The topographical anatomy of the round window and related structures for the purpose of cochlear implant surgery

The treatment of total deafness using a cochlear implant has now become a routine medical procedure. The tendency to expand the audiological indications for cochlear stimulation and to preserve the remnants of hearing has brought new problems. The authors have studied the topographical anatomy of the internal structures of the ear in the area where cochleostomy is usually performed and an implant electrode inserted. Ten human temporal bones were obtained from cadavers and prepared in a formalin stain. After dissection of the bone in the area of round and oval windows, the following diameters were measured using a microscope with a scale: the transverse diameters of the cochlear and vestibular scalae at the level of the centre of the round window and 0.5 mm anteriorly to the round window, the distance between the windows and the distances from the end of the spiral lamina to the centre of the round window and to its anterior margin. The width of the cochlear scala at the level of the round window was 1.23 mm, and 0.5 mm anteriorly to the round window membrane it was 1.24 mm. The corresponding diameters for the vestibular scala are 1.34 and 1.27 mm. The distances from the end of the spiral lamina to the centre of the round window and to its anterior margin are 1.26 and 2.06 respectively. The authors noted that the two methods of electrode insertion show a difference of 2 mm in the length of the stimulated spiral lamina. The average total length of the unstimulated lamina is 2.06 and 4.06 in the two situations respectively

Luminescence of Ce3+ multicenters in Ca2+ -Mg2+ -Si4+ based garnet phosphors

Comparison of the luminescent properties of Ca3Sc2Si3O12: Ce and Ca2YMgScSi3O12: Ce single crystalline films (SCF) phosphors, grown by the liquid phase epitaxy method, was performed in this work. We have observed formation of the Ce3+ multicenters in Ca3Sc2Si3O12: Ce and Ca2YMgScSi3O12: Ce in the emission and excitation spectra as well as in the decay kinetics of the Ce3+ luminescence in SCFs of these garnets. Such Ce3+ multicenters possess different crystal field strength due to the inhomogeneous local surroundings of the dodecahedral positions of garnet host at the substitution of the octahedral positions by hetero-valence Mg2+ and Sc3+ ions and the tetrahedral positions by Si4+ ions. We confirm the presence of an effective energy transfer between different Ce3+ multicenters in Ce3+ doped Ca3Sc2Si3O12 and Ca2YMgScSi3O12 garnets. The positive trends in variations of the spectroscopic properties of the Ca2YMgScSi3O12: Ce garnet with respect to Ca3Sc2Si3O12: Ce garnet were observed also due to substitution of the dodecahedral sites of the garnet host by Y3+ ions and the octahedral sites by Mg2+ ions, which can be suitable for the development of new converters of white LEDs. Namely, due to the Y3+-Mg2+ doping, the luminescence spectrum of Ce3+ ions in Ca2YMgScSi3O12: Ce SCFs significantly extends in the red range in comparison with the Ca3Sc2Si3O12: Ce SCF counterpart

Luminescent and scintillation properties of Ce3+ doped Ca2RMgScSi3O12 (R = Y, Lu) single crystalline films

The work is dedicated to the growth and investigation of the luminescent and scintillation properties of single crystalline films (SCFs) of Ca2-xR1+xMg1+xSc1-xSi3O12:Ce (R = Y, Lu) mixed garnets with x = 0-0.25, grown using the liquid phase epitaxy method onto Y3Al5O12 substrates from PbO-B2O3 based flux. The absorption, luminescent and scintillation properties of Ca2-xY1+xMg1+xSc1-xSi3O12:Ce and Ca2-xLu1+xMg1+xSc1-xSi3O12:Ce SCFs with x = 0 and 0.25 were investigated and compared with the reference YAG:Ce and LuAG:Ce SCFs. Using the Ca2+, Mg2+ and Si4+ alloying, the Ce3+ emission spectra in Ca2-xR1+xMg1+xSc1-xSi3O12:Ce (R = Y, Lu; x = 0-0.25) SCFs can be notably extended in the red range in comparison with YAG: Ce and LuAG: Ce SCFs due to the increase of crystal field strength and Ce3+ multicenter creation in the dodecahedral positions of the lattices of these mixed garnet compounds. Due to the formation of Ce4+ ions, the as-grown Ca2-xR1+xMg1+xSc1-xSi3O12:Ce (R = Y, Lu) SCFs at x = 0 and 0.25 show relatively low light yield. However, after annealing in reducing atmosphere (95% N-2 + 5% H-2) at T > 1000 degrees C, a recharging Ce4+ -> Ce3+ takes place. After that, these SCFs possess the light yield about of 30% and 31% in comparison with the reference YAG: Ce and LuAG: Ce SCFs, respectively, and a fast scintillation response with the decay times in the ns range under a-particles excitation by Pu-239 (5.15 MeV) source

Differential livelihood adaptation to social-ecological change in coastal Bangladesh

Social-ecological changes, brought about by the rapid growth of the aquaculture industry and the increased occurrence of climatic stressors, have significantly affected the livelihoods of coastal communities in Asian mega-deltas. This paper explores the livelihood adaptation responses of households of different wealth classes, the heterogeneous adaptation opportunities, barriers and limits (OBLs) faced by these households and the dynamic ways in which these factors interact to enhance or impede adaptive capacities. A mixed methods approach was used to collect empirical evidence from two villages in coastal Bangladesh. Findings reveal that households’ adaptive capacities largely depend on their wealth status, which not only determine their availability of productive resources, but also empower them to navigate social-ecological change in desirable ways. Households operate within a shared response space, which is shaped by the broader socio-economic and political landscape, as well as their previous decisions that can lock them in to particular pathways. While an adaptive response may be effective for one social group, it may cause negative externalities that can undermine the adaptation options and outcomes of another group. Adaptation OBLs interact in complex ways; the extent to which these OBLs affect different households depend on the specific livelihood activities being considered and the differential values and interests they hold. To ensure more equitable and environmentally sustainable livelihoods in future, policies and programs should aim to expand households’ adaptation space by accounting for the heterogeneous needs and complex interdependencies between response processes of different groups

Processes of elite power and low-carbon pathways: experimentation, financialisation, and dispossession

What is a low-carbon pathway? To many, it is a way of mitigating climate change. To others, it is about addressing market failure or capturing the co-benefits attached to low-carbon systems, such as jobs or improved health. To still others, it represents building adaptive capacity and resilience in the face of climate change. However, these interpretations can fail to acknowledge how pathways of low-carbon transitions can also become intertwined with processes and structures of inequality, exclusion and injustice. Using a critical lens that draws from a variety of disciplines, this article explores three ways through which responses to climate change can entrench, exacerbate or reconfigure the power of elites. As society attempts to create a low-carbon society, including for example via coastal protection efforts, disaster recovery, or climate change mitigation and renewable energy, these efforts intersect with at least three processes of elite power: experimentation, financialisation, and dispossession. Experimentation is when elites use the world as a laboratory to test or pilot low-carbon technologies or policy models, transferring risks yet not always sharing benefits. Financialisation refers to the expansion and proliferation of finance, capital, and financial markets in the global economy and many national economies, processes of which have recently extended to renewable energy. Dispossession is when elites use decarbonisation as a process through which to appropriate land, wealth, or other assets (and in the process make society more majoritarian and/or unequal). We explore these three themes using a variety of evidence across illustrative case studies, including hard and soft coastal protection measures (Bangladesh, Netherlands), climate risk insurance (Malawi), and renewable energy auctions and associated processes of finance and investment (South Africa and Mexico)

Układ sterowania CNC z napędami skokowymi

In the paper the conception of CNC system with stepper motor drives is presented. The system consists of a PC computer and a stand-alone CNC controller based on FPGA (Field Programmable Gate Array). In order to eliminate geometric discontinuities of motion trajectory in "G" and "M" codes, special conversion to NURBS (Non Uniform Rational B-Spline) curves on the PC is realized. Additionally, optimization of the motion trajectory feedrate is achieved by using the Look-Ahead algorithm. In the standalone CNC controller the software processor and CLK pulses generator are implemented. CLK pulses with high resolution and varying time period are sent to each of drives independently. An appropriate test to verify the correctness of CNC system was realized.Na rysunku 1 przedstawiono schemat blokowy proponowanego układu sterowania CNC. Układ może być użyty do sterowania napędami skokowymi jak i serwonapędami. Złożony jest z komputera PC oraz autonomicznego sterownika CNC (rys. 2). Na komputerze PC wykonywane są obliczenia związane z realizacją funkcji interpretera kodu numerycznego, konwertera opisu trajektorii ruchu z kodów "G" i "M" na opis z wykorzystaniem krzywych NURBS (ang. Non Uniform Rational B-Spline) oraz profilowania prędkości parametrycznej z wykorzystaniem algorytmu Look-Ahead. Autonomiczny układ sterownika CNC realizuje zadania związane z generacją sygnałów sterujących CLK z dużą rozdzielczością dla poszczególnych napędów skokowych osi mechanicznych. Opis trajektorii ruchu w kodach G1, charakteryzuje się występowaniem nieciągłości geometrycznych. Proponowanym opisem trajektorii ruchu jest opis z wykorzystaniem krzywych NURBS. Opis za pomocą krzywych NURBS umożliwia minimalizację występowania nieciągłości geometrycznych. Na rysunku 3 przedstawiono przykład trajektorii ruchu, opisanej z wykorzystaniem krzywych NURBS. W celu optymalnego dostosowania prędkości realizacji trajektorii ruchu zastosowano profilowanie prędkości po krzywej "S" z jednoczesną analizą zadanej trajektorii ruchu w przód - algorytm Look-Ahead. Na rysunku 4 przedstawiono budowę autonomicznego sterownika CNC. Sterownik zbudowany jest na układzie FPGA (ang. Field Programmable Gate Array). W układzie FPGA zaimplementowano procesor MicroBlaze oraz układ generacji sygnałów sterujących CLK dla napędów skokowych. Generator impulsów z dużą rozdzielczością oblicza okresy impulsów CLK dla każdej z osi i niezależnie wysyła je do napędów skokowych. Badania układu CNC miały na celu sprawdzenie poprawności działania aplikacji uruchomionej na komputerze PC (algorytmu Look- Ahead i konwersji z kodów "G" i "M" na opis z wykorzystaniem NURBS) oraz komunikacji poprzez port USB. W autonomicznym sterowniku CNC przeprowadzono badania związane z poprawnością przetwarzania otrzymywanych danych z komputera PC poprze port USB. Przykłady trajektorii ruchu w postaci okręgu i linii łamanej opisanej w kodzie G1 przedstawiono na rysunku. 5. Na rysunku 6 przedstawiono oscylogramy impulsów CLK wysyłanych do napędów skokowych

Wydajne osadzanie cienkich warstw związków chemicznych – modelowanie procesu reaktywnego rozpylania magnetronowego

Deposition of compound thin films with reactive magnetron sputtering method causes a lot of difficulties, of which the main ones are the instability of the process and decrease of the deposition rate. Computer simulations were performed using Berg’s model assumptions. Firstly, effect of basic process parameters on aluminum oxide deposition was examined, also theoretical characteristics of the deposition of Al2O3, AlN, TiO2, TiN were compared. Next, the parameters for efficient deposition of titanium oxide were determined. Simulations were confirmed by the results of experimental work. The purpose of presented work was to define, with Berg’s model, mechanisms which enable deposition, in metallic mode of magnetron work, of oxides with properties near to stochiometric. Presented analysis results were compared to real process parameters observed during reactive sputtering .Osadzanie cienkich warstw związków metodą reaktywnego rozpylania magnetronowego sprawia wiele trudności, spośród których głównymi są niestabilność procesu i spadek szybkości osadzania. Komputerowe symulacje wykonano wykorzystując założenia modelu Berga. W pierwszej kolejności sprawdzono wpływ podstawowych parametrów procesu na osadzanie tlenku glinu. Porównano również teoretyczne charakte-rystyki osadzania Al2O3, AlN, TiO2, TiN. Następnie określono parametry umożliwiające wydajne osadzanie tlenku tytanu. Symulacje potwierdzono wynikami prac eksperymentalnych. Głównym celem pracy była próba określenia mechanizmów umożliwiających osadzanie w modzie metalicznym tlenków o właściwościach zbliżonych do warstw o składzie stechio-metrycznym