Effect of rapid thermal annealing of sputtered aluminium nitride film in an oxygen ambient

Aluminium nitride (AlN) thin films were deposited by radio frequency (RF) magnetron sputtering on p-type silicon (Si) substrate of (1 0 0) orientation using only argon (Ar) gas at substrate temperature of 300 °C. In order to achieve improved electrical properties, we performed post-deposition rapid thermal annealing (RTA). Sputtered AlN films were annealed in an oxygen ambient at temperatures of 600, 700, and 800 °C using RTA for 30 min. The orientation of the AlN crystal in the film was investigated using X-ray diffraction (XRD). The characteristic spectra by functional group were analyzed by Fourier transformation infrared (FTIR) spectroscopy. The electrical properties of the AlN thin films were studied through capacitance–voltage (C–V) characteristics in metal–insulator–semiconductor (MIS) device using the films as insulating layers. The flatband voltages (V_FB) in C–V curves were found to depend on crystal orientations. Negative V_FB was found in the case when AlN (1 0 0) peak was found. Also, when AlN (1 0 3) peak was observed upon increasing the annealing temperature, the value of V_FB was positive and after annealing at 700 °C, AlN (1 0 3) peak intensity was found to be maximum and V_FB was as high as+6.5 V.     

An exploratory study into factors of service quality for application service providers

An examination of the services offered by application service providers (ASPs) indicates that their current service quality needs to be improved to satisfy current and future clients. This study attempted to fulfill this need by identifying the dimensions of service quality for the ASP industry through both qualitative and quantitative approaches. As a result, seven dimensions were identified (features, availability, reliability, assurance, empathy, conformance, and security). In addition, an initial checklist was developed to help ASPs assess and diagnose their service quality performance. Some insights and implications to the ASP practitioners were also discussed.     

Titanium Oxide Thin Films on Organic Interfaces through Biomimetic Processing

Titanium oxide (TiO₂) thin films have been deposited on silicon, glass, and plastic substrates by destabilization of an aqueous titanium lactate solution at low temperatures (<100°C). The process uses a commercially available, low-cost precursor and is simple to perform; it involves only control of pH in aqueous, chelated titanium solutions. With this solution technique, high deposition rates (>50 nm/min), film thickness (>100 nm), and excellent film uniformity have been obtained. Uniform coatings can be applied on complex-shaped polymeric substrates and porous membranes. Films can be formed on both sulfonated and untreated polymeric surfaces. As-deposited films on plastic substrates consist of amorphous, hydrated TiO₂. On sulfonated self-assembled monolayers on silicon substrates, nanocrystalline TiO₂ films have been formed. The deposited films exhibit strong ultraviolet (UV) absorption with excellent transmission in the visible wavelength range, which indicates that the coatings may be useful as protective UV blockers for polymeric materials.     

Curve Matching,Time Warping,and Light Fields: New Algorithms for Computing Similarity between Curves

The problem of curve matching appears in many application domains, like time series analysis, shape matching, speech recognition, and signature verification, among others. Curve matching has been studied extensively by computational geometers, and many measures of similarity have been examined, among them being the Fréchet distance (sometimes referred in folklore as the “dog-man” distance). A measure that is very closely related to the Fréchet distance but has never been studied in a geometric context is the Dynamic Time Warping measure (DTW), first used in the context of speech recognition. This measure is ubiquitous across different domains, a surprising fact because notions of similarity usually vary significantly depending on the application. However, this measure suffers from some drawbacks, most importantly the fact that it is defined between sequences of points rather than curves. Thus, the way in which a curve is sampled to yield such a sequence can dramatically affect the quality of the result. Some attempts have been made to generalize the DTW to continuous domains, but the resulting algorithms have exponential complexity. In this paper we propose similarity measures that attempt to capture the “spirit” of dynamic time warping while being defined over continuous domains, and present efficient algorithms for computing them. Our formulation leads to a very interesting connection with finding short paths in a combinatorial manifold defined on the input chains, and in a deeper sense relates to the way light travels in a medium of variable refractivity. Alon Efrat earned his Bachelor in Applied Mathematics from the Technion, Israel’s Institute of Technology in 1991, earned his Master in Computer Science from the Technion in 1993, and his Ph.D. in Computer Science from Tel-Aviv University in 1998. During the years 1998–2000 he was a Post Doctorate Research Assistant at the Computer Science Department at Stanford University, and at IBM Almaden Research Center. Since 2000, he is an assistant Professor at the Computer Science Department at the University of Arizona. His main research areas are Computational Geometry, and its applications. Quanfu Fan is a Ph.D. student in the department of Computer Science at the University of Arizona. His research interests include object recognition and image understanding, information retrieval, and geometric algorithms.     

Summary report on the ISOBM TD-6 workshop: analysis of 20 monoclonal antibodies against Sialyl Lewisa and related antigens. Montreux, Switzerland, September 19-24, 1997

The ISOBM TD-6 Workshop is the first international workshop on monoclonal antibodies against the Sialyl Lewisa (SLea) antigen. Eight research groups participated in a blind study to characterize the epitope binding, relative affinity and performance in immunoradiometric assays, of a panel of 20 monoclonal antibodies. The antibodies were tested against a diverse panel of neoglycoconjugates, purified antigens and human serum pools from gastrointestinal malignancies. Epitope specificities were determined for the majority of antibodies in the panel. Cross-reactivity with related saccharide structures was noted in several antibodies. Overall, the results of the TD-6 Workshop show further development of SLea immunoassays may yield yet more specific assays for the detection and management of gastrointestinal and other malignancies.     

Advantages of switched reluctance motor applications to EV and HEV:design and control issues

Land vehicles need their drivetrain to operate entirely in constant power in order to meet their operational constraints, such as initial acceleration and gradability, with minimum power rating. The internal combustion engine (ICE) is inappropriate for producing this torque-speed profile. Therefore, multiple gear transmission is necessary with the ICE in a vehicle. Some electric machines, if designed and controlled appropriately, are capable of producing an extended constant power range. The purpose of this paper is to investigate the capabilities of the switched reluctance motor (SRM) for electric vehicle and hybrid electric vehicle applications. This investigation is carried out in two steps. The first step involves the machine design and the finite-element analysis to obtain the static characteristic of the motor. In the second step, the finite-element field solutions are used in the development of a nonlinear model to investigate the dynamic performance of the designed motor     

Tighter bounds on full access probability in fault-tolerantmultistage interconnection networks

This paper proposes a cut-based technique to compute bounds on the full access probability of an extra stage shuffle exchange network (ESEN) and a wrap-around inverse banyan network (WIBN). Note that the problem of finding an exact full access probability is known to be NP-hard. Our results obtain tighter bounds as compared to those using existing techniques. For a small size multistage interconnection network, it deviates less from the exact value. We also notice that our proposed lower bound is conservative. Further, the lower bound is important as it suggests that a network is at least this much reliable     

Viral immune evasion due to persistence of activated T cells without effector function

We examined the regulation of virus-specific CD8 T cell responses during chronic lymphocytic choriomeningitis virus (LCMV) infection of mice. Our study shows that within the same persistently infected host, different mechanisms can operate to silence antiviral T cell responses; CD8 T cells specific to one dominant viral epitope were deleted, whereas CD8 T cells responding to another dominant epitope persisted indefinitely. These virus-specific CD8 T cells expressed activation markers (CD69(hi), CD44(hi), CD62Llo) and proliferated in vivo but were unable to elaborate any antiviral effector functions. This unresponsive phenotype was more pronounced under conditions of CD4 T cell deficiency, highlighting the importance of CD8- CD4 T cell collaboration in controlling persistent infections. Importantly, in the presence of CD4 T cell help, adequate CD8 effector activity was maintained and the chronic viral infection eventually resolved. The persistence of activated virus-specific CD8 T cells without effector function reveals a novel mechanism for silencing antiviral immune responses and also offers new possibilities for enhancing CD8 T cell immunity in chronically infected hosts.