Assessment of tropical climates in relation to human habitation

1. Introductory consideration is given to the items entering into the heat balance of the human body and included in the operation of climate. 2. Brief reference is made to the various attempts at combining the four heat elements in a single assessment, and the main features of the “effective temperature” scheme outlined. 3. The effective temperature scheme as a means of assessing hot climates is investigated by applying it to the meteorological data for Queensland. 4. Effective temperature is found to be a better index of the heat elements in climate than the dry-bulb temperature in the summer months, especially in the inland (arid) areas. 5. It is suggested that the effective temperature scheme gives rather too much weight to dry-bulb temperature in the higher range. 6. A comparative analysis of the climates of twelve Queensland towns is made in some detail. 7. A method of classifying hot climates in their relationship to European settlement on the basis of effective temperature studies is suggested for wider use

Buffer Reservation for TCP over ATM Networks

Transmission Control Protocol (TCP) has already been a widely used protocol in many networks. Recent studies show that the performance of TCP over ATM networks is severely degraded. In this paper, we propose to apply the buffer reservation technique on TCP traffic over ATM networks. While the ATM block transfer (ABT) method (Boyer, 1992) is to reserve bandwidth for bursts of cells, our proposed buffer reservation scheme is to reserve buffer space for TCP packets. We study the performance achieved by the Delayed Transmission (DT) and the Immediate Transmission (IT) buffer reservation schemes. Simulation results show that under the DT buffer reservation scheme, TCP can achieve better throughput and delay performance compared to the plain TCP and the TCP with Early Packet Discard (EPD) except in the WAN environment with short TCP packet length. In the WAN environment with short TCP packet length, the IT scheme can achieve similar throughput performance but smaller delay compared to the plain TCP and the TCP with EPD

Effect of placement method on geotechnical behaviour of hydraulic fill sands

Results of an investigation of the geotechnical behavior of a hydraulic sand placed at a land reclamation site in Hong Kong are presented and interpreted. The study was conducted to aid in developing guidelines for quality control of hydraulic landfill placement. The work described consisted of: (1) field investigations; (2) static and cyclic triaxial testing; and (3) calibration chamber tests to study the cone penetration test versus Dr relationships for marine sands obtained from the reclamation sites. The results of this study clearly indicate that the placement technique is the single most important factor controlling the geotechnical behavior of a given type of sand when placed as a hydraulic fill. The weakest zone is generally located just beneath the water level where fill deposition is placed by pipeline discharge

Metemoglobinemia e nitrato nas águas Methemoglobin and nitrate levels in drinking water

Foram determinados os níveis de metemoglobina em 116 crianças (idade média de 15 meses) do Estado de São Paulo (Brasil). Dois grupos foram formados: Grupo 1, por 92 crianças que consumiam água com teores de nitrato inferiores ao limite de 10 mg N/litro; e Grupo 2, por 24 crianças que bebiam água de poço com níveis de nitratos superiores ao permitido. A metemoglobinemia média do Grupo 1 (0,56%) mostrou-se estatisticamente diferente e inferior (alfa = 0,05) à do Grupo 2 (0,76%).<br>Methemoglobin levels were determined in the blood samples of 116 children (average age, 15 months) living in the State of S. Paulo (Brazil). Blood from two groups was analyzed: Group 1 was formed by 92 children who drank water with nitrate levels below 10 mg N/liter; whereas Group 2 was formed by 24 children who drank well water with nitrate above the level permitted. The methemoglobin average for Group 1 (0.56%) was statistically different and less that for Group 2 (0.76%)