Analyzing the Thermodynamic Efficiency of Cooling Cycles Depending on the Determinant Thermal and Physical Properties of Operating Media

The goal of this research was to develop the methods used for the analysis of the thermodynamic efficiency of the ordinary single-stage and regenerative cooling cycles depending on the determinant thermal-&-physical properties of cooling agents. The thermodynamic efficiency of the steam –compressive single-stage ordinary and regenerative cycles of cooling machines operating on different cooling agents has been investigated. The dependence was established between the effectiveness value of the use of the regeneration for the cooling cycle and the modified Clausius criterion of the cooling agent. Generalized regressive dependences were obtained for the evaluation of the efficiency of the ordinary and regenerative cycles based on the determinant modified Clausius criterion and these give us an opportunity to establish the fields for the preferential use of the promising cooling agents for regenerative cycles and establish requirements to the properties of cooling agents during their choice. These contribute to the selection of the rational flowchart for the specified thermal and physical characteristics of the cooling agent and for the thermal behavior of the unit operation and form appropriate rational geometric characteristics for the heat exchangers and interconnecting piping. The suggested methods enable the determination of the expected characteristics of the unit and the boundary attainable values of its efficiency in the conditions of the limited information on the thermal-&-physical properties of new (by-way) cooling agents without waiting for the appearance of accurate state diagrams. Analytical equations used for the estimation of the cooling factor depending on the modified Clausius criterion allow us to perform the front-end project computations making use of only absolute values of evaporation and condensation temperatures. The effect of the steam depression, the dryness value and the efficiency factor of the regenerative heat exchanger on the cooling factor of the cycle has been studied. A practical value of the obtained data consists in the opportunity of the objective and operative estimation of the efficiency of the use of the cooling agent for the regenerative and steam compressing cycles of the cooling machine using no multiparameter optimization procedure.

DEFECT PRODUCT COMPARISON OF THE USE OF ALCOHOL-BASED FOUNTAIN SOLUTION AND ALCOHOL-FREE IN OFFSET PRINTING

One of the main components of the fountain solution used for the offset printing technique is isoprophil alcohol (IPA), which is related to its function as a surface tension reducing agent, cooling agent for printing plates and at the same time having anti-bioorganic function. However, complaints have also been made about the weaknesses in the use of IPA related to odor, toxicity and too high evaporation rate during its use. Therefore, in this article, IPA is compared to the "alcohol-free" type when used in the field as a wetting solution mixture using a KBK offset printing machine to produce magazines using of AP 115 paper. The difference in the use of the two surfaces the tension reducing agents are identified by the waste parameters that are used, generated during consistent printing under controlled process conditions. The results obtained indicate that the use of IPA is always higher, but the use of `` non alcoholic '' tends to be more stable in controling the process.Keywords—Isoprophil Alcohol (IPA), alcohol-free fontain solution, offset printing

Effect of Cooling Agent on Temperature Profile During Molding Injection: Case Study for Polylactic Composites

The paper presents a theoretical study for the cooling of polymer samples in an injection molding process. The study is applied for neat polylactic acid (PLA), PlA-talc and PLA-starch composite samples representing specimens for mechanical tests reported in literature. A one dimensional model was developed for the heat transport through the thickness of the sample from the polymer to the cooling agent: air in natural convection and water flowing through cooling channels. The heat of solidification of molten polymer was also considered. The model was solved in the frame of Matlab software. The results obtained consist in the evaluation of the final time required to reaches a temperature of about 60�C in the core of the specimen and the evaluation of the temperature profile along the cooling process. When using cooling air in natural convection the temperature profile shows insignificant space variation, but the duration of cooling is about 6 min. The use of cooling water proved to be more efficient in terms of cooling time is about 15-25s, while the temperature gradient in the thickness of the specimen is quite significant at any moment of time.

Effect of pre-cooling agent on intensity of pricking pain at intraoral injection site in adults: An experimental study.

Objective: To determine the effect of pre-cooling agent on the intensity of pricking pain at the intraoral injection site in adult patients. Method: An in-vivo interventional study, using split-mouth technique was conducted in the Department of Operative Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, DUHS, Karachi, between September 2018 to August 2019. Total 152 adult patients meeting the inclusion criteria were selected, and consent form was signed to investigate the pricking pain perception during needle administration. Topical anesthesia (benzocaine gel) was applied on left side (control) for 1 min whereas on the experimental (right) side the refrigerated cartridge was placed for 2 minutes. Infiltration anesthesia was then administered on both sides respectively. Patient’s pain perception ratings were measured through Visual analog scale (VAS). After profound anesthesia was achieved, restorative treatment was performed under rubber dam isolation. Statistical analysis was done using SPSS Version 24. Results: The effect of pre-cooling agent i.e. refrigerated cartridge, was statistically significant (P-value <0.05) on the intensity of pricking pain at the intraoral injection site among the age group of 41 to 50 years and female participants of 21to 30 years whereas the effect of pre-cooling agent was found statistically insignificant among the male participants of the age group of 21 to 30 years and irrespective of gender within 31 to 40 years of age. Conclusion: Pre-cooling agent was found effective in decreasing pricking pain sensed by the patients. Precooling agent can be used without topical anesthesia before administering infiltration because cryoanesthesia Continuous...

AUTOMATED INSTALLATION FOR MILK COOLING USING A NATURAL COOLING AGENT

In the chain from milk production to the sale of dairy products, the process of ensuring the required temperature is the main one. Moreover, to cool the milk, the tempera-ture of the cooling agent should be above milk freezing. Taking into account the fact that the process of cooling and storing milk in a chilled form imposes strict requirements for reliability and quality of management on farms, compressor refrigeration units have been used in recent years despite high energy consumption. Theanalysis of technical solu-tions in this direction by the example of farms of the Altai and Novosibirsk Regions showed that during the greatest boom of the livestock industry, film-tray, spray-cooling tow-er, and pipe and tank installations using natural cooling agents were widely used. Taking into account the climatic features of the area when choosing water cooling units as an intermediate coolant made it possible to significantly reduce energy consumption for milk cooling especially in winter. However, the complexity of controlling the process of preparing the intermediate coolant with unpredictable environmental parameters did not allow for high reliability and quality of manual control. A device for cooling the in-termediate coolant with the main -natural cold in winter with an automatic direct-acting regulator that provides the required operating mode of the cooling unit is proposed. The variants of automatic device operation both when the outdoor air temperature decreases and increases are con-sidered. An automated installation for cooling the interme-diate coolant with natural cold may be recommended both for cattle farms and processing enterprises

Kumud–A review: Explore the hidden value of Herb

Kumud,a herb listed in Nighantu under many names, is one of the herbs beneficial to the Rakta and Pitta Doshas. It is a well-known ayurvedicherb with numerous therapeutic benefits. It is also known as the blue lotus, red and blue aquatic plant, star lotus, or manel flower. Indian Blue Lotus is another name for it. It's native to Asia's southern and eastern regions, and it's also Bangladesh and Sri Lanka's national flower. Utpalais its Sanskrit name. It is a well-known herb that is mentioned in Indian classical texts and used in the Siddha therapeutic system. It's often utilized in pittaproblems because of its bitter taste. It helps to reduce fever and functions as a cooling agent for the body. Along with its traditional applications, many studies have shown it to have hepatoprotective, antioxidant, antidiabetic, DNA-protecting, antibacterial, analgesic, and anti-inflammatory properties. The current review focuses on traditional herb's modern pharmacological activities.

Thermal Conductivity of Lightweight Concrete Block with Various Cooling Agent

Energy was the important sources to human life. Due to increases energy demand in daily life, the energy consumption was increase day by day because of the heat load from solar radiation and heat produced by people. Toward sustainable development, this research was carried out to develop a lightweight concrete (LWC) block with various cooling agent such as glycerine, propylene glycol, coconut shell and gypsum powder. Six lightweight concrete (LWC) block with the size 250mm (L) × 250mm (W) × 100mm (T) were tested for thermal conductivity value. From the experimental result, it shows that lightweight concrete (LCW) block with various cooling agent obtained thermal conductivity value of 0.17W/mK - 0.36W/mK lower than thermal conductivity value for normal lightweight concrete (0.8W/mK) depending on concrete density. The lightweight concrete (LCW) block with cooling agent having low thermal conductivity value will reduce energy consumption in building.