Air-impingement De-shelling of Chestnuts (C. mollisima): Process Parameter Optimization

2008 ◽  
Vol 4 (2) ◽  
Author(s):  
Zhen-jiang Gao ◽  
Hai Lin ◽  
Hongwei Xiao
Keyword(s):  
Air Temperature ◽  
Water Loss ◽  
Processing Time ◽  
Prediction Models ◽  
Optimum Conditions ◽  
Air Velocity ◽  
Processing Industry ◽  
Air Impingement ◽  
Predicted Values ◽  
Optimized Conditions

Presently in China de-shelling of chestnuts is done manually, which is tedious, time consuming and labor intensive. The de-shelling operation has become the greatest problem and poses a bottleneck to the chestnut processing industry in China. To overcome this problem, the objective of this study is to derive optimum conditions for chestnut de-shelling using air-impingement de-shelling technology. Response surface methodology was employed to analyze the effects of air temperature (163-197oC), processing time (109-311s) and air velocity (6.68-9.73m/s) on the rate of water loss, de-shelling rate and lightness. Prediction models were also established. Optimum conditions obtained were 179oC of air temperature, 278s of processing time and 7.83m/s of air velocity. Values predicted by the models for the water loss, de-shelling rate and lightness under optimized conditions are 4.14%, 86.95% and 58.65, respectively. The experimental data fit well with the predicted values.

Optimización del escaldado de calabacita criolla (Cucurbita pepo) deshidratada a temperaturas bajas y tiempos largos / Optimization of stepwise blanching of dehydrated zucchini (Cucurbita pepo)

1998 ◽  
Vol 4 (3) ◽  
pp. 159-167 ◽  
Author(s):  
A. Quintero-Ramos ◽  
A.L. Sánchez de la Paz ◽  
J.A. Meza-Velázquez ◽  
J.A. Jiménez ◽  
G. Barbosa-Cánovas ◽  
...  
Keyword(s):  
Prediction Model ◽  
Cutting Force ◽  
Cucurbita Pepo ◽  
Prediction Models ◽  
Optimum Conditions ◽  
Color Parameter ◽  
Lack Of Fit ◽  
Surface Method ◽  
Predicted Values ◽  
Experimental Values

Low-temperature prolonged blanching was applied to sliced zucchini prior to dehydration. Treatment was optimized by a response surface method. The variables studied were: blanching temperature (50, 55, 65, 75 and 79 °C) and blanching time (23, 79, 30, 45, 60, 66 min). Color, texture (cutting force) and rehydration rate of the product were also evaluated. The optimum conditions for the texture, color (parameter b*) and rehydration rate (RR) of the pretreatment were: temper ature, 61-66 °C for 52-56 min. The prediction model was applied with these conditions and the following values were obtained: rehydration rate 5.14, texture 28.82 Newtons and the color para meter b' (blue-yellow) 34.0. The prediction models for maximum cutting force and parameter b* showed a significant fit ( p ≤ 0.05) of the experimental values and the prediction model for the RR showed a lack of fit ( p ≤ 0.05) whereas the parameters L* and a* were not affected significantly. These optimum conditions were verified experimentally, and the experimental values agreed very closely with the predicted values.

Effects of air temperature, air velocity and feeding level on apparent digestibility, water intake, water loss and growth in calves given a milk substitute diet

1989 ◽  
Vol 48 (1) ◽  
pp. 51-65 ◽  
Author(s):  
M. S. Cockram ◽  
T. G. Rowan
Keyword(s):  
Air Temperature ◽  
Water Intake ◽  
Water Loss ◽  
Free Water ◽  
Total Water ◽  
Air Velocity ◽  
Feeding Level ◽  
Air Temperatures ◽  
Milk Substitute ◽  
Total Water Intake

ABSTRACTSix groups of eight 2-day-old calves were placed successively in a controlled environment chamber. Three groups were exposed to air temperatures of 10° and 25°C. A liquid diet of skimmed-milk substitute and 4 I/day of drinking (free) water was offered to each calf. Within each group, calves were allocated to either a low (<0·2 m/s) or a high (>3 m/s) air velocity and to either a low (30 g dry matter (DM) per kg M0·75per day) or a high (40 g DM per kg M0·75per day) feeding level. At 8 days of age the apparent digestibilities of DM at air temperatures of 10° and 25°C were 0·77 (s.e. 0·126) and 0·82 (s.e. 0·126) respectively (P > 0·05). The apparent digestibilities of DM were greater at the low feeding level with low air velocity than for either this feeding level with high air velocity or the high feeding level at both air velocities (P< 0·05) between which there was no significant difference (P > 0·05). At 8 days of age there were significant air temperature × air velocity (P< 001) and air velocity × feeding level interactions in the intake of free water (P< 005). There was a significant air temperature × feeding level interaction for total water intake (P< 0·05). Urinary water loss relative to total water intake was significantly greater at the low air velocity than at the high air velocity (P< 0·05).In a further two groups of eight calves given 30 g DM per kg M 75 per day at 8 days of age, the apparent digestibilities of DM at air temperatures of 10° and 25°C were 0·71 (s.e. 0·020) and 0·90 (s.e. 0·013) respectively (P< 0·01). In the same calves given 40 g DM per kg M0·75per day at 20 days of age, the apparent digestibilities of DM at air temperatures of 10° and 25°C were 0·89 (s.e. 0·009) and 0·93 (s.e. 0·011) respectively (P< 0·05). The free and total water intakes, the ratios of (total water intake-faecal water loss): total water intake and the urinary losses of water were significantly greater at the air temperature of 25°C than at 10°C (P< 0·05). Live-weight gains were lower at 10°C than at 25°C (P< 0·01).The results suggested that air temperature, air velocity and feeding level can affect the health and growth of calves less than 4 weeks of age.

Removal of copper (Cu2+) by preparation modified carbon from macadamia shells by chemical agent with H2O2 in wastewater

2020 ◽  
pp. 215-221
Keyword(s):  
Heavy Metal ◽  
Processing Time ◽  
Chemical Agent ◽  
Optimum Conditions ◽  
Adsorption Ability

Macadamia shells were used to prepare modified carbon by chemical agent H2O2 (25%) in 48 hours with coke ratio: H2O2 = 1:10. Modified carbon from Macadamia shells with chemical agent H2O2 has capable of adsorption heavy metal copper (Cu 2+) at an assumption concentration is 30ppm in the optimum conditions such as pH = 4, dose is 1.8 g/l, and the processing time is 30 minutes. The result showed that the adsorption ability of the material reached the highest efficiency is 78.33%. This result showed that modified carbon from shells Macadamia by chemical agent H2O2 capable of removing applications on heavy metal copper (Cu2+) in wastewater.

Dilution studies on three marine outfalls in South Africa

1995 ◽  
Vol 32 (2) ◽  
pp. 297-304
Author(s):  
Willem A. M. Botes ◽  
J. F. Kapp
Keyword(s):  
South Africa ◽  
South African ◽  
Field Data ◽  
Prediction Models ◽  
Feasibility Studies ◽  
The South ◽  
Average Current ◽  
Predicted Values ◽  
Prediction Techniques ◽  
Domestic Effluent

Field dilution studies were conducted on three “deep” water marine outfalls located along the South African coast to establish the comparibility of actual achievable initial dilutions against the theoretical predicted values and, where appropriate, to make recommendations regarding the applicability of the different prediction techniques in the design of future outfalls. The physical processes along the 3000 km long coastline of South Africa are diverse, ranging from dynamic sub-tropical waters on the east coast to cold, stratified stagnant conditions on the west coast. Fourteen existing offshore marine outfalls serve medium to large industries and various local authorities (domestic effluent). For this investigation three outfalls were selected to represent the range of outfall types as well as the diversity of the physical conditions of the South African coastline. The predicted dilutions, using various approaches, compared well with the measured dilutions. It was found that the application of more “simple” prediction techniques (using average current velocities and ambient densities) may be more practical, ensuring a conservative approach, in pre-feasibility studies, compared to the more detailed prediction models, which uses accurate field data (stratification and current profiles), when extensive field data is not readily available.

Deformation of Potato during Convective Drying

2014 ◽  
Vol 592-594 ◽  
pp. 2728-2732 ◽  
Author(s):  
V.P. Chandramohan ◽  
Prabal Talukdar
Keyword(s):  
Air Temperature ◽  
Drying Shrinkage ◽  
Convective Drying ◽  
Air Velocity ◽  
Maximum Dimension ◽  
Potato Slice ◽  
Generic Solution

Deformation of potato is estimated by experimentally during convective drying. Size of the potato slice is 4cm x 2cm x 2cm. The percentage changes in length, breadth and width of potato are estimated during drying. Shrinkage of the object during drying is estimated. Air velocity chosen for this present analysis is 2 m/s and the range of air temperature is selected as 40 to 70 °C. The product experiences the maximum dimension changes upto 30% in length and 47.5 % in both breadth and width wise. The parameters are non dimensionalised to get generic solution.

Evaluation of the influence of ambient air temperature and air velocity on mortar cement durability using a forced convection solar dryer

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Younes Bahammou ◽  
Mounir Kouhila ◽  
Haytem Moussaoui ◽  
Hamza Lamsyehe ◽  
Zakaria Tagnamas ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Forced Convection ◽  
Air Temperature ◽  
Building Materials ◽  
Ambient Air ◽  
Physical Significance ◽  
Drying Process ◽  
Air Velocity ◽  
Content Type ◽  
Ambient Air Temperature

PurposeThis work aims to study the hydrothermal behavior of mortar cement toward certain environmental factors (ambient air temperature and air velocity) based on its drying kinetics data. The objective is to provide a better understanding and controlling the stability of mortar structures, which integrate the sorption phenomenon, drying process, air pressure and intrinsic characteristics. This leads to predict the comportment of mortar structures in relation with main environmental factors and minimize the risk of cracking mortar structures at an early age.Design/methodology/approachThermokinetic study was carried out in natural and forced convection solar drying at three temperatures 20, 30 and 40°C and three air velocities (1, 3 and 5 m.s-1). The empirical and semiempirical models tested successfully describe the drying kinetics of mortar. These models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures.FindingsThe models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures. The average activation energy obtained expressed the temperature effect on the mortar diffusivity. The drying constant and the diffusion coefficient can be used to predict the influence of these environmental factors on the drying behavior of various building materials and therefore on their durability.Originality/valueEvaluation of the effect of several environmental factors and intrinsic characteristics of mortar structures on their durability.

Experimental and Theoretical Investigation of Performance of a Solar Chimney Model, Part I: Experimental Investigation

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Essaied M Shuia ◽  
Bashir H Arebi ◽  
Ibrahim A abuashe
Keyword(s):  
Experimental Data ◽  
Wind Speed ◽  
Solar Radiation ◽  
Air Temperature ◽  
Solar Collector ◽  
Experimental Results ◽  
Internal Diameter ◽  
Solar Chimney ◽  
Air Velocity ◽  
Collector Temperature

This paper presents the experimental data that was collected from small pilot solar chimney. The experimental data together with ambient conditions are used to evaluate the performance and study the behavior of the solar chimney; this data will be used for comparison with theoretical models in another paper [part II). The solar chimney prototype was designed and constructed at the Subrata Faculty of Engineering-Libya. The data were collected over several days of June 2011. The solar chimney system contains two main components; the solar collector and the solar chimney. The solar collector root‘ has a circular area of126 m3, the solar chimney is a PVC tube with internal diameter of 0.2 m and the total height of chimney is 9.3 m. The measurements include the intensity of solar radiation inside/outside the collector, temperature and velocity of air at the entrance of the chimney, temperature and speed of wind outside the collector, temperature of the ground inside collector al1d temperature measurements of air at speci?c points at different levels throughout the collector. Solar irradiance was found to affect the chimney temperature and subsequently affects chimney air velocity. The experimental results showed that temperature differences of (30 - 45°C) were recorded between the ambient temperature and that of air inside the chimney in the middle of the day, where the highest air temperature of 73.4°C was recorded at the entrance of the solar chimney. The maximum air velocity of 3.6 m/s was recorded inside the solar chimney at noon on 9 June. Wind speed outside the collector had a small effect on the speed of the air inside the chimney and tends to change slightly, hence, can neglect influence of wind speed on the performance of the system. Also the experimental results indicate that such type of system can trap a suf?cient amount of solar radiation, which elevates the air temperature to a suf?cient value able to generate enough air ?ow to operate a wind turbine to produce electricity; this means the solar chimney system for electricity production can work in the north-western part of Libya in the summer time at least.

Temperature Distribution of Hot Air Flow in Heating Zone for Drying Application

2014 ◽  
Vol 627 ◽  
pp. 153-157
Author(s):  
Nawadee Srisiriwat ◽  
Chananchai Wutthithanyawat
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Power Supply ◽  
Air Flow ◽  
Heating Zone ◽  
Velocity Control ◽  
Rectangular Duct ◽  
Air Velocity ◽  
Hot Air ◽  
Set Up

The temperature distribution of hot air flow in heating zone of a rectangular duct has been investigated for drying application. The experimental set-up consists of a heater and a fan to generate the hot air flow in the range of temperature from 40 to 100°C and the range of air velocity between 1.20 and 1.57 m/s. An increase of the heater power supply increases the hot air temperature in the heating zone while an increase of air velocity forced by fan decreases the initial temperature at the same power supply provided to generate the hot air flow. The temperature distribution shows that the hot air temperature after transferring through air duct decreases with an increase of the length of the rectangular duct. These results are very important for the air flow temperature and velocity control strategy to apply for heating zone design in the drying process.

Thermal Lethality of Salmonella in Chicken Leg Quarters Processed via an Air/Steam Impingement Oven

2004 ◽  
Vol 67 (3) ◽  
pp. 493-498 ◽  
Author(s):  
R. Y. MURPHY ◽  
K. H. DRISCOLL ◽  
L. K. DUNCAN ◽  
T. OSAILI ◽  
J. A. MARCY
Keyword(s):  
Relative Humidity ◽  
Surface Area ◽  
Air Temperature ◽  
Cooking Time ◽  
Air Velocity ◽  
Poultry Products ◽  
Product Surface ◽  
Cooking Times

Chicken leg quarters were injected with 0.1 ml of the cocktail culture per cm2 of the product surface area to contain about 7 log(CFU/g) of Salmonella. The inoculated leg quarters were processed in an air/steam impingement oven at an air temperature of 232°C, an air velocity of 1.4 m/s, and a relative humidity of 43%. The endpoint product temperatures were correlated with the cooking times. A model was developed for pathogen thermal lethality up to 7 log(CFU/g) reductions of Salmonella in correlation to the product mass (140 to 540 g) and cooking time (5 to 35 min). The results from this study are useful for validating thermal lethality of pathogens in poultry products that are cooked via impingement ovens.

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