No description available.

No description available.

No description available.

No description available.

The use of nano/meso-particles (NP/MP) as constituent of topical formulations of drug and cosmetics has been a topic of considerable interest for the past 20 years. However, the transport mechanism of nanoparticle-associated drug/active following topical application on the skin is still unclear. No general answers have been obtained to such questions as the depth of intact NP penetration into the skin, the skin distribution of active substances, and the fate of the vehicles on/in the skin. The main objective of this thesis, therefore, was to observe the in vitro penetration of fluorescently-labeled nanoparticle vehicle and “active” on/within the skin by using laser scanning confocal microscopy (LSCM). Furthermore, the concentration profile of the “active” in the outermost skin layer, stratum corneum, has been assessed by using tape stripping technique combined with HPLC analysis. The factors, including particle size, hydrophobicity, shell thickness of nanocapsules and surface charge, have been investigated with regard to their abilities to influence the penetration of “active” into the skin. The methods for NP preparation and characterization have also been developed. The results demonstrated that the delivery of “active” into the stratum corneum from NP/MP were influenced by a number a factors, including particle size, hydrophobicity, surface charge and shell thickness of capsules. The “active” delivery (i) is greater from larger vectors; (ii) increases as the hydrophobicity of NP/MP increases; (iii) is favoured by cationic NP; (iv) is favoured from capsules with a smaller shell thickness. NP vehicle and “active” mainly co-localize in skin “furrows” and around hair follicles after topical application. No evidence shows NP penetrate beyond the superficial layer of the skin. In the stratum corneum, the “active” remains in part associated with NP, but the release f the “active” clearly occurs to some extent followed by its penetration into deep layers of the stratum corneum. Overall, through this work, the fate of nanoparticle vehicle and the “active” has been distinguished and the physicochemical properties of the nanoparticles that determine their behaviour once applied to the skin, and the kinetics with which an “active” is released, has also been understood.

No description available.

The short range of low energy electrons from 2 to 9 MeV has made them useful for the treatment of superficial lesions covering large areas of the body, such as mycosis fungoides and other cutaneous lymphomas. At these electron energies, the beam penetration falls off rapidly beyond a shallow depth. Thus superficial lesions can be treated up to few millimeters without exceeding the tolerance of the bone marrow. The purpose of this project was to study the effect of the beam modifiers on the characteristics of the Varian 2100C 6 MeV beam using high dose rate total skin electron mode (HDTSe). The technique developed in the study was a modified Stanford Technique. In this technique, the patient is treated with dual six fields using + 17.5o angle above and below the horizontal line at 350 cm SSD. The patient is rotated every 60o intervals so that the whole skin surface is covered with the beam. The scattering filter used in the study was two strips of non-exposed developed radiographic films. The filter was mounted on the HDTSe applicator. The dose uniformity within a rectangle of 160 cm x 60 cm was found to be + 3% along the vertical direction and + 4% along the horizontal direction which meets the beam requirements recommended by the AAPM report (23) [61]. The use of the scattering filter has improved the dose uniformity, but it increased the x-ray contamination beyond the 30 mm depth to about 1.5% which makes the technique

Dose assessments produced using the computer code MCNP are important to simulate events that are difficult to recreate experimentally. An emergency scenario involving whole-body skin contamination is one example of such an event. For these scenarios, an anthropomorphic phantom of a 10-year-old male with uniform skin contamination was created and combined with MCNP for dose calculations. Activity on the skin was modeled with gamma-ray sources at energies of 50 keV, 100 keV, 250 keV, 500 keV, 750 keV, 1 MeV, 1.25 MeV, 1.5 MeV, and 2 MeV. The radionuclides 60Co, 137Cs, and 131I were also modeled. The effective dose to the body and major organs was calculated for each scenario. Exposure rate contour lines were also produced around the body. The activity required to result in a dose equal to the legal limit of 0.1 mSv for minors was calculated for each scenario. The highest activity required to produce this limit was from the 50 keV gamma-ray source. This activity was increased by an arbitrary value, approximately tenfold the current value, to represent an emergency scenario. This new activity concentration of 1 mCi per 100 cm2 was used to produce doses for each of the scenarios. The lowest effective dose for the body was 0.82 mSv, produced from the 50 keV source. The highest effective dose was 19.59 mSv, produced from the 2 MeV source. The exposure rates nearest the body were approximately 1.25 R/h, decreasing to100 mR/h approximately 60 cm from the body. The data points were found to be dependent on the energy of the gamma ray. These data can also be improved by deriving solutions previously assumed in this scenario. For example, the skin may be broken down into multiple regions to allow for independent calculations for regional contamination. The activity on the skin can also be derived from air concentration models, allowing for the use of other models to be used in conjunction with this research.

The goal of this work was to evaluate matrix acidizing treatments of vertical and horizontal wells in carbonate reservoirs. Twenty field cases for acidizing treatments were analyzed by evaluating the skin factor evolution from on-site rate/pressure data during the treatment. A skin monitoring method based on the concept of inverse injectivity (Hill and Zhu, 1996) was used to calculate the skin factor evolution. Viscous diversion techniques were analyzed by using the viscous diversion skin model that accounts for viscosity contrast between the reservoir fluid and the injected fluid. The estimated skin evolution during the treatment was validated using the post-treatment well performance. From the post-treatment analysis, it was observed that emulsified acid was not an efficient viscous diverter because only 27% of the wells treated with emulsified acid showed evidence of viscous diversion. Therefore, other viscous diversion techniques are needed to ensure uniform acid coverage. In addition, treatments that involved diversion techniques such as foam, associative-polymers, and viscoelastic surfactants were also evaluated. Thus, the post-treatment evaluation was used to improve and optimize the acid treatment designs. This study was beneficial to diagnose if excess acid volumes were used, or effective diversion was achieved during the acid treatment.

This thesis is to develop the power line carrier based identifier for the determination of customers served by each distribution transformer. The signal transmission characteristics of the power line carrier (PLC) over low voltage distribution lines and investigated. By executing the connectivity validation with the identifier developed, the accuracy of outage management system database can be enhanced for different types of customers (commercial /office buildings, commercial/ buildings, residential buildings) Various application functions such as contingency maintenance, transformer load management and customer outage management can be supported by outage management system (OMS) system more effecting. The mathematical models of 1£r2W, 1£r3W, 3£r3W and 3£r4W distribution have been developed by including the high frequency equivalent circuits of transformers, low voltage lines and customer loads in the computer simulation. The systems of signal coupling circuit, data processing, man machine interface have been designed with the embedded firmware for the PLC identifier. To demonstrate the effectiveness of the PLC identifier, a field test has been performed in Tainan District of Taipower. It is found that the customers served by each distribution transformer can be determined correctly with the PLC identifier developed.