1 Across: Expression used to frighten animals away (4)
1 Down: A shoelace (N. Amer.) (10)

2 Down: Home Access Network (1,1,1)

3 Down: Unhealthy and compulsive preoccupations (10)

4 Across: "I'll ..., and I'll puff, and I'll blow your house in" (Three Little Pigs nursery rhyme) (4)

5 Down: Educational institution for higher learning (10)

6 Down: A person who establishes an institution (7)

7 Down: Famous Chinese tourist attraction, Great Wall ... (2,5)

8 Down: Odd bits of paper used for making notes (5,5)

9 Across: Abbreviation of Habakkuk (in biblical references) (3)

10 Down: (of a solid) forming a solution (10)

11 Across: SOHO, small office, home ... (6)

12 Down: Money-spinner for a charity (4)

13 Across: Japanese ornamental trees (6)

14 Across: Union Executive Committee (1,1,1)

15 Across: Saturday sabbath observer ... Adventist (7-3)

16 Across: Seeks answers to (4)

17 Down: Gear consisting of a set of tools for a specified purpose (3)

18 Across: Data Exchange Interface (1,1,1)

19 Across: It is (literary) ('3)

20 Across: Girl's name, a rearrangement of "are" (3)

21 Across: Objects (8)

22 Down: English cricketer, Cecil "..." Parkin (3)

23 Across: US president and actor, Ronald ... (6)

24 Down: Bosses (9)

25 Across: Open Eye Visuals (1,1,1)

26 Across: Pronounce clearly (9)

27 Across: Scamper (6)
27 Down: Make felt-like (4)

28 Down: Crowded, no ... swing a cat (4,2)

29 Down: Nevertheless (3)

30 Down: Deep pulsating pain (5)

31 Down: Approached without being detected, ... up on (5)

32 Across: Beyond Earth Orbit (1,1,1)
32 Down: Glee (5)

33 Across: Thus (5)

34 Down: Otherwise, or ... (4)

35 Across: Male goat (5,4)
35 Down: Navigational float (4)

36 Across: A suffix of "composite" (3)

37 Across: Events (9)

38 Across: Tie something again (5)

39 Across: Send a text message to a mobile phone (3)