Vacuum Cooling of Cooked Mussels (Perna perna)

2006 ◽  
Vol 12 (1) ◽  
pp. 19-25 ◽  
Author(s):  
E. Huber ◽  
L. P. Soares ◽  
B. A. M. Carciofi ◽  
H. Hense ◽  
J. B. Laurindo
Keyword(s):  
Weight Loss ◽  
Cold Water ◽  
Temperature Drop ◽  
Relative Weight ◽  
Cooling Water ◽  
Hot Water ◽  
Process Time ◽  
Promising Alternative ◽  
Industrial Processing ◽  
Vacuum Cooling

Mussels pass through a thermal treatment during industrial processing with hot water or steam and then are pre-cooled before the manual extraction of the meat. This pre-cooling is classically accomplished by the immersion of the cooked mussels in cold water. In this work, vacuum cooling of mussels after the cooking stage was used as a technique to quickly decrease the product temperature and to avoid a possible microbial contamination by the cooling water or by manipulation. In about 3 minutes, mussels were cooled from about 90 °C to 20 °C. The relative weight loss during the vacuum cooling of the whole sample (meat and shell) was about 8% of the initial sample’s weight, for temperatures drop cited above. In this way, there was a 8.7 0.26 °C temperature drop for each 1% of weight loss. For separated meat (without shell), the ratio was 7.5 0.30 ºC per 1% weight loss, which agreed with the literature for vacuum cooling of meats in general. A simple numerical simulation was able to determine weight loss during the vacuum cooling process, providing data that agreed very well with experimental results. The vacuum cooling technique is a promising alternative for processing pre-cooked mussels, because process time is shortened and cross-contamination risk is significantly reduced in the cooling stage. The water loss is not a serious problem when the cooled mussels are canned in brine.

Feasibility Study of Absorption Chillers With a Low Temperature Heat Source

2004 ◽  
Author(s):  
Viktoria Martin ◽  
Fredrik Setterwall
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Heat Sink ◽  
Waste Heat ◽  
Temperature Drop ◽  
Cooling Water ◽  
Hot Water ◽  
Dramatic Effect ◽  
Absorption Chillers ◽  
Custom Made

Low temperature energy powering an absorption chiller will make more energy sources available for comfort cooling as compared to conventional heat driven chillers. Solar energy, industrial waste heat and heat from combined power and heat generation are examples of sources for driving energy. Also, the distribution of energy for comfort cooling could be made efficiently by transportation of hot water to the chiller situated near to the customers. Absorption chillers driven by temperatures lower than 90°C (194°F) are in general not available as an “off-the-shelf product.” Usually the low temperature driven chillers are custom made to fit to the local conditions with respect to temperatures of the driving energy and of the cooling water. The optimal design of a chiller is dependant on the temperature of the driving energy as well as on the temperature of the available heat sink for cooling the absorber and the condenser. A scheme for optimization of the chiller with respect to the size of the heat transfer surfaces and of the temperature drop of the driving energy and of the cooling water is presented herein. Presented results illustrate the dramatic effect on the size of the absorber by changing the cooling water temperature, and the equally dramatic effect on the size of the condenser and generator by changing the temperature of the driving energy. Clearly, lowering the heat source temperature and/or increasing the heat sink temperature increases the capital cost for a chiller. However, when coupled to combined heat and power generation, reasonable pay-back times have here been demonstrated for low temperature driven absorption chillers due to the increased electricity production in the overall system.

Fluid Mechanical Design of a Dry-Cooling System Thermal Storage Reservoir, or Stratification Minimization in Horizontal Channel Flow

1983 ◽  
Vol 105 (2) ◽  
pp. 174-180 ◽  
Author(s):  
E. C. Guyer ◽  
M. W. Golay
Keyword(s):  
Cold Water ◽  
Cooling System ◽  
Plug Flow ◽  
Cooling Water ◽  
Thermal Storage ◽  
The United States ◽  
Hot Water ◽  
Flow Mode ◽  
Storage Reservoir ◽  
Dry Cooling

The use of a capacitive Thermal Storage Reservoir (TSR) initially filled with cold water as part of a dry cooling system for a central power station is attractive economically if the reservoir can be designed to operate in an approximate “plug-flow” mode—discharging cold water to the condenser and filling with hot water from the cooling tower. Such a system would avoid the loss of station capacity associated with dry cooling at high dry-bulb temperatures, and the economic penalties due to such losses when they are coincident with electrical demand peaks (as is common in the United States). The initial employment of this concept is most likely to occur in solar-powered thermal electric power stations in arid climates in view of the likely low thermal efficiency and limited cooling water access of such plants. Buoyant flow stratification hinders attaining this goal since it can cause “short circuiting” of the TSR. For adequate flow control, a long narrow reservoir configuration is desirable. In investigating the behavior of such a TSR experimentally, it was found over the range of cases examined that injection of water into a long narrow reservoir which is initially at a different temperature always results in a stratified flow superimposed upon the gross plug flow of the TSR, and it was found that acceptable performance could be obtained inexpensively by placing flow-constricting barriers at regular intervals along the reservoir length. Experimental investigation of barrier design and spacing has permitted definition of a practical prototype TSR design which provides approximately 87 percent of the thermal capacity of a plug flow TSR.

scholarly journals Effect of Temperature Fluctuation and Nutritional Status on Starry Flounder, Platichthys stellatus, Survival and Adaptive Physiological Response

2021 ◽  
Vol 9 (12) ◽  
pp. 1361
Author(s):  
So-Sun Kim ◽  
Gyeong-Sik Han ◽  
Hae-Kyun Yoo ◽  
Ki-Tae Kim ◽  
Soon-Gyu Byun ◽  
...  
Keyword(s):  
Weight Loss ◽  
Water Temperature ◽  
Cold Water ◽  
Temperature Drop ◽  
Effect Of Temperature ◽  
Feeding Groups ◽  
Starry Flounder ◽  
Protein Levels ◽  
Platichthys Stellatus ◽  
Significant Difference

Starry flounder (Platichthys stellatus) is a commercially important cold-water fish. Our aim was to investigate the effects of fluctuating water temperature on flounders after periods of starvation and feeding. Fish were divided into starvation and feeding groups. The water temperature was increased stepwise in experiment 1; more focused variations, based on the results of experiment 1, were studied in experiment 2. At temperatures ≤27 °C, there was no significant difference observed in survival. At 28 °C, mortality increased, survival was lower (21%) in the starvation group than in the feeding group (46%), and weight loss was the highest (15%) in the starvation group. In experiment 2, survival was ≥86%, and there was no significant difference between the starvation/feeding groups. However, when the water temperature was increased to 27 °C after being decreased to 12 °C, weight loss was the highest (11%). Glucose, cortisol, superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels increased with increasing water temperature, and then gradually decreased. Glutamic pyruvic transaminase (GPT)/glutamic oxaloacetic transaminase (GOT) levels showed large variations among individuals. Triglyceride, cholesterol, and protein levels gradually decreased with long-term starvation. Survival was not affected by water temperature drop ≤27 °C after starvation/feeding. These results indicate that 27 °C is the upper limit of tolerable water temperature for the survival of starry flounders. Therefore, aquaculture farms should ensure maintaining water temperatures at ≤27 °C during high-temperature periods.

scholarly journals ANALISIS TEMPERATUR ANALISIS TEMPERATUR LINGKUNGAN TERHADAP KINERJA COOLING TOWER TIPE INDUCED DRAFT UNIT 2

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Harwan Ahyadi
Keyword(s):  
Power Plant ◽  
Energy Conversion ◽  
Cooling Tower ◽  
Cold Water ◽  
Cooling Water ◽  
Hot Water ◽  
Plant Industry ◽  
Geothermal Power Plant ◽  
Geothermal Power

Cooling tower is very necessary in every industry, especially in the geothermal power plant industry in the framework of implementation for efficiency and energy conversion where a tool or unit is used for circulation of cooling water. The function of the cooling tower is to process hot water into cold water, so that it can be used again. In the cooling tower specification data, the range value is 16.7 ° C, with an approach of 6.5 ° C, and with an efficiency of 71.98%. The results of the calculation of the analysis obtained a range value of 22.3 ° C, with an approach of 6.3 ° C, and with an efficiency of 77.97%. From the results of the analysis, the range, approach, and efficiency values were increased by 5.92% compared to the cooling tower specification data. Keywords: Cooling Tower, Inducted Draft, Range, Approach, Efficiency

scholarly journals STUDY ON BOTTOM WATER INTAKE FOR CONDENSER COOLING SYSTEM OF POWER STATION SITED ON A BAY

1966 ◽  
Vol 1 (10) ◽  
pp. 83
Author(s):  
Shin-ichi Senshu ◽  
Akira Wada
Keyword(s):  
Cold Water ◽  
Sea Water ◽  
Cooling System ◽  
Lower Layer ◽  
Thermal Power ◽  
Cooling Water ◽  
Hot Water ◽  
Power Station ◽  
Reclaimed Land ◽  
Intake Structure

This report concerns study on a method of taking the cold water from bottom layer with relation to the design of the intake structure of cooling water for the power station sited on a bay. The quantity of cooling water used for condenser system increases year by year along with the construction of thermal power stations of large capacity. If the bottom sea water of low temperature is taken into the condenser cooling system, remarkable saving of fuel expenses can be expected due to the improvement of heat efficiency of turbine. Especially, in case that the location of intake structure of cooling water is chosen at the interior of the reclaimed land or the bay, it is absolutely necessary to take the colder water from the lower layer of the sea, in order to prevent taking hot water over the sea basin where the water temperature of the surface layer is raised by the evacuation of heat of released industrial water. Various hydraulic problems concerning thermal density flow phenomena were examined aiming to obtain the design method of the most effective intake works of cooling water, and the authors proposed a curtain-wall type intake structure. Some results of analysis are described in this paper.

Experimental Investigation of Heat Transfer Enhancement by Using Different Number of Fins in Circular Tube

2018 ◽  
Vol 6 (3) ◽  
pp. 1-12
Author(s):  
Kamil Abdul Hussien
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Cold Water ◽  
Finned Tube ◽  
Hot Water ◽  
Copper Tube ◽  
Smooth Tube ◽  
Tube Heat Exchanger ◽  
Mass Flow Rates ◽  
Flow Heat

Abstract-The present work investigates the enhancement of heat transfer by using different number of circular fins (8, 10, 12, 16, and 20) in double tube counter flow heat exchanger experimentally. The fins are made of copper with dimensions 66 mm OD, 22 mm ID and 1 mm thickness. Each fin has three of 14 mm diameter perforations located at 120o from each to another. The fins are fixed on a straight smooth copper tube of 1 m length, 19.9 mm ID and 22.2 mm OD. The tube is inserted inside the insulated PVC tube of 100 mm ID. The cold water is pumped around the finned copper tube, inside the PVC, at mass flow rates range (0.01019 - 0.0219) kg/s. The Reynold's number of hot water ranges (640 - 1921). The experiment results are obtained using six double tube heat exchanger (1 smooth tube and the other 5 are finned one). The results, illustrated that the heat transfer coefficient proportionally with the number of fin. The results also showed that the enhancement ratio of heat transfer for finned tube is higher than for smooth tube with (9.2, 10.2, 11.1, 12.1 13.1) times for number of fins (8, 10, 12, 16 and 20) respectively.

scholarly journals Effect of Hot-Water Blanching Pretreatment on Drying Characteristics and Product Qualities for the Novel Integrated Freeze-Drying of Apple Slices

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hai-ou Wang ◽  
Qing-quan Fu ◽  
Shou-jiang Chen ◽  
Zhi-chao Hu ◽  
Huan-xiong Xie
Keyword(s):  
Electron Microscopy ◽  
Freeze Drying ◽  
Hot Water ◽  
The Novel ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Drying Characteristics ◽  
Promising Alternative ◽  
Freeze Dried ◽  
Apple Slices

The effect of hot-water blanching (HWB) on drying characteristics and product qualities of dried apple slices with the novel integrated freeze-drying (NIFD) process was investigated by comparing with 3 different FD methods. Compared with the NIFD process without HWB pretreatment (VF-FD), the NIFD process with HWB pretreatment (HWB-VF-FD) resulted in a significantly higher mass loss and more sufficient freezing in vacuum-frozen samples, significantly higher rehydration ratio (RR), higher shrinkage ratio (SR), smaller Vitamin C (VC) content and lower hardness and better apparent shape in freeze-dried samples, and fewer change to the color of the dried or rehydrated samples (p<0.05). Compared with the conventional FD process with HWB pretreatment (HWB-PF-FD), HWB-VF-FD cost significantly less processing time and FD time and obtained significantly higher RR (p<0.05), almost the equivalent SR, VC content, and hardness, and similar appearance in dried samples. The microstructure of apple cell tissues was analyzed by transmission electron microscopy and scanning electron microscopy to interpret the above differences in drying characteristics and product qualities. The results suggested that the NIFD process of apple slices with HWB pretreatment was a promising alternative method to decrease drying time, achieve similar product quality, and simplify the process steps of the conventional FD technology.

scholarly journals Predictors of Postprandial Hypoglycemia After Gastric Bypass Surgery: a Retrospective Case-Control Study

2021 ◽  
Author(s):  
Elric Zweck ◽  
Matthias Hepprich ◽  
Marc Y. Donath
Keyword(s):  
Weight Loss ◽  
Gastric Bypass ◽  
Gastric Bypass Surgery ◽  
Glycosylated Hemoglobin ◽  
Relative Weight ◽  
Meal Test ◽  
Retrospective Case ◽  
Mixed Meal ◽  
Absolute Weight ◽  
Mixed Meal Test

Abstract Background Postprandial hypoglycemia after bariatric surgery is an exigent disorder, often impacting the quality of life. Distinguishing clinically relevant hypoglycemic episodes from symptoms of other origin can be challenging. Diagnosis is demanding and often requires an extensive testing such as prolonged glucose tolerance or mixed-meal test. Therefore, we investigated whether baseline parameters of patients after gastric bypass with suspected hypoglycemia can predict the diagnosis. Methods We analyzed data from 35 patients after gastric bypass with suspected postprandial hypoglycemia and performed a standardized mixed-meal test. Hypoglycemia was defined by the appearance of typical symptoms, low plasma glucose, and relief of symptoms following glucose administration. Parameters that differed in patients with and without hypoglycemia during MMT were identified and evaluated for predictive precision using receiver operating characteristic (ROC) areas under the curve (AUC). Results Out of 35 patients, 19 (54%) developed symptomatic hypoglycemia as a result of exaggerated insulin and C-peptide release in response to the mixed-meal. Hypoglycemic patients exhibited lower glycosylated hemoglobin A1c (HbA1c) and higher absolute and relative weight loss from pre-surgery to study date. HbA1c and absolute weight loss alone could achieve acceptable AUCs in ROC analyses (0.76 and 0.72, respectively) but a combined score of absolute weight loss divided by HbA1c (0.78) achieved the best AUC. Conclusions HbA1c and weight loss differed in patients with and without symptomatic hypoglycemia during mixed-meal test. These baseline parameters could be used for screening of postprandial hypoglycemia in patients after gastric bypass and may facilitate the selection of patients requiring further evaluation. Graphical abstract

Experimental investigation of degassing properties of geothermal fluids

2021 ◽  
Author(s):  
Chris Boeije ◽  
Pacelli Zitha ◽  
Anne Pluymakers
Keyword(s):  
High Pressure ◽  
Temperature Drop ◽  
Hot Water ◽  
Visual Cell ◽  
Dissolved Gas ◽  
Bubble Point ◽  
Free Gas ◽  
Bubble Point Pressure ◽  
Geothermal Fluids ◽  
Point Pressure

&lt;p&gt;Geothermal energy, the extraction of hot water from the subsurface (500 m to 5 km deep), is generally considered one of the key technologies to achieve the demands of the energy transition. &amp;#160;One of the main problems during production of geothermal waters is degassing. Many subsurface waters contain substantial amounts of dissolved gasses. As the hot water travels up the production well, the pressure and/or temperature drop will cause dissolved gas to come out of the solution. This causes several problems, such as corrosion of the facilities (due to pH changes and/or degassing-related precipitation) and in some cases even to blocking of the reservoir as the free gas limits the water flow. &amp;#160;To better understand under which conditions free gas nucleates, we need confirmation of theoretical bubble point pressure and temperature, and understand what controls the evolution of the bubble front:&amp;#160; i.e. what are the conditions under which free gas emerges from the solution and at what rate are bubbles created?&lt;/p&gt;&lt;p&gt;An experimental setup was designed in which the degassing process can be observed visually. The setup consists of a high-pressure visual cell which contains water saturated with dissolved gas at high-pressure. The pressure within the cell can be reduced in a reproducible manner using a back-pressure regulator at the outlet of the system. A high-speed camera paired with a uniform LED light source is used to record the degassing process. The pressure in the cell is monitored using a pressure transducer which is synchronized with the camera. The resulting images are then analysed using a MATLAB routine, which allows for determination of the bubble point pressure and rate of bubble formation.&lt;/p&gt;&lt;p&gt;The first two sets of experiments at ambient temperatures (~20 &lt;sup&gt;o&lt;/sup&gt;C) were carried out using two different gases, N&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;. Initial pressure was 70 and 30 bar for the N&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt; experiments respectively. In these first experiments we determined the influence of the initial fluid used to pressurize the system. Using gas as the initial fluid causes a large amount of bubbles, whereas only a single bubble was observed for a system where degassed water is used as the initial fluid. An intermediate system where degassed water is pumped into a system full of air at ambient conditions and is subsequently pressurized yields a number of bubbles in between the two systems described previously. All three methods give reproducible bubble point pressures within 2 bar (i.e. pressure where the first free bubble is formed). There are clear differences in bubble point between N&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.&lt;/p&gt;&lt;p&gt;A series of follow-up experiments is planned that will investigate specific properties at more extreme conditions: at higher pressures (up to 500 bar) and temperatures (500 &lt;sup&gt;o&lt;/sup&gt;C) and using high-salinity brines (2.5 M).&lt;/p&gt;

scholarly journals The Effect of Thermo-Mechanical Processing on Physical Properties of Processed Amaranth and Oat Bran Composites

2017 ◽  
Vol 6 (2) ◽  
pp. 82
Author(s):  
Sean X. Liu ◽  
Diejun Chen ◽  
George E. Inglett ◽  
Jingyuan Xu
Keyword(s):  
Physical Properties ◽  
High Speed ◽  
Functional Foods ◽  
Cold Water ◽  
Essential Amino Acids ◽  
Hot Water ◽  
Blood Cholesterol ◽  
Gluten Free ◽  
Oat Bran ◽  
Amaranth Flour

Amaranth-oat composites were developed using gluten free amaranth flour containing essential amino acids and minerals with oat products containing β-glucan, known for lowering blood cholesterol. Amaranth flour and oat bran concentrate (OBC) composites (1:4) were processed using different technologies, including dry mixing, baking, steaming, cold wet blending, and high speed homogenizing (Polytron PT6000) with cold water or hot water. The results showed that water holding capacities, pasting, and rheological properties were dramatically increased by wet blending, Polytron with cold water, and Polytron with hot water followed by drum drying. The processing procedures created dissimilar physical properties that will enhance the application of ancient grains and oat for functional foods that are suitable for people who are gluten-intolerant. In addition, the dietary fiber contents of composites were increased by the incorporation of OBC. The composites can be inexpensively prepared and processed. The new healthful products will be affordable for people who suffer from celiac disease or gluten-intolerant. These innovative gluten-free functional food products will help millions of gluten sensitive consumers enjoy heart-healthy functional foods.

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