Applying rail transit construction waste to make building materials: using the theory of sustainable development.

With the rapid development of the rail industry, a large amount of construction waste will be generated during the construction phase, posing a significant risk of environmental pollution and exacerbating the plight of global resource shortages. This study establishes a green disposal system for rail transportation based on the theory of sustainable development. Shield slag, shield weathered sand, shale, and engineering slag are used as raw materials, and sintered bricks are adopted as their innovative disposal method. The heavy metals in the four types of construction waste and recycled products were tested by X-ray fluorescence analysis technique to analyze the actual environmental pollution risk and explore the influence of the firing stage on the performance of the recycled products through the enrichment factor evaluation method. The results of the physical and chemical property tests of the fired samples showed that the environmental pollution risk of the four recycled products after firing was at a low-risk level (EF < 2), the strength test results showed that the best specimens had a strength rating of 20 MPa and the other performance indicators (frosting degree, lime bursting test) measured also met the requirements of the recycled bricks. This study achieves the harmless treatment of construction waste, provides a disposal system for the green recycling of construction waste from rail transport, and provides a theoretical basis for subsequent studies on the effects of different external conditions on such recycled products.

Evaluation of the cost-effectiveness of home monitoring of uterine contractions.

In 1988, the major health insurance carrier in the state of Hawaii initiated a prospective study to determine the cost-effectiveness of ambulatory uterine activity monitoring. At the end of the study, 79 patients had completed 3189 days on the monitor. Thirty-six patients (45.6%) did not have preterm labor; the daily monitoring resulted in an average loss to the insurance carrier of $3300 per patient, or $118,800. Forty-three patients (54.4%) experienced preterm labor and were found to have benefited from the monitoring system. Earlier detection of preterm labor and better management of oral tocolysis in this group resulted in earlier initiation of maternal tocolytic therapy, which ultimately decreased the preterm birth rate and hospitalization days in the neonatal intensive care unit. Cost analysis of this group demonstrated an average savings of $24,000 per patient, or an overall savings of $1,032,000. The total group of high-risk patients (79) resulted in a net savings to the insurance carrier of $913,200, or $11,500 per patient, suggesting that use of the ambulatory uterine activity monitoring system significantly reduced the cost associated with preterm labor and early delivery.