Characterization of Mechanical Properties at the Micro/Nano Scale: Stiction Failure of MEMS, High-Frequency Michelson Interferometry and Carbon NanoFibers

Different forces scale differently with decreasing length scales. Van der Waals and surface tension are generally ignored at the macro scale, but can become dominant at the micro and nano scales. This fact, combined with the considerable compliance and large surface areas of micro and nano devices, can leads to adhesion in MicroElectroMechanical Systems (MEMS) and NanoElectroMechanical Systems (NEMS) - a.k.a. stiction-failure. The adhesive forces between MEMS devices leading to stiction failure are characterized in this dissertation analytically and experimentally. Specifically, the adhesion energy of poly-Si μcantilevers are determined experimentally through Mode II and mixed Mode I&II crack propagation experiments. Furthermore, the description of a high-frequency Michelson Interferometer is discussed for imaging of crack propagation of the μcantilevers with their substrate at the nano-scale and harmonic imaging of MEMS/NEMS. Van der Waals forces are also responsible for the adhesion in nonwoven carbon nanofiber networks. Experimental and modeling results are presented for the mechanical and electrical properties of nonwoven (random entanglements) of carbon nanofibers under relatively low and high-loads, both in tensions and compression. It was also observed that the structural integrity of these networks is controlled by mechanical entanglement and flexural rigidity of individual fibers as well as Hertzian forces at the fiber/fiber interface

Examining psychology of science as a potential contributor to science policy

The psychology of science is the least developed member of the family of science studies. It is growing, however, increasingly into a promising discipline. After a very brief review of this emerging sub-field of psychology, we call for it to be invited into the collection of social sciences that constitute the interdisciplinary field of science policy. Discussing the classic issue of resource allocation, this paper tries to indicate how prolific a new psychological conceptualization of this problem would be. Further, from a psychological perspective, this research will argue in favor of a more realistic conception of science which would be a complement to the existing one in science policy

First record of the loach fish Paracobitis cf. malapterura in the Kavir basin, northern Iran

The loach fish Paracobitis cf. malapterura Valenciennes, 1846 (Nemacheilidae), formerly believed to be an endemic species in the Caspian Sea basin, was recorded for the first time in the upper Kavir basin. This extension of its recorded range makes it likely that it has been overlooked in other parts of the Kavir basin

Effective Entity Augmentation By Querying External Data Sources

Users often want to augment and enrich entities in their datasets with relevant information from external data sources. As many external sources are accessible only via keyword-search interfaces, a user usually has to manually formulate a keyword query that extract relevant information for each entity. This approach is challenging as many data sources contain numerous tuples, only a small fraction of which may contain entity-relevant information. Furthermore, different datasets may represent the same information in distinct forms and under different terms (e.g., different data source may use different names to refer to the same person). In such cases, it is difficult to formulate a query that precisely retrieves information relevant to an entity. Current methods for information enrichment mainly rely on lengthy and resource-intensive manual effort to formulate queries to discover relevant information. However, in increasingly many settings, it is important for users to get initial answers quickly and without substantial investment in resources (such as human attention). We propose a progressive approach to discovering entity-relevant information from external sources with minimal expert intervention. It leverages end users\u27 feedback to progressively learn how to retrieve information relevant to each entity in a dataset from external data sources. Our empirical evaluation shows that our approach learns accurate strategies to deliver relevant information quickly

The Effect of Premedication With Oral Acetaminophen on the Prevention of Localized Pain Resulting from Intravenous Propofol Injection: A Randomized Double Blind Placebo Clinical Trial

Background: Propofol is one of the most widely used medications in anesthesia and intensive care. Propofol Intravenous injection is painful for patients at the injection site. The aim of this study was to determine the effect of premedication with oral acetaminophen in prevention of local pain caused by intravenous injection of propofol. Methods: This study was a double-blind randomized controlled trial. Data were collected from July 2020 to July 2021 in Shariati Hospital. All stages of premedication and induction of anesthesia were the same in all three groups of patients. Pb, P500 and P1000 groups (patients with oral placebo, 500 or 1000 mg of oral paracetamol, respectively) received the medication 1 hour before transfer to the operating room. Results: In this study, 150 patients were included. 44.7% were men, 55.3% women, and mean age of patients was 36.82 ± 10.24. The highest severity of reported pain was in the group of patients receiving placebo. Patients receiving 1 gram of acetaminophen had the lowest reported pain. Patients receiving 500 mg of acetaminophen reported significantly less pain than patients receiving placebo and more pain than patients in the group receiving 1 g of acetaminophen. Age, gender and weight did not have any significant effect on the pain severity. Conclusion: When compared to placebo, the use of oral acetaminophen as a premedication considerably lowers discomfort induced by intravenous propofol infusion. A dosage of 1 g of oral acetaminophen is more effective than 500 mg in decreasing pain. The level of pain and acetaminophen's pain-relieving effects were not affected by age, gender or weight

Electric Field Induced Alignment of Carbon Nanotubes: Methodology and Outcomes

In the current chapter, achievement of aligned carbon nanotube (CNT) network within the matrix via various kinds of electric fields (AC and DC) was evaluated. In this case, alignment mechanism of CNTs within the matrix and two useful techniques for justification of CNT alignment throughout the matrix were examined and presented, respectively. Afterward, effective factors in matter of CNT alignment and applicable procedures for fabrication of nanocomposites containing aligned CNTs were studied and presented, respectively. At the end, significant effects of CNT alignment on overall properties of nanocomposites that include electrical and mechanical properties were evaluated. Achieved results revealed that alignment of CNTs within the matrix can lead to significant improvement in the electrical and mechanical properties of nanocomposites at the same filler loading compared with randomly distribution of CNTs within the matrix, while production steps and conditions can also highly affect the outcome data

Emotional Intelligence Components in Alcohol Dependent and Mentally Healthy Individuals

Objective. Emotional intelligence might play an important role in the onset and persistence of different psychopathologies. This study investigated the relationship between emotional intelligence and alcohol dependence. Methods. In this case-control study, participants included alcohol dependent individuals and mentally healthy inpatients. Each group consisted of 40 individuals (male/female: 1). The diagnosis was based on the criteria of the DSM-IV-TR using the Structured Clinical Interview for DSM-IV (SCID-IV). All the participants completed Bar-On emotional intelligence test. Results. 20 males and 20 females were included in each group. Mean age of alcohol dependent participants and controls was 31.28 ± 7.82 and 34.93 ± 9.83 years in that order. The analyses showed that the alcohol dependent individuals had a significant difference compared with the control group and received lower scores in empathy, responsibility, impulse control, self-esteem, optimism, emotional consciousness, stress tolerance, autonomy, problem-solving, and total score of emotional intelligence components. Conclusion. Patients with alcohol dependence have deficits in components of emotional intelligence. Identifying and targeted training of the individuals with lower scores in components of emotional intelligence may be effective in prevention of alcohol dependence