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Статті в журналах з теми "Stable heat load"
1
Трушляков, Євген Іванович. "МЕТОДОЛОГИЧЕСКИЙ ПОДХОД К ЭНЕРГОСБЕРЕГАЮЩЕМУ ХЛАДОСНАБЖЕНИЮ СИСТЕМ КОНДИЦИОНИРОВАНИЯ ВОЗДУХА АДАПТАЦИЕЙ К ТЕКУЩИМ КЛИМАТИЧЕСКИМ УСЛОВИЯМ". Aerospace technic and technology, № 4 (14 жовтня 2018): 58–62. http://dx.doi.org/10.32620/aktt.2018.4.08.
Повний текст джерелаАнотація:
The methodological approach was suggested to define a rational heat load of the air conditioning system (ACS) with taking into consideration the current climatic conditions of operation. The proposed approach is based on the hypothesis of sharing the current changeable heat load on the relatively stable share as the basic one for choosing installed (designed) refrigeration capacity of the refrigeration machine, operating with high energy efficiency in nominal or similar modes, and unstable heat load, corresponding to ambient air precooling at changeable current temperatures. To prove the methodological approach to defining a rational heat load of the ACS was carried out the analysis of current values of heat loads of the refrigeration machine ACS during cooling ambient air from its changeable current temperature to the temperature of 10, 15 and 20 ºС . It is shown that due to the different rates of annular refrigeration capacity production increment to cover the current heat loads with increasing the installed refrigeration capacity of the refrigeration machine, caused by the changes in heat load according to current climatic conditions during all the year round, it is necessary to choose a such heat load on the refrigeration machine of ACS (its installed refrigeration capacity), that provides a maximum or similar annular refrigeration capacity production at relatively high rates of its increment. Therein, the value of heat load for ambient air precooling is calculated according to remained principle as the difference between the rational total heat load and its basic relatively stable share. The proposed method is useful for defining a basic installed refrigeration capacity of the refrigeration machine of ACS with the accumulation of excessive (unapplied) refrigeration capacity at lowered current heat loads on ACS and its application for ambient air precooling, that is for covering unstable heat load share on ACS
2
Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Сергій Георгійович Фордуй, Сергій Анатолійович Кантор та Богдан Сергійович Портной. "МЕТОДОЛОГІЧНІ ПІДХОДИ ДО ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ ЗА ЗМІННИХ КЛІМАТИЧНИХ УМОВ". Aerospace technic and technology, № 7 (31 серпня 2019): 71–75. http://dx.doi.org/10.32620/aktt.2019.7.09.
Повний текст джерелаАнотація:
One of the most attractive reserves for improving the energy efficiency of air conditioning systems is to ensure the operation of refrigeration compressors in nominal or close to nominal modes by selecting a rational design heat load and distributing it within its design value according to the behavior of the current heat load under variable current climatic conditions to provide the maximum or close to maximum annual cooling capacity generation according to cooling duties of air conditioning. In the general case, the overall range of current thermal loads of any air conditioning system includes a range of unstable loads associated with the precooling of ambient air with significant fluctuations in cooling capacity according with current climatic conditions, and a relatively stable range of cooling capacity consumed to further reduce air temperature from a certain threshold temperature to the final outlet temperature. It is quite obvious that a stable range of heat load can be ensured within operating a conventional compressor in a mode close to the nominal mode while precooling the ambient air with significant fluctuations in heat load requires regulation of the cooling capacity through the use of a variable speed compressor. Thus, in response of the behavior of the change in current heat loads, any air conditioning system, whether the central air-conditioning system with its heat procession in a central air conditioner, or a combination thereof with a local recirculation system of indoor air, essentially consists of two subsystems: pre-cooling the ambient air and then cooling it to the set point temperature. The proposed method of distribution of design heat load depending on the behavior of the current heat load is useful for the rational design of central air conditioning systems and their combined versions with the local air conditioning system.
3
Cai, Bing, Weizhong Deng, Tong Wu, Tingting Wang, Zhengyuan Ma, Wei Liu, Lei Ma, and Zhichun Liu. "Experimental Study of a Loop Heat Pipe with Direct Pouring Porous Wick for Cooling Electronics." Processes 9, no. 8 (July 30, 2021): 1332. http://dx.doi.org/10.3390/pr9081332.
Повний текст джерелаАнотація:
A pouring silicate wick was manufactured to explore the influence of process and physical properties on the production and performance of loop heat pipes (LHP). This paper theoretically analyzed the advantages of pouring porous wick and introduced the technology of pouring silicate directly on evaporator. Based on this, the heat transfer performance of copper-methanol LHP system with pouring porous wick was tested under different positions. The results showed that with the input of multiple heat sources, the LHP could start up and maintain a stable temperature from 40 W to 160 W. When the vapor grooves were located above the compensation chamber, it was difficult to start up positively. By adding gravity assistance, the system could obtain more stable liquid supply and vapor flow, so as to realize start up. In the variable heat load test, the LHP showed good adaptability to the change of heat load. The thermal resistance of the system decreased with the increase of heat load. The thermal resistance of the evaporator almost unchanged and was always lower than 0.05 °C/W, which indicated that the pouring porous wick in the evaporator had good heat load matching.
4
Jin, Yun Xue, Qiang Qiang Tong, Xiao Ya Wang, and Hong Mei Chen. "Effect of T6 Heat Treatment on Dry Sliding Frictional Wear Characteristics of Al-20Si-5Cu Alloy." Advanced Materials Research 750-752 (August 2013): 591–95. http://dx.doi.org/10.4028/www.scientific.net/amr.750-752.591.
Повний текст джерелаАнотація:
The effect of T6 heat treatment on dry sliding friction and wear characteristics of Al-20Si-5Cu under a fixed sliding speed of 200r/min and sliding time of 30mins was illustrated in this paper. The result reveals that T6 heat treatment can improve morphology of primary Si and Al2Cu particles, enhance the hardness of the matrix. Wear rate increased with increasing of applied load. T6 heat treated samples have high wear resistance which is related to the improvement of microstructure, particularly with their increased hardness of matrix. But friction coefficient varies with heat treatment processes and has no sensitivity to applied loads, which fluctuates in a small range, so the friction coefficient can be considered to be stable. The wear mechanisms of T6 heat treated samples are also changed with increasing of applied load, from oxidative wear to fatigue wear.
5
Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Сергій Анатолійович Кантор та Веніамін Сергійович Ткаченко. "ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ КОНДИЦІЮВАННЯ ЗОВНІШНЬОГО ПОВІТРЯ СИСТЕМИ КОМБІНОВАНОГО ТИПУ". Aerospace technic and technology, № 4 (31 серпня 2019): 9–14. http://dx.doi.org/10.32620/aktt.2019.4.02.
Повний текст джерелаАнотація:
One of the most attractive reserves of enhancing the energetic efficiency of air conditioning systems is to provide the operation of refrigeration compressors in nominal or close to nominal modes by choosing rational design cooling loads (cooling capacities) and their distribution according to a cooling load behaviour within the overall design (installed) cooling load band to match current changeable climatic conditions and provide close to maximum annual cooling capacity generation according to cooling duties. The direction of increasing the efficiency of outdoor air conditioning in combined central-local type systems by rationally distributing the heat load - cooling capacity of the central air conditioner into zones of variable heat load in accordance with current climatic conditions and its relatively stable value, i.e. cooling capacity required for further air cooling at the entrance to the indoor recirculation air conditioning system is justified. By comparing the values of the excessive production of cold and its deficit within every 3 days for a rational design heat load of the air conditioning system (cooling capacity of the installed refrigeration machine), which provides close to maximum annual production of cold, and the corresponding values of the excess and deficit of cooling capacity in accordance with current climatic conditions during July substantiated the feasibility of accumulating the excess of cooling capacity of a central air conditioner at low current loads and its use for covering cooling deficit at elevated heat loads through pre-cooling the outdoor air. It is developed a scheme of a combined central-local air conditioning system, which includes the subsystems for the outdoor air conditioning in a central air conditioner and the local indoor recirculated air conditioning.
6
Kancherla, Prasada Rao, and Venkata Appa Rao Basava. "Experimental Investigation On Cylinder Vibration Analysis, Combustion, Emission and Performance Of An IDI Engine." International Journal of Manufacturing, Materials, and Mechanical Engineering 7, no. 1 (January 2017): 18–36. http://dx.doi.org/10.4018/ijmmme.2017010102.
Повний текст джерелаАнотація:
An experimental study was conducted to evaluate the performance, emissions, combustion and heat release rate of an Indirect Diesel Injection (IDI) engine fuelled with Mahua methyl ester (MME) along with Methanol (M) additive blends. Smoke, NOx, CO, HC and CO2 emissions were recorded and various engine performance parameters were measured. A comparative study was conducted using diesel, MME and Methanol additive blends on an IDI engine. There is substantial improvement can be observed from the net heat and cumulative heat release rate plots in which the 3% additive blend reached the performance of diesel fuel and the corresponding cylinder vibration plots indicated smoother combustion. Five additive blends were tested, the blending ratios of 1/99, 2/98, 3/97, 4/96 and 5/95 (by vol.) and five discrete part load conditions viz. No Load, 0.77 kW, 1.54 kW, 2.31 kW, and 2.70 kW loads without gear box and clutch assembly ensuring stable engine operation. 57% HC, 20% CO, 14% NOx, 27% smoke reductions were observed at 3% additive at maximum opted load (2.70 kW and 1500 rpm) of the engine.
7
Трушляков, Євген Іванович, Микола Іванович Радченко, Андрій Миколайович Радченко, Сергій Георгійович Фордуй, Сергій Анатолійович Кантор, Веніамін Сергійович Ткаченко та Богдан Сергійович Портной. "ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ ШЛЯХОМ РОЗПОДІЛУ ТЕПЛОВОГО НАВАНТАЖЕННЯ ЗА СТУПЕНЕВИМ ПРИНЦИПОМ". Aerospace technic and technology, № 8 (31 серпня 2019): 49–53. http://dx.doi.org/10.32620/aktt.2019.8.07.
Повний текст джерелаАнотація:
Maintaining the operation of refrigeration compressors in nominal or close modes by selecting a rational design thermal load and distributing it in response to the behavior of the current thermal load according to the current climatic conditions is one of the promising reserves for improving the energy efficiency of air conditioning systems, which implementation ensures maximum or close to it in the annual cooling production according to air conditioning duties. In general case, the total range of current thermal loads of any air-conditioning system includes a range of unstable loads caused by precooling of ambient air with significant fluctuations in the cooling capacity according to current climatic conditions, and a range of relatively stable cooling capacity expended for further lowering the air temperature from a certain threshold temperature to the final outlet temperature. If a range of stable thermal load can be provided within operating a conventional compressor in a mode close to nominal, then precooling the ambient air with significant fluctuations in thermal load requires adjusting the cooling capacity by using a variable speed compressor or using the excess of heat accumulated at reduced load. Such a stage principle of cooling ensures the operation of refrigerating machines matching the behavior of current thermal loads of any air-conditioning system, whether the central air conditioning system with ambient air procession in the central air conditioner or its combination with the local indoors recirculation air conditioning systems in the air-conditioning system. in essence, as combinations of subsystems – precooling of ambient air with the regulation of cooling capacity and subsequent cooling air to the mouth of the set point temperature under relatively stable thermal load.
8
Komarov, V. A., E. A. Kishov, O. G. Laikova, and A. A. Pavlov. "Digital design of heat-resistant dimensionally stable carbon laminate (CFRP) structures." VESTNIK of Samara University. Aerospace and Mechanical Engineering 20, no. 1 (April 20, 2021): 75–86. http://dx.doi.org/10.18287/2541-7533-2021-20-1-75-86.
Повний текст джерелаАнотація:
Special features of designing heat-resistant dimensionally stable structures are considered. A new design procedure is proposed, in which finite elements are used as a language for describing the load-bearing structure of a construction and the distribution of material in it considering the possibility of setting the desired structure of a composite material. The design task is formulated in terms of nonlinear mathematical programming. A sequence of digital models is used for its approximate solution in the interactive mode. The specific features of finite element modeling of thin-walled structures made of laminated composite material are discussed. The technique is demonstrated using the example of the development of a large-size space telescope body.
9
Radchenko, Mykola, Tadeusz Bohdal, Andrii Radchenko, Eugeniy Trushliakov, Veniamin Tkachenko, Oleksii Zielikov, and Felix Tzaran. "Alternative variable refrigerant flow (VRF) air conditioning systems with rational distribution of thermal load." E3S Web of Conferences 323 (2021): 00028. http://dx.doi.org/10.1051/e3sconf/202132300028.
Повний текст джерелаАнотація:
One of the most attractive reserves of enhancing the energetic efficiency of air conditioning systems (ACS) is to provide operation of compressors in closed to nominal modes by choosing the rational design refrigeration capacities and their distribution according to current thermal loading to provide closed to maximum annual refrigeration energy generation. Generally, the overall thermal load band of any ACS comprises the unstable load range, corresponding to ambient air precooling with significant load fluctuations, and a comparatively stable load part for further air conditioning from a threshold temperature to a target value. The stable thermal load range can be covered by operation of conventional compressor in closed to nominal mode, meantime ambient air precooling needs load modulation by applying a variable speed compressor. A proposed ACS enables a wide range of refrigerant flow variation without heat flux drop in air coolers and can be considered as advanced alternative to variable refrigerant flow systems.
10
Wang, Xin Hua, Si Wei Zhang, and De Guo Wang. "Research on Friction and Wear Performance of Brake Disc Pair Materials for New Type of Drilling Rig." Key Engineering Materials 373-374 (March 2008): 438–41. http://dx.doi.org/10.4028/www.scientific.net/kem.373-374.438.
Повний текст джерелаАнотація:
Tribological performance of new brake pair is studied at different temperatures, load and speed by variable temperature friction and wear test. The research indicates that brake pair has better frictional characteristics at variable temperature as well as heat-fade resistance performance at high temperatures. Wear rate of brake block and brake disc increases with friction temperature rising, however wear-resisting performance of brake disc is comparatively stable. Load has less influence on frictional coefficient of brake pair. Wear rate of brake disc and brake block increases with load increasing, but brake block has comparatively stable wear-resisting performance. Frictional coefficient of brake pair increases and tends to stabilize gradually along with sliding speed increasing, and speed has less influence on wear rate of brake block and brake disc. Initial heat-fading occurs in brake block material along with frictional temperature rising, secondary solidification may happen when frictional temperature reaches a certain value. When temperature rises much higher, brake block begins to soften and plastic flow intensifies, in addition thermal decomposition occurs in organic substance and wear-resisting performance becomes poorer. Build-up welding material has strong age-hardening effect and stable thermal structure, which leaves surface hardness and structure performance of brake disc unchanged at high temperatures.
Дисертації з теми "Stable heat load"
1
Trushliakov, Eugeniy, Andrii Radchenko, Mykola Radchenko, Serhiy Kantor та Oleksii Zielikov. "The Efficiency of Refrigeration Capacity Regulation in the Ambient Air Conditioning Systems". Thesis, 2020. https://doi.org/10.1007/978-3-030-50491-5_33.
Повний текст джерелаАнотація:
The Efficiency of Refrigeration Capacity Regulation in the Ambient Air Conditioning Systems / E. Trushliakov, A. Radchenko, M. Radchenko, S. Kantor, O. Zielikov // Proceedings of the 3rd Intern. Conf. on Design, Simulation, Manufacturing: The Innovation Exchange «Advances in Design, Simulation and Manufacturing III». – Kharkiv, 2020. – Vol. 244. – P. 343–353.Abstract. The operation of the ambient air conditioning systems (ACS) is characterized by considerable fluctuations of the heat load in response to the current climatic conditions. It needs the analyses of the efficiency of the application of compressors with frequency converters for refrigeration capacity regulation in actual climatic conditions. A new method and approach to analyzing the effectiveness of ACS cooling capacity adjusting by using the compressor with changing the rotational speed of the motor as an example have been developed, according to which the overall range of changeable heat loads is divided into two zones: the zone of ambient air processing with considerable fluctuations of the current heat load, that requires effective refrigeration capacity regulation by the compressor with frequency converters (from 100% rated refrigeration capacity down to about 50%) and not an adjustable zone of reduced refrigeration capacity below 50% rated refrigeration capacity of the compressor. The magnitudes of threshold refrigeration capacity between both zones are chosen according to the rational value of installed (design) refrigeration capacity on the ACS, required for cooling the ambient air to a target temperature that ensures the maximum annual refrigeration capacity production in actual current climatic conditions. The proposed method and approach to the analysis of the efficiency of the refrigeration capacity regulation of the ACS compressor by distributing the overall range of changes in current heat loads allows increasing the efficiency of utilizing the installed refrigeration capacity in prevailing climatic conditions.
Книги з теми "Stable heat load"
1
Best, Antony, ed. British Foreign Secretaries and Japan, 1850-1990. GB Folkestone: Amsterdam University Press, 2018. http://dx.doi.org/10.5117/9781898823735.
Повний текст джерелаАнотація:
This book reviews the role of British Foreign Secretaries in the formulation of British policy towards Japan from the re-opening of Japan in the middle of the nineteenth century to the end of the twentieth century. It also takes a critical look at the history of British relations with Japan over these years. Beginning with Lord John Russell (Foreign Secretary 1859-1865) and concluding with Geoffrey Howe (Secretary of State for Foreign & Commonwealth Affairs, 1983-1989), the volume also examines the critical roles of two British Prime Ministers in the latter part of the twentieth century, Edward Heath and Margaret Thatcher, who ensured that Britain recognized both the reality and the opportunities for Britain resulting from the Japanese economic and industrial phenomenon. Heath’s main emphasis was on opening the Japanese market to British exports. Thatcher’s was on Japanese investment. This volume is a valuable addition to the Japan Society’s series devoted to aspects of Anglo-Japanese relations which includes ten volumes of Britain & Japan: Biographical Portraits as well as British Envoys in Japan.
2
Staël, Madame de, and John Isbell. Corinne. Edited by Sylvia Raphael. Oxford University Press, 2008. http://dx.doi.org/10.1093/owc/9780199554607.001.0001.
Повний текст джерелаАнотація:
‘Look at her, she is the image of our beautiful Italy.’ Corinne, or Italy (1807) is both the story of a love affair between Oswald, Lord Nelvil and a beautiful poetess, and an homage to the landscape, literature and art of Italy. On arriving in Italy, Oswald immediately falls under Corinne’s magical spell as she is crowned a national genius at the Captitol. Yet, on returning to England, he succumbs to convention and honours his late father’s wish by marrying the dutiful English girl, Lucile, despite having learned that Corinne is Lucile’s Italian half-sister. Corinne dies of a broken heart and Lord Nelvil is left with a seared conscience. Staël weaves discreet French Revolutionary political allusion and allegory into her romance, and its publication saw her order of exile renewed by Napoleon. Indeed, the novel stands as the birth of modern nationalism, and introduces to French usage the word ‘nationalitié’. It is also one of the first works to put a woman’s creativity centre stage. Sylvia Raphael’s new translation preserves the natural character of the French original and the edition is complemented by notes and and introduction which serve to set an extraordinary work of European Romanticism in its historical and political contexts.
3
Strain, James J., and Michael Blumenfield, eds. Depression as a Systemic Illness. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190603342.001.0001.
Повний текст джерелаАнотація:
Depression has been declared by the World Health Organization in March of 2017 to be the illness with the greatest burden of disease in the world. This volume attempts to examine the current state of our understanding of depressive disorders, from the animal models, allostatie load, patterns of recurrence, effects on other illnesses, for example, cancer, neurological, cardiovascular, wound healing, etc. It is from this perspective that the editors declare that depression is a systemic illness, not just a mental disorder. Therefore, primary care physicians need to know how to diagnose, treat, and refer when necessary for the non-complicated, non-refractory forms of depression. From this perspective models of mental health training for the primary care physician are reviewed. Then a new model, the medical model, a step beyond collaborative care is described. Non complicated depressive illness needs to be addressed by the primary care physician much as they do asthma, diabetes, hyptertension, and congestive heart failure. Even collaborative care models are unable as the number of psychiatrists is too few even in developed countries, let alone in developing ones to work with primary care. Medical schools and residency training programs need to incorporate curriculum and clinical experiences to accommodate developing expertise to diagnose, treat, and refer when necessary in this most common medical malady. Finally, a modified electronic medical record is proposed as a collaborating agent for the primary care physician.
4
Best, Antony, and Hugh Cortazzi, eds. British Foreign Secretaries and Japan 1850-1990. Amsterdam University Press, 2018. http://dx.doi.org/10.1017/9781898823742.
Повний текст джерелаАнотація:
This book reviews the role of British Foreign Secretaries in the formulation of British policy towards Japan from the re-opening of Japan in the middle of the nineteenth century to the end of the twentieth century. It also takes a critical look at the history of British relations with Japan over these years. Beginning with Lord John Russell (Foreign Secretary 1859-1865) and concluding with Geoffrey Howe (Secretary of State for Foreign and Commonwealth Affairs, 1983-1989), the volume also examines the critical roles of two British Prime Ministers in the latter part of the twentieth century, Edward Heath and Margaret Thatcher, who ensured that Britain recognized both the reality and the opportunities for Britain resulting from the Japanese economic and industrial phenomenon. Heath’s main emphasis was on opening the Japanese market to British exports. Thatcher’s was on Japanese investment. <br><br>This volume is a valuable addition to the Japan Society’s series devoted to aspects of Anglo-Japanese relations which includes ten volumes of <i>Britain & Japan: Biographical Portraits</i> as well as <i>British Envoys in Japan</i>.
5
Hutchinson, Mark P., ed. The Oxford History of Protestant Dissenting Traditions, Volume V. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198702252.001.0001.
Повний текст джерелаАнотація:
This collection of targeted essays by an international team of leading scholars extends the previous four volumes of the Oxford History of Protestant Dissenting Traditions series into the twentieth century, following the spatial, cultural, and intellectual changes in dissenting identity and practice as these once European traditions globalized and settled down in other places. The migration of these traditions across cultural and national boundaries asked the key question, ‘Dissenting … from what?’ Whereas in Europe dissent was against the often religious state, (D)issent in a globalizing world could redefine itself against colonialism, against other secular and religious monopolies, or even against its own success. Traditions shifted along new continua—more or less indigenized, more or less experiential, more or less mobile and ‘productive’. The authors of this volume trace the encounters of dissenting Protestant traditions with modernity and globalization (Brown), changing imperial politics (Heath), challenges to biblical, denominational, and pastoral authority (Hutchinson), local cultures and languages (Yeo, Carter, Lord), and some of the century’s major themes, such as race and gender (Rademaker), new technologies (Asamoah-Gyadu), and organizational change (Ensign-George). In so doing they point to a vast array of local and globalizing illustrations which will enliven conversations about the role of religion, and in particular Christianity, be these in the classroom, the congregation, or the coffee shop. The volume draws on expertise from scholars located in many of the century’s points of intense change, from a range of national, cultural, and disciplinary backgrounds.
Частини книг з теми "Stable heat load"
1
Emple, Artem, and Kelly M. Axsom. "Orthotopic Heart Transplant Management." In Cardiothoracic Critical Care, 241–46. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780190082482.003.0025.
Повний текст джерелаАнотація:
This chapter details the management of orthotopic heart transplant, which is a treatment for end-stage heart failure. Early and intensive hemodynamic monitoring after heart transplant is critical for management. The chapter distinguishes primary graft dysfunction (PGD) from secondary graft failure. PGD is defined as left ventricular, right ventricular, or biventricular dysfunction that occurs within 24 hours after surgery and is not associated with a discernible cause. Although the etiology of PGD is poorly understood, donor-related, recipient-related, and procedure-related factors all play a role. Once PGD is diagnosed, pharmacotherapy with vasopressors, inotropes, and pulmonary vasodilators should be instituted and maximized while consulting the surgical team for early initiation of mechanical circulatory support. The chapter then considers the risk factors for PGD. The right ventricle in general, and specifically in a transplanted heart, is extremely sensitive to volume and pressure loads. As such, preload and afterload should be judiciously managed.
2
Rimmer, John. "Isle of Man." In The International Protection of Adults. Oxford University Press, 2015. http://dx.doi.org/10.1093/9780198727255.003.0019.
Повний текст джерелаАнотація:
The Isle of Man is a British Crown possession. It had been subject to Norwegian, then competing claims of Scottish and English suzerainty. The English asserted a claim to its possession. English monarchs made successive grants of the Island to individuals. Ultimately, it was granted to Sir John Stanley, subject to English suzerainty. In 1765, by the Act of Revestment, the Island was transferred (with the Lordship) to the British Crown. The British monarch is therefore head of state as the Lord of Man. The Island has never formed part of the metropolitan territories of the United Kingdom, however.
3
Billheimer, John. "Stage Fright (1950)." In Hitchcock and the Censors, 160–66. University Press of Kentucky, 2019. http://dx.doi.org/10.5810/kentucky/9780813177427.003.0021.
Повний текст джерелаАнотація:
Stage Fright was the first picture Hitchcock produced under his new contract with Warner Bros. Filmed in England, it featured lyrics by Cole Porter, Marlene Dietrich as a femme fatale, and a controversial flashback seeded with misinformation. The primary concern of the censors was Dietrich’s rendition of Porter’s song ‘The Laziest Gal in Town.’ The Breen office found both the song and the performance so offensive that it had the chutzpah to edit the lyrics of one of the most accomplished songwriters of the day. The censors objected to Porter’s use of the Lord’s name (as in ‘Lord knows’), as well as Dietrich’s cleavage and gyrations. Both Porter and Hitchcock accommodated the censors, changing ‘Lord knows’ to ‘you know,’ dressing Dietrich from head to toe in a cleavage-hiding white gown, and cutting away from the star’s most suggestive movements.
4
Yang, Yanping, and Yonglin Cai. "Screening of Nasopharyngeal Carcinoma." In Pharynx - Diagnosis and Treatment. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97398.
Повний текст джерелаАнотація:
Nasopharyngeal carcinoma (NPC) is one of head and neck cancer. It has a complicated etiology involving Epstein–Barr virus (EBV) infection, environment changes, and genetic susceptibility. Early symptoms of NPC are unspecific, so most NPC patients are diagnosed at a late stage. An effective population screening strategy could increase the early detection and early diagnosis rate. As far, serological detection of EBV antibodies such as VCA-IgA, EA-IgA, and EBNA1-IgA, are widely used in NPC mass screening; EBV DNA load detection in plasma or nasopharyngeal swab was applied to screen in endemic populations for assessing the feasibility. However, the current screening schemes still have disadvantages such as lowly positive predictive value, unclear effectiveness of screening and cost-effectiveness. In the present chapter, we try to review the different screening strategies for NPC to understand the future direction of development.
5
Haroutounian, Joanne. "Kindling the Spark: Early Development." In Kindling the Spark. Oxford University Press, 2002. http://dx.doi.org/10.1093/oso/9780195129489.003.0020.
Повний текст джерелаАнотація:
Alullaby winds its way through the intimate confines of the nursery, as a restless baby is soothed to sleep. The rhythm and rocking chair synchronize a pulse as a mother sings softly to her child. The baby listens to the gentle flow of the melody, which drifts into a hum that vibrates against the sleeping child’s tiny head. A few short years later, Mom smiles as she looks in to her three-year-old’s room. Her daughter is nestled in the same rocking chair, singing a rather lopsided version of the same lullaby, gently stroking a rag doll wrapped in a frayed old baby blanket. Children listen before they are born. They are aware of their mother’s heartbeat and the different environmental sounds that filter into the cozy womb. They are surrounded by the low-pitched pulsating sounds of their mother’s cardiovascular system at work. Studies show that pregnant singers find their babies much quieter when they are singing. Instrumentalists report the opposite effect, with lots of internal activity when they are performing. Even before birth, a child recognizes the sound of a mother’s voice and responds to music or familiar sounds. Prenatal studies abound that can measure the movements and startle reflexes of these yet-to-be-born listeners. Loud, sudden noises (above 100 db) cause the fetal heart to beat faster and an immediate startle response. One experiment zapped 15 seconds of a Bach organ prelude (at 100 db) through headphones nestled close to a mother’s abdomen. Not surprisingly, the fetal heart rate accelerated within five seconds of this musical stimulation. Once a baby is born, the effects of these prenatal sounds still have an influence on behavior. Studies of newborns by Salk in the 1960s resulted in the popularity of crib devices that play the sound of an adult heartbeat to soothe babies to sleep. Other studies show the same soothing effect for seven-day-old neonates listening to taped sounds of intrauterine background noises. From birth, the mother’s voice is distinguished from other women’s voices and recognized more readily than the father’s voice—again stemming from prenatal listening experiences.
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Deutermann, Allison K. "Sound in Mind and Body: Hearing Early Modern Revenge Tragedy." In Listening for Theatrical Form in Early Modern England. Edinburgh University Press, 2016. http://dx.doi.org/10.3366/edinburgh/9781474411264.003.0002.
Повний текст джерелаАнотація:
This chapter traces how revenge tragedy took shape on the early modern stage, outlining the model of violent, invasive hearing on which the genre would increasingly depend. Many late-sixteenth century plays delight in sonic excess, combining cannon fire, trumpets, and alarums with the rumbling thunder of bombastic speech. In these productions, loud noises are often associated with violence, and particularly vengeance. Revenge is said to ‘thunder’ into bodies, or to ‘shriek’ and ‘cry’ out; noise itself becomes a weapon. Contemporary anatomy texts support such thinking, as do early modern theories of theatrical influence and effects. Increasingly, revengers’ speeches become weapons to be wielded precisely -- that is, directly into the ears of specific, intended victims --rather than released indiscriminately into crowds of hearers. Through Kyd’s The Spanish Tragedy andShakespeare’s 3 Henry VI and Titus Andronicus, this chapter argues that revenge tragedy is intimately bound up in thinking about what sound can do to listeners both on and off the stage. The theatrical form proves explicitly invested in the question of what it means to hear plays in performance.
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Rehart, Stefan, and Martina Henniger. "Avascular necrosis." In Oxford Textbook of Rheumatology, 1266–73. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0148.
Повний текст джерелаАнотація:
Avascular necrosis (AVN) represents an important disease process of the cartilage-bone complex, which can occur at any age. According to aetiology one may discriminate between rare idiopathic avascular necroses and more common forms that occur as an effect of the underlying disease or rather the therapy, the secondary avascular necroses. Pathophysiologically it is assumed that a circulatory disorder leads to an ischaemic necrosis of bone, bone marrow, and adjunct cartilage. Sites of the human skeleton with predilection to AVN are the femoral head, humeral head, femoral condyle, proximal tibia, and ossicles of the foot and hand. Clinical signs are unspecific, but in the region of the load-bearing lower extremities pain occurs usually early. Plain radiographs, MRI, and sometimes also skeletal scintigraphy are used for diagnosis and staging. Usually 4-5 stages are distinguished; there are extra classification systems for individual entities. Spontaneous healing in terms of a return to normal without further damage can be found in small, circumscribed areas, but the bigger and the nearer the joint the more unlikely this is. Depending on region, stage of disease, age of the patient, concomitant diseases and cause, several conservative and surgical therapies may be applied. Conservative treatments include exoneration and relief of the extremity, physiotherapy, and if necessary medical treatment. The need for surgical intervention becomes more likely as AVN increases in size and gets closer to the joint. Surgical therapies include core decompression, revascularizing techniques, vascular bone transplant, corrective/transposition osteotomy, arthrodesis/joint reinforcement, or joint replacement.
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Wittenberg, Elaine, Joy V. Goldsmith, Sandra L. Ragan, and Terri Ann Parnell. "The Family Caregiving Imperative." In Caring for the Family Caregiver, 1–31. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780190055233.003.0001.
Повний текст джерелаАнотація:
The majority of adults will develop or contract one or more chronic illnesses in the latter third of their lives. They will live protractedly with illness for years before death. About one in six Americans (adult aged, as there are no reliable numbers on caregivers under the age of 18) provide an estimated 37 billion hours of unpaid care to family or friends. This population of caregivers shoulders a heavy load with little support, putting their own health in peril. A description of the caregiving population, their tasks, and financial costs are detailed. The four most common chronic illnesses of dementia, cancer, diabetes, and heart disease are specifically examined from a caregiving perspective. An argument is presented that situates the patient and caregiver as one unit of care, prioritizing family communication as a key part of health communication and decision-making. The summative force of perceived, experienced, and anticipated communication for the caregiver with patient, providers, family, and system is described. Caregiver effectiveness and well-being can be improved through better communication and improved health literacy, which also improves patient outcomes. The integration of family illness narratives that situate the informal caregiver’s experiences are presented. Four featured caregiver stories are detailed and set the stage for a typology of caregivers, which will unfold across the volume.
Тези доповідей конференцій з теми "Stable heat load"
1
Heggs, Peter John, and Abdelmadjid Alane. "Vacuum Operation of a Thermosyphon Reboiler." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22373.
Повний текст джерелаАнотація:
The research facility at the University of Manchester in the Morton Laboratory is a full scale replica of an industrial sized natural circulation thermosyphon reboiler, which comprises 50 tubes of 3 m length and 25.4 mm OD. The facility is operated under vacuum. Water is used as the process fluid and condensing steam is the heating source. Experimental datasets were obtained for the reboiler and have been presented in the form of profile plots of feed rate, fluid recirculation, recirculation ratio and vapour quality. The data elucidate the effect of pressure [0.1 to 1.0 bar] and heat duties [78 to 930 kW] on the performance of the reboiler. Three distinct modes of operation have been observed. Mode one is defined as a flow-induced instability or geysering (low heat duty) and exists below a definite transitional point that is independent of process pressure. Mode two is a region of stable operation that occurs above the threshold of the flow-induced instability, while mode three, which is defined as the heat-induced instability (density-wave instability), is pressure dependent obtained at high duties and is characterised by violent oscillations. These instability thresholds represent the lower and upper limits of operation of the reboiler. The region of stable operation is enveloped between the two limits and is very dependent on process pressure as it progressively becomes smaller as the vacuum becomes lower. These studies led to unique experimental observations, which revealed the existence of intermittent reversed flow in the entire loop. The use of throttling in the heat-induced unstable region to return to stable operation tends to be over a narrow range, outside of which the sole way to regain stability is to lower the heat load or increase the process pressure. In the region of flow-induced instability, throttling the fluid at the inlet is useless and actually makes the situation worse. These instabilities are alleviated by increasing the heat load.
2
Mourad, Abdel-Hamid I., and Aladdin Abu-Assi. "Effect of Machining Process on Stable Crack Growth." In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-78085.
Повний текст джерелаАнотація:
This paper aims to present an experimental evidence of the effect of machining process on stable crack growth behaviour (SCG) through AISI 4340 low alloy steel. Brittle fracture behaviour had been discovered in a batch of compact tension CT specimens, unlike previous batches that had shown ductile (stable crack growth) behaviour. This was unexpected, and indeed, was anomalous. An investigation was thus carried out to understand what processes that have affected the behaviour. Such anomalous brittle behaviour was observed while performing the fracture test on the affected specimen. The load-load displacement (P-ΔLL) curves show that the “normal” specimen exhibiting stable crack growth and the non-linear region, in the anomalous curve of the anomalous specimens, is rather limited. This indicates very limited, if any, stable crack growth. Fracture tests were carried out on CT specimens with different heat treatments to find the cause of this unexpected embrittlement. Microhardness measurements, tensile tests and microscopic (SEM) examination were also carried out and reported. The results suggest that, a great attention is needed during machining process to avoid accidental changes in the properties and to avoid misleading experimental results.
3
Vetrovec, John. "High-Performance Heat Sink for Hybrid Electric Vehicle Inverters." In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-28776.
Повний текст джерелаАнотація:
We report a novel active heat sink (AHS) that allows high-density electronic components to operate at a stable temperature over a broad range of ambient conditions. AHS receives heat at high flux and transfers it at reduced flux to environment, coolant fluid (e.g., air or engine coolant), heat pipe, or structures. Temperature of the heat load can be controlled electronically. Target applications for AHS include thermal management of high-power inverters for hybrid electric vehicles. Depending on the configuration, AHS can handle a heat load of several hundred watts at a heat flux over 1,000 W/cm2 with a thermal resistance as low as 0.1 °C/W. AHS physics, engineering design for inverter applications, performance simulations, and initial test data are presented.
4
Benra, Friedrich-Karl, and Hans Josef Dohmen. "Unsteady Three-Dimensional Flow Phenomena in an Axial Flow Pump at Different Operating Points." In ASME 2008 Fluids Engineering Division Summer Meeting collocated with the Heat Transfer, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/fedsm2008-55344.
Повний текст джерелаАнотація:
In highly loaded axial flow pumps considerable changes of the flow behavior are known when altering the flow rate from design point operation to part load operation. The flow structure which is changing from stable operating conditions to stalled flow conditions has been investigated experimental by Kosyna and Stark. The measured results are compared to results obtained by numerical simulations in a previous paper of the authors. Time dependent three dimensional flow fields in this axial flow pump have been investigated by unsteady Reynolds averaged Navier-Stokes simulations. The time resolved flow fields are compared to the time averaged results of the measurements for the design point and also for part load operating conditions. The change in the vortex structure induced by the tip leakage flow is investigated in detail for different conditions of operation. Also the part load recirculation vortex dominating the rotor tip flow at deep stall conditions as well as the cross passage vortex is visualized by evaluating the numerical results.
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Takamatsu, Tomonao, Katsumi Hisano, and Hideo Iwasaki. "Improvement of Heat Transfer Performance of Loop Heat Pipe for Electronic Devices." In ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/ipack2011-52095.
Повний текст джерелаАнотація:
In this paper is presented the results on performance of the cooling model using Loop Heat Pipe (LHP) system. In recent years, ever-ending demand of high performance CPU led to a rapid increase in the amount of heat dissipation. Consequently, thermal designing of electronic devices need to consider some suitable approach to achieve high cooling performance in limited space. Heat Pipe concept is expected to serve as an effective cooling system for laptop PC, however, it suffered from some problems as follows. The heat transport capability of conventional Heat Pipe decreases with the reduction in its diameter or increase in its length. Therefore, in order to use it as cooling system for future electronic devices, the above-mentioned limitations need to be removed. Because of the operating principle, the LHP system is capable of transferring larger amount of heat than conventional heat pipes. However, most of the LHP systems suffered from some problems like the necessity of installing check valves and reservoirs to avoid occurrence of counter flow. Therefore, we developed a simple LHP system to install it on electronic devices. Under the present experimental condition (the working fluid was water), by keeping the inside diameter of liquid and vapor line equal to 2mm, and the distance between evaporator and condenser equal to 200mm, it was possible to transport more than 85W of thermal energy. The thickness of evaporator was about 5mm although it included a structure to serve the purpose of controlling vapor flow direction inside it. Successful operation of this system at inclined position and its restart capability are confirmed experimentally. In order to make the internal water location visible, the present LHP system is reconstructed using transparent material. In addition, to estimate the limit of heat transport capability of the present LHP system using this thin evaporator, the air cooling system is replaced by liquid cooling one for condensing device. Then this transparent LHP system could transport more than 100W of thermal energy. However, the growth of bubbles in the reserve area with the increase in heat load observed experimentally led to an understanding that in order to achieve stable operation of the LHP system under high heat load condition, it is very much essential to keep enough water in the reserve area and avoid blocking the inlet with bubbles formation.
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Wang, Pengfei, Diyi Chen, and Huanhuan Li. "Hamiltonian Modeling and Energy Analysis of a Hydro Electric Generating Set in the Sudden Load Decreasing Transient." In ASME 2020 Fluids Engineering Division Summer Meeting collocated with the ASME 2020 Heat Transfer Summer Conference and the ASME 2020 18th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/fedsm2020-20113.
Повний текст джерелаАнотація:
Abstract Hydroelectric generation system is mainly composed of penstock, hydro-turbine, generator, servicing facility and power load, its stability is directly related to the dynamic characteristics of each subsystem, but not completely dependent on the behavior of the subsystems. To better study the transient energy characteristics and stabilization mechanism of the hydroelectric generating set in the sudden load decreasing transient. And make full use of strengths of generalized Hamiltonian system in describing energy flow, the Hamiltonian model of a hydroelectric generating set including the turbine, water diversion system and generator is established by the method of orthogonal decomposition. Firstly, the energy flow of the hydroelectric generating set in the framework of generalized Hamiltonian theory is proved theoretically to be consistent with the real system, and the transient process of sudden load decreasing can be described effectively. Moreover, the variation laws of the flow, the rotating speed and the power angle of the set in the sudden load decreasing transient are studied respectively. The results indicate that the constructed Hamilton function can effectively describe the energy change of the system. It provides theoretical support for the stable operation of the hydroelectric generating set in the sudden load decreasing transient, and a new research idea for the stable operation of the set in other transient processes.
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Wong, Shwin-Chung, and Chung-Wei Chen. "Visualization and Evaporation Resistance Measurement for Groove-Wicked Flat Plate Heat Pipes." In ASME 2011 9th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2011. http://dx.doi.org/10.1115/icnmm2011-58220.
Повний текст джерелаАнотація:
This work experimentally studied the evaporation characteristics in groove-wicked flat-plate heat pipes. The parallel, U-shaped grooves have a width of 0.25 mm and a depth of 0.16 mm. Uniform heating was applied to the copper base plate near one end, and a cooling water jacket was connected at the other end. The evaporation resistance was calculated based on the difference of the plate temperature and the vapor temperature respectively under and above the center of the heated zone. Water was used as the working fluid. With stepwise increase of heat load, the behavior of the working fluid in the grooves was visualized, and the evaporation resistances were measured. Above a certain heat load, longitudinal liquid recession can be visualized with a steep-sloped liquid front. Behind the short liquid front is the accommodation region where the meniscus appeared to anchor on the top corners of the groove walls. Under a thermally stable situation, longitudinal oscillations of the liquid front existed in many grooves. Also, the liquid motion in different grooves seemed independent, forming a constantly varying zigzag front line. With increasing heat load, the liquid fronts gradually left the heated zone, accompanied by increasing plate temperatures. The evaporation resistance data appeared larger and more scattered than those associated with mesh or powder wicks in our published experiments, presumably due to the relatively large groove size and surface roughness from etching. No boiling was observed in all present tests. The evaporation resistances for groove wicks increase monotonically in response to the gradually enlarged dryout region with increasing heat load.
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Mwesigye, Aggrey, Hiep V. Nguyen, Reza Daneshazarian, Ayman Bayomy, Pedram Atefrad, and Seth B. Dworkin. "Transient Thermal Performance and Ground Temperature Variation for a Heat Pump System Using High Thermal Conductivity Energy Piles." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-12005.
Повний текст джерелаАнотація:
Abstract To reduce the cost of ground source heat pump systems (GSHPs), the use of foundation piles as ground heat exchangers is a promising alternative. Unlike conventional systems, no additional drilling costs are incurred, greatly reducing the initial cost. In this study, the influence of varying pile sizes and grout backfill material thermal conductivity on the performance of a foundation pile ground heat exchanger is numerically modelled and optimized. Piles with diameters between 0.15 m and 2 m with a depth of 30 m, and backfill material with thermal conductivities of 2.0 W/mK and 3.6 W/mK have been considered. The study was accomplished using a thoroughly validated finite element model that determines the ground temperature distribution and energy transfer rates accurately. First, steady state performance was determined for different inlet temperatures in the range 0 to 45°C, then, using an actual heating and cooling load profile for a balanced building, the performance of the heat pump system was determined over a 4-year period. From the study, only the 2000 mm pile gives the most stable performance for the load used with COPs between 3.1 and 6.2 for the 2.0 W/mK backfill material. Smaller piles are shown to be unsuitable for the load, leading to malfunctioning of the heat pump in the cooling season. For a 1200 mm pile, the COP is in the range 0–6.0, but does not handle the cooling loads in the summer. Improving the thermal conductivity from 2.0 W/mK to 3.6 W/mK for the 1200 mm significantly improves the cooling performance and helps avoid failure of the heat pump. The cooling COP increases to about 2.0 from below zero values when the thermal conductivity is 2.0 W/mK for the 1200 mm pile.
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Tudor, V., and M. Cerza. "Start Up and Transient Response to Power Input of a Capillary Assisted Thermosyphon for Shipboard Electronics Cooling." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22843.
Повний текст джерелаАнотація:
The future capabilities of naval ships will be directly related to the electronic components used in advanced radar systems, fire control systems, electric propulsion and even electric weapons. The next generation of naval warships will fall under the concept of an all electric ship, where turbines convert all the power produced by the engine into electricity. This electrical power can then be distributed given the ship’s mission and operating profile. The current need for advanced electronics cooling techniques is paramount since power dissipation levels are rapidly exceeding the capabilities of forced air convection cooling. This paper reports an experimental investigation of the start-up and transient response to heat load change of a capillary assisted thermosyphon (CAT) for the shipboard cooling of electronics components. The capillary assisted thermosyphon differs from a capillary pumped loop or loop heat pipe system in that the basic cooling-loop is based on a thermosyphon. The capillary assist comes from the fact that there is a wicking structure in the flat evaporator plate. The wicking structure allows uniformly spread of the working fluid across the flat plate evaporator in the areas under the heat sources as well as providing additional capillary pumping assist to the loop. A vertical flat plate, CAT evaporator was designed and tested under a fixed thermal sink temperature of 21°C. The condenser cold plate cooling water flow rate was fixed as 3.785 liters per minute (i.e. 1 gpm). The heat input varied from 250 to 1000W — evenly spread over the area of the evaporator. The CAT flat plate evaporator performed very well under this range of heat inputs, sink temperature, and cold plate flow rate. The main result obtained showed that the CAT loop reached steady state operation within 10 min. to 15 min. The average plate temperature did not exceed 70°C for the maximum heat input of 1000W. The CAT evaporator operating temperature increased with increasing heat input for all conditions tested and reached 60°C at 1000W. The continuous and stable operation of the CAT loop during start-up, steady-state and during transient/sudden heat input variations indicates that the CAT loop is a viable solution for high flux electronics components cooling.
10
Salem, Rami, Julien Marty, and Marc Errera. "Steady Conjugate Heat Transfer Method for High Temperature Gradient in Turbomachinery Applications." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-91578.
Повний текст джерелаАнотація:
Abstract The high-pressure (HP) turbine and compressor blades are subjected to severe aero-thermal loads either caused by high inlet temperature resulting from the combustion chamber or by the shock wave at the blade surface. In this paper, a partitioned conjugate heat transfer (CHT) approach is used to assess 3D cases with high temperature gradient. On one hand, the high temperature resulting from the combustion chamber generates high azimuthal and radial non uniformities on the nozzle guide vane (NGV), known as hot streak. Since the engine efficiency is directly related to the turbine inlet temperature, manufacturers are seeking to improve thermal barrier coatings (TBC) to allow higher temperature. On the other hand, compressor rotor blades are also subjected to high thermal loads caused by the shock waves. Since the shock wave substantially contributes to the heat transfer, an accurate prediction of the wall temperature is thus required in order to properly estimate the rotor efficiency. However, the thermal load gradient caused by the hot streak, the use of thermal barrier coating or the shock wave have an impact on the overall computation stability. This paper assess the stability for a Dirichlet-Robin interface condition. Indeed an optimal relaxation parameter value is given for the Robin condition to provide a stable CHT computation. The impact on stability of the transient coupling time-step, the coupling frequency and the thermal conductivity is also assessed and the new transient coupling time-step defined allows to correctly stabilize the coupled simulation.
Звіти організацій з теми "Stable heat load"
1
Andersson, Göran. Thematic synthesis “Energy Networks” of the NRP “Energy”. Swiss National Science Foundation (SNSF), December 2019. http://dx.doi.org/10.46446/publication_nrp70_nrp71.2019.2.en.
Повний текст джерелаАнотація:
Switzerland’s energy grids are reliable and stable – but they are facing new challenges. These include the fact that the new renewable energy sources, namely photovoltaic systems and wind farms, only produce electricity on an irregular basis. Greater flexibility is therefore required in the energy grid: with new storage solutions for electricity and heat on the supply side and automated load management on the demand side. The potential synergies between the various energy sources must also be exploited.
2
Brosh, Arieh, David Robertshaw, Yoav Aharoni, Zvi Holzer, Mario Gutman, and Amichai Arieli. Estimation of Energy Expenditure of Free Living and Growing Domesticated Ruminants by Heart Rate Measurement. United States Department of Agriculture, April 2002. http://dx.doi.org/10.32747/2002.7580685.bard.
Повний текст джерелаАнотація:
Research objectives were: 1) To study the effect of diet energy density, level of exercise, thermal conditions and reproductive state on cardiovascular function as it relates to oxygen (O2) mobilization. 2) To validate the use of heart rate (HR) to predict energy expenditure (EE) of ruminants, by measuring and calculating the energy balance components at different productive and reproductive states. 3) To validate the use of HR to identify changes in the metabolizable energy (ME) and ME intake (MEI) of grazing ruminants. Background: The development of an effective method for the measurement of EE is essential for understanding the management of both grazing and confined feedlot animals. The use of HR as a method of estimating EE in free-ranging large ruminants has been limited by the availability of suitable field monitoring equipment and by the absence of empirical understanding of the relationship between cardiac function and metabolic rate. Recent developments in microelectronics provide a good opportunity to use small HR devices to monitor free-range animals. The estimation of O2 uptake (VO2) of animals from their HR has to be based upon a consistent relationship between HR and VO2. The question as to whether, or to what extent, feeding level, environmental conditions and reproductive state affect such a relationship is still unanswered. Studies on the basic physiology of O2 mobilization (in USA) and field and feedlot-based investigations (in Israel) covered a , variety of conditions in order to investigate the possibilities of using HR to estimate EE. In USA the physiological studies conducted using animals with implanted flow probes, show that: I) although stroke volume decreases during intense exercise, VO2 per one heart beat per kgBW0.75 (O2 Pulse, O2P) actually increases and measurement of EE by HR and constant O2P may underestimate VO2unless the slope of the regression relating to heart rate and VO2 is also determined, 2) alterations in VO2 associated with the level of feeding and the effects of feeding itself have no effect on O2P, 3) both pregnancy and lactation may increase blood volume, especially lactation; but they have no effect on O2P, 4) ambient temperature in the range of 15 to 25°C in the resting animal has no effect on O2P, and 5) severe heat stress, induced by exercise, elevates body temperature to a sufficient extent that 14% of cardiac output may be required to dissipate the heat generated by exercise rather than for O2 transport. However, this is an unusual situation and its affect on EE estimation in a freely grazing animal, especially when heart rate is monitored over several days, is minor. In Israel three experiments were carried out in the hot summer to define changes in O2P attributable to changes in the time of day or In the heat load. The animals used were lambs and young calves in the growing phase and highly yielding dairy cows. In the growing animals the time of day, or the heat load, affected HR and VO2, but had no effect on O2P. On the other hand, the O2P measured in lactating cows was affected by the heat load; this is similar to the finding in the USA study of sheep. Energy balance trials were conducted to compare MEI recovery by the retained energy (RE) and by EE as measured by HR and O2P. The trial hypothesis was that if HR reliably estimated EE, the MEI proportion to (EE+RE) would not be significantly different from 1.0. Beef cows along a year of their reproductive cycle and growing lambs were used. The MEI recoveries of both trials were not significantly different from 1.0, 1.062+0.026 and 0.957+0.024 respectively. The cows' reproductive state did not affect the O2P, which is similar to the finding in the USA study. Pasture ME content and animal variables such as HR, VO2, O2P and EE of cows on grazing and in confinement were measured throughout three years under twenty-nine combinations of herbage quality and cows' reproductive state. In twelve grazing states, individual faecal output (FO) was measured and MEI was calculated. Regression analyses of the EE and RE dependent on MEI were highly significant (P<0.001). The predicted values of EE at zero intake (78 kcal/kgBW0.75), were similar to those estimated by NRC (1984). The EE at maintenance condition of the grazing cows (EE=MEI, 125 kcal/kgBW0.75) which are in the range of 96.1 to 125.5 as presented by NRC (1996 pp 6-7) for beef cows. Average daily HR and EE were significantly increased by lactation, P<0.001 and P<0.02 respectively. Grazing ME significantly increased HR and EE, P<0.001 and P<0.00l respectively. In contradiction to the finding in confined ewes and cows, the O2P of the grazing cows was significantly affected by the combined treatments (P<0.00l ); this effect was significantly related to the diet ME (P<0.00l ) and consequently to the MEI (P<0.03). Grazing significantly increased O2P compared to confinement. So, when EE of grazing animals during a certain season of the year is estimated using the HR method, the O2P must be re measured whenever grazing ME changes. A high correlation (R2>0.96) of group average EE and of HR dependency on MEI was also found in confined cows, which were fed six different diets and in growing lambs on three diets. In conclusion, the studies conducted in USA and in Israel investigated in depth the physiological mechanisms of cardiovascular and O2 mobilization, and went on to investigate a wide variety of ruminant species, ages, reproductive states, diets ME, time of intake and time of day, and compared these variables under grazing and confinement conditions. From these combined studies we can conclude that EE can be determined from HR measurements during several days, multiplied by O2P measured over a short period of time (10-15 min). The study showed that RE could be determined during the growing phase without slaughtering. In the near future the development microelectronic devices will enable wide use of the HR method to determine EE and energy balance. It will open new scopes of physiological and agricultural research with minimizes strain on animals. The method also has a high potential as a tool for herd management.