He adds, "I'm having an ongoing challenge to see my work outside myself.
The understanding of cracking mechanisms in concrete materials has presented an ongoing challenge and has not, to date, reached a high level of satisfaction.
Securing funds for personnel and equipment has been an ongoing challenge at some institutions, particularly when faculty and administrators have not fully backed the idea of reaching out to postdocs.
Challenges: Finding the right talent — salespeople, developers and designers — has been an ongoing challenge.
"It has been an ongoing challenge to persuade Saudi officials to treat terrorist financing emanating from Saudi Arabia as a strategic priority," the cable said, concluding that "donors in Saudi Arabia constitute the most significant source of funding to Sunni terrorist groups worldwide".
"It has been an ongoing challenge to persuade Saudi officials to treat terrorist financing emanating from Saudi Arabia as a strategic priority," said a classified cable sent by Secretary of State Hillary Rodham Clinton in December 2009, concluding that "donors in Saudi Arabia constitute the most significant source of funding to Sunni terrorist groups worldwide".
The drive to achieve low emissions from gas turbines has been an ongoing challenge for over 30 years with the reduction of NOx levels representing the most difficult issue.
For a bit of background here, attracting new users to mobile applications has been an ongoing challenge for app developers, especially as Apple's iTunes App Store's Top Charts highlight more recently popular and growing applications, not new launches.
However, the nature of interfaces in solids is highly complex and it has been an ongoing challenge to link material performance with the internal interface structure and related atomic transport mechanisms.
Given that approximately 60%% of America's young children (birth through age five) are in at least one weekly non-parental care arrangement and about two-thirds of them are in center-based care (Iruka & Carver, 2006), the goal of providing quality ECEC services while considering the expense and accessibility has been an ongoing challenge for U.S. policymakers.
