Predictors of aggressive behavior in children with autism spectrum disorder

Introduction: Aggressive behaviour is not the main symptom of autism spectrum disorders, and if it occurs in this population, it is a consequence of some other factors. Objectives: With regard to that, the aim of this paper isto determine to what extent certain aspects of executive functions, severity of autism, sleep habits, and parenting actions contribute to the manifestation of different forms of aggressive behaviourin children with an autism spectrum disorder. Methods: The sample included 40 children with autism spectrum disorders, 5-7 years of age (M=6.18, SD= .55). The following instruments were used in the assessment: The Children's Scale of Hostility andAggression –Reactive/Proactive, Gilliam Autism Rating Scale –Third Edition, The Children's Sleep Habits Questionnaire andBehaviorRating Inventory of Executive Function. Results: The obtained results showed that sleep problems were the most significant predictor of verbal, physical and covert aggression. From the domain of behavioural aspects of executive functions, only task monitor was a significant predictor of bullying, and inhibit and shift were significant predictors of hostility. From the field of autistic disorders, significant predictors of aggressive behaviour were emotional responses (as predictors of bullying, covert aggression and hostility), and maladaptive speech (as a predictor of verbal aggression, covert aggression and hostility). Punitive discipline was a significant factor only in explaining verbal aggression. Conclusion: Practical implications of this research indicate that, in treating aggressive behaviour in children with ASD, more attention should be paid to sleep habits, practising task monitor, inhibit and shift skills, and avoiding rigorous punitive measures

Modification of existing turboshaft engine in order to operate on synthetic gas

Sintetički gas je danas ko-proizvod procesa kao što su gasifikacija otpada i prerade biomase, uglja i drugih potencijalnih goriva. Iako sastav sintetičkog gasa zavisi od prethodnih procesa, generalno se sastoji od mešavine vodonika, ugljen-monoksida i metana u različitim odnosima. Ideja da se sintetički gas dobijen preradom otpada koristi kao gorivo za turbo-generator je veoma privlačna, ali i vrlo zahtevna. U ovom radu je prezentovana modifikacija postojećeg turbo-vratilnog motora da bi mogao da koristi sintetički gas kao gorivo. Pored problema kao što su mala toplotna moć, drugačiji stehiometrijski odnos u poređenju sa kerozinom i visok procenat vodonika, inženjerski zadatak je bio da se problem reši sa minimalnim brojem izmena. Problem je rešen modifikaciojom postojećih vazdušnih raspršivača i verifikovan je eksperimentalno.Synthetic gas is nowadays the co-product of procceses such as waste gasification and processing biomass, coal and other potentional fuels. Although its composition depends on previous process, synthetic gas is generally mixture of hydrogen, carbon-monoxide and methane in different ratios. The idea to use gases from waste as a fuel for gas-turbine generator producing electric energy is very attractive but also challenging. In this paper is presented modification of an existing turbo-shaft engine in order to be capable to operate with synthetic gas. Together with problems such as low heating value of the gas, different stochiometric ratio of gas and air compared to kerosene/air combination and high hydrogen contents, the engineering task was to do it with minimum number of changes. Problem is solved by adjusting existing airblast atomizers and experimentally verified

Predictors of Aggressive Behaviour in Children with Autism Spectrum Disorder

Introduction: Aggressive behaviour is not the main symptom of autism spectrum disorders, and if it occurs in this population, it is a consequence of some other factors. Objectives: With regard to that, the aim of this paper is to determine to what extent certain aspects of executive functions, severity of autism, sleep habits, and parenting actions contribute to the manifestation of different forms of aggressive behaviour in children with an autism spectrum disorder. Methods: The sample included 40 children with autism spectrum disorders, 5-7 years of age (M=6.18, SD= .55). The following instruments were used in the assessment: The Children’s Scale of Hostility and Aggression – Reactive/Proactive, Gilliam Autism Rating Scale – Third Edition, The Children’s Sleep Habits Questionnaire and Behavior Rating Inventory of Executive Function. Results: The obtained results showed that sleep problems were the most significant predictor of verbal, physical and covert aggression. From the domain of behavioural aspects of executive functions, only task monitor was a significant predictor of bullying, and inhibit and shift were significant predictors of hostility. From the field of autistic disorders, significant predictors of aggressive behaviour were emotional responses (as predictors of bullying, covert aggression and hostility), and maladaptive speech (as a predictor of verbal aggression, covert aggression and hostility). Punitive discipline was a significant factor only in explaining verbal aggression. Conclusion: Practical implications of this research indicate that, in treating aggressive behaviour in children with ASD, more attention should be paid to sleep habits, practising task monitor, inhibit and shift skills, and avoiding rigorous punitive measures

Contribution to research of spoiler and dome deflector TVC systems in rocket propulsion

Ustrojen je fizički model spojlera i kupolastog deflektora u sustavu upravljanja vektorom potiska (UVP) razmatrajući zaključke prethodnih i sadašnjih ispitivanja. Prema logici fizičkog modela razvijen je matematički model. Algoritam modela i rezultati su analizirani i objašnjeni. Konačno, rezultati modela su potvrđeni testovima realnog motora.Physical model of spoiler and dome deflector thrust vector control (TVC) system was established considering previous and current research observations. According to logic of physical model an engineering mathematical model is derived. Model algorithm and results were analysed and explained. Finally, model data were confirmed with real motor tests

Modification of existing turboshaft engine in order to operate on synthetic gas

Sintetički gas je danas ko-proizvod procesa kao što su gasifikacija otpada i prerade biomase, uglja i drugih potencijalnih goriva. Iako sastav sintetičkog gasa zavisi od prethodnih procesa, generalno se sastoji od mešavine vodonika, ugljen-monoksida i metana u različitim odnosima. Ideja da se sintetički gas dobijen preradom otpada koristi kao gorivo za turbo-generator je veoma privlačna, ali i vrlo zahtevna. U ovom radu je prezentovana modifikacija postojećeg turbo-vratilnog motora da bi mogao da koristi sintetički gas kao gorivo. Pored problema kao što su mala toplotna moć, drugačiji stehiometrijski odnos u poređenju sa kerozinom i visok procenat vodonika, inženjerski zadatak je bio da se problem reši sa minimalnim brojem izmena. Problem je rešen modifikaciojom postojećih vazdušnih raspršivača i verifikovan je eksperimentalno.Synthetic gas is nowadays the co-product of procceses such as waste gasification and processing biomass, coal and other potentional fuels. Although its composition depends on previous process, synthetic gas is generally mixture of hydrogen, carbon-monoxide and methane in different ratios. The idea to use gases from waste as a fuel for gas-turbine generator producing electric energy is very attractive but also challenging. In this paper is presented modification of an existing turbo-shaft engine in order to be capable to operate with synthetic gas. Together with problems such as low heating value of the gas, different stochiometric ratio of gas and air compared to kerosene/air combination and high hydrogen contents, the engineering task was to do it with minimum number of changes. Problem is solved by adjusting existing airblast atomizers and experimentally verified

A novel 6 DOF thrust vector control test stand

U ovom radu se predlaže inovativnu konstrukciju ispitnog stola za precizno mjerenje vektora potiska raketnog motora tijekom njegovog rada. Jasno je izložena konstrukcija ispitnog stola kao i procedure te matematički model za kalibraciju ispitnog stola. Metoda obrade podataka dobivenih ispitivanjem kao i rezultati ispitivanja "jet tab" sustava za upravljanje vektorom potiska detaljno su prezentirani. Eksperimenti su pokazali da je ispitni stol iznimno funkcionalan, a da dobineni rezultati imaju odličnu ponovljivost i poklapanje s rezultatima autora koji su koristili ispitne stolove drugačije konstrukcije za mjerenje istog ili sličnog mehanizma za upravljanje vektorom potiska.This study proposes an innovative test stand design to accurately measure rocket motor thrust vector during its operation. Test stand design is clearly presented as well as procedure and mathematical model for its calibration. A method of processing data obtained from the experiments and the results of the jet tab system for thrust vector control are presented in detail. Experiments have shown that the test stand is highly functional and the results obtained have excellent repeatability and matching with the results of the other authors who have used different construction test stands for measurement of the same or a similar mechanism for thrust vector control

Study of innovative subsonic ramjet

Subsonic ramjets, due to its simplicity, nowadays could be very attractive for expendable unmanned applications. However, due to very low efficiency at low Mach numbers, practically there isn’t any important application at subsonic speed. In 50’s subsonic ramjet was used for tip jet applications. Later in 70’s there was a study of Fan Augmented Ramjet (FARJ) where a fan was in-tended to be powered by a piston engine, both in subsonic and supersonic regimes. Almost at the same time it was analyzed ejector augmented subsonic ramjet. Both of these studies did not find real application of such engines. Finally, there was an attempt for the use of an Electric Ducted Fan, used in RC models, with a combustor but exit fan pressure was almost at atmospheric pressure which results in very low efficiency. This paper presents a study of propulsion system which consists of a pitot intake, electrically powered compressor/fan, combustor and nozzle (Electrically Fan Augmented Ram Jet, EFARJ). The electric motor connection to the compressor/fan is direct, without gearbox, which implies usage of a high-speed brushless motor. Such propulsion system is compared to pure ramjet and finally it is compared to performances of small expendable turbojet. Comparison is made regarding costs, weight and thrust/consumption. The study shows that the proposed propulsion system could be competitive for expendable, low speed and short duration applications