Luces y sombras del turismo industrial como dinamizador turístico en la provincia de Girona

XII Coloquio de Geografía del Turismo, Ocio y Recreación de la Asociación de Geógrafos Españoles. Colmenarejo (Madrid), del 17 al 19 de junio de 2010.Este texto se desarrolla en el marco del proyecto de investigación "Turismo, territorio e identidad: procesos de revalorización de espacios y actividades en el medio rural español. Un análisis comparado de los casos de Cataluña, Galicia y Murcia", del Plan Nacional de I+D+i, financiado por el Ministerio de Ciencia e Innovación. Referencia: CS02009-11793Publicad

La imagen turística y la historia de la ciudad: Barcelona y su atractividad a lo largo de un siglo XX expandido

XII Coloquio de Geografía del Turismo, Ocio y Recreación de la Asociación de Geógrafos Españoles. Colmenarejo (Madrid), del 17 al 19 de junio de 2010

A multi-chip-nodule micro-system for soil moisture measurements

This study presents a Multi-Chip-Module-based (MCM) micro-system suited for irrigation control and management applications. The micro-system includes the soil moisture sensor and an analogue-to-digital converter with signal processing circuitry. The same basic fabrication concepts and materials which made microelectronics successful are now being adapted to making low-cost, small, and high-performance sensor systems with integrated electronics on the same micro-system. Since this sensor has low-cost fabrication for mass production, a network could be implemented in order to achieve an accurate measurement of the soil moisture at the plant root level. A dual-probe heat-pulse technique is used (measurement of the maximum temperature rise at some distance from the heater, after applying a heat-pulse) to determine the volumetric heat capacity and, hence, the water content of the soil. The sensor module is about 30 mm long, 6 mm wide, and 0.8 mm in height; the probe pitch is 3 mm allowing small-scale spatial measurements of soil moisture, which can be made near the soil surface where large root densities are found. The heater uses a nickel-chrome resistor for resistive heating (thermo resistive effect – Joule heat). The temperature sensors (probe and reference) are highaccuracy CMOS smart temperature sensors

A CMOS mixed-signal interface with a RF transmitter for a micromachined soil moisture sensor

This paper describes a CMOS mixed-signal interface with a RF transmitter. This die is assembled in a Multi-Chip-Module (MCM) micro-system together with the micromachined soil moisture sensor to achieve a cost effective solution with accurate and reliable measurements for soil moisture in agriculture. The soil moisture probe, based on Dual-Probe Heat-Pulse (DPHP) method, is fabricated in bulkmicromachining technology. The DPHP method is based on the measurement of the maximum temperature rise at some distance from the heater, after applying a heat-pulse. The measurement of the temperature rise is obtained by subtracting soil temperature from the probe temperature. The mixed-signal interface is based on a pre-amplification stage and first-order sigma-delta modulator. The bit-stream output of the modulator is then applied to a counter as a first order decimation filter thus providing a 12-bit readout sample. Prior to transmission, data is encoded as a pulse width modulated (PWM) signal and then transmitted by means of an amplitude shift-keying (ASK) modulation. The transmitter features a VCO phase locked to the quartz crystal reference of 13.56 MHz to achieve a carrier frequency of 433.92 MHz. A RF power amplifier based on class E topology was chosen. The CMOS mixed-signal interface with a RF transmitter has been implemented in a single-chip using a standard CMOS process (AMI 0.7 µm, n-well, 2 metals and 1poly)

Modeling and simulation of a silicon soil moisture sensor based on the DPHP method for agriculture

A silicon soil moisture sensor, based in the dual-probe heat-pulse (DPHP) method, was modeled and simulated for achieving, with low cost, accurate and reliable measurements. This method is based on the application of a heat pulse during a fixed interval of time. The maximum rise in temperature (∆Tm) is monitored by the measurement probe, placed at a certain distance of the heater source. A lowcost high-performance and small temperature sensor (a dynamic VPTAT generator) is required to be placed into the probe which have 0.912 mm in diameter and 20 mm long. If one considers the range of water contents, ratio of water mass to dry soil mass, in a typical agricultural soil (0.05 to 0.35m3 m¡3), the average sensitivity of the dual probe is about 1:95ºC per unit change (m3m-3 in water content forq = 400 Jm-1

Modeling, simulation and testing of a silicon soil moisture sensor based on the dual-probe heat-pulse method

A silicon soil moisture sensor, based in the dual-probe heat-pulse (DPHP) method, was modeled, simulated and tested for achieving, with low-cost, accurate and reliable measurements. This method is based on the application of a heat pulse during a fixed interval of time. The maximum rise in temperature (ΔTM) is monitored by the measurement probe, placed at a certain distance of the heater source. A low-cost high-performance and small temperature sensor (a dynamic VPTAT generator) was designed and fabricated to be placed into the probe which have 0.912 mm inner diameter and 20 mm long. If one considers the range of water contents, ratio of water mass to dry soil mass, in a typical agricultural soil (0.05–0.35m3 m−3), the average sensitivity of the dual probe is about 1.95º C per unit change (m3 m−3) in water content for q = 400 Jm−1

A bulk-micromachined soil moisture probe with a mixed-signal interface

This paper presents a Multi-Chip-Module based (MCM) microsystem for irrigation management suitable for greenhouse environmental control. The proposed microsystem includes a soil moisture microsensor, analog interface and sigma-delta converter, and signal processing for digital filtering. A heat-pulse technique is used to determine the volumetric heat capacity and thus the water content of a porous media, such as the soil. This method is based on the Joule effect (heater probe) and on the Seebeck effect (temperature probe). By using CMOS standard processes (low-cost) and wireless capabilities, a wireless network architecture can be implemented for measuring the soil moisture at the plant root level

A MCM-based microsystem for soil moisture measurements

This work presents a Multi-Chip-Module (MCM) based microsystem for irrigation control in agriculture. The proposed microsystem includes a soil moisture microsensor, an analog-to-digital converter, signal processing circuits (digital filtering and sensor interface) and a RF 433MHz transmitter. A heat--pulse technique is used to determine the volumetric heat capacity and hence the water content of a porous media, such as the soil. This method is based on the Joule effect (heater probe) and in Seebeck effect (temperature probe). By using CMOS standard processes (low-cost) a network could be implemented in order to achieve an accurate measurement of the soil moisture at the plant root level

A wireless RF CMOS interface for a soil moisture sensor

This paper describes a wireless RF CMOS interface for a soil moisture sensor. The mixedsignal interface is based on a 2ndorder switched capacitor, fully differential sigma-delta modulator with an effective resolution of 17-bit. The modulator bit stream output is applied to a counter as a first order decimation filter and encoded as a pulse width modulated signal. This signal is then transmitted by means of an amplitude shift keying modulation, through a power amplifier operating at 433:92 MHz in class-E mode. The soil moisture sensor is based on Dual-Probe Heat-Pulse method and is implemented using an integrated temperature sensor and heater. After applying a heat-pulse, the temperature rise that is a function of soil moisture, generates a differential voltage that is amplified and applied to the mixed-signal interface input. The described interface can also be used with other kinds of environmental sensors in a wireless network for agricultural environments such as greenhouses. The CMOS mixedsignal interface has been implemented in a single-chip using a standard CMOS process (AMI 0.7 um, n-well, 2 metals and 1 poly)