The tower crane is an electromechanical equipment that is used for the vertical transport of materials in a construction project and together with the two riggers form the work team to carry out this task. One of the main problems in the construction of multifamily buildings corresponds to the use of the tower crane because vertical transport causes non-contributory times, which is, dead times and waits above expectations. This research analyzes the current vertical transport process and proposes its optimization through some management tools with the aim of improving the productivity of the use of the tower crane by reducing non-contributory times. To this end, the productivity of the work team is recorded in several projects with similar characteristics, then the main problems are selected to analyze them and finally the process is optimized. The results determined that non-contributory times can be reduced by 10% if there is an orderly and continuous process.

Atmospheric monitoring of radionuclides as part of the International Monitoring System requires the capability to differentiate between a radionuclide signature emanating from peaceful nuclear activity and one emanating from a well-contained underground nuclear explosion. While the radionuclide signatures of nuclear weapons are generally well known, radionuclides must first pass through hundreds of meters of earth to reach the surface where they can be detected and analyzed. Less well known is the affect that subsurface vertical transport has on the isotopic signatures of nuclear explosions. In this work, a model is developed, and tested, simulating the detonation of a simple underground nuclear explosion and the subsequent vertical transport of resulting radioxenon to the surface. First, the fast-fission burn of a fissile spherical core surrounded by a layer of geologic media is modeled, normalized to 1 kton total energy. The resulting source term is then used in the testing and evaluation of the constructed vertical transport model, which is based on the double-porosity model of underground fluid transport driven by barometric pumping. First, the ability of the vertical transport code to effectively model the underground pressure response from a varying surface pressure is demonstrated. Next, a 100-day simulation of the vertical migration of a static source is examined, and the resulting cumulative outflow of roughly 1% initial inventory outflow per cycle is found to closely follow the analytical predictions. Finally, calculated radioxenon source terms are utilized to model the resulting vertical transport and subsequent surface outflow. These results are found to be consistent with the physical expectations of the system, and lastly a cursory sensitivity analysis is conducted on several of the physical parameters of the model. The result is that the vertical transport model predicts isotopic fractionation of radioxenon that can potentially lie outside of currently accepted standard bounds. / text

All-optical time-resolved measurement techniques provide a powerful tool for investigating critical parameters that determine the performance of infrared photodetector and emitter semiconductor materials. Narrow-bandgap InAs/GaSb type-II superlattices (T2SLs) have shown great promise as a next generation source of these materials, due to superior intrinsic properties and versatility. Unfortunately, InAs/GaSb T2SLs are plagued by parasitic Shockley-Read-Hall recombination centers that shorten the carrier lifetime and limit device performance. Ultrafast pump-probe techniques and time-resolved differential transmission measurements are used here to demonstrate that Ga-free InAs/InAsSb T2SLs and InAsSb alloys do not have this same limitation and thus have significantly longer carrier lifetimes. Measurements at 77 K provided minority carrier lifetimes of 9 μs and 3 μs for an unintentionally doped mid-wave infrared (MWIR) InAs/InAsSb T2SL and InAsSb alloy, respectively; a two order of magnitude increase compared to the 90 ns minority carrier lifetime measured in a comparable MWIR InAs/GaSb T2SL. Through temperature-dependent lifetime measurements, the various carrier recombination processes are differentiated and the dominant mechanisms identified for each material. These results demonstrate that these Ga-free materials are viable options over InAs/GaSb T2SLs for potentially improved infrared photodetectors. In addition to carrier lifetimes, the drift and diffusion of excited charge carriers through the superlattice growth layers (i.e. vertical transport) directly affects the performance of photodetectors and emitters. Unfortunately, there is a lack of information pertaining to vertical transport, primarily due to difficulties in making measurements on thin growth layers and the need for non-standard measurement techniques. However, all-optical ultrafast techniques are successfully used here to directly measure vertical diffusion in MWIR InAs/GaSb T2SLs. By optically generating excess carriers near one end of a MWIR T2SL and measuring the transit time to a thin, 2 lower-bandgap superlattice placed at the other end, the time-of-flight of vertically diffusing carriers is determined. Through investigation of both unintentionally doped and p-type superlattices at 77 K, the vertical hole and electron diffusion coefficients are determined to be 0.04±0.03 cm2/s and 4.7±0.5 cm2/s, corresponding to vertical mobilities of 6±5 cm2/Vs and 700±80 cm2/Vs, respectively. These measurements are, to my knowledge, the first direct measurements of vertical transport properties in narrow-bandgap superlattices. Lastly, the widely tunable two-color ultrafast laser system used in this research allowed for the investigation of nonlinear optical properties in narrow-bandgap semiconductors. Time-resolved measurements taken at 77 K of the nondegenerate two-photon absorption spectrum of bulk n-type GaSb have provided new information about the nonresonant change in absorption and two-photon absorption coefficients in this material. Furthermore, as the nondegenerate spectrum was measured over a wide range of optical frequencies, a Kramers-Kronig transformation allowed the dispersion of the nondegenerate nonlinear refractive index to be calculated.

<p>Дефинисани су експeримeнтaлни поступци за oдрeђивaњe губитака и стeпeнa искoришћeњa пoстрojeњa у зaвиснoсти oд рeлaтивнoг oптeрeћeњa кaбинe (кoшa) у експлоатационим условима, као и за oдрeђивaњe мeхaничких кaрaктeристикa чeличних ужaди.<br />Дата је мoгућнoст примeнe мeтoдa нумeричкe aнaлизe зa рeшaвaњe систeмa ПДЈ хипeрбoличнoг типa са константним параметрима и граничним условима што одговара случајевима осциловања кабине (коша) након заустављања (кочења) погонског мотора.<br />Развијени су aдeквaтни прoрaчунски мoдeли који омогућују комплексну динaмичку aнaлизу лифтoвa и извoзних пoстрojeњa у функцији прoмeнљиве крутoсти и граничних услова. Дефинисан је утицај променљиве крутости нa стaбилнoст крeтaњa, кроз прoмeну слободне дужине ужади.</p> / <p>Definisani su eksperimentalni postupci za određivanje gubitaka i stepena iskorišćenja postrojenja u zavisnosti od relativnog opterećenja kabine (koša) u eksploatacionim uslovima, kao i za određivanje mehaničkih karakteristika čeličnih užadi.<br />Data je mogućnost primene metoda numeričke analize za rešavanje sistema PDJ hiperboličnog tipa sa konstantnim parametrima i graničnim uslovima što odgovara slučajevima oscilovanja kabine (koša) nakon zaustavljanja (kočenja) pogonskog motora.<br />Razvijeni su adekvatni proračunski modeli koji omogućuju kompleksnu dinamičku analizu liftova i izvoznih postrojenja u funkciji promenljive krutosti i graničnih uslova. Definisan je uticaj promenljive krutosti na stabilnost kretanja, kroz promenu slobodne dužine užadi.</p> / <p>We have defined the experimental procedures for defining the dissipation and the utility factor of vertical transport machines depending on the relative loading of the cabin (cage) in exploiting conditions, as well as for the setting the mechanical charactristics of the steel ropes.<br />There is given the option of applying the numerical analyses methods for solving the PDE systems of the hyperbolic type with constant parameters and boundary conditions, which is suitable for the cases when there are oscillations of the cabin (cage) after stopping (braking) the driving motor.<br />The adequate calculation models have been developed and they enable a complex dynamic analyses of elevators and mine elevators in the function of variable stiffness and boundary conditions. We also defined the influence of the variable stiffness on the stability of movement, through a change in the ropes&rsquo; free length.</p>

Task of this diploma thesis is to design service lift which is driven by unordinary mechanism using thrust chain. Main parts of this diploma are design and description of main construction parts, strength analysis and drive design.

The diploma thesis deals with the analysis of the transport-geographical attributes of the South Bohemian Region. Basically, the thesis considers two important characteristics of the settlement structure-transport relationship. These are transport regionalization and hierarchization of the transport centres. Besides the viewpoint of the public transport the diploma thesis also deals with the individual automobile transport. The first chapters describe goals of the thesis and analyse relevant literature. These are followed by detailed methodological part containing the description of the choice of the settlement centres, delimitation of the transport regions and the analysis of hierarchy of the transport nodes. The further chapters analyse the real condition of the South Bohemian Region itself from the points of view of the attributes mentioned above.