About the Author

Daniel P. Duffy

Daniel P. Duffy, P.E., writes frequently on the topics of landfills and the environment.

Articles by Daniel P. Duffy

Continuous Improvement

Waste

Continuous Improvement

Waste collection does not stay constant. Like any other industry, it changes and grows with each new innovation in machinery or technique. Other industries consciously adopt the formal process of “continuous improvement” to advance their capabilities and improve the quality of their products and services. Waste collection is no different.

Construction

Measuring Earthwork Volumes

Formulas and methods for determining the volumes and areas of regular shapes and surfaces go back at least as far as ancient Greece. Pythagoras and other mathematicians determined the formulas that are still used to calculate the volumes of spheres and pyramids, as well as the areas of curve conic

Straight and True

Construction

Straight and True

People have an amazing ability to adapt to and even become blasé about technological wonders. The things that we take for granted (flying, television, cell phones, the Internet) would seem like something out of science fiction to anyone 100 years ago. Now, we can’t imagine what life was like without

Great Things Come in Small Packages

Energy

Great Things Come in Small Packages

The famous saying “smaller is better” is not necessarily true. A more accurate statement would be that “appropriate scale is better.” This brings us to the use of microturbines and their appropriate applications. Micro turbines are not actually tiny; they are still relatively large and powerful machines. But compared to

Estimating Earthwork Volumes

Construction

Estimating Earthwork Volumes

Formulas and methods for determining the volumes and areas of regular shapes and surfaces go back at least as far as ancient Greece. Pythagoras and other mathematicians determined those formulas that are still used to calculate the volumes of spheres and pyramids, as well as the areas of curve conic

Construction

Measuring Earthwork Volumes

Formulas and methods for determining the volumes and areas of regular shapes and surfaces go back at least as far as ancient Greece. Pythagoras and other mathematicians determined those formulas that are still used to calculate the volumes of spheres and pyramids, as well as the areas of curve conic

Pump System Longevity and Extreme Operating Regimes

Water

Pump System Longevity and Extreme Operating Regimes

A pump is a mechanism that utilizes mechanical force to overcome distance, elevation, and friction to move water or another liquid through a conduit to a point where it can be discharged, stored, or utilized. Like all mechanical devices, pumps can wear out or break over time. A pump’s operational

Commercial Waste Containers For Specific Wastes

Waste

Commercial Waste Containers For Specific Wastes

Commercial waste pick up is not just a matter of size. Though certainly larger than residential carts and waste cans, commercial containers come with additional features made necessary by the volume and weight of their waste loads. Commercial containers are made with different materials, often with reinforced structures to manage