Due to the property of the photonic crystal, like bandgap, many researches on them are discussed. Photons with wavelength within the bandgap cannot propagate through the crystal. Then placing some defects in the crystal, because the periodic arrangement is destroyed, it is possible to build a waveguide to guide light along certain path. One kind is coupled cavity waveguide. The photons can propagate in a coupled-cavity waveguide by coupling without radiation losses. So it is widely used to implement a variety of optical devices. In this thesis, we use coupled cavity waveguide to construct devices. And the characteristics of Mach-Zehnder interferometer and power splitter are discussed. Then we propose two logic gate structures with an input port and two control ports. The state of control port determines the electric field at the output port. Besides, the four-port channel drop filter is proposed. It will make the three wavelengths ¢w1310, 1490 and 1550 nm¢w propagate in different waveguides. So it could be used as a wavelength demultiplexer for FTTH. Finally, the property of the PC-based rat-race circuit is investigated. By adjusting the phase of the control signal, we could decide the input signal to exit from output 1 or output 2. In this way, we could use it to function as a switch.

The expanding wireless market has resulted in complex integrated transceivers that involve RF, analog and mixed-signal circuits, resulting in expensive and complicated testing. The most important challenges that test engineering faces today are (1) providing a fast and accurate fault-diagnosis and performance characterization so as to accelerate the time-to-market and (2) providing an inexpensive test strategy that can be integrated with the design so as to aid the high-volume manufacturing process. The first part of the research focuses on the design of an RMS detector for built-in-self-test (BIST) of an RF integrated transceiver that can directly provide information at various test points in the design. A cascode low noise amplifier (LNA) has been chosen as the device under test (DUT). A compact (< 0.031 mm2) RF RMS detector with negligible input capacitance (< 13 fF) has been implemented in 0.35 µm CMOS technology along with the DUT. Experimental results are currently being assimilated and compared with the simulation results. Frequency limitations were encountered during the testing process due to unexpected increase in the value of the N-well resistors. All other problems faced during the testing, as well as the results obtained so far, are presented in this thesis. In the second part of the research, the use of the RMS detector for BIST has been extended to a continuous-time high-frequency boost-filter. The proposed HF RMS detector has been implemented along with a 24 dB 350 MHz boost filter as the DUT on 0.35 µm CMOS technology. The HF RMS detector occupies 0.07 mm2 and has an input capacitance of 7 fF. The HF RMS detector has a dynamic range greater than 24 dB starting from -38 dBm of input power. The bandwidth and boost of the filter have been accurately estimated in simulation using the HF RMS detector. The sensitivity of an intermediate band pass node of the filter has also been monitored to predict the filter's sensitivity to Q errors. The final part of the research describes the design of a single-ended to differential converter for use in a broadband transceiver operating from 50-850 MHz. This circuit is used as the second stage in the transceiver after the LNA. The design has been simulated on a 0.35 um CMOS process and has a power consumption of 13.5 mW and less than 8 dB of noise figure over the entire band. It is capable of driving a 500fF load with less than 1dB of gain ripple over the entire band (50-850 MHz).

This Bachelor thesis at KTH Royal Institute of Technology in Stockholm covers a model-based analysis of thrust washer bearings in heavy trucks. This work treats Scania CV AB’s range-splitter gearbox. In this gearbox there are thrust washer bearings which are analyzed in this study. The purpose of the study is to examine the stresses the bearings are experiencing during load, determine which bearing (front or rear) that is most highly stressed, and discuss the cause for that. At large axial forces, which in turn lead to greater friction and thermal stress, there is a large risk for severe wear. Theoretically, there should not be any axial forces in a planetary gearbox with straight cut-gears, but because of the shape of the planet wheel carrier and the torque from the engine, the carrier and the needle bearings are distorted, which will cause an axial force. The axial force is not easily measured. Furthermore, it is also constantly changing during an actual driving sequence. Based on engineering judgement, the axial force was estimated to be 647 N. The axial force leads to all parts of the gearbox being pushed together axially, and cause friction forces to appear in surfaces that rotate relative each other. This process is analyzed with the FEM-program Ansys. Three possible scenarios were identified: (1) when the planetary wheel rotates relative the thrust washer bearing; (2) when the planetary wheel and needle bearing rotate relative the thrust washer bearing and (3) when the planet wheel carrier rotates relative the thrust washer bearing. The frictional heat power was simplified and analyzed as a heat power source and estimated to be 90 W. Cooling was modeled in Ansys as convection, with a film coefficient of 25 W/m2C. The initial temperatures used in the analysis were 22 and 90 °C. According to this, an equivalent stress of 12.3 MPa, and a maximum principal stress of 7.63 MPa, was located at the front thrust washer bearing. This occurs when the planet wheel and the needle bearing rotate relative to the thrust washer bearing, with an initial temperature of 90 °C. To validate the model, temperature sensors could be placed near the thrust washer bearings. However, since everything is rotating, this can be a difficult task. This report gives Scania a potential explanation to why the front and rear bearings in the gearbox are worn differently. / I det här kandidatexamensarbetet som genomfördes vid Kungliga Tekniska Högskolan i Stockholm gjordes en modellbaserad analys av axialglidlager som används i tunga lastbilar. Arbetet baserades på Scania CV ABs växellådor med range-splitter. I dessa sitter axialglidlager (även kallade brickor). Syftet var att undersöka hur stor påfrestning dessa utsätts för och försöka utröna vilken av brickorna (fram eller bak) som utsätts för störst belastning, samt diskutera vad detta skulle kunna bero på. Vid oönskade axiella krafter, som i sin tur leder till högre friktion och termoelastiska spänningar, är risken för nötning på brickorna stor. Teoretiskt sett ska det inte uppstå några axiella krafter i en planetväxel med rakkugg, men på grund av planethjulsbärarens utformning och det ingående momentet från motorn kan det uppstå en förvridning av hela bäraren och nållagren. Detta leder i sin tur till att en axiell kraft uppkommer. Denna kraft beräknades till 647 N med konservativa ingenjörsmässiga antaganden, eftersom axiella kraften inte kan mätas och ständigt varieras beroende på körprofil. Den axiella kraften medför att alla delar i planetväxeln pressas samman axiellt. En friktionskraft uppstår då mellan ytor som roterar i förhållande till varandra. Detta förlopp har analyserats med hjälp av FEM-programmet Ansys. Tre möjliga belastningsfall identifierades: (1) när planethjulet roterar mot axialglidlagret; (2) när planethjulet och nållagret roterar mot axialglidlagret, samt (3) när planethjulsbäraren roterar mot axialglidlagret. Den friktionsvärme som uppstår förenklades i modellen till en värmeeffekt på 90 W. Den värme som leds bort representerades som konvektion, med ett konvektionstal på 25 W/m2C. Som initialtemperaturer för FEM-analyserna användes 22 °C och 90 °C. En effektivspänning på 12,3 MPa och en största huvudspänning på 7,63 MPa uppstod i den främre brickan vid fallet när planethjul och nållager roterade mot axialglidlagret vid en intialtemperatur på 90 °C. För att kontrollera modellens rimlighet skulle temperaturgivare kunna installeras vid brickorna. Detta kan i praktiken dock bli svårt att genomföra då hela systemet roterar. Detta arbete ger Scania en möjlig förklaring till vad som skulle kunna orsaka en ojämn nötning fram och bak.

The purpose of this study on hand injury from powered wood splitters was to describe injury epidemiology and anatomy, to rate injury severity, to evaluate the outcome after injury and to describe factors of possible importance for the occurrence of injury. By searching a computerized patient registry, 131 patients injured by wood splitters from 1995 to 2001 were identified. Information was obtained from hospital records and radiographs, a written questionnaire and a structured telephone interview. Injury severity was rated according to the Hand Injury Severity Scoring System (HISS system) and the Injury Severity Score (ISS). Outcome was evaluated with the Disabilities of the Arm, Shoulder and Hand outcome questionnaire (DASH) and, in 26 of the most severely injured patients, with the Sollerman test. Forty-six percent of the injuries occurred during April or May. Wedge splitters caused 82 % of all injuries and most often injured the index finger, while screw splitters caused 18 % of all injuries and most often injured the metacarpus. Screw splitters caused palmar perforation and thumb avulsion. Sixty-three percent of all patients had an amputation or devascularising injury. The reliability of HISS rating was good. The mean Hand Injury Severity Score (HISS) was 63 which is equivalent to a severe hand injury. The mean ISS was 3.7. Nineteen percent of patients had minor, 31 % had moderate, 23 % had severe and 27 % had major injury according to the HISS system. Children had more severe injuries than adults. There was no significant difference regarding HISS or DASH scores between wedge and screw splitter injuries. The mean DASH score was 15, indicating moderate residual sequelae, but patients without sequelae and patients with grave sequelae were found in all HISS severity grades. There was a weak but significant correlation between the HISS and DASH scores. The mean Sollerman score in the injured hand was 66, indicating significantly impaired hand function. Twenty-nine percent of splitters were home-made. Very few machines had the safety measures required by European Standards. Children were present during splitting in at least 15 % of cases. Not being alone at the machine was one cause of wedge splitter injury. Glove use was one cause of screw splitter injury. Hand injury from powered wood splitters is a significant problem. Many of the injuries are severe, and cause long term sequels and impairment of hand function. Prevention is essential and should focus on unsafe machines and dangerous patterns of use.

Connectivity is a fundamental tool for matroid theorists, which has become increasingly important in the eventual solution of many problems in matroid theory. Loosely speaking, connectivity can be used to help describe a matroid's structure. In this thesis, we prove a series of results that further the knowledge and understanding in the field of matroid connectivity. These results fall into two parts. First, we focus on 3-connected matroids. A chain theorem is a result that proves the existence of an element, or elements, whose deletion or contraction preserves a predetermined connectivity property. We prove a series of chain theorems for 3-connected matroids where, after fixing a basis B, the elements in B are only eligible for contraction, while the elements not in B are only eligible for deletion. Moreover, we prove a splitter theorem, where a 3-connected minor is also preserved, resolving a conjecture posed by Whittle and Williams in 2013. Second, we consider k-connected matroids, where k >= 3. A certain tree, known as a k-tree, can be used to describe the structure of a k-connected matroid. We present an algorithm for constructing a k-tree for a k-connected matroid M. Provided that the rank of a subset of E(M) can be found in unit time, the algorithm runs in time polynomial in |E(M)|. This generalises Oxley and Semple's (2013) polynomial-time algorithm for constructing a 3-tree for a 3-connected matroid.

1 x N optical power splitters using hybrid sol-gel glasses based on buried waveguide structure on silicon substrate were fabricated. The advantage over conventional ridge structures is the fact that Y branch of the splitters can be easily obtained with the buried structure using standard photo lithography processes. Now we can successfully make the width of Y branch of less of 1um. Proximity printing was used to define the waveguide trench on sol-gel films. Then burying the sol-gel glass into the trench to define waveguide core. Finally the waveguide was packaged for measurement after coating a sol-gel top cladding layer onto the guiding layer. The propagation losses of this waveguide device are 0.69 dB/cm and 0.70 dB/cm for TE and TM polarized lights. The coupling losses are 1.57 dB and 1.89 dB for TE and TM lights with a index contrast of 0.66 %. The insertion loss and the branching loss of the 1¡Ñ2 splitter are 5.7 dB and 0.3 dB¡Arespectively.

A rigorous power coupling model for three-core optical waveguides is proposed based on a full-wave vector boundary element method (VBEM). In addition to the influence of the state of the polarization (SOP) of the input light on the coupling behavior of the three-core optical waveguides can be simulated, the polarization dependent loss (PDL) of the three-core optical waveguides can also be investigated by combining the Mueller matrix method into the power coupling model. In this dissertation, the power coupling model is applied to investigate two kinds of power splitters. The first power splitters are constructed of step-index single mode fibers called triangular 3 3 fused tapered couplers. The influence of the SOP of the input light on the coupling behavior of the triangular 3 3 fused tapered couplers and the effect of fabricating parameters of the coupler, fusion degree, and heated length on the PDL of the coupler are investigated in this dissertation. The second kind of power splitters are constructed of photonic crystal fibers (PCFs). And, several fundamental coupling properties of three-core photonic crystal fibers (PCFs) with equilateral triangular cores are investigated numerically included coupling length, bandwidth, and polarization dependent loss (PDL). It is found the three-core PCFs are good candidate to be realized as an ultra-compact power splitter. And, for three-core PCFs that chose a proper coupling point can raise the yield and performance stability of the power splitter. In addition to the coupling behavior of the power splitters, two-dimensional photonic crystals (PCs) are also studied in this dissertation based on finite-difference time-domain (FDTD) method. The phase interference phenomenon due to the multiple plane-wave signals as initial conditions of the FDTD method for computing band structure of two-dimensional PCs is studied in this dissertation. It is found some normal modes supposed to exist could be lost if the phase interference is nearly out of phase at eigenfrequency. To overcome this problem, we proposed a new solving procedure based on FDTD algorithm which can avoid mode loss phenomenon and obtain complete normal modes over interested frequency range.

In this work, an innovative approach for effective modeling of substrate integrated waveguide (SIW) devices is firstly proposed. Next, a novel substrate integrated waveguide power splitter is proposed to feed antenna array elements in series. This feed network inherently provides uniform output power to eight quadrupole antennas. More importantly, it led to a compact configuration since the feed network can be integrated inside the elements without increasing the overall array size. Its design procedure is also presented. Then, a series feed network was used to feed a novel compact omnidirectional antenna array. Targeting the 5G 26 GHz mm-wave frequency band, simulated results showed that the proposed array exhibits a broad impedance bandwidth of 4.15 GHz and a high gain of 13.6 dBi, which agree well with measured results. Its attractive features indicate that the proposed antenna array is well suitable for millimeter-wave wireless communication systems.

In many irrigation systems and networks, there are multiple water users and shareholders who take their water from different locations along a single canal or pipeline. Often, irrigation splitter boxes are used to divert water to multiple shareholders from a single location. The splitter boxes, which can be small and compact, are generally installed at different locations along a piped irrigation supply line. The purpose of a splitter box is to split a specific amount of water so that each user receives their allotted portion, regardless of the flow rate in the system. Each splitter box usually includes two compartments, separated by a wall that acts as a weir for the water to flow over. The water in the supply pipe enters the box and fills the upstream compartment until it spills over the weir. As water flows over the weir, it is separated by vertical dividers. Each divider is positioned to split a certain percentage of the total flow to one of the outlet pipes, which carry the water to various destinations. In general, splitter boxes perform very well at lower flow rates. However, if high flow rates are present in the box, due to under-design of the box or for any reason, the water surface becomes turbulent and the flow profile over the weir becomes disturbed and nonuniform. Because of these conditions, the flow becomes unevenly distributed and an accurate flow split cannot be achieved. This study focuses on developing a solution that can be installed in flow splitter boxes to effectively dissipate energy and uniformly distribute the flow across the length of the weir during times of high flow rates.

This thesis presents a theoretical and numerical investigation of silicon-on-insulator trench based passive optical components, bend and splitter, respectively. Compact 90 degree and 105 degree bend and splitter are designed with high index-contrast rib waveguide at wavelength 1550nm and serve as building blocks of splitting network in micro-cantilever biosensing application. The main characteristic of trench based bend and splitter structures is their miniature size and their low radiation loss due to the strong light confinement in high index-contrast systems. Thus large scale, high density optical integrated splitting network becomes possible with the associated advantages of compactness. With FDTD simulation, we show that single-mode trench based bends and splitters exhibit around 16000nm X 16000nm overall size with low loss for different bending angle. Total efficiency is about 92.9% (90 degree bend), 89.3% (105 degree bend), 92% (90 degree splitter) and 84% (90 degree splitter) respectively.