Ports of entry

Ports of entry are places where one may lawfully enter a country by crossing land and sea borders‭. ‬This thesis frames the space conceptually where the boundaries of place, time, culture, and identity are crossed through existing ports or by building new ones. ‬ As an Iranian immigrant in the United States‭, ‬displacement of identity informs my worldview and design practice‭. ‬I find myself between two worlds, one inherited and the other adopted. ‬Both worlds are simultaneously active and exert their forces on my thought process‭. However, their interrelated dynamic is ambivalent because their path intersects and diverges unforeseeably‭. ‬My position‭, ‬like a pendulum‭, ‬never settles within this dual dynamic‭. ‬It sways from one direction to another—re-approaching one world after distancing itself from the other‭. ‬This instability manifests in my design with forms that move‭, ‬multiply‭, ‬shift in scale‭, ‬and are assembled and disassembled rapidly‭.‬ In my work‭, ‬events serve as ports of entry to new territories‭. ‬Events reveal the identity of a place, allowing me to relate to it on my own terms and to arrive at a space of belonging. ‬I navigate the trajectory of the events because it reveals how the past informs our present condition. ‬I collect fragments of evidence‭, ‬present or lost‭, ‬real or fictional‭, ‬past or present‭, ‬to tell contextual narratives about space‭, ‬site‭, ‬matter‭, ‬and time‭.

Numerical solution of linear time delay systems using Chebyshev-tau spectral method

In this paper, a hybrid method based on method of steps and a Chebyshev-tau spectral method for solving linear time delay systems of differential equations is proposed. The method first converts the time delay system to a system of ordinary dierential equations by the method of steps and then employs Chebyshev polynomials to construct an approx- imate solution for the system. In fact, the solution of the system is expanded in terms of orthogonal Chebyshev polynomials which reduces the solution of the system to the solution of a system of algebraic equations. Also, we transform the coefficient matrix of the algebraic system to a block quasi upper triangular matrix and the latter system can be solved more efficiently than the first one. Furthermore, using orthogonal Chebyshev polynomials enables us to apply fast Fourier transform for calculating matrix-vector multiplications which makes the proposed method to be more efficient. Consistency, stability and convergence analysis of the method are provided. Numerous numerical examples are given to demonstrate efficiency and accuracy of the method. Comparisons are made with available literature

A Nonlinear Model for Incorporating the Coupled Effects of Surface Energy and Microstructure on the Electromechanical Stability of NEMS

Surface energy and size phenomenon can play significant roles in physical performance of nano-electromechanical systems. Herein, the static and dynamic pull-in behavior of nano-tweezers and nano-switch fabricated from conductive cylindrical nano-wires is studied. The Gurtin–Murdoch surface elasticity in combination with the couple stress theory is employed to incorporate the coupled effects of surface energy and microstructure dependency (size phenomenon). Using Green–Lagrange strain, the higher-order surface stress components are incorporated in the nonlinear governing equation. The effect of gas damping is considered in the model as well as structural damping. The governing equation is solved using the reduced order method. The effects of various parameters on the static and dynamic pull-in parameters, phase plans and stability threshold of the nano-structures are demonstrated

A 2-DOF microstructure-dependent model for the coupled torsion/bending instability of rotational nanoscanner

It has been well established that the physical performance of nanodevices might be affected by the microstructure. Herein, a two-degree-of-freedom model base on the modified couple stress theory is developed to incorporate the impact of microstructure in the torsion/bending coupled instability of rotational nanoscanner. Effect of microstructure dependency on the instability parameters is determined as a function of the microstructure parameter, bending/torsion coupling ratio, van der Waals force parameter and geometrical dimensions. It is found that the bending/torsion coupling substantially affects the stable behavior of the scanners especially those with long rotational beam elements. Impact of microstructure on instability voltage of the nanoscanner depends on coupling ratio and the conquering bending mode over torsion mode. This effect is more highlighted for higher values of coupling ratio. Depending on the geometry and material characteristics, the presented model is able to simulate both hardening behavior (due to microstructure) and softening behavior (due to torsion/bending coupling) of the nanoscanners. © 2016, Springer-Verlag Berlin Heidelberg

Fizikalna i mehanička svojstva drva graba dominantnih i potisnutih stabala

Physical and mechanical properties are important factors in determining the suitability and application of wood material. This study aimed to investigate physical and mechanical properties of hornbeam wood (Carpinus betulus L.) in dominant and suppressed trees. Disks and logs of wood were cut at breast height to examine physical properties (oven- dried density, basic density, longitudinal shrinkage, tangential shrinkage, radial shrinkage, and volumetric shrinkage) and mechanical properties (static bending, compression strength parallel to the grain, compression perpendicular to the grain and hardness). T-test analysis indicated that forest mass (dominant-suppressed trees) affected the mechanical properties significantly (except modulus of elasticity). No significant difference was found between dominant and suppressed trees in terms of physical properties. MOE and MOR are higher in suppressed trees than in dominant trees. The average values of compression strength parallel to the grain, compression strength perpendicular to the grain and hardness of hornbeam wood were higher in the dominant trees than in the suppressed stands. In terms of mechanical properties of hornbeam wood in suppressed and dominant trees, the quality of wood is fair.Fizikalna i mehanička svojstva važni su čimbenici pri određivanju prikladnosti i primjene drvnog materijala. Ova je studija usmjerena na istraživanje fi zikalnih i mehaničkih svojstava drva graba (Carpinus betulus L.) dominantnih i potisnutih stabala. Diskovi i uzorci drva izrezani su na prsnoj visini stabla kako bi se odredila fizikalna svojstva (gustoća apsolutno suhog drva, nominalna gustoća drva, uzdužno utezanje, tangencijalno utezanje te radijalno i volumno utezanje) i mehanička svojstva (statičko savijanje, tlačna čvrstoća paralelno s vlakancima, tlačna čvrstoća okomito na vlakanca i tvrdoća). Analiza statističkim T-testom pokazala je da je šumska biomasa dominantnih i potisnutih stabala značajno utjecala na mehanička svojstva drva graba (osim na modul elastičnosti). Međutim, nije zabilježena značajna razlika u fizikalnim svojstvima drva dominantnih i potisnutih stabala. Dobivene vrijednosti MOE i MOR za drvo potisnutih stabala veće su od vrijednosti dobivenih za drvo dominantnih stabala. Prosječne vrijednosti tlačne čvrstoće paralelno s vlakancima, tlačne čvrstoće okomito na vlakanca i tvrdoće grabova drva dominantnih stabala bile su veće u usporedbi s drvom stabala iz potisnutih sastojina. Prema dobivenim vrijednostima mehaničkih svojstava drva može se zaključiti da je drvo graba i dominantnih i potisnutih stabala prosječne kvalitete

The Transformation of Medical and Health Discourse in Iran from the Constitutional to the End of the First Pahlavi

زمینه و هدف: در این پژوهش، گذار گفتمانی علم پزشکی ایران، از پروسه سنتی به مدرن در دوره مشروطه تا پایان پهلوی اول را مورد توجه قرار داده‌ایم. هدف از بررسی این موضوع، بررسی تحول علم پزشکی سنتی به مدرن و کاستی‌های این اقدام، به دلیل عدم تلفیق این دو گفتمان می‌باشد و از طرفی اهمیت حفظ سلامت جوامع در طول تاریخ که خود ترقی هر جامعه‌ای را نشان می‌دهد، است. وضعیت سلامت و بهداشت همگانی ایرانی‌ها در دوره مشروطه و پهلوی اول که برهه مورد توجه در این پژوهش می‌باشد، آن‌گونه که بررسی تاریخ اجتماعی به ویژه در حوزه پزشکی جامعه نشان می‌دهد، ابتدا چندان مطلوب نبود، اما به تدریج با توجه حکومت‌ها به ویژه دردوره پهلوی اول روند تحول علم پزشکی و سلامت جامعه را به سمت گفتمان مدرن آن می‌توان شاهد بود. مواد و روش‌ها: تبیین مراحل تحول گفتمان پزشکی سنتی به مدرن، هدفی است که این پژوهش می‌کوشد با روش توصیفی ـ تحلیلی و با تکیه بر منابع کتابخانه‌ای، اسناد آرشیوی و مطبوعات این دوره تاریخی به بررسی این جنبه علمی در تاریخ ایران، بپردازد. ملاحظات اخلاقی: در مراجعه به متون، صداقت و امانتداری در پژوهش، استناد به منابع و انتشار آن‌ها رعایت شده است. یافته‌ها: اهمیت تحقیق در بررسی این گذار تاریخی در علم پزشکی و نتایجی که در ایران به دنبال آورد، می‌باشد. در واقع شدت بیماری‌ها، به ویژه عارضه‌های واگیردار در سراسر کشور به حدی گسترده بود که همین امر موجب تلنگری برای حاکمان و روشنفکران بود، اگرچه در دوره مشروطه، قوانینی در راستای این امر وضع شد، اما به مرحله اجرایی درنیامد. نتیجه‌گیری: با آغاز دوره پهلوی اول روند رو به بهبود سلامت و تحولات بزرگی در علم پزشکی به وجود آمد، اما در نتیجه این تحول، به دلیل عدم سازگاری میان دو گفتمان سنتی و مدرن در این علم منجر به حذف یکی و رونق دیگری شد. عرصه گفتمان علم پزشکی مدرن با تکیه بر جایگاه بیماری و بدن به اوج خود خود رسید، اما وجود آمرانگی در تحقق این علم و کنارگذاشتن طب سنتی، عواقبی به دنبال داشت که در دوره‌های بعد نمود پیدا کرد.Background and Aim: This has considered the discourse of Iranian medical process from the traditional to the modern situation since the constitutional period until the end of the first Pahlavi era. The purpose of this study is to examine the evolution of traditional medical science into modern one and its shortages due to the disintegration of these two discourses, on the other hand this study shows the importance of preserving the health of societies throughout their history. This study focuses on the general health status of Iranians in the constitutional and Pahlavi era. This phenomenon in the social history of Iran, especially in the field of community medicine, was not favorable according to this research. But gradually, with the paying attention of the governments, especially during the First Pahlavi era, the trend of medical science and community health towards modern discourse occurred. Materials and Method: Explanationn of the steps of the transformation of traditional medical discourse to the modern one is the main aim of this study. The method of this research is descriptive-analytical relying on the library resources, archival documents also medical press in this part of the history of Iran. Ethical Considerations: In referring to texts and research, honesty and trustworthiness also citing to the sources and publications have been respected. Findings: The importance of this research is to examin the historical transition in medical science and its results in Iran. In fact, the severity of the diseases, especially the infectious diseases, was so widespread throughout the country that it made the rulers and intellectuals more awareness. Regarding this issue although laws were enacted during the constitutional period, but they did not exuted at all. Conclusion: With the begining of the first Pahlavi era, there was an increasing trend in health and major developments in medical science occured. But as a result of this evolution, the inconsistency between the two traditional and modern discourses actually it resulted in the elimination of one and the boom of the other. The discourse of modern medical science reached its climax, relying on the locus of disease and the body, but abandon the traditional medicine had many unexeptable consequence in the later periods.   Please cite this article as: Javanmardi F, Abadian H, Fallah Tootkar F, Rahimi AR. The Transformation of Medical and Health Discourse in Iran from the Constitutional to the End of the First Pahlavi. Med Hist J 2018; 10(36): 25-41

Modeling the effect of microstructure on the coupled torsion/bending instability of rotational nano-mirror in Casimir regime

t has been well-established that the physical performance of nano-devices might be affected by the microstructure. Herein, a 2-degree-of-freedom model based on the modified couple stress elasticity is developed to incorporate the impact of microstructure in the torsion/bending coupled instability of rotational nano-electromechanical mirror. The governing equation of the mirror is derived incorporating the effects of electrostatic Coulomb and corrected Casimir forces with the consideration of the finite conductivity of interacting surfaces. Effect of microstructure-dependency on the instability parameters are determined as a function of the microstructure parameter, bending/torsion coupling ratio, vacuum fluctuation parameter and geometrical dimensions. It is found that the bending/torsion coupling substantially affects the stable behavior of the mirrors especially those with long rotational beam elements. Depending on the geometry and material characteristics, the presented model is able to simulate both hardening behavior (due to microstructure) and softening behavior (due to torsion/bending coupling) of the nano-mirror

Dynamic instability analysis of U-shaped electromechanical nano-sensor operated in vdW regime

U-shape nanoelectromechanical systems (NEMS) are potential for developing miniature sensors. While the electro-mechanical performance of conventional beam-type NEMS has been exclusively addressed in the literature, few works have considered this phenomenon in U-shaped systems. Herein, the static and dynamic pull-in instability of the U-shaped NEMS is investigated under the presence of vdW force. Based on the recently developed consistent couple stress theory (CCST), the size-dependent constitutive equation is derived. Two types of the beam cross-sections including rectangular and circular geometries are considered. The nonlinear equations are solved by employing Ray-leigh-Ritz solution method. The developed model is validated by comparison with the results presented in literature. The effect of various parameters on the static and dynamic pull-in parameters, phase plans and stability threshold of the system is discussed. The obtained results reveal that the vdW attraction decreases the pull-in voltage while the size dependency enhances the instability voltage. On the other hand, the presented model demonstrates that characteristics of the tip-plate can change the pull-in parameters significantly