available cash balances, and, if necessary, sales of accounts receivable and borrowings from our revolving credit facility. We fund our investing activities primarily from cash provided by our operating and financing activities. Based on our current outlook, we believe that net cash provided by operating activities and available borrowings under the term note payable with TCW and the term note payable to a seller of TMX Engineering, LLC (“TMX”) (collectively, the “Note Payable”) will be sufficient to fund our cash requirements for at least the next twelve months. As we continue to expand our business, including by any acquisitions we may make, we may in the future require additional working capital for increased costs.
Operating Activities
Net cash provided by operating activities was $19,087,019 in the nine months ended September 30, 2024 compared to $13,209,417 in the nine months ended September 30, 2023. The changes in accounts receivable, contract assets, contract liabilities during the nine months ended September 30, 2024 were due to initial and subsequent measurement of contracts with customers, changes in business volume, and progress of existing contracts. Changes in operating assets and liabilities including accounts receivable, contract assets, and contract liabilities between the nine months ended September 30, 2024 and September 30, 2023 were $(12,064,807), $13,153,931, and $(23,547,427), respectively. The increase in the source of cash of $5,877,602 was primarily attributable to the increase in revenues, favorable timing of cash payments to vendors and positive net income from RMS since the acquisition date on February 16, 2024.
Net cash provided by operating activities was $20,326,561 in the year ended December 31, 2023 compared to ($5,892,750) in the year ended December 31, 2022. The changes in accounts receivable, contract assets, contract liabilities during 2023 were due to initial and subsequent measurement of contracts with customers, changes in business volume, and progress of existing contracts. Changes in operating assets and liabilities including accounts receivable, contract assets, and contract liabilities between the year ended December 31, 2023 and December 31, 2022 were $18,706,182, $(14,743,542), and $11,357,534, respectively. The increase in the source of cash of $26,219,311 was primarily attributable to the increase in revenues and related timing of cash receipts. We actively manage our accounts receivable, contract assets, and contract liabilities, along with the related aging and collection efforts.
Investing Activities
Net cash used in investing activities totaled $41,973,894 for the nine months ended September 30, 2024 and $4,142,280 for the nine months ended September 30, 2023. For the nine months ended September 30, 2024, total purchases of property and equipment of $11,139,017 was added to the $30,834,877 cash paid to acquire RMS, net of cash acquired. For the nine months ended September 30, 2023, property and equipment purchases of $4,705,740 were partially offset by sales of marketable securities of $563,460. The change of $37,831,614 was principally attributable to acquisition costs in 2024. No material commitments for capital expenditures exist.
Net cash used in investing activities totaled $16,211,837 for the year ended December 31, 2023 and $21,258,081 for the year ended December 31, 2022. For the year ended December 31, 2023, total purchases of property and equipment of $16,775,297 was partially offset by the sale of marketable securities of $563,460. For the year ended December 31, 2022, property and equipment purchases of $21,268,504 were partially offset by sales of marketable securities of $10,423. The change of $5,046,244 was principally attributable to decrease in purchases of property and equipment. No material commitments for capital expenditures exist.
Financing Activities
Net cash provided by financing activities in the nine months ended September 30, 2024 totaled $25,103,395. For the nine months ended September 30, 2024, we increased our term note agreement by $35,000,000 which is
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