scholarly journals Evaluating the Performances of Interval Starting Accessibility Drying (ISAD) through Protein and Total Polyphenol Contents of Blue Crabmeat (Portunus segnis)

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1698
Author(s):  
Hela Gliguem ◽  
Wafa Hajji ◽  
Chaima Rekik ◽  
Karim Allaf ◽  
Sihem Bellagha
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Evaporation Rate ◽  
Quality Parameters ◽  
Operating Conditions ◽  
Convective Drying ◽  
Residual Water ◽  
Fishing Activity ◽  
Total Polyphenol ◽  
Portunus Segnis

Blue crab (Portunus segnis) proliferation on Tunisian coasts started in 2014/2015. It has heavily impacted the balance of other species, local biodiversity, and fishing activity. Limiting these drawbacks may be achieved through ways promoting crabmeat. For this purpose, two different drying modes were tested: Conventional convective drying (CCD) and interval starting accessibility drying (ISAD) under 45 °C and relative humidity of 40%. Several air velocities were assayed under CCD: 1.5, 2.5, 3.5, and 5 m.s−1. Two different ISAD tests were run with different time-related conditions: drying period of 15 s and tempering period of 15 or 60 s. Drying modes and operating conditions performances were compared through proteins and total polyphenol contents (TPCs) evolution during the treatment. Important polyphenol and protein losses were observed between raw and processed crabmeat. Airflow velocities have a significant effect on crabmeat quality preservation. ISAD method under 15 s/60 s allowed the best preservation of these quality parameters. TPC and proteins losses and kinetics during drying under CCD or ISAD were modelled and correlations were established between the quality parameters, the residual water content at all drying times, and the evaporation rate.

Determining Water Content at Saturation for Three Common Wind Turbine Gearbox Oils: Mobilgear SHC XMP 320, AMSOIL EP Gear Lube ISO-320 and Castrol Optigear A320

2013 ◽  
Author(s):  
Matthew S. Whitten ◽  
Kim A. Stelson
Keyword(s):  
Relative Humidity ◽  
Service Life ◽  
Wind Turbine ◽  
Water Content ◽  
Energy Demand ◽  
Operating Conditions ◽  
Energy Output ◽  
Wind Turbine Gearbox ◽  
Saturation Limit ◽  
Field Samples

To meet America’s growing energy demand, wind turbines will need to become larger and more cost effective [1]. However, estimates show that the average wind farm energy output is 10 percent less than predicted and that half of this short fall is due to gearbox downtime [2]. Increasing service life of the gearbox begins with monitoring the oil and controlling contamination by both particles and water. When online relative humidity monitoring is not available, oil samples from the gearbox need to be analyzed for quality and remaining service life. Field samples sent to a lab for testing often report water content as parts per million (ppm). Because the gearbox oil should be dried or replaced before the relative humidity reaches 100 percent (saturation limit), a relationship between ppm and the oil’s saturation limit needs to be established. The present research characterizes this relationship using an environmental chamber to simulate operating conditions and Karl Fischer titration to measure the water content. The resulting plots are of water content (ppm) at saturation versus temperature for three common wind turbine gearbox oils: Mobilgear SHC XMP 320, AMSOIL EP Gear Lube ISO-320 and Castrol Optigear A320.

scholarly journals Energetic and exergetic analysis of a convective drier: A case study of potato drying process

2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné
Keyword(s):  
Energy Consumption ◽  
Research Work ◽  
Specific Energy Consumption ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Convective Drying ◽  
Drying Time ◽  
Energy And Exergy ◽  
Exergy Losses

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.

PEF as pretreatment to ultrasound-assisted convective drying: Influence on quality parameters of orange peel

2021 ◽  
pp. 102753
Author(s):  
Ronaldo E. Mello ◽  
Alessia Fontana ◽  
Antonio Mulet ◽  
Jefferson Luiz G. Correa ◽  
Juan A. Cárcel
Keyword(s):  
Orange Peel ◽  
Quality Parameters ◽  
Convective Drying ◽  
Ultrasound Assisted

Determination of readiness for laying based on material moisture, corresponding relative humidity, and water release

2020 ◽  
Vol 62 (10) ◽  
pp. 1033-1040
Author(s):  
Christoph Strangfeld ◽  
Sabine Kruschwitz
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Embedded Sensors ◽  
Residual Water ◽  
Floor Covering ◽  
Water Release ◽  
Content Determination ◽  
Two Samples ◽  
Moisture Content Determination

Abstract The moisture content of the subfloor has to be determined before installation to avoid damage to the floor covering. Only if readiness for layering is reached, can an installation without damage be expected in all cases. In general, three approaches exist to measure residual water content: determination of moisture content, determination of water release, or determination of the corresponding relative humidity. All three approaches are tested under laboratory conditions at eight screed types including two samples thicknesses in each case. Moisture content and water release are measured by sample weighing, the corresponding relative humidity is measured by embedded sensors. All three approaches are compared and correlated. The evaluations show only a weak correlation and, in several cases, contradicting results. Samples are considered ready for layering and not ready for layering at the same time, depending on the chosen approach. Due to these contradicting results, a general threshold for a risk of damage cannot be derived based on these measurements. Furthermore, the experiment demonstrates that the measurement of corresponding relative humidity is independent of the screed type or screed composition considered. This makes humidity measurement a potentially very promising approach for the installation of material moisture monitoring systems.

Modeling Vapor Transport in a Hollow Fiber Membrane Humidifier Using ε-NTU Approach

2020 ◽  
Author(s):  
Hoang Nghia Vu ◽  
Xuan Linh Nguyen ◽  
Sangseok Yu
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Fuel Cell ◽  
Relative Humidity ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Water Content ◽  
Vapor Transport ◽  
Overall Mass Transfer Coefficient ◽  
Mass Exchanger

Abstract In a fuel cell vehicle, the water content of the gas supply within certain ranges plays a key role in improving the performance of a proton exchange membrane. The lower limit of water content in the air supply is to avoid the problem of drying-out, while the upper prevents flooding. Water management can be accomplished by a membrane humidifier which allows water vapor to permeate the mixture from the side having the higher water concentration, moving to the other side of the membrane. In this study, the variation in water content collected at the outlet of a membrane humidifier is investigated with a one-dimensional mass exchanger model and various operating variables. The vapor concentration of outlet flows is affected by operating temperature and relative humidity of the membrane humidifier. Relative humidity of the dry side at the point of outlet flow, to be supplied to the fuel cell module, is the key characteristic. The analogy of the effectiveness-NTU approach for heat transfer is used to analyze the characteristics of the mass exchanger. Mass flux through the membranes is estimated with an overall mass transfer coefficient which represents vapor transport characteristics moving through the membrane module. This coefficient has a similar role to the overall heat transfer coefficient in heat exchanger analysis. This parametric study is conducted to understand the effects of different variables. The Effectiveness-NTU methodology of mass transfer uses the overall mass transfer coefficient and the mass transfer rate, as evaluated experimentally. Simulink software is then employed to deliver outcomes of the model for different operating conditions.

scholarly journals Assessment of lettuce quality during storage at low relative humidity using Global Stability Index methodology

2012 ◽  
Vol 32 (2) ◽  
pp. 366-373 ◽  
Author(s):  
María Roberta Ansorena ◽  
María Victoria Agüero ◽  
María Grabriela Goñi ◽  
Sara Roura ◽  
Alejandra Ponce ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Relative Humidity ◽  
Global Stability ◽  
Water Content ◽  
Relative Water Content ◽  
Storage Time ◽  
Stability Index ◽  
Total Chlorophyll ◽  
External Zone ◽  
Relative Water

During postharvest, lettuce is usually exposed to adverse conditions (e.g. low relative humidity) that reduce the vegetable quality. In order to evaluate its shelf life, a great number of quality attributes must be analyzed, which requires careful experimental design, and it is time consuming. In this study, the modified Global Stability Index method was applied to estimate the quality of butter lettuce at low relative humidity during storage discriminating three lettuce zones (internal, middle, and external). The results indicated that the most relevant attributes were: the external zone - relative water content, water content , ascorbic acid, and total mesophilic counts; middle zone - relative water content, water content, total chlorophyll, and ascorbic acid; internal zone - relative water content, bound water, water content, and total mesophilic counts. A mathematical model that takes into account the Global Stability Index and overall visual quality for each lettuce zone was proposed. Moreover, the Weibull distribution was applied to estimate the maximum vegetable storage time which was 5, 4, and 3 days for the internal, middle, and external zone, respectively. When analyzing the effect of storage time for each lettuce zone, all the indices evaluated in the external zone of lettuce presented significant differences (p < 0.05). For both, internal and middle zones, the attributes presented significant differences (p < 0.05), except for water content and total chlorophyll.

Quality Assessment and Mathematical Modeling of Hot-Air Convective Drying of Persimmon (Diospyros kaki L.) Fruit

2017 ◽  
Vol 13 (7) ◽  
Author(s):  
Claudia Giovagnoli-Vicuña ◽  
Nelson O. Moraga ◽  
Vilbett Briones-Labarca ◽  
Pablo Pacheco-Pérez
Keyword(s):  
Quality Parameters ◽  
Time Function ◽  
Convective Drying ◽  
Diospyros Kaki ◽  
Drying Process ◽  
Temperature Function ◽  
Persimmon Fruit ◽  
Hot Air ◽  
Volume Method ◽  
Good Agreement

Abstract The influence of drying on the color, porosity, shrinkage and moisture of persimmon fruit during convective drying was determined by computer vision. The experiments were performed with persimmon fruit that were cut into slab 20 × 20 mm, which were arranged into a bigger slab, 60 × 60 mm. Drying process was carried out at 60 °C. Noticeable changes in quality parameters (color, porosity and shrinkage) could be observed during the drying process, where the central region of the sample evidenced less changes. Persimmon’s physical properties were experimentally obtained as the temperature function and heat and mass convective coefficients were adjusted as a time function. A numerical simulation using the Finite Volume Method allowed to describe the evolution of temperature and moisture content distributions during drying. The numerical and experimental results of temperature and moisture during persimmon drying were found to be in a good agreement.

WATER RELATIONS OF ASEXUAL SPORES OF SPHAEROTHECA MACULARIS (WALLR. EX. FR.) COOKE AND ERYSIPHE POLYGONI DC.

1965 ◽  
Vol 11 (3) ◽  
pp. 531-538 ◽  
Author(s):  
J. S. Jhooty ◽  
W. E. McKeen
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Osmotic Pressure ◽  
Water Relations ◽  
Erysiphe Polygoni ◽  
Significant Change ◽  
Sphaerotheca Macularis ◽  
Glass Surfaces

The conidia of Sphaerotheca macularis germinate best at a relative humidity (R.H.) of 99 and 100% on glass surfaces, and germination does not occur if the R.H. is below 93%. Conidia of Erysiphe polygoni DC. germinate at 3% R.H. The water content of conidia of S. macularis and E. polygoni is 53 and 69% respectively. The osmotic pressure of S. macularis conidia is about 18 atm and their density varies from 1.10 to 1.11 g/ml. There is no significant change in the diameter and length of the conidia during germination.

scholarly journals Effects of Saline Solutions on the Desiccation Cracking and Shrinkage Behavior of Gaomiaozi Bentonite

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Long Tan ◽  
Penglin Zheng ◽  
Qingbing Liu
Keyword(s):  
Water Content ◽  
Saline Solution ◽  
Shrinkage Strain ◽  
Sample Surface ◽  
Water Evaporation ◽  
Gmz Bentonite ◽  
Residual Water ◽  
High Concentration ◽  
Desiccation Cracking ◽  
Saline Solutions

Bentonite, when used as buffer/backfill material in the deep disposal of high-level radioactive waste (HLW), could undergo desiccation shrinkage or even cracking due to the heat released from HLW, impairing the efficiency of the barrier system. Furthermore, in-service buffer materials are inevitably in contact with the groundwater, which sometimes contain high salt concentrations. The groundwater salinity may modify the properties of bentonite and hence affect the process of desiccation and its performance. To investigate this effect, in this study, a series of temperature-controlled desiccation tests was conducted on compacted specimens of Gaomiaozi (GMZ) bentonite preliminarily saturated with two different saline solutions (NaCl and CaCl2) at the concentration varying from 0.5 to 2.0 mol/L. The experimental results indicated that, as the concentration of saline solution increases, the initial saturated water content of bentonite decreases, whereas the residual water content at the completion of the desiccation test increases. The water evaporation rate is reduced for the specimens saturated with a high-concentration saline solution, and CaCl2 has a more significant influence on water evaporation than NaCl. The evolution of cracks on the sample surface during the desiccation process can be divided into four stages: crack growth, maintenance, closure, and stabilization; an increase in the salt concentration effectively inhibits crack development. It was shown that the infiltration of saline solutions alters the microstructure of bentonite by changing the arrangement of clay particles from a dispersed pattern to more aggregate state, which results in a decrease in shrinkage strain and shrinkage anisotropy.

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