Modeling of fractal antennas

In this Master Thesis the characteristics of the chosen fractal microstrip antennas are investigated. For modeling has been used the structure of the square Serpinsky fractal curves. During the elaboration of this Master thesis the following steps were undertaken: 1) calculation and simulation of square microstrip antennа, 2) optimizing for obtaining the required characteristics on the frequency 2.5 GHz, 3) simulation and calculation of the second and third iteration of the Serpinsky fractal curves, 4) radiation patterns and intensity distribution of these antennas. In this Master’s Thesis the search for the optimal position of the port and fractal elements was conducted. These structures can be used in perspective for creation of antennas working at the same time in different frequency range.

Optimization and Measuring Techniques for Collect-and-Place Machines in Printed Circuit Board Industry

This thesis considers optimization problems arising in printed circuit board assembly. Especially, the case in which the electronic components of a single circuit board are placed using a single placement machine is studied. Although there is a large number of different placement machines, the use of collect-and-place -type gantry machines is discussed because of their flexibility and increasing popularity in the industry. Instead of solving the entire control optimization problem of a collect-andplace machine with a single application, the problem is divided into multiple subproblems because of its hard combinatorial nature. This dividing technique is called hierarchical decomposition. All the subproblems of the one PCB - one machine -context are described, classified and reviewed. The derived subproblems are then either solved with exact methods or new heuristic algorithms are developed and applied. The exact methods include, for example, a greedy algorithm and a solution based on dynamic programming. Some of the proposed heuristics contain constructive parts while others utilize local search or are based on frequency calculations. For the heuristics, it is made sure with comprehensive experimental tests that they are applicable and feasible. A number of quality functions will be proposed for evaluation and applied to the subproblems. In the experimental tests, artificially generated data from Markov-models and data from real-world PCB production are used. The thesis consists of an introduction and of five publications where the developed and used solution methods are described in their full detail. For all the problems stated in this thesis, the methods proposed are efficient enough to be used in the PCB assembly production in practice and are readily applicable in the PCB manufacturing industry.

Development and characterization of thin printed films for gas sensing applications

The monitoring and control of hydrogen sulfide (H2S) level is of great interest for a wide range of application areas including food quality control, defense and antiterrorist applications and air quality monitoring e.g. in mines. H2S is a very poisonous and flammable gas. Exposure to low concentrations of H2S can result in eye irritation, a sore throat and cough, shortness of breath, and fluid retention in the lungs. These symptoms usually disappear in a few weeks. Long-term, low-level exposure may result in fatigue, loss of appetite, headache, irritability, poor memory, and dizziness. Higher concentrations of 700 - 800 ppm tend to be fatal. H2S has a characteristic smell of rotten egg. However, because of temporary paralysis of olfactory nerves, the smelling capability at concentrations higher than 100 ppm is severely compromised. In addition, volatile H2S is one of the main products during the spoilage of poultry meat in anaerobic conditions. Currently, no commercial H2S sensor is available which can operate under anaerobic conditions and can be easily integrated in the food packaging. This thesis presents a step-wise progress in the development of printed H2S gas sensors. Efforts were made in the formulation, characterization and optimization of functional printable inks and coating pastes based on composites of a polymer and a metal salt as well as a composite of a metal salt and an organic acid. Different processing techniques including inkjet printing, flexographic printing, screen printing and spray coating were utilized in the fabrication of H2S sensors. The dispersions were characterized by measuring turbidity, surface tension, viscosity and particle size. The sensing films were characterized using X-ray photoelectron spectroscopy, X-ray diffraction, atomic force microscopy and an electrical multimeter. Thin and thick printed or coated films were developed for gas sensing applications with the aim of monitoring the H2S concentrations in real life applications. Initially, a H2S gas sensor based on a composite of polyaniline and metal salt was developed. Both aqueous and solvent-based dispersions were developed and characterized. These dispersions were then utilized in the fabrication of roll-to-roll printed H2S gas sensors. However, the humidity background, long term instability and comparatively lower detection limit made these sensors less favourable for real practical applications. To overcome these problems, copper acetate based sensors were developed for H2S gas sensing. Stable inks with excellent printability were developed by tuning the surface tension, viscosity and particle size. This enabled the formation of inkjet-printed high quality copper acetate films with excellent sensitivity towards H2S. Furthermore, these sensors showed negligible humidity effects and improved selectivity, response time, lower limit of detection and coefficient of variation. The lower limit of detection of copper acetate based sensors was further improved to sub-ppm level by incorporation of catalytic gold nano-particles and subsequent plasma treatment of the sensing film. These sensors were further integrated in an inexpensive wirelessly readable RLC-circuit (where R is resistor, L is inductor and C is capacitor). The performance of these sensors towards biogenic H2S produced during the spoilage of poultry meat in the modified atmosphere package was also demonstrated in this thesis. This serves as a proof of concept that these sensors can be utilized in real life applications.

Niagara Falls Taxi Service, N.Y., Scenic motor trips [printed advertisement], ca. 1917.

One pamphlet advertising scenic motor trips conducted by the Niagara Falls Taxi Service, Inc., ca. 1917.

Report of the committee appointed to inquire what amendments are necessary to the Act granting bounties in land and extra pay to certain Canadian volunteers: January 11, 1817, read, and, together with the bill herewith reported, ordered to be printed. (1817)

Includes (p. 3-4) a letter from the Acting Secretary of War to the chairman of the committee dated Department of War, December 26th, 1816.

Printed Blank of Incomplete Indenture

Printed Blank of incomplete indenture. Only the first line is filled in with the name Simon McGillivray. No other details are included except the date, Dec. 3, 1829.

Printed Blank Sent to Messrs. Woodruff

Printed blank sent to Messrs. Woodruff and Woodruff from the Syracuse and Oswego Line Lake Boats saying that the tea and tobacco have been sent from New York to St. Catharines by schooner, Oct. 9, 1849.

Printed Blank from James McWhirter to S.D. Woodruff

Printed blank from James McWhirter of Woodstock, official assignee, addressed to S.D. Woodruff in regard to the Oct. 10th meeting regarding William Little, an insolvent. This document is slightly stained. This does not affect the text, Sept. 20, 1866.

Printed Blank Regarding the Insolvent Act of 1864 from James McWhirter to S.D. Woodruff

Printed blank regarding the Insolvent Act of 1864, this was sent to S. D. Woodruff in the matter of William Little, an insolvent. There was to be a meeting on the 10th day of October for public examination of the insolvent. The document was signed by James McWhirter, official assignee, Sept. 20, 1866.

Printed Blank of Certificate of Goods and Exportation

Printed blank of certificate of goods and exportation from a district other than the district of original importation from the District of Niagara, Port of Lewiston. The certificate is for 2 boxes containing Gravatt’s level ordered from Troughton and Simms, London and sent to Mr. S.D. Woodruff, Dec. 21, 1846.

Editorial which was printed in the Niagara Falls (Ontario) Evening Review on May 20, 1937, entitled “Captain Creighton Probably called it Clifton First”.

Editorial (1 typed page) which was printed in the Niagara Falls (Ontario) Evening Review on May 20, 1937, entitled “Captain Creighton Probably called it Clifton First”. This is printed on Lundy’s Lane Historical Society Letterhead by Mrs. Stanley Tolan. The article mentions “Samuel DeVeaux who created a “Niagara Falls Tourist Guide” which was published in 1839, April 24, 1948.

Form letter: a printed, 2 1/2 page copy of Jarvis Conklin and Co. Mortgage, Loans and Municipal Bonds letter to S.D. Woodruff, signed by James Conklin

Form letter: a printed, 2 1/2 page copy of Jarvis Conklin and Co. Mortgage, Loans and Municipal Bonds letter to S.D. Woodruff, signed by James Conklin, n.d.

Advertisement (printed 1 page) advertising Charles Dwight, agent for The Western Bond Board of Kansas City

Advertisement (printed 1 page) advertising Charles Dwight, agent for The Western Bond Board of Kansas City, 1872, n.d.

Printed blank to Samuel Woodruff for collection of $3400.00 sent by Kountze Brothers Bankers

Printed blank to Samuel Woodruff for collection of $3400.00 sent by Kountze Brothers Bankers, New York, May 22, 1882.