Academia.edu no longer supports Internet Explorer.
To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser.
he wall of a refrigerator is constructed of fiberglass insulation sandwiched between two since the e k = 15.1 W/m⋅°C for sheet metal ion can be ° C = 45 Using the thermal resistance network, heat transfer Chapter 3, Problem 35. The wall of a refrigerator is constructed of fiberglass insulation (k = 0.035 W/m ⋅ °C) sandwiched between two layers of 1-mm-thick sheet metal (k = 15.1 W/m ⋅ °C). The refrigerated space is maintained at 3°C, and the average heat transfer coefficients at the inner and outer s of the wall are 4 W/m 2 ⋅ °C and 9 W/m 2 ⋅ °C, respectively. The kitchen temperature avera 25°C. It is observed that condensation occurs on the outer surfaces of the refrigerator when the temperature of the outer surface drops to 20°C. Determine the minimum thickness of fibergla insulation that needs to be used in the wall in order to avoid condensation on the outer surfaces
This book aims to give students of engineering a thorough grounding in the subject of heat transfer. The book is comprehensive in its coverage without sacrificing the necessary theoretical details. The book is designed as a complete course text in heat transfer for degree courses in mechanical and production engineering and combined studies courses in which heat transfer and related topics are an important part of the curriculum. Students on technician diploma and certificate courses in engineering will also find the book suitable although the content is deeper than they might require. The entire book has been thoroughly revised and a large number of solved examples and additional unsolved problems have been added. This book contains comprehensive treatment of the subject matter in simple and direct language. The book comprises eight chapters. All chapters are saturated with much needed text supported and by simple and self-explanatory examples. Chapter one includes general introduction to transient conduction or unsteady conduction, definition of its fundamental terms, derivation of equations and a wide spectrum of solved examples. In chapter two the time constant and the response of temperature measuring devices were introduced and discussed thoroughly. This chapter was supported by different solved examples. Chapter three discusses the importance of transient heat conduction in solids with finite conduction and convective resistances. At the end of this chapter a wide range of solved examples were added. These examples were solved using Heisler charts. In chapter four transient heat conduction in semi – infinite solids were introduced and explained through the solution of different examples using Gaussian error function in the form of tables and graphs. Chapter five deals with the periodic variation of surface temperature where the periodic type of heat flow was explained in a neat and regular manner. At the end of this chapter a wide range of solved examples was introduced. Chapter six concerns with temperature distribution in transient conduction. In using such distribution, the one dimensional transient heat conduction problems could be solved easily as explained in examples. In chapter seven additional examples in lumped capacitance system or negligible internal resistance theory were solved in a systematic manner, so as to enable the students to understand and digest the subject properly. Chapter eight which is the last chapter of this book contains unsolved theoretical questions and further problems in lumped capacitance system. How these problems are solved will depend on the full understanding of the previous chapters and the facilities available (e.g. computer, calculator, etc.). In engineering, success depends on the reliability of the results achieved, not on the method of achieving them. I would like to express my appreciation of the assistance which I have received from my colleagues in the teaching profession. I am particularly indebted to Professor Mahmoud Yassin Osman for his advice on the preparation of this textbook. When author, printer and publisher have all done their best, some errors may still remain. For these I apologies and I will be glad to receive any correction or constructive criticism.
The elusive name of God, revealed to Moses in Exodus 3, 14-15, undergoes, in the passage from Hebrew to Greek and Latin, a historically decisive ontological recon guration. From a cryptic name which reveals the always novel dimension of God, but also his historical delity towards Israel, it becomes the name of the perfection of the Absolute as an identical and immutable being. Studying the ambiguous interpretation of the Name of God in Clement of Alexandria and Augustine, the paper analyzes the retractatio made by the theology of grace of the Latin thinker in respect of a restitution of the Christian revelation as a Platonizing theological ontology, typical of Clement and the ‘ rst Augustine’ himself. If being becomes the name of the Christian God, the One remains, for Clemente, his apophatic meta-ontological secret. In Augustine, however, the name of God doubles in nomen aeternitatis, revealing the absolute ontological transcendence of the Deus in se, and in nomen misericordiae, revealing the singular advent of the Deus ad nos as undue and irresistible grace. The deep secret of God is, therefore, his eventual and donative excess with respect to his own absolute being. God reveals his deepest personal secret by barging in as a Spirit or Gift into the historical, passionate and dispersed contingency of the ego, thus ‘inventing’ a new notion of person, ecstatic because it is an exceptional and singular epiphany from the Absolute. Lo sfuggente e differente nome di Dio, rivelato a Mosè in Esodo 3, 14-15, subisce, nel passaggio dall’ebraico al greco e al latino, una ricon gurazione ontologica storicamente decisiva: da nome criptico che rivela la dimensione sempre ulteriore e avveniente di Dio, ma comunque anche la sua storica fedeltà nei confronti di Israele eletto come i suoi padri, diviene nome della perfezione dell’Assoluto quale essere identico e immutabile. Studiando l’interpretazione ambigua del Nome di Dio in Clemente d’Alessandria e Agostino, si evidenziano la retractatio e lo scarto che la teologia della grazia del pensatore latino compiono nei confronti della restituzione della rivelazione cristiana come platonizzante ontologia teologica, attestata con rigore esemplare da Clemente e dallo stesso ‘primo Agostino’. Se l’essere diviene il nome del Dio cristiano, l’Uno ne rimane, per Clemente, l’apofatico segreto meta-ontologico. In Agostino, invece, il nome di Dio si sdoppia in nomen aeternitatis rivelativo dell’assoluta trascendenza ontologica del Deus in se e in nomen misericordiae rivelativo dell’avvento singolare del Deus ad nos come grazia indebita e irresistibile. Il segreto profondo e ulteriore di Dio è, quindi, il suo eccesso eventuale e donativo rispetto al suo stesso essere assoluto. Dio rivela il suo più profondo segreto personale irrompendo quale Spirito o Dono nella contingenza storica, passionale e dispersa dell’io, “inventando” quindi una nuova nozione di persona, estatica perché eccezionale e singolare epifania dall’Assoluto. Keywords: Name of God /onthology /Gift / Spirit / singularity. Parole chiave: Nome di Dio / ontologia / Dono /Spirito / singolarità.
Golden Ratio Of Social Science And Education, 2024
The Mayanist, 2024
Journal of Archaeological Science, 2024
International Journal of Business Innovation and Research, 2020
COSMOS: an international journal of art and higher education, 2023