The Company has two operating segments: 1) Oilfield and Industrial Technologies and Services and 2) Environmental Technologies and Services. Discrete financial information is available for each operating segment. Management of each operating segment reports to our Chief Executive Officer, the Company’s chief operating decision maker, who regularly evaluates income before income taxes as the measure to evaluate segment performance and to allocate resources. The accounting policies of each segment are the same as those described in the summary of significant accounting policies in Note 1.

The Company’s Oilfield and Industrial Technologies and Services segment manufactures and sells technology ceramic products and services, base ceramic proppant and frac sand for both the oilfield and industrial sectors. These products have different technology features and product characteristics, which vary based on the application for which they are intended to be used. The various ceramic products’ manufacturing processes are similar.

Oilfield ceramic technology products, base ceramic proppant and frac sand proppant are manufactured and sold to pressure pumping companies and oil and gas operators for use in the hydraulic fracturing of natural gas and oil wells. This segment also promotes increased production and Estimated Ultimate Recovery (“EUR”) of oil and natural gas by providing industry-leading technology to Design, Build, and Optimize the Frac^®. Through our wholly-owned subsidiary StrataGen, Inc., we sell one of the most widely used fracture stimulation software under the brand FracPro and provide fracture design and consulting services to oil and natural gas E&P companies under the brand StrataGen.

Our industrial ceramic technology products are manufactured at the same facilities and using the same machinery and equipment as the oilfield products, however they are sold to industrial companies. These products are designed for use in various industrial technology applications, including, but not limited to, casting and milling. Our chief operating decision maker reviews discreet financial information as a whole for all of our manufacturing, consulting and software businesses. Manufacturing includes the manufacture of technology products, base ceramics, industrial ceramics, sand and contract manufacturing, regardless of the industry the products are ultimately sold to. See Note 2 for disaggregated revenue information.

Our Environmental Technologies and Services segment designs, manufactures and sells products and services intended to protect operators’ assets, minimize environmental risks, and lower lease operating expense (“LOE”). AGPI, a wholly-owned subsidiary of ours, provides spill prevention, containment and countermeasure systems for the oil and gas industry. AGPI uses proprietary technology designed to enable its clients to extend the life of their storage assets, reduce the potential for hydrocarbon spills and provide containment of stored materials.

Summarized financial information for the Company’s operating segments for the two-year period ended December 31, 2018 is shown in the following tables. Intersegment sales are not material.

	Oilfield and Industrial Technologies and Services			Environmental Technologies and Services			Total
	($ in thousands)
2018
Revenue from external customers	$	178,609		$	32,136		$	210,745
(Loss) income before income taxes		(77,264	)		2,723			(74,541	)
Total assets		456,416			17,950			474,366
Capital expenditures		1,093			946			2,039
Depreciation and amortization		33,452			1,153			34,605
2017
Revenue from external customers	$	165,557		$	23,199		$	188,756
Loss before income taxes		(255,097	)		(46	)		(255,143	)
Total assets		524,952			15,646			540,598
Capital expenditures		2,371			227			2,598
Depreciation and amortization		43,005			1,277			44,282

Long-lived assets, consisting of net property, plant and equipment and other long-term assets, as of December 31 in the United States and other countries are as follows:

	2018		2017
Long-lived assets:
United States	$	272,903	$	326,665
International		5,910		6,482
Total	$	278,813	$	333,147

Revenues outside the United States accounted for 19% and 21% of the Company’s revenues for 2018 and 2017, respectively. Revenues for the years ended December 31 in the United States, Canada and other countries are as follows:

	2018		2017
Revenues:
United States	$	171,167	$	149,041
Canada		6,086		7,439
Other international		33,492		32,276
Total	$	210,745	$	188,756

The following schedule presents customers, primarily from the Oilfield and Industrial Technologies and Services segment, from whom the Company derived 10% or more of total revenues for the years ended December 31: