The world population will reach 7 billion in late 2011, a demographic milestone that is causing renewed attention to the challenges caused by population growth. This article looks at the last 50 years of demographic change, one of the most extraordinary periods in demographic history. During this period, world population grew at rates that have never been seen before and will almost surely neve...

Economic satiation is the idea that once people have attained an adequate level of income and consumption they reach a satiation point at which income and consumer goods become less effective as reinforcers and as sources of satisfaction. Advocates of a sustainable society have seen economic satiation as a natural method for reducing the overconsumption of goods and thereby producing environmen...

European farming is dealing with global questions as food safety, climate change and energy, while attempting to sustain competitiveness in world markets, higher standards of food production and responding to new demands for public goods and services. The energy requirements of food production are here a central issue. But a literature review on this topic, centered in the Mediterranean, reveal...

A non-preemptive, zero time lag multi-project scheduling problem with multiple modes and limited renewable and nonrenewable resources is considered. A 2stage decomposition approach is adopted to formulate the problem as a hierarchy of 0-1 mathematical programming models. At stage one; each project is reduced to a macro-activity with macro-modes. The macro-activities are combined into a single m...

Energy, exergy, economic, exergoenvironmental, and environmental analyses are reported for a novel polygeneration system consisting of geothermal cycle, CO2 reverse osmosis unit, an electrodialysis lithium bromide absorption chiller, liquefaction unit natural gas. The proposed is able to produce electricity, cooling, desalinated water, sodium hydroxide, hydrogen. To study the aspects facility, ...

A preliminary assessment of the direct and indirect environmental support to the stability and sustainability of the urban system of Rome, Italy, was performed by means of the emergy synthesis approach. A raw inventory of mass and energy flows is firstly provided. Then raw data are converted into emergy flows driving the urban system. Finally, performance indicators are calculated. Emergy synth...

With its focus on the quantity of production, often to the exclusion of other goals, today's food system is on an unsustainable course. The problem begins with and is driven by industrialized production of both crops and animals. Industrialization is a product of technological change, public policy, and, most recently, globalized trade. The lack of sustainability derives from reliance on the in...

Extensive usage of private vehicles has led to increased traffic congestion, carbon emissions, and usage of nonrenewable resources. These concerns have led to the wide adoption of vehicle sharing (ex: bike sharing, car sharing) systems in many cities of the world. In vehiclesharing systems, base stations (ex: docking stations for bikes) are strategically placed throughout a city and each of the...

The world’s supply of petroleum hydrocarbons, which serve as feedstock for the fuel and chemical industries, is rapidly diminishing to satisfy the global demand for energy and consumer goods. In response to this increasing demand and limited supply, the cost of crude oil has risen to over $100 per barrel in 2012, a 10-fold increase compared to prices in the late 1990s [1]. As fossil fuels are n...

BACKGROUND Water is considered as the main source of life but water resources are limited and nonrenewable. Different factors have caused groundwater to decrease. Therefore, modeling and predicting groundwater level is of great importance. METHODS Monthly groundwater level data of about 20 years (October 1991 to February 2012) from the Hamadan-Bahar Plain, west of Iran were used based on peiz...