Recent Advances in Wearable Transdermal Delivery Systems

Wearable transdermal delivery systems have recently received tremendous attention due to their noninvasive, convenient, and prolonged administration of pharmacological agents. Here, the material prospects, fabrication processes, and drug‐release mechanisms of these types of therapeutic delivery systems are critically reviewed. The latest progress in the development of multifunctional wearable devices capable of closed‐loop sensation and drug delivery is also discussed. This survey reveals that wearable transdermal delivery has already made an impact in diverse healthcare applications, while several grand challenges remain.     

A genetic approach to automate preliminary design of gear drives

Determination of volume or weight of a gearbox is an important issue in preliminary design of power transmission applications. Trial and error procedure or some gear standards information sheets are commonly used in traditional design. The purpose of this paper is to automate preliminary design of gear drives by minimizing volume of gear trains. A stochastic approach Genetic Algorithm (GA) was applied to a parallel axis two stage helical gear trains problem. Static and dynamic penalty functions were introduced to the objective function for handling the design constraints. The results were compared with a deterministic design procedure developed. GA based approach produced quite well results promptly supplying preliminary design parameters of gear drives for different gear ratios to the designer.     

CuSCN Modified Back Contacts for High Performance CZTSSe Solar Cells

Optimization of the back contact interface is crucial for improving the performance of Cu₂ZnSnS₄ (CZTS) thin film solar cells. In this paper, self-depleted CuSCN is deployed as an intermediate layer at the Mo/CZTS interface to improve the quality of the back contact. This CuSCN layer, obtained via aqueous solution processing, reduces the thickness of Mo(S,Se)₂ and eliminates multi-layer crystallization of the absorber by suppressing the undesirable reaction between Mo and Se during the selenization process. By regulating the selenium infiltration into the CZTS precursor films during the selenization process, highly crystalline, single-layer Cu₂ZnSn(S,Se)₄ (CZTSSe) absorber layers are realized. The single-layer CZTSSe absorber exhibits reduced carrier recombination, enhanced carrier density and increased work function. The improved back contact and absorber layer enables 11.1% power-conversion-efficiency to be achieved.     

Material Flow Control and Optimization in High‐Pressure Sheet Metal Forming by Active‐Elastic Tools

High‐pressure forming of metal sheets is an innovative forming technology for the production of complex components and offers high potentials to improve the properties and qualities of sheet metal parts. This report describes investigations of a newly developed active‐elastic tool system referred to as ACTEC system. Unlike the use of a comparable semi‐rigid tool system, the ACTEC system shows improvements with respect to the material flow in the flange area and reduced sheet thinning in critical corner regions of the workpiece. In addition, the clamping forces respectively sealing forces necessary to avoid leakage in the tool system during the forming process can be reduced. Moreover, the specific design of the ACTEC‐system as well as current experimental examinations are presented and discussed.     

Waalbot: An Agile Small-Scale Wall-Climbing Robot Utilizing Dry Elastomer Adhesives

This paper proposes a small-scale agile wall-climbing robot, which is able to climb on smooth vertical surfaces using flat adhesive elastomer materials for attachment. Using two actuated legs with rotary motion and two passive revolute joints at each foot, this robot can climb and steer in any orientation. Due to its compact design, a high degree of miniaturization is possible. It has onboard power, computing, and wireless communication, which allow for semiautonomous operation. Various aspects of a functioning prototype design and performance are discussed in detail, including leg and foot design and gait dynamics. A model for the adhesion requirements and performance is developed and verified through experiments. Using an adhesive elastomer (Vytaflex 10), the current prototype can climb 90deg slopes at a speed of up to 6 cm/s and steer to any angle reliably on a smooth acrylic surface as well as transition from floor walking to wall climbing. This robot is intended for inspection and surveillance applications, and ultimately, for space missions.     

Whole-Cell Fatty Acid Composition of Total Coliforms to Predict Sources of Fecal Contamination

The objective of this study was to test the hypothesis that total coliforms isolated from human and nonhuman sources have distinctly different whole-cell fatty acid methyl ester (FAME) profiles. The FAME profiles studied included total coliforms isolated from sewage; feces of livestock, including bovine (dairy cattle), poultry, and swine; and feces of wildlife, including waterfowl and deer. Multiple samples within each category were collected and 303 total coliform isolates were cultured. It was found that the FAMEs 12:0 2OH and 14:0 2OH were exclusively associated with sewage samples, whereas the FAMEs 18:0 and 19:0 ISO were identified only in isolates from the livestock samples. In addition to the presence of signature FAMEs, the average relative masses of 16:1 ω7c, 18:1 ω7c, and 19:0 CYCLO ω8c were significantly different between human and nonhuman sources of total coliforms. A linear discriminant function based on these differences discriminated total coliform isolates of human origin against the other five host categories at a 77% rate of correct classification (RCC). These results strongly support the validity of our hypothesis and suggest that the FAME profiles of total coliforms have the potential to be used as a phenotypic microbial source tracking (MST) tool for predicting the sources of microbial contamination in water environments.     

A Feasibility study for the Development of a Prospective Compaction Functionality test and the Establishment of a Compaction data BANK

The feasibility for the development of a standard compaction functionality testing method, which is capable of comparing the relative tabletability features of different materials and different lots of the same material with high sensitivity, was tested using an Integrated Compaction Research System. The following factors were optimized: tablet weight, lubrication, tooling, punch displacement profile, pressure range, as well as other pre-, during and post-compaction parameters. The optimized test conditions were found to be as follows: the amount of material to be compacted was calculated to produce a compact with a true volume of 0.25ml; internal lubricant with magnesium stearate at a concentration of 0.5%; standard 10.3mm, flat-faced, round BB tooling; constant punch velocities of 100mm/s and 300mm/s; and a pressure range of 25 to 550MPa. Several model powders which included microcrystalline cellulose, dicalcium phosphate dihydrate, calcium sulfate, dextrates, lactose anhydrous, and spray dried lactose were tested. Using the data generated in this work, the establishment of a compaction data bank that can be utilized as a reference source for tablet formulation studies was also found to be feasible.     

Priority determination in strategic energy policies in Turkey using analytic network process (ANP) with group decision making

In developing countries, energy consumption is continuously increasing in parallel to the developing technology. Turkey is one of these countries with its increasing population and energy demand, which increases every year with a very high rate, that is, 8% annually. Moreover, along with the increasing energy demand, the strategic energy policies have to be analyzed scientifically including the geographical importance for the realization phase. It is necessary to prioritize the determined policies and plan them according to the economic situation of the country. Hence, alternative energy policies have been prioritized objectively with scientific methods including the related institutions' evaluation. In this study, a model based on analytic network process, a group decision‐making technique, is proposed for evaluating strategic energy policies. The model is used to assign priorities to strategic energy policies of Turkey. With this model, various people are included in the decision‐making process and the effectiveness of the process is increased. Copyright © 2008 John Wiley & Sons, Ltd.     

Room-temperature interface state analysis of Au/Poly(4-vinyl phenol)/p-Si structure

The Poly(4-vinyl phenol) insulator layer was grown by spin coating technique onto p-Si substrate. Diode ideality factor (n), insulator layer thickness (δ), space charge region width (W_D), interface state density (N_ss), series resistance (R_s), acceptor concentration (N_A) of the Au/Poly(4-vinyl phenol)/p-Si structure have been extracted from the current–voltage (I–V), frequency dependent capacitance–voltage (C–V) and conductance–voltage (G–V) measurements. It is pointed out that the interface states lead to deviation of the ideality factor value from 1 and frequency dispersion of the C–V characteristics. N_ss profiles as a function of (E_ss−E_v) obtained using I–V and low frequency C–V measurements are in good agreement. N_ss values varying between 10¹² and 10¹³ eV⁻¹ cm⁻² mean that Poly(4-vinyl phenol) is a candidate for insulator layer forming on Si as powerful as SiN₄, SnO₂, TiO₂.