Intrinsic stress, mismatch strain, and self-assembly during deposition of thin films subjected to an externally applied force

A relation is derived between the mismatch strain, the film thickness, and the displacement of a linear elastic structure under external loading during material deposition. If any two of these variables can be experimentally determined, then the remaining variable can be determined. The method allows one to experimentally determine the mismatch strain by measuring the film thickness and the displacement of a point on the structure that is not undergoing deposition. The intrinsic stresses can be used to self-assemble microstructures during material deposition. Assembly of two components is considered: one component is subjected to deposition and is modeled as an Euler-Bernoulli beam, and the other component is not subjected to deposition and is modeled as a linear spring. For the purposes of this paper, the definition of assembly requires that the beam do work on the spring. The analysis is experimentally verified by electroplating nickel onto an AFM cantilever beam in contact with a second AFM beam (serving as the spring) that does not undergo deposition. This paper was recommended for publication in revised form by Associate Editor Maenghyo Cho Sang-Hyun Kim obtained his B. S. (1993) and M.S. (1995) degrees in Aerospace Engineering from Pusan Nation University and Ph.D. (2005) in Aerospace Engineering from Texas A&M University. After getting Ph.D., he joined Micro Systems Lab. at Samsung Advanced Institute of Technology (SAIT) and worked in the field of MEMS designs, especially microsensors, microactuator and inkjet print head. He is currently working as a faculty member in Mechanical Systems Engineering at Hansung University. His research interest lies in design, fabrication and test of MEMS/NEMS. He is also interested in the development of design platform of multi-physics and multiscale phenomena.     

Characterization and Analysis of Tetranitrate Esters

Thermal behaviors, vapor pressures, densities, and drop weight impact results, as well as analytical protocols, are reported for three tetranitrate esters: erythritol tetranitrate (ETN), 1,4‐dinitrato‐2,3‐dinitro‐2,3bis(nitratomethylene) butane (DNTN), and pentaerythritol tetranitrate (PETN). ETN and DNTN both melt below 100 °C and have ambient vapor pressures comparable to TNT. While LC/MS was shown to be a viable technique for analysis of all three tetranitrate esters, only ETN was successfully analyzed by GC/MS. Performance of these nitrate esters as evaluated in lab using the small‐scale explosivity device (SSED) suggested RDX≫DNTN>PETN>ETN. Detonation velocities were calculated using Cheetah 6.0. Since the starting material is now widely available, it is likely that law enforcement will find ETN in future improvised explosive devices. This paper with its analytical schemes should prove useful in identification of this homemade explosive.     

Characterization and Modeling of Laser Micromachined Periodically Corrugated Metallic Terahertz Wire Waveguides

Finite element method simulations of periodically corrugated metal terahertz wire waveguides have been conducted with concurrent analysis done on both the near-field confinement properties and the far-field emission properties at the end of the waveguides. This modeling was used to guide the choice of design parameters for the fabrication of waveguides with laser micromachining. The waveguides were characterized with a fiber-coupled terahertz time-domain spectroscopy and imaging system. The propagation properties as well as the frequency dependent diffraction at the end of the wire waveguides were examined and compared to straight, non-engineered metallic wire waveguides.     

A preclinical study of the effect of the animal polysaccharide chonsurid on reparative osteogenesis of the jaws

Experimental studies making use of morphological and x-ray methods demonstrated that in comparison with control (filling of mandibular bone defects with blood clots) chonsuride, an animal polysaccharide, promoted earlier filling of postoperative bone cavities with connective tissue replacement of this tissue with coarse-fiber bone tissue. Secondary restructuring and mineralization of bone regenerate were enhanced as well.     

Gravity flow test comparisons for mildly thick consistency

Simple measurement tools that provide objective information about the consistency of thickened liquids have received increasing attention given possible application to clinical practice for dysphagia. The International Dysphagia Diet Standardization Initiative (IDDSI) advocates the use of the IDDSI Flow Test for measuring thickness and verifying a prescribed level of consistency. This study compares gravity flow test measurements taken with two 10-ml syringes of starch and gum-thickened samples prepared to a mildly thick consistency using product label information. One of the 10-ml syringes met IDDSI specification and the other 10-ml syringe did not. Thickened samples also were measured using the line spread apparatus. The results showed that two syringes yielded significantly different gravity flow test measurements, often resulting in changes to the classification level of thickness. There was no effect of thickening agent. Line spread measurements did not vary from one another. Study findings indicate the importance of continued testing with the IDDSI Flow Test and education/awareness about the use of the IDDSI reference syringe. An essential aspect about the use of thickened liquids in dysphagia management is that beverage preparations represent their prescribed level of modification. The findings of this study indicate the importance of following syringe specifications when conducting gravity flow testing using the IDDSI methodology. The implication is that the wrong 10-ml syringe could result in errant clinical decisions in determining the accuracy of texture modifications, resulting in care providers who are more likely to over or under thicken modifications to achieve a targeted level of thickness.     

Medico-genetic study of residents of Marii El republic: burden of hereditary diseases in four regions of the republic

A medical genetic study of Orshanskii, Morkinskii, Sovetskii, and Semurskii raions (districts) of the Marii El Republic was performed. The total number of subjects examined was 115,743. Meadow Maris and Russians accounted for the most part of the populations of the districts studied. A total of 147 families with presumably autosomal dominant (AD) pathology and 150 families with presumably autosomal recessive (AR) or X-linked pathology (270 and 169 affected persons, respectively) were revealed. Segregation analysis demonstrated a good agreement between the observed and expected segregation frequencies for both AR and AD diseases, as well as a considerable number of sporadic cases of presumably AD diseases. The incidence of hereditary diseases was estimated separately for different population groups. Significant differences in this incidence were revealed between the urban and rural, as well as between the Russian and Mari populations; the average incidence was 2.33 affected subjects per 1000 people. The incidence of AR diseases was significantly higher in Maris than in Russians (1.34 x 10(-3) and 0.82 x 10(-3), respectively). The populations studied exhibited a significant, high correlation between the incidence of AR diseases and the levels of random and local inbreeding. The incidence of X-linked recessive diseases was approximately the same as in Russian populations studied earlier. Its average value was 0.5 per 1000 men; the incidence in the Mari and Russian populations did not differ significantly. The higher AD incidence in the total population studied and the higher AR incidence in the Meadow Mari population compared to the populations studied earlier are discussed.