Performance of Thermal Insulation Covering Materials to Reduce Postharvest Losses in Okra

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 392
Author(s):  
Jutarat Rattanakaran ◽  
Rattapon Saengrayap ◽  
Nattapol Aunsri ◽  
Sirada Padee ◽  
Chureerat Prahsarn ◽  
...  
Keyword(s):  
Mass Loss ◽  
Thermal Insulation ◽  
Temperature Profiles ◽  
Linear Low Density Polyethylene ◽  
Heat Temperature ◽  
Chain Management ◽  
Temperature Changes ◽  
Pulp Temperature ◽  
Alternative Material ◽  
Postharvest Loss

The efficiency of different thermal insulation covers in minimizing temperature fluctuations in cool chain management was investigated to reduce postharvest loss and maintain okra quality during storage and transportation. The four thermal insulation covering materials: (1) heat reflective sheet with thin nonwoven (HRS + TNNW), (2) heat reflective sheet with thick nonwoven (HRS + TKNW), (3) metalized Tyvek® (MTyvek) and (4) metalized foam sheet (MFS) were studied and compared with perforated linear low-density polyethylene (P-LLDPE) as the typical handing package for okra distribution alongside no covering as the control. The material properties, transpiration rate, vital heat, temperature profiles (air and pulp temperatures), relative humidity, mass loss and incidence of decay were determined throughout a simulated supply chain. Results exhibited that HRS + TNNW and HRS + TKNW covers had the lowest thermal heat energy (Qx) and moderate R-value. These two covers maintained low temperature fluctuation with the lowest rate of air and pulp temperature changes, reflecting in lowest mass loss and decay in okra. The HRS + TNNW cover yielded less decay (1%) in okra, compared to commercial covers; MTyvek (16%) and MFS (9%). Results showed that HRS + TNNW exhibited great potential as a thermal insulation cover to reduce postharvest loss in okra (5%) compared to typical handling (11–18%) and could be considered as alternative material to reduce the use of foam sheets in cool chain management distribution packaging of okra under ambient environment conditions.

scholarly journals Application of Room Cooling and Thermal Insulation Materials to Maintain Quality of Okra during Storage and Transportation

Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 188
Author(s):  
Jutarat Rattanakaran ◽  
Rattapon Saengrayap ◽  
Chureerat Prahsarn ◽  
Hiroaki Kitazawa ◽  
Saowapa Chaiwong
Keyword(s):  
Mass Loss ◽  
Thermal Insulation ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Cool Temperature ◽  
Linear Low Density Polyethylene ◽  
Insulation Materials ◽  
Pulp Temperature

A combination of room cooling and the use of thermal insulation materials to maintain okra quality under simulated storage and transportation was evaluated. Okra pods were packed in plastic baskets and either cooled at 18 °C or not cooled in a room for 2 h. After either room cooling or no cooling, the okra pods were covered with three different materials: (1) perforated linear low-density polyethylene (P-LLDPE), (2) two layers of heat-reflective sheet with thin nonwoven (HRS+TNNW), and (3) metalized foam sheet (MFS). Typical handling (TP) without cooling and covering with P-LLDPE was used as the control. The six treatments were conducted during simulated storage (18 °C for 48 h) and transportation (30 °C for 15 h). Results showed that MFS gave the best insulation properties (Qx and R-values), followed by HRS and TNNW. After room cooling, both HRS+TNNW and MFS materials delayed the time for pulp temperature to reach 18 °C (10 h), compared to P-LLDPE (2 h). TP presented the highest mass loss (17.8%) throughout simulated conditions, followed by cooling plus P-LLDPE (15.2%) and either of the thermal insulation materials with or without room cooling (3.6% to 5.2%), respectively. TP, cooling plus P-LLDPE, and no cooling plus MFS (44% to 56%) showed the highest percentage of decay, while cooling combined with both HRS+TNNW and MFS gave the lowest decay incidence (11–21%). Findings demonstrated that room cooling combined with HRS+TNNW had the highest efficiency for preserving cool temperature and reducing decay, compared to TP and room cooling plus MFS.

A model to predict the kinetics of mass loss in wood during thermo-vacuum modification

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ottaviano Allegretti ◽  
Ignazia Cuccui ◽  
Nasko Terziev ◽  
Laerte Sorini
Keyword(s):  
Mass Loss ◽  
Treatment Process ◽  
Linear Trend ◽  
Thermal Modification ◽  
Thermal Treatments ◽  
Temperature Profiles ◽  
Relative Area ◽  
Heat Power ◽  
Kinetics Of

AbstractMass loss (ML) of wood caused by thermal degradation is one of the most important features of the thermal treatments and referred to as an indicator of intensity and quality of the process. The ML is proportional to the quantity of the effective heat power exchanged during the treatment process, represented by the area of the temperature profile versus time during the process. In this paper a model for the ML prediction based on the relative area was discussed. The model proposed an analytical solution to take into account the non-linear trend of ML when plotted versus temperature and time as observed in isothermal experiments. The model was validated comparing calculated and measured final ML of samples treated during thermal modification tests with different temperature profiles. The results showed that the relative area calculated in a transformed time-temperature space improves the correlation with the measured ML.

scholarly journals Impact of postglacial warming on borehole reconstructions of last millennium temperatures

2012 ◽  
Vol 8 (3) ◽  
pp. 1059-1066 ◽  
Author(s):  
V. Rath ◽  
J. F. González Rouco ◽  
H. Goosse
Keyword(s):  
Climate Models ◽  
Ground Surface ◽  
Geothermal Gradient ◽  
Temperature Profiles ◽  
Temperature Changes ◽  
Open Questions ◽  
Temperature Signal ◽  
Borehole Temperatures ◽  
Borehole Temperature ◽  
The Impact

Abstract. The investigation of observed borehole temperatures has proved to be a valuable tool for the reconstruction of ground surface temperature histories. However, there are still many open questions concerning the significance and accuracy of the reconstructions from these data. In particular, the temperature signal of the warming after the Last Glacial Maximum is still present in borehole temperature profiles. It is shown here that this signal also influences the relatively shallow boreholes used in current paleoclimate inversions to estimate temperature changes in the last centuries by producing errors in the determination of the steady state geothermal gradient. However, the impact on estimates of past temperature changes is weaker. For deeper boreholes, the curvature of the long-term signal is significant. A correction based on simple assumptions about glacial–interglacial temperature changes shows promising results, improving the extraction of millennial scale signals. The same procedure may help when comparing observed borehole temperature profiles with the results from numerical climate models.

The effect of polyester recycled tire fibers mixed with ground tire rubber on polyethylene composites. Part II

2018 ◽  
Vol 34 (3) ◽  
pp. 128-142 ◽  
Author(s):  
Siavosh Moghaddamzadeh ◽  
Denis Rodrigue
Keyword(s):  
Injection Molding ◽  
Low Density Polyethylene ◽  
Temperature Profiles ◽  
Linear Low Density Polyethylene ◽  
Mechanical Tension ◽  
Screw Speed ◽  
Tire Rubber ◽  
Ground Tire Rubber ◽  
Extruder Screw ◽  
Physical Density

This work reports on the mechanical (tension, flexion, and impact) and physical (density and hardness) properties of polyester recycled tire fibers (RTFs) mixed with ground tire rubber and linear low-density polyethylene with and without styrene–ethylene–butylene–styrene grafted maleic anhydride as a compatibilizer. In particular, the effect of RTF content (10, 25, and 50 wt%), extruder screw speed (110, 180, and 250 r/min), and temperature profiles (extrusion and injection molding) was studied. The results showed that the best properties were obtained at the highest RTF content (50%) and extruder screw speed (250 r/min) combined with the lowest temperature profile in both extrusion and injection molding when the compatibilizer was added.

scholarly journals Field measurement of ground temperatures in Bandung: devices and the results of measurement

2020 ◽  
Vol 200 ◽  
pp. 02009
Author(s):  
Muhammad Nur Fajri Alfata ◽  
Amalia Nurjannah
Keyword(s):  
Temperature Sensor ◽  
Field Measurement ◽  
Ground Temperature ◽  
Passive Cooling ◽  
Temperature Profiles ◽  
Temperature Changes ◽  
Ground Temperatures ◽  
Different Depths ◽  
Measurement Devices ◽  
Main Component

Ground cooling is considered to be one of the passive cooling strategies in buildings although its application is rarely found in Indonesia. Effectiveness of this strategy depend on the ground temperature profiles. Meanwhile, comprehensive data of ground temperature as a basis of design for ground cooling are still rarely found in Indonesia. This research aims to develop the measurement devices for collecting ground temperatures data and to investigate the ground temperatures in different depths (i.e., 1m, 2m, …, 9m). For measurement, an instrumentation system was developed with the main component of Arduino Mega 2560 as microcontroller. T-type thermocouples with diameter of 0, 5mm mounted in the metal cones were used as the temperature sensor and placed at the different depths. The field measurement was conducted from August to November 2019 in Bandung, West Java, Indonesia. This study demonstrated that the developed instrument system had good performance both in measuring and data acquisition. Model equation was developed to predict the ground temperature at certain depth regardless ground materials and humidity level. The results indicated that the ground temperature significantly lower to 5m-depth. However, the reduction of the temperature after 5m was not significant; the deeper the ground, the temperature changes are negligible.

scholarly journals Electricity Generation from Low and Medium Temperature Industrial Excess Heat in the Kraft Pulp and Paper Industry

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8499
Author(s):  
Igor Cruz ◽  
Magnus Wallén ◽  
Elin Svensson ◽  
Simon Harvey
Keyword(s):  
Electricity Generation ◽  
Kraft Pulp ◽  
Process Integration ◽  
Paper Industry ◽  
Temperature Profiles ◽  
Medium Temperature ◽  
Heat Temperature ◽  
Excess Heat ◽  
Technical Potential ◽  
Temperature Excess

The recovery and utilisation of industrial excess heat has been identified as an important contribution for energy efficiency by reducing primary energy demand. Previous works, based on top-down studies for a few sectors, or regional case studies estimated the overall availability of industrial excess heat. A more detailed analysis is required to allow the estimation of potentials for specific heat recovery technologies, particularly regarding excess heat temperature profiles. This work combines process integration methods and regression analysis to obtain cogeneration targets, detailed excess heat temperature profiles and estimations of electricity generation potentials from low and medium temperature excess heat. The work is based on the use of excess heat temperature (XHT) signatures for individual sites and regression analysis using publicly available data, obtaining estimations of the technical potential for electricity generation from low and medium temperature excess heat (60–140 °C) for the whole Swedish kraft pulp and paper industry. The results show a technical potential to increase the electricity production at kraft mills in Sweden by 10 to 13%, depending on the level of process integration considered, and a lower availability of excess heat than previously estimated in studies for the sector. The approach used could be adapted and applied in other sectors and regions, increasing the level of detail at which industrial excess heat estimations are obtained when compared to previous studies.

Influence of Temperature and Pressure on Nozzle Array Fluidic Gyroscope

2014 ◽  
Vol 945-949 ◽  
pp. 2195-2198
Author(s):  
Jing Bo Chen ◽  
Lin Hua Piao ◽  
Jing Jing Zhao ◽  
Xia Ding
Keyword(s):  
Model Building ◽  
Structure Optimization ◽  
Dimensional Model ◽  
Heat Temperature ◽  
Temperature Changes ◽  
Pressure Distributions ◽  
Equation Solving ◽  
Element Simulation ◽  
Array Structure ◽  
Temperature And Pressure

In this paper, the temperature and pressure distribution in sensitive element of nozzle array structure gyroscope is analyzed. Using ANSYS-FLOTRAN CFD software, the finite element simulation is conducted by a series of procedures, such as two-dimensional model building of fluidic gyroscope, mesh, load applying and equation solving. The temperature and pressure distributions of nozzle array structure fluidic gyroscopes are calculated. The results show that the thermal wires heat temperature of the surrounding gas which place at 1.5mm from the outlet, and which produce internal temperature gradient in sensitive cavity, temperature changes symmetry of the cavity center. The pressure near the outlet is higher than any other position in the cavity, and which is 0.21109Pa. In this paper, the structure optimization of nozzle array gyroscope which provides effective theoretical basis for improving its performance.

scholarly journals Temperature Measurements in the Detonation Chamber Supplied by Air from Centrifugal Compressor and Gaseous Hydrogen

2017 ◽  
Vol 2017 (3) ◽  
pp. 7-23
Author(s):  
Jan Kindracki
Keyword(s):  
Centrifugal Compressor ◽  
Gaseous Hydrogen ◽  
Temperature Profiles ◽  
Radial Temperature ◽  
Jet Engine ◽  
Temperature Changes ◽  
Turbine Performance ◽  
Cooling Method ◽  
Key Issues ◽  
The Relationship

Abstract In this paper, the experimental results of a detonation chamber fed by air from a centrifugal compressor are presented. The detonation chamber was equipped with many different sensors, mostly thermocouples, which were placed in 11 different positions. The distribution of temperature changes along the chamber and radial temperature profile at the outlet are provided. The results here confirm the existence of high mixture stratification. Such mixture stratifications and temperature profiles may be used as an additional chamber wall cooling method. The experiments performed, address key issues regarding the chamber choking problem caused by turbines. The relationship between the turbine performance and detonation chamber are crucial for proper control of turbine jet engine.

scholarly journals Mass Balance of Rhonegletscher During 1882/83–1986/87

1990 ◽  
Vol 36 (123) ◽  
pp. 199-209 ◽  
Author(s):  
Jiyang Chen ◽  
Martin Funk
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Confidence Level ◽  
Little Ice Age ◽  
Ice Age ◽  
Thickness Change ◽  
Temperature Changes ◽  
Covered Area ◽  
Positive Balance ◽  
Precipitation Changes

AbstractThe glaciological investigations on Rhonegletscher were started in 1874. The mass-balance data measured during 1884/85–1908/09 and during 1979/80–1981/82 are presented. Two methods are used for estimating the mass changes. During 1882/83–1968/69, the cumulative specific net balance is −24 ± 6 m w.e. at the 90% confidence level by the regression model of annual mass balance, annual precipitation, and summer air temperature (the PT model), while the thickness change revealed by the maps is −23 ± 5 m w.e. The cumulative specific net balance during 1882/83–1986/87 is −26 ± 6 m w.e. at the 90% confidence level.The study shows that Rhonegletscher generally experienced mass loss, especially during the periods from the late 1920s through the early 1960s with some short periods of positive balance. The glacier tongue retreated by 970 m during 1882–1986, that is, from 1780 ma.s.l. (1882) to 2130 ma.s.1. (1986). During 1882–1969, the ice-covered area decreased by 4.37 km2 and the volume by 4.71 × 108 m3.The PT models of Rhonegletscher and other alpine glaciers suggest that the contribution of the temperature changes to the mass balance is of more importance than that of the precipitation changes. The great mass loss reflects the climatic warming after the end of the Little Ice Age, with the warmest period occurring around the 1940s in this region.

Sign in / Sign up

Export Citation Format

Share Document