Search

This work studied the impact of flood and through-tool cutting fluid delivery methods during the drilling of carbon fibre reinforced polymer (CFRP) composite panels against a dry baseline condition. The cutting fluid considered was a water-based, composite-specific fluid, and the cutting tool was a O6.35 mm diamond-coated drill bit. After an initial design of experiments (DOE) approach enabled the establishment of appropriate cutting parameters to minimise delamination, both delivery methods and dry baseline drilling were compared in terms of tool wear and hole quality. The increased heat removal efficiency of through-tool delivery method is theorized to have prevented the localised softening of the resin and consequently maintained high abrasiveness of the composite workpiece, ultimately developing the highest tool wear for the given parameters. After drilling 600 holes, dry drilling exhibited the best results and lowest variation of hole quality metrics, i.e. the most stable process. However, after drilling 300 holes, flood delivery produced a better performance for cylindricity and perpendicularity and similar exit delamination factor (Fd) than dry drilling. Interestingly, through-tool delivery exhibited a slightly better performance than dry drilling when the analysis and comparison is conducted after the first 100 holes drilled only. These results indicate that hole diameter is highly dependent on tool wear and demonstrates that heat evacuation helps to produce holes with better cylindricity and perpendicularity, since hole distortion is highly affected by heat up and cool down cycles and the different coefficient of thermal expansion (CTE) across the laminate.

We present experimental results of soft errors produced by proton and neutron irradiation of minimum-size six-transistors (6T) and eight-transistors (8T) bit-cells SRAM memories produced with 65 nm CMOS technology using an 18 MeV proton beam and a neutron beam of 4.3–8.5 MeV. All experiments have been carried out at the National Center of Accelerators (CNA) in Seville, Spain. Similar soft error rate levels have been observed for both cell designs despite the larger area occupied by the 8T cells, although the trend for multiple events has been higher in 6T., This work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO/FEDER) under projects CICYT-TEC2011-25017 and TEC2014-52878-R.

We analyze the evolution of SRAM memory logic contents under irradiation by defining the memory state as the number of cells storing a given logic value (i.e. number of cells storing a logic-1). We find that the memory state evolution under irradiation follows an Ehrenfest urn model due to the constant effect of single event upsets, and that in large memories it can be associated to an Ornstein-Uhlenbeck process. Memory state transient analysis has been applied to determine the device Soft error rate for an SRAM fabricated in a 65 nm commercial CMOS process obtaining a very good correlation. Furthermore, our analysis shows that the technique is applicable to systems composed by various dissimilar memory components, providing–under certain circumstances–the specific Soft Error Rate of each component.

This work investigated the influence of the material properties and cutting speed on the heat dissipation in the drilling of carbon fibre reinforced plastic (CFRP) composites using uncoated WC-Co tools. The first stage of the investigation compared the heat dissipation in drilling three different CFRP systems by measuring the temperatures developed at different distances around the borehole using thermocouples and an infra-red camera. The second stage studied the influence of cutting speed on the maximum temperatures developed in the workpiece in drilling a selected CFRP system in a cutting speed range from 50 to 200 m/min. The cross-linking density of the polymer matrix and the degree of crystallinity and structure of the carbon fibres exhibited a significant influence on the overall temperature and on the heat dissipation, whereas 150–200 m/min cutting speeds yielded higher concentration of heat, compared to 50–100 m/min cutting speeds.

We report the complete coding sequence of a new HLA-B27 subtype, B*2712, which was found in a Caucasian Spanish family within the chromosome A2-Cw2-B*2712-DR15-DQ6. B*2712 was first detected as a segregating B blank Bw6-associated antigen. Extensive serologic analysis demonstrated that this new B27 subtype was not recognised by any of the B27-monospecific antibodies, giving positive reactions only with some monoclonal reagents against B40 or B27,40. Sequencing analysis showed a high similarity with B*2708, only differing in three clustered amino acid residues at positions 69 to 71 located in the alpha helix of the alpha1 domain. Residues 69 and 71 point towards the T-cell receptor, while amino acid 70 points to the antigen binding site. Loss of the conserved structure of pocket B as well as the differentiated pocket F configuration suggests that B*2712 does not confer ankylosing spondylitis susceptibility. Misleading serologic definition supports the usefulness of DNA-typing methods to complement HLA class I typing.

This paper presents experimental results of Soft errors produced by proton interaction in SRAM memories implemented with a 65nm CMOS technology using the 18 MeV proton facility at the National Center of Accelerators (CNA) in Seville.

The electronics for monolithically integrated gas sensor arrays fabricated using a compatible CMOS process have been developed. Circuitry includes the heater driver for temperature control and an interface circuit for inspection of the four sensors in the array. The operating temperature of the sensing resistors is between 200° and 400°C. The proposed temperature controller is capable of regulating the temperature of a 2100 × 2100 μm hotplate up to 400°C with a resolution of 2°C with 5 V supply voltage. A readout circuit based on a ring-oscillator has been included to measure the sensing resistance change upon gas exposure over a high dynamic range. Because it is robust, small, low priced and offers future capabilities with adequate signal processing, the system would be able to cover most of today's gas sensor markets.

The advances of the semiconductor industry enable microelectromechanical systems sensors, signal conditioning logic and network access to be integrated into a smart sensor node. In this framework, a mixed-mode interface circuit for monolithically integrated gas sensor arrays was developed with high-level design techniques. This interface system includes analog electronics for inspection of up to four sensor arrays and digital logic for smart control and data communication. Although different design methodologies were used in the conception of the complete circuit, high-level synthesis tools and methodologies were crucial in speeding up the whole design cycle, enhancing reusability for future applications and producing a flexible and robust component.

This work investigates the applicability of Taylor’s model on the drilling of CFRP using uncoated WC-Co tools, by assessing the influence of cutting speed (Vc) on tool wear. Two different resins, possessing low and high glass transition temperatures (Tg), and two different reinforcements, high strength and high modulus woven fabrics, were combined into three different systems. Flank wear rate gradient exhibited to be more reinforcement dependent, while the actual flank wear rate showed to be sensible also to the type of resin. In terms of tool life, all CFRP systems adjusted into a power-type tool life vs. cutting speed curve through the full range of cutting speeds (1,000 RPM to 18,000 RPM). Therefore, Taylor’s model can be applied to estimate the tool life in the drilling of CFRP using uncoated WC-Co tools with good accuracy.

Several works have been carried out in relation to the disposal of residues from conventional coal combustion processes [1] , [2] . However, these residues are different from those proceeding from fluidised bed combustion systems, mainly due to the sorbent (limestone or dolomite) used to the removal of SO2 emissions. In this paper the environmental implications [3] of the disposal of residues from fluidised bed combustion systems are studied. The procedures to evaluate the leaching behaviour of these residues have been done at three levels: shaking, column and lysimeter studies. Comparison between the three methods has been carried out, concluding that the results obtained with columns tests and lysimeter tests are very similar. So, to evaluate the environmental impact of fly ashes, it would not be necessary to do lysimeter tests (which are expensive and need a lot of time) in order to know the behaviour of ashes once they are disposed of.

The solid combustion residues generated during fluidized bed coal combustion and pulverized coal differ as a result of different operating conditions. This paper summarizes a study carried out on the combustion residues arising from two types of fluidized bed combustors, both pressurized bubbling and atmospheric circulating (Escatron power plant and Ciemat pilot plant, respectively), and a pulverized coal power plant. The influence of the combustion system on the characteristics of the residues and the problems related to their disposal, from the point of view of leaching characteristics, were studied. The results show that the main components of the solid residues from fluidized bed coal combustion are those arising from the sulphation reaction and by-products of this reaction, while the inorganic constituents of coal are the main components from pulverized coal combustion residues. Resulting from this composition the most important components, as regards to concentration, are calcium and sulphate in the leachates from fluidized bed combustion residues, while the leachates from pulverised coal combustion residues contain only the elements from the mineral matter. One other interesting observation is the high concentration of free-lime in circulating fluidized bed combustion residues as compare to the pressurized bed combustion residues.

The broad HLA-B16 serologic specificity is divided into B38 and B39 splits associated to Bw4 and Bw6, respectively. Differential serologic variants have been defined for several molecular subtypes of B39 and for B38. We found a Spanish Caucasian individual carrying a B16 Bw4-associated antigen which was not recognized by reagents against B16 splits. Sequencing analysis showed a new B16 subtype termed B*3803. HLA class I sequence-based typing (SBT) analysis demonstrated that B*3803 co-segregates with A*2608 and Cw*1203, forming a common Caucasian haplotype. Sequence comparison with B*38 and B*39 subtypes evidences that although B*3803 is close related to B*3802, it only differs from B*39021 by six clustered nucleotide position in the Bw4/Bw6 motif, and strongly suggests that B*3803 could have evolved from, or be the ancestral gene of the Oriental-associated B*3802 and B*39021 alleles. However, more complex patterns of genetic events should be considered due to the Caucasian background of the B*3803 individual an its associated haplotype Note.

HLA-J345, in contrast to B44, does not show molecular polymorphism. We have found a group of Caucasian Spanish individuals, sero-logically typed as B45, showing an unexpected HLA-B12 PCR-SSO subtyp-ing pattern. Complete coding region sequencing and B45 subtyping by PCR-SSO demonstrated that the j345 serologic specificity is constituted by two molecular alleles: B*4501 and B*5002. B*5002 is recognized by polyclonal and monoclonal allosera against B12 and B45, whereas it is not detected by B21, B49, or B50 reagents, providing a new example of poor correlation between serology and structure. B*5002 explains an important subset (18%) of the B45-positive individuals of the Spanish population studied, and almost half are included in a very infrequent haplotypic association, Cw6-B*5002-DRB1*0406-DQA1*03-DQB1*0402.

A pulsed laser system has been used to induce single event upsets (SEU) in highly-scaled SRAM devices. The events are induced from the circuit topside in areas where the higher metal layers have been eliminated by design from the circuit layout. The presence of metal tracks for voltage biasing, bit-line and word-line routing, difficult carrying out measurements to obtain the minimum energy required to induce an SEU. Off-chip transient currents caused by laser pulses have been measured; data indicates that most of such current is due to photocurrents generated in the well-substrate diode.

Resumen . Presentamos el caso de una mujer de 44 anos remitida a nuestra consulta por cuadro de ictericia, coluria y acolia. Al revisar la historia clinica de la paciente se comprobo que el IgM frente al virus de la hepatitis A (VHA) era positivo 4 y 2 anos antes, asi como en el momento de ser visitada por nosotros. Usando el sistema de puntuacion del Grupo Internacional para el Estudio de la Hepatitis Autoinmune, la paciente presentaba una puntuacion de 16 sin tener en cuenta el marcador de la hepatitis VHA y de 13 si este se tenia en cuenta. Probablemente la persistencia de este marcador viral a lo largo de tantos anos se relaciona con la hipergammaglobulinemia policlonal existente en estos enfermos, por lo que pensamos que la inclusion de este anticuerpo como dato negativo en el diagnostico de la hepatitis autoinmune debe realizarse con precaucion.

The measurement of plutonium isotopes, 239Pu and 240Pu, at 670 kV on the compact accelerator mass spectrometry (AMS) system at the Centro Nacional de Aceleradores (CNA) in Seville, Spain, is now a reality. In this work, we present first Pu AMS results for environmental samples: a sediment core collected in a submarine canyon in the Mediterranean coast of the Spanish region of Palomares, affected by a nuclear accident in 1966. From the study of the 240Pu/239Pu atomic ratio profile, showing on average levels lower than 11%, we confirm that the weapon-grade plutonium released on land during the accident, with a characteristic 240Pu/239Pu atomic ratio of 5.8%, has found its way into the marine environment. A two-plutonium sources mixture model (Palomares and fallout) is used to elucidate the percentage of the plutonium coming from the accident. As a validation exercise of the Pu AMS measuring technique and in order to obtain the 238Pu/(239+240)Pu activity ratios, samples were also studied by alpha-spectrometry (AS). The obtained AS 239+240Pu activity concentration results fit in with the AMS ones in a wide dynamic range, thus validating the AMS technique. © 2009 Elsevier B.V. All rights reserved., This work has been financed through the projects FIS2004-0495 of the Spanish Ministry of Science and Education, and RNM-419 of the Junta de Andalucía.

We present the design and operation of a monitor circuit that captures the effect of ionizing particles on sensitive CMOS IC internal nodes. The circuit implements a Single Event Effects (SEE) detector and a quick sampling block that captures the SEE induced waveform shape currents during a certain time window. These values can be read externally through a dedicated decoding circuitry. The circuit has been designed and fabricated on a 130nm technology. Preliminary experimental results and detailed simulations are provided to demonstrate the feasibility of the system implemented.

Soft errors resulting from the impact of charged particles are emerging as a major issue in the design of reliable circuits at deep sub-micron dimensions even at ground level. To face this challenge, a designer must dispose of a variety of mitigation schemes adapted to their specific design constraints. Built In Current Sensors have been proposed as a detection scheme for single event upsets in SRAM. In this paper, Power-Bus current transients in SRAM memories for Single Event Upset Detection have been analyzed in a 65nm CMOS technology. The different types of current roles which are applied during the simulation is discussed. The results show the important contribution of leakage currents in the response of the memory cell to an external event.

In this paper a multichip module system for automotive applications is described. The MCM substrate is a IMS (Isolated Metal Substrate), which has been used for integration of analog signal processing stages, complex logic circuits and even power switching transistors. The main functionality of the door module implemented with this MCM, is the control of the power window motor with antipinch feature, although the prototype has been completed with communication (LIN-bus).

HLA-DRB1 is the most polymorphic gene described so far, and their encoded molecules disclose a major role in allogeneic responses. We describe in this report a new DRB1 allele in a Spanish Caucasian bone marrow donor, initially defined by PCR-SSO as a DRB1*11-like allele. Complete exon 2 cDNA-sequencing reveled that this allele was identical to DRB1*1119 except for a single substitution at position 178, which generates an amino acid change (Tyr-His) at position 60. This residue is shared by several DRB1*14 subtypes and DRB1*0808. The new allele was officially named DRB1*1131.

A mixed-mode temperature control system for gas sensors is described in this work. It has been designed to be capable of controlling different gas sensor structures. The temperature range and accuracy depend on the gas sensor structure but are usually in the range of from room temperature up to 600/spl deg/C within 1/spl deg/C accuracy. The circuit has been designed with 0.8 /spl mu/m HV CMOS AMS technology in order to support the 15 V biasing voltage that is necessary to reach these high temperatures. A serial peripheral interface communication port allows real time monitoring of the heater resistance. It also allows setting of the parameters of the control and temperature reference.

A mixed-mode interface circuit for monolithically integrated gas sensor arrays has been developed. Circuitry includes the heater driver for the temperature control, interface electronics for inspection of up to four sensors array and interface logic for smart control. Because of its characteristics as robustness, small, size, low price and future capabilities with the adequate signal processing the system composed by the sensor and the application specific integrated circuit would be able to cover most of today markets considered for gas sensors.

In this paper a multichip module system for automotive applications is described. The use of microsystems in automotive industry allows size reduction of electronic units and also a reduction in its cost. The presented microsystem is based on a IMS (Isolated Metal Substrate) substrate, which has been used for integration of analog signal processing stages, complex logic circuits, sensors and even power transistors. The functionality of the microsystem is the control of a power window motor with antipinch feature. The system architecture is based on a single microcontroller and a multipurpose ASIC. The trapping detection strategy is based on current sensing and signal processing.

Resumen Preservacion con celsior en trasplante renal. nuestra experiencia Objetivos Analizar comparativamente la incidencia de necrosis tubular aguda (NTA) y funcion del injerto renal segun el liquido de preservacion empleado. Wisconsin vs Celsior. Material y metodos Desde enero de 1994 a diciembre de 2002 se implantaron 229 injertos renales, 190 de ellos preservados con Wisconsin (82,9%) y 39 con Celsior (17,1%). En este trabajo, tras comprobar la homogeneidad estadistica de ambos grupos, se analiza comparativamente la incidencia de NTA y la evolucion de la creatinina serica en funcion del liquido de preservacion empleado. Resultados No hay diferencia significativa en la incidencia de NTA entre los grupos Celsior (23%) y Winsconsin (36%). Se obtiene resultado similar en proporcion de NTA en el subgrupo de injertos con periodos de isquemia fria superior a 12 h, con independencia del liquido de preservacion empleado. El grupo Celsior presenta menores niveles de creatinina serica a 1, 3, 6 y 12 meses postransplante renal, con una diferencia estadistica significativa (p0,05). Conclusiones La preservacion renal con Celsior proporciona resultados equivalentes a Wisconsin en relacion a incidencia de NTA y funcion renal, con la ventaja de un menor coste.

In this paper a multichip module system for automotive applications is described. The MCM substrate is a IMS (isolated metal substrate), which has been used for integration of analog signal processing stages, complex logic circuits and even power transistors. The functionality of the door module implemented with this MCM, is the control of the power window motor with antipinch feature. A prototype that also includes central lock control, courtesy light control and drivers for communication of the module to the rest of the vehicle electronic systems has been completed.

This paper presents a system suitable for DfTT (Design for Thermal Testability) purposes that allows temperature monitoring and programmable overtemperature detection implemented in CMOS technology. It has been developed for on-line monitoring in automotive applications. The system includes a temperature sensor, based on the Base-emitter Voltage of a CMOS Lateral Bipolar Transistor, that achieves a non-linearity lower than 0,4/spl deg/C in the range comprised between [-40/spl deg/C, 85/spl deg/C]. The system is compatible with the Boundary Scan protocol. The chip functions are discussed in detail.

TACROLIMUS is a well-established basic immunosuppressive drug in renal transplantation (RT), but the efficacy and safety comparisons with the new formulation of microemulsified cyclosporine, Neoral, come only from a multicenter study. In the only published 3-month multicenter trial, tacrolimus triple therapy with azathioprine and steroids was associated with less acute rejection episodes (in number and severity) than was triple therapy with Neoral. However, these large multicenter international trials are frequently quite heterogeneous and include too short follow-up. Consequently, they may not reliably reflect the impact of new immunosuppressive regimens on routine clinical practice. We have reviewed the 5-year experience in our unit with RT treated with Neoral or tacrolimus.

HLA-B14 serological subtyping is very limited probably due to the internal position of the unique amino acid residue that differentiates B64 and B65 molecules. In order to carry out an accurate B14 subtyping we have designed a semi-nested PCR-SSP procedure that can differentiate B*1401 and B*1402 in any HLA-A, -B or -C antigen combination. A panel of 133 B14-positive and 31 B14-negative healthy and unrelated Spanish individuals were studied. Additionally, 45 B14-bearing haplotypes (-A,-B,-C,-DRB1,-DRB3/DRB4/DRB5,-DQA1,- DQB1) were available through family studies. The relative frequencies of HLA-B14 subtypes were 74% for B*1402 and 26% for B*1401, in agreement with those found in other Central European populations, but differing from those in Wales, where the relative presence of B64 goes to 41%. A total of 11/17 and 18/28 different haplotypes for B*1401 and B*1402, respectively, were identified. Both alleles showed the strongest association to Cw8 (43/45), indicating a primary ancestral B14-Cw8 association. However, B14 subtypes evidenced very distinguishable haplotype distributions. B*1401 is strongly associated with the common HLA class II haplotype DRB1*0701-DQA1*0201-DQB1*02 (13/17), while B*1402 is mainly associated to DRB1*0102 (16/28). Three major haplotypes were identified: A32-Cw8-B*1401-DR7-DQ2 (5/17), A33-Cw8-B*1402-DRB1*0102-DQ5 (5/28) and A2-Cw8-B*1402-DRB1*0102-DQ5 (5/28).

HLA-B44 is the most frequent HLA-B allele in Caucasian populations. Several B44 subtypes, B*4402-B*4406, have been identified in individuals with this ethnic origin. Mismatches among B44 subtypes have been described as major targets for allogeneic responses in bone marrow transplantation. We have developed a PCR-SSO method, based on a B12- specific DNA amplification of exon 2 through exon 3 and subsequent non radioactive hybridization with eight probes, which allow us to discriminate all B12 homozygous combinations. We applied this method to determine the frequency of B44 subtypes in a Spanish population, as well as their HLA-A,-C,-DRB1,-DRB3/DRB4/ DRB5,-DQA1 and -DQB1 associated haplotypes. A total of 141 healthy unrelated Spanish individuals and 31 B44-bearing haplotypes were investigated. Four B44 alleles were identified, B*4402 (33%), B*4403 (66%), B*4404 (0.7%), and B*4405 (0.7%). Haplotype analysis showed a clear differentiated distribution pattern for the two major B44 subtypes. B*4402 is associated with Cw5 (11/13) and A2 antigens (10/13). In contrast, B*4403 is mainly found together with DRB1*0701 (14/16). An inverted B*4402/B*4403 frequency in comparison with other European and North American Caucasian populations, revealed the existence of an extended haplotype diversity between populations of the same ethnic origin. Apart from anthropological studies, high resolution typing for HLA class I antigens presenting molecular polymorphism will be of great relevance in unrelated bone marrow transplantation.

Routine serological HLA typing of s Syrian family revealed a Bw4-associated HLA-B blank antigen showing Mendelian segregation together with the haplotype A1, Cw2, DR11, DQ7 (a father and one of his children, cells NO. 5958641 and No. 1958125). A more extensive serological analysis was done by using additional polyclonal and monoclonal antibodies (mAb; One-Lambda BL-60 and LM172 plates) as well as the 12th International Workshop class I mAb plate. Both cells showed no conclusive typing reactions with sera towards HLA-B27 and HLA-B37 antigens. Two mAb, PAMELA (27,44,38) and FAY (13,27,37,47), were able to recognize this antigen. The great majority of polyclonal reagents against B37 showed negative reactions, while weak results were frequently observed with anti-B27 allosera. 8 refs., 1 fig., 1 tab.

The wastes from fluidized beds combustors are unlike those discharged from conventional pulverized fuel furnaces. In general, they consist of a mixture of bed ash, sorbent reaction products, and unreacted sorbent. The residues from two modes of operation (CFBC and PFBC) have some differences, as result of different operating regimes, and the effect of pressure on mineral equilibrium The influences of type of fluidized bed combustor (PFBC and ACFBC) on the characteristics of the residues and the problematic related with disposal of these ashes from the point of view of leaching are studied.

This study focused on the thermal degradation of the polymer phase of carbon fibre reinforced polymer (CFRP) composites through thickness by applying the nanoindentation technique. The results were compared for the elastic modulus (E) and hardness (H) of a non-aged sample and the samples aged at 200 C and 350 C during a short period of 60 s, in order to experimentally simulate the thermal conditions of drilling. Compared to the non-aged specimen, the results showed an increase of 16% in the elastic modulus and 12% in the hardness for the specimen aged at 200 C. In contrast, the results for the specimen aged at 350 C showed a variation of 0.8% and � 3% in the elastic modulus and hardness respectively. These results contribute to a better understanding of the effect of the heat developed during the machining of composites on the properties of the resin phase in CFRP. Hereby we present the evidence of a postcuring effect at the temperatures close to the glass transition temperature (Tg) in the drilling of CFRPs. 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://

This paper describes a 12-bit current mode digital to analog converter. Circuit topology uses two arrays of 64 equal current sources, each one generating both the current associated to six bits, corresponding to either MSB or LSB parts. The main novelty of that topology is the method used to limit the maximum current provided by the LSB block, which ensures a monotonic behavior of the system. The circuit has been designed and fabricated using a 0.35 /spl mu/m CMOS process and occupies an area of 0.17 mm/sup 2/.

A monolithically integrated gas sensor array with conventional CMOS electronics has been developed. Circuitry includes the heater driver for the temperature control and the signal interface electronics for inspection of the four sensors in the array. Because of its characteristics as robustness, small, size, low price and future capabilities with the adequate signal processing the system would be able to cover most of today's markets considered for gas sensors.