Mathematical Sciences

... 10.1080/03610910903168595 Mauricio Sadinle a b * pages 1909-1924. ... Breiman , L. ( 1994 ). The 1991 census adjustment: undercount or bad data? Statistical Science 9 ( 4 ): 458 – 475 . [CrossRef], [Web of Science ®] View all references; Hogan, 199325. Hogan , H. ( 1993 ). ...

... 10.1080/03610910903168595 Mauricio Sadinle a b * pages 1909-1924. ... Breiman , L. ( 1994 ). The 1991 census adjustment: undercount or bad data? Statistical Science 9 ( 4 ): 458 – 475 . [CrossRef], [Web of Science ®] View all references; Hogan, 199325. Hogan , H. ( 1993 ). ...

A model for laser-assisted particle removal was developed. The model was applied to micrometer-sized particles of gold, copper, and tungsten on silicon substrates. A two-dimensional heat transfer model is used to calculate the temperature profiles and the thermal expansion for the metallic particles and the silicon substrate irradiated with ultraviolet nanosecond laser pulses. The particle/substrate system was modeled as a simple spring oscillator under the sudden thermal expansion excitation pulse and a concept of degree of coupling between the laser induced thermal expansion associated frequency and the particle/substrate system is introduced. In terms of this degree of coupling a simple method to determine the most appropriate laser pulse duration is proposed. The theoretical results were compared with previously reported experimental observations. The experimental cleaning efficiency for the different particle materials and size distributions, as well as the possibility of substrate contamination due to metal evaporation are well accounted by the theoretical model.

Fault simulator is proposed to understand and evaluate all possible fault propagation scenarios, which is an essential part of safety design and operation design and support of chemical/production processes. Process models are constructed and integrated with fault models, which are formulated in qualitative manner using fault semantic networks (FSN). Trend analysis techniques are used to map real time and simulation quantitative data into qualitative fault models for better decision support and tuning of FSN. The design of the proposed fault simulator is described and applied on experimental plant (G-Plant) to diagnose several fault scenarios. The proposed fault simulator will enable industrial plants to specify and validate safety requirements as part of safety system design as well as to support recovery and shutdown operation and disaster management.

... A case study is presented from FMCG products raw data. Different product ... 4. Case study and results. Data used in the selected case study are from real FMCG industry with different products and different time series types. They are ...

The origin of the kinks in semiconductor lasers light-current characteristic (L(l)) is theoretically alld experimentally analyzed. The devices are straight separate confinement heterostructure lasers. We have developed a model to calculate L(l) which considers two thermal loss mechanisms: the leakage current and Auger recombination. It is shown that the kinks in the light-current characteristic appear at temperatures at which the

The effect of the cavity length and emission wavelength on T(sub 0) was investigated for straight separate confinement heterostructure lasers grown by low temperature liquid phase epitaxy (LT-LPE) method. For lasers with active layer thickness d = 30 nm, the theoretical calculations of the temperature dependence of I(sub th) supported the kinks observed experimentally. The result for short lasers with

Systematic measurements of the AC susceptibility as a function of temperature and magnetic field amplitude Hac for the Fe and Zn codoped (Bi1.6Pb0.4)(Sr1.8 Ba0.2)Ca2(Cu1-x-y ZnxFey)3Oz (x = 0.00;0.02 and y = 0.00;0.01) system are reported. Above Hac = 200 A/m, the linear dependence of Tp for maximum of imaginary chi''(T) peak as a function of AC field amplitude agree with Muller critical state model. The intergrain pinning force density decreases in doped and codoped samples.

The intergranular properties of (Y1-x-yZrxCay)Ba2Cu3O7-δ ceramics were studies by using temperature-dependent ac susceptibility measurements at zero dc magnetic field. The intergranular critical current density was determined from ac susceptibility data by varying the field amplitude Hac. From the imaginary part of the complex susceptibility, χ″(T), we have determined the temperature dependence of the critical current density by using the Bean's model. The ac field dependencies of the intergrain χ″-peak temperatures Tp are linear and agree with Müller critical state model. The results were analyzed in terms of superconductor-insulator-superconductor (SIS)-and superconductor-normal-superconductor (SNS)-type models for granular superconductors.

The R3Co11B4 compounds belong to the Rn+1Co3n+5B2n intermetallic systems. The R3Co11B4 borides crystallize in a hexagonal structure of Ce3Co11B4 type having the space group P6/mmm. The composition dependencies of the lattice parameters in (Y1-xTbx)3Co11B4 compounds are linear and different for a and c parameters. The magnetic properties of (Y1-xTbx)3Co11B4 compounds were investigated in the temperature range 4.2–950 K and external fields up to 10 T. The Y3Co11B4 compound is ferromagnetically ordered. For the compounds with x>0, a ferrimagnetic ordering is evidenced. The Curie temperatures increase when yttrium is substituted by terbium, as a consequence of the increase of the exchange interactions in the system. The magnetic behavior of cobalt in the above system is analyzed.

The underdoped YBa2 (Cu0.96Fe0.04)3Oy superconducting system has been prepared and investigated. The effect of oxygen content and the thermal treatment (fast quenching of underdoped samples from 250 K to 4.5 K) on the electrical resistance were studied. The semiconductor behaviour of electrical resistance after the fast quenching of the samples agree with a model for the stripe formation in Cu(2)O2 plane. The presence of two resistive transitions (Tc1=18 K and Tc2=36 K ) were evidenced for y=6.75 sample. The disappearance of the low transition after the thermal treatment were analysed in relation with the role of Fe clusters on the order of apical oxygen. The decrease of Tc by increasing oxygen deficiency was attributed to the fragmentation and stripe pinning in Cu(2)O2 planes as a result of the disorder produced by the Fe clusters in Cu(1)O chains.

A complete characterisation of an Oxford Instruments Vibrating Sample Magnetometer (VSM) has been made in order to check the limits and the reproducibility of the system as well as the measurement accuracy. Several measurement cycles have then been carried out to check the extent of the difference between the actual sample temperature and the sensor reading, and the weight of this difference on the magnetization data as a function of the temperature. Moreover an unexpected lowering of a reference signal has been observed at low temperatures, most probably due to shielding currents in the structure; this effect influences the sample signals, and has to be taken into account during data analysis. Being the magnetization a relative measurement, a great attention must be paid to the calibration procedure. Calibrations with 99.999% pure Nickel and Palladium, which have magnetization signals two order of magnitude apart, give comparable calibration constants. We observed that in order to ...