How to prevent multiple form submissions and put a limited time on form submissions?

1. How can I prevent multiple submissions from the same email on a form?

2. How do we set an "active" time for the form? For example if we only want form submissions to be accepted for 48 hours, how can we put a time limit on the form submissions? If there is no functionality available for this now, can someone think of a workaround? All i am coming up with is removing the form from the landing page and putting up a notice that the survey has closed.