Wool fibres for the sorption of volatile organic compounds (VOCs) from indoor air

This thesis reports the investigations of sheep wool’s ability to sorb volatile and very volatile organic compounds (v/VOCs). Indoor air quality and occupants health can be adversely affected by the presence of even low gaseous concentrations of v/VOCs. Sheep wool’s fibres, with their keratinous chemical functionalities, provide platforms for sorption of the said compounds. Wools from different breeds of sheep are studied with regards to the sorption of four volatile organic compounds in their gaseous state, which represents a wide range of polarity and basic chemical diversity: formaldehyde, toluene, limonene and dodecane. A gas-tight set-up was constructed and analytical techniques were optimised. It was found that there is variation between the different wool types in addition to difference between scoured and unscoured wools. Total sorption capacity of formaldehyde is also examined, with variations opposing the trend seen for the sorption of the more non-polar VOCs at low concentrations. Sorption patterns were studied with respect to increasing concentrations. Characteristics of the different wool types are reported and linked to the observed sorption behaviour. Moisture uptake is studied across different wool types and the use of the Vrentas-Vrentas mathematical model is discussed. The mean cluster size of water molecules in the wool fibres is compared. The sorption kinetic behaviour of the wool fibres is analysed using the Parallel Exponential Kinetic model, and the sorption parameters were used to calculate the modulus of the wool fibres. Chemical and mechanical modifications along with the use of additives are studied to enhance wool’s sorption ability. Adding polar functionalities onto the fibres’ surface hinders total sorption capacity of formaldehyde and the sorption of all four v/VOCs at low concentrations. Adding a large non-polar functionality also hinders total sorption capacity of formaldehyde, but increases the sorption at low concentrations of non-polar compounds without reducing the sorption of polar formaldehyde. Ball milling increases surface area and the sorption of all four compounds at low concentrations. Carbon fibre as an additive excels at the sorption of non-polar compounds, whereas a coating of chitosan increases the total sorption capacity of formaldehyde without effecting the sorption patterns of any of the v/VOCs at low concentrations. The effect of the modifications on other fibre properties is also reported

Dynamic Optimized Bandwidth Management for Teleoperation of Collaborative Robots

A real-time dynamic and optimized bandwidth management algorithm is proposed and used in teleoperated collaborative swarms of robots. This method is effective in complex teleoperation tasks, where several robots rather than one are utilized and where an extensive amount of exchanged information between operators and robots is inevitable. The importance of the proposed algorithm is that it accounts for Interesting Events (IEs) occurring in the system\u27s environment and for the change in the Quality of Collaboration (QoC) of the swarm of robots in order to allocate communication bandwidth in an optimized manner. A general dynamic optimized bandwidth management system for teleoperation of collaborative robots is formulated in this paper. The suggested algorithm is evaluated against two static algorithms applied to a swarm of two humanoid robots. The results demonstrate the advantages of dynamic optimization algorithm in terms of task and network performance. The developed algorithm outperforms two static bandwidth management algorithms, against which it was tested, for all performance parameters in 80% of the performed trials. Accordingly, it was demonstrated that the proposed dynamic bandwidth optimization and allocation algorithm forms the basis of a framework for algorithms applied to real-time highly complex systems

Uncommon Variant of Wellens’ Syndrome: A Case Report and Review of Literature

A 48-year-old male was admitted to the emergency department because of intermittent chest pain of 2 days duration. At the time of examination, he was pain-free. An electrocardiogram (ECG) showed biphasic T waves in leads V2 to V6. Troponin-I level was negative. During his transfer to the cardiac catheterization laboratory, he had a short episode of chest pain. His ECG was normal. Despite the unusual extension of biphasic T waves to the lateral precordial leads, the condition was recognized as Wellens’ syndrome, which typically associates biphasic or deep symmetric T wave inversion in leads V2 and V3 during pain-free periods with a critical stenosis in the proximal left anterior descending artery. The syndrome is uncommon to medical practice but should be recognized immediately in the emergency department because it represents a pre-infarction stage and carries a high risk of mortality.

Icatibant, An Inhibitor Of Bradykinin Receptor 2, For Hereditary Angioedema Attacks: Prospective Experimental Single-cohort Study.

Hereditary angioedema (HAE) with C1 inhibitor deficiency manifests as recurrent episodes of edema involving the skin, upper respiratory tract and gastrointestinal tract. It can be lethal due to asphyxia. The aim here was to evaluate the response to therapy for these attacks using icatibant, an inhibitor of the bradykinin receptor, which was recently introduced into Brazil. Prospective experimental single-cohort study on the efficacy and safety of icatibant for HAE patients. Patients with a confirmed HAE diagnosis were enrolled according to symptoms and regardless of the time since onset of the attack. Icatibant was administered in accordance with the protocol that has been approved in Brazil. Symptom severity was assessed continuously and adverse events were monitored. 24 attacks in 20 HAE patients were treated (female/male 19:1; 19-55 years; median 29 years of age). The symptoms were: subcutaneous edema (22/24); abdominal pain (15/24) and upper airway obstruction (10/24). The time taken until onset of relief was: 5-10 minutes (5/24; 20.8%); 10-20 (5/24; 20.8%); 20-30 (8/24; 33.4%); 30-60 (5/24; 20.8%); and 2 hours (1/24; 4.3%). The time taken for complete resolution of symptoms ranged from 4.3 to 33.4 hours. Adverse effects were only reported at injection sites. Mild to moderate erythema and/or feelings of burning were reported by 15/24 patients, itching by 3 and no adverse effects in 6. HAE type I patients who received icatibant responded promptly; most achieved improved symptom severity within 30 minutes. Local adverse events occurred in 75% of the patients.132261-