Surveillance and security technology supplier Quadnetics Group has acquired battlefield technology specialist Persides Technology for £260,000. The acquisition of Persides, an existing partner to Quadnetics' defence business, is expected to enable the group to retain greater margins on sales of its radio frequency detection system Chili.Open cast coal miner Atlantic Coal has placed 75m new ordinary shares with the Blackrock UK Smaller Companies Fund at a price of 0.4p per share. The newly issued shares represent 3.77% of the enlarged issued share capital of Atlantic Coal. The company believes the share placing lifts Blackrock's stake in Atlantic Coal to about 7.24%.As part of the placing, one warrant to subscribe for a new ordinary share is being issued to Blackrock for every new share subscribed for. The Warrants are exercisable at 0.65p per new ordinary share for a period of two years from the date of admission of the placing shares to trading on AIM.Corporate finance specialist Westhouse saw its shares stumble at the start of 2011 after the company announced the acquisition of Smith's Holdings Limited, the independent corporate broking and investor relations services provider, for £0.74m, paid for in a mixture of shares and cash. The cash element of the consideration is £135,000. In the consolidated accounts for the 12 months to 31 March 2010, Smith's Holdings reported a turnover of £715,277 and loss for the year of £67,741. Net assets of Smith's Holdings as at 31 March 2010 were £550,389.