%, which made the boiling test unable to identify moisture susceptibility. It was found that the boiling water could not strip asphalt from aggregate after a long time of aging even though the moisture damage occurred and weakened the bond between asphalt and aggregate. In addition, the water quality could considerably influence the boiling test results, and the use of distilled water might underestimate the moisture damage of asphalt mixtures subjected to acid rain.

The interface design of storage and examination system for BWR spent nuclear fuel dry storage demonstration project in Taiwan

Due to the lack of Boiling Water Reactor (BWR) fuel examination data after dry storage, Taiwan Power Company and Institute of Nuclear Energy Research jointly launched the “Taiwan Nuclear Fuel Storage Demonstration Project” to collect fuel characteristics data under simulated dry storage. To meet the project requirements, BWR fuel rods in different fuel designs will be selected and then store in simulated storage containers in different environments for 10 years. The interface considerations and design results of the auxiliary equipment for spent nuclear fuel storage, transfer, and non-destructive testing in the simulation stage of spent fuel dry storage were summarized. In addition, the possibility of operating at high heating power and avoiding deformation of the components due to thermal extension of the storage containers after heating was included in the design consideration. A simplification concept was introduced, with frequent NDT (Non-destructive Testing) inspections that will be performed through the spent fuel transfer process. The test results showed that the interface design can meet the requirements of long-term experiment, maintenance and radiation protection requirements, and is ready for further demonstration.

Effects of different thermal processing methods on bioactive components, phenolic compounds, and antioxidant activities of Qingke (highland hull-less barley)

Qingke (highland hull-less barley) is a grain replete with substantial nutrients and bioactive ingredients. In this study, we evaluated the effects of boiling (BO), steaming (ST), microwave baking (MB), far-infrared baking (FB), steam explosion (SE), and deep frying (DF) on bioactive components, phenolic compounds, and antioxidant activities of Qingke compared with the effects of traditional roast (TR). Results showed that the soluble dietary fiber, beta-glucan and water-extractable pentosans of Qingke in dry heat processes of TR, SE, MB and FB had a higher content compared with other thermal methods and had a better antioxidant activity of hydroxyl radical scavenging and a better reduction capacity, while those in wet heat processes of BO and ST had a better antioxidant activity of ABTS radical scavenging and a better Fe2+ chelating ability. DF- and SE-Qingke had a higher content of tocopherol, phenolic, and flavonoid. Overall, 6 free phenolic compounds and 12 bound phenolic compounds of Qingke were identified, and free phenolic compounds suffered more damage during thermal processing. Principal component analysis showed that SE had more advantages in retaining and improving the main biological active ingredients of Qingke, and it may be the best method for treating Qingke.

Validation and application of numerical modeling for in-vessel melt retention in corium pools

In a hypothetical severe accident scenario in light water reactors (LWR), after the loss of primary coolant, the melted core moves to the lower plenum of the reactor pressure vessel and accumulate there. The melted core cautiously releases the decay heat which forms a pool of melted core, called corium, and turbulent natural convection starts. The decay heat transferred by the corium to the vessel may result in vessel failure due to the focusing effect in the absence of an effective cooling system. A numerical analysis is carried out using STAR-CCM+ commercial software to investigate the ability of the existing turbulence models and Algebraic Heat Flux Model (AHFM) to simulate the natural convective heat transfer phenomena in the corium pools. Efforts have been made to predict the BALI experimental results which are designed to simulate the heat transfer in corium pools, in the framework of severe accident studies. For BALI experiments various test campaigns are run varying the internal Rayleigh number, the viscosity of the simulant fluid, and test facility height. Various such experimental cases are verified and compared with numerical simulations. Temperature profiles along a vertical line, surface heat flux along the curved surface, average Nusselt number on the top, and curved surfaces are estimated. The effect of wall boundary conditions on heat transfer is analyzed. The numerical analysis is extended to Pressurized Water Reactor (PWR) and Boiling Water Reactor (BWR) geometries. The CFD analysis predicts the stratified zone and upper mixing zone very well, and the temperature profiles and average heat transfer values are in agreement with the experiments.

Critical heat flux on zircaloy and accident tolerant fuel cladding under prototypical conditions of pressurized and boiling water reactors

First of a kind high spatial and temporal resolution temperature measurements of Pressurized Water Reactor and Boiling Water Reactor simulated fuel pins (high heat flux cosine profile heaters) in annular rod type geometry during nucleate boiling, departure from nucleate boiling and re-wetting has been performed. Distributed fiber optic measurements of the cladding axial temperature with spatial resolutions down to 2.5 mm axially at up to three equally spaced azimuthal locations per rod have demonstrated the similarities and differences of the different accident tolerant fuel cladding materials. These experiments show the performance of accident tolerant cladding with a precise measurement of the location and evolution of dryout followed by the re-wetting phenomena (see supplementary time history of a critical heat flux event). Experimental parameters varied coolant mass fluxes from 1695 to 2712 kg/m2s, pressures from 10 to 20 MPa, and inlet subcooling from 10 to 55 °C. It was found that the coatings and different material have little effect on the value of the critical heat flux. Any discrepancies between the local critical heat flux verified among the cladding material are attributed to different departure from nucleate boiling phenomena captured during the experiment with the high-resolution optical fiber temperature data. Substantial differences in the performance of the different cladding material to survive a critical heat flux event were however observed by post-test X-ray and optical inspection. External evident damage and internal cracks to the simulated fuel pin having the bare zircaloy cladding were observed in regions associated with the occurrence of the critical heat flux for longer periods. Such damages were associated with zirconium oxidation, and not noticed on the Cr coated zircaloy or FeCrAl claddings. These results indicate that the use of FeCrAl or a Cr coated zircaloy as cladding in Pressurized Water Reactor and Boiling Water Reactor may increase the survivability of the cladding material for short transients.

Seed Longevity of Tagasaste (Chamaecytisus palmensis) after Seed Treatment Using Boiling Water as Affected by Storage Durations

Storage duration and seed treatments before storage are important factors responsible for retaining seed longevity. Hence, germination of tagasaste seed in the laboratory or nursery has been difficult and problematic without seed treatment, and yet, there is no information about the tagasaste seed longevity after treatment. Thus, this research was carried out to investigate the longevity of tagasaste seed after seed treatment for optimum germination percentage. The tagasaste seed was collected from the field of Holetta Agricultural Research Centre and treated monthly from March 2016 through February 2017. The germination test for the treated seed was done in the month of March for three consecutive years (2017, 2018, and 2019). The experiment was conducted in a randomized complete block design with three replications. The data were analyzed using the SAS software, and the least significant difference was employed for mean separation. The germination percentage was not significantly P > 0.05 different within the months of the first, second, and third years of storage durations. While, the germination percentage of the seed stored after treatment for one, two, and three years was nonsignificant P > 0.05 . Therefore, the treated seed of tagasaste can be stored under the ambient conditions of a tropical highland environment for about three years without significant loss in germination percentage. However, the study should be conducted for more years to know the effect of storage duration on seed viability of tagasaste after seed treatment.

Effects of radiofrequency blanching on lipoxygenase inactivation, physicochemical properties of sweet corn (Zea mays L.), and its correlation with cell morphology

This study investigated the effects of radiofrequency (RF) and boiling-water (BW) blanching on lipoxygenase (LOX) activity, physicochemical properties, and changes in the cellular morphology of sweet corn kernels. First, a speed-adjustable device was introduced to rotate the sample for improving heating uniformity. Then, the maximum RF heating rate and uniform temperature distribution of samples were obtained under 160 mm electrode gap, 120 g sample weight, and 14 r/min rotating speed. With increased RF heating temperature ranging from 50 °C to 80 °C, the residual activity of LOX significantly decreased to 4.68%. Samples blanched by RF treatment maintained better color, texture, and nutrient content than those by BW when similar levels of enzyme inactivation were achieved. Micrographs also showed the cells were increasingly damaged with increased RF heating temperature, whereas the cells were damaged much more severely when treated with BW. Besides, microscopic destruction of cells also explains the changes in physicochemical properties.