Window Enlargement Research Articles

ANALIZA PARAMETRÓW MAJĄCYCH WPŁYW NA ZMIANĘ ZAPOTRZEBOWANIA NA CHŁÓD W OKRESIE LETNIM W BUDYNKU ZAMIESZKANIA ZBIOROWEGO

Artykuł przedstawia analizę problemu zapotrzebowania na chłodzenie pomieszczeń w okresie letnim wynikającego z powiększenia okien na elewacjach południowych. Celem badania jest analiza parametrów mających wpływ na zmianę zapotrzebowania na chłód i wybór najkorzystniejszych z nich. Parametry poddane analizie to: temperatura wewnętrzna w pomieszczeniu (zakres 21–24°C), współczynnik przenikania ciepła przez przenikanie dla okien U (zakres: 0,7 – 1,3 ), współczynnik zacienienia przez urządzenia przeciwsłoneczne fc (zakres: 0,15 – 0,95) oraz współczynnik zacienienia okna przez zewnętrzne elementy zacieniające Fsh,ob.,k (zakres: 0,7 – 1,0).

A tool to estimate indoor temperature in buildings with a risk of overheating in the temperate European climate zone

A regression model is proposed, as a simple tool, for estimating indoor temperature in thermally insulated buildings, applicable to situations when only natural ventilation in midsummer is concerned. Knowledge of this temperature, at a primary stage of a design process, might help avoiding the risk of overheating during summertime. The proposed regression model is applicable for buildings located in the temperate European climate zone. To create the regression model, the values of indoor temperature are calculated for incrementally increasing thermal resistance of outside walls, and gradual enlargement of windows. The outside partitions were covered with an insulating material with a thickness of 3 to 30 cm. For every insulation layer the window surface to wall surface ratio (wwr) was changing from 5% to 50%. The wwr changes were applied to a selected window, facing east, south and west in turn while wwr for the remaining orientations was kept at a constant value 1/10 of the wall. The considered building is representative for a single family house located at an open space. The algorithm of computations was based on the finite differences method, where feedback between the thermal model and the airflow model was applied.

Strength Analysis of Superyacht Superstructures with Large Openings

The superyacht manufacturing industry is currently facing big challenges, mainly related to the present economic crisis. Manufacturers are then competing on the ground of better and more aesthetic external and interior designs. This trend often leads to structural strength related issues, which can compromise the static or dynamic stability of superyacht hull. In several instances, the aforementioned fact is met, as in large openings and docks to recover tenders and the enlargement of windows to allow for better lighting of internal living spaces. So, for what the hull is concerned, large windows replaced small portholes on the yacht sides at mid length, rising non trivial problems about longitudinal strength. The same trend appeared on superstructures sides where traditional windows have been enlarged till to become glass doors extended from deck to deck allowing passengers to enjoy full sea landscapes. Despite the positive effect on the general design performance, this nice innovation implies serious structural problems. In fact in side areas where these doors are fitted the only structural elements are represented by very slender vertical stiffeners. The combined action of bending and compressive loads, together with the fact that superstructures are usually made by aluminium light alloy, can be the cause of buckling phenomena with severe consequences on structure and glass integrity. The same aspect has a negative influence on the bending efficiency of superstructures, meaning by that the level of cooperation of superstructures with hull strength. In this paper the contribution to steel hull strength of light alloy superstructures with large openings is studied by the finite element approach. The contribution of glazing windows to the primary response to global bending moment has been assessed as well.

Round window versus cochleostomy technique in cochlear implantation: histologic findings.

Cochleostomy or round window enlargement techniques for cochlear implant electrode insertion result in more abnormal tissue formation in the basal cochlea and are more apt to produce endolymphatic hydrops than round window electrode insertion. Twelve temporal bones from implanted patients were examined under light microscopy and reconstructed with 3-dimensional reconstruction software to determine cochlear damage and volume of neo-ossification and fibrosis after electrode insertion. Amount of new tissue was compared between 3 groups of bones: insertion through the round window (RW), after enlarging the RW (RWE) and cochleostomy (Cochl). The probable role of the electrode was evaluated in each case with hydrops. More initial damage occurred in the Cochl and RWE groups than in the RW group, and the difference was significant between RWE and RW in cochlear segment I (p < 0.026). The volume of new bone in Segment I differed significantly between groups (p < 0.012) and was greater in the RWE group than in either the Cochl or RW groups (post hoc p's < 0.035 and 0.019, respectively). Hydrops was seen in 5 cases, all in the Cochl and RWE groups. Blockage of the duct was because of new tissue formation in 4 of the 5 hydrops cases. With the electrodes in this series, implantation through the RW minimized initial intracochlear trauma and subsequent new tissue formation, whereas the RW extension technique used at the time of these implantations produced the greatest damage. Future studies may clarify whether today's techniques and electrodes will produce these same patterns of damage.

Removal of nitric oxide by activated ammonia generated by vacuum ultraviolet radiation

To broaden and lower the narrow temperature window of the selective non-catalytic reduction (SNCR) of nitric oxide (NO), the use of activated ammonia as the reduction agent was examined. A 172nm VUV (vacuum ultraviolet) excimer lamp was employed as the excitation source for molecular ammonia. Activated ammonia generated by VUV radiation in a photochemical reactor was injected into a model flue gas (NO/O2/N2) at room temperature. The effects of reaction temperatures, oxygen concentrations, and NH3/NO molar ratios (MRs) on NO removal were investigated in a lab-scale plug flow reactor. Temperatures ranged from 500°C to 850°C. A temperature window enlargement of 150°C was achieved at the lower boundary of the temperature window. The results are the first clear observations of low temperature SNCR by activated ammonia. Above 600°C, NO removal was affected by injection of activated ammonia, while around 750°C, conventional SNCR by injection of molecular ammonia was effective. An approximate 80% NO removal was attained at 700°C with an MR=2.0 and 8.3% O2. Although the chemical compositions of activated ammonia remained unknown during the present study, the results suggested that effective chemical species for NO removal such as NH2 and H2 were produced from activated ammonia above 600°C. The number of photons emitted per mole of molecular ammonia, Np, was proposed to evaluate the effects of NH3 concentrations and residence times of NH3 gas in the photochemical reactor. The optimum Np range was found to be the point at which maximum NO removal was attained.

Sampling-based RBDO using the stochastic sensitivity analysis and Dynamic Kriging method

This paper presents a sampling-based RBDO method using surrogate models. The Dynamic Kriging (D-Kriging) method is used for surrogate models, and a stochastic sensitivity analysis is introduced to compute the sensitivities of probabilistic constraints with respect to independent or correlated random variables. For the sampling-based RBDO, which requires Monte Carlo simulation (MCS) to evaluate the probabilistic constraints and stochastic sensitivities, this paper proposes new efficiency and accuracy strategies such as a hyper-spherical local window for surrogate model generation, sample reuse, local window enlargement, filtering of constraints, and an adaptive initial point for the pattern search. To further improve computational efficiency of the sampling-based RBDO method for large-scale engineering problems, parallel computing is proposed as well. Once the D-Kriging accurately approximates the responses, there is no further approximation in the estimation of the probabilistic constraints and stochastic sensitivities, and thus the sampling-based RBDO can yield very accurate optimum design. In addition, newly proposed efficiency strategies as well as parallel computing help find the optimum design very efficiently. Numerical examples verify that the proposed sampling-based RBDO can find the optimum design more accurately than some existing methods. Also, the proposed method can find the optimum design more efficiently than some existing methods for low dimensional problems, and as efficient as some existing methods for high dimensional problems when the parallel computing is utilized.

321 エキシマランプで励起したアンモニアガスの脱硝特性(排ガス処理(プラズマ))

To broaden and lower the narrow temperature window of the selective non catalytic reduction (SNCR) of nitric oxide (NO), the use of activated ammonia as the reduction agent was examined A xenon excimer lamp emitting a wavelength of 172 nm (i.e., vacuum ultraviolet; VUV) was employed as the excitation source for molecular ammonia. The effects of reaction temperatures, oxygen concentrations, and NH_3/NO molar ratios (MRs) on NO removal were investigated in a lab-scale plug flow reactor. Temperatures ranged from 500℃ to 850℃. A temperature window enlargement of 150℃ was achieved at the lower boundary of the temperature window. Above 600℃, NO removal was effected by injection of activated ammonia, while around 750℃, conventional SNCR by injection of molecular ammonia was effective. An approximate 80% NO removal was attained at 700℃ with an MR=2.0 and 8.3% O_2.

Effect of steaming treatment in the structure and reactivity of FCC catalysts

AbstractThe shape selectivity properties of USY zeolite crystallites is discussed, and is based on catalyst characterization, molecular simulation, catalytic experiments of model compounds and kinetic modeling. Typical FCC catalysts are prepared with different HY crystallite sizes (0.4 and 0.9 μm), and are structurally and chemically characterized with nitrogen and argon adsorption/desorption isotherms, temperature‐programmed desorption of ammonia and infrared spectroscopy. Catalyst characterization is carried out before and after the hydrothermal treatment (steaming) of the catalyst. Pore‐size distribution analysis demonstrates that the effect of the steaming treatment in the Y zeolite results in window enlargement. The influences of structural changes of steam treatment on reactivity is evaluated with the catalytic conversion of 1,2,4‐trimethylbenzene in a novel fluidized CREC riser simulator. It is proven that steaming enlarges zeolite windows and influence the 1,2,4‐TMB product distribution. A slight modification of the window diameter is proven to significantly affect the adsorbent‐adsorbate interactions. Focus is particularly given to the catalyst selectivity toward the tetramethylbenzene isomers, and the “transition‐state shape selectivity” is proven to be controlling the product distribution and is consistent with molecular mechanics calculations. © 2005 American Institute of Chemical Engineers AIChE J, 2006

Process Window Enlargement for Borderless Contact Formation by BPSG Stack Structure

Anomalous oxynitride loss after steam borophosphosilicate glass (BPSG) flow is observed for a borderless contact structure, and such loss engenders possible bit line shorts to word line. This phenomenon becomes more severe for BPSG film with higher phosphorous concentration. Phosphoric acid generation is deduced as the major mechanism. To enlarge process windows, a BPSG/undoped silicate glass stack has been proposed to withstand etch by acid. From practical application to 256 Mb dynamic random access memory process, this stack also shows a higher bit line contact yield and comparable contact sheet resistance with conventional stacks. More important, this technique could be fully integrated into incumbent ultralarge scale integrated technologies.

Treatment time reduction for large thermal lesions by using a multiple 1D ultrasound phased array system

To generate large thermal lesions in ultrasound thermal therapy, cooling intermissions are usually introduced during the treatment to prevent near-field heating, which leads to a long treatment time. A possible strategy to shorten the total treatment time is to eliminate the cooling intermissions. In this study, the two methods, power optimization and acoustic window enlargement, for reducing power accumulation in the near field are combined to investigate the feasibility of continuously heating a large target region (maximally 3.2 × 3.2 × 3.2 cm3). A multiple 1D ultrasound phased array system generates the foci to scan the target region. Simulations show that the target region can be successfully heated without cooling and no near-field heating occurs. Moreover, due to the fact that there is no cooling time during the heating sessions, the total treatment time is significantly reduced to only several minutes, compared to the existing several hours.

Time-varying narrow-band interference rejection in asynchronous multiuser DS/CDMA systems over frequency-selective fading channels

In this paper, we handle the problem of joint suppression of multiple-access interference (MAI) and narrowband interference (NBI) in fading, dispersive channels. The detectors we consider are linear, one-shot structures, which allow for possible window enlargement and signal-space oversampling to improve performance. We focus on both zero-forcing and minimum-mean square-error design strategies, showing that the presence of NBI generally requires a time-varying processing of the observables, no matter what the optimization criterion. A thorough performance assessment of the proposed detectors is also presented, either through analytical formulas or through computer simulations. We finally deal with the problem of blind suppression of both MAI and NBI, introducing batch-estimation procedures to be implemented offline, which require very little and sometimes no prior knowledge as to the interference structure.