Wettability of anisotropic and porous particles adsorbed to fluid interfaces

The wettability of particles and the way they attach to liquid interfaces is important for many technologies where powders are mixed with liquids or used as emulsifiers. Most such powders are highly agglomerated into larger aggregates that are highly porous. The attachment of such porous particles to liquid–fluid interfaces has not been studied in detail, especially in cases where the porous particles are impregnated with another fluid phase. The overall aim of the thesis is to study the behaviour of particles at the liquid–fluid interface with an emphasis on non– spherical and porous solid particles. We study the orientation of anisotropic microparticles and measure the contact angle of smooth and porous microparticles with the gel–trapping technique (GTT) to find the wettability of microparticles adsorbed in fluid interfaces. This technique allows us to obtain micrographs by scanning electron microscopy (SEM) for particles resting on polydimethylsiloxane (PDMS), which replicates the non–polar phase and allows for measuring the particle contact angle. We show the results of the typical attachment and orientation of needle–like (aragonite), rhombohedra–like (calcite) microcrystals and ethyl cellulose micro–rods, as well as highly porous hydrophilic and hydrophobic silica microparticles at these liquid interfaces. The importance of these results is in gaining an understanding of the adsorption behaviour and demonstrating actual information on anisotropic particles which have potential applications in industrial formulations and products. We also investigate how carboxylate modified latex (CML) microparticles adsorb at liquid surfaces and the preferred type of emulsion they can stabilise depending on the particle size and the surface density of carboxylic groups. We also study, both theoretically and experimentally, the effect of salt in the aqueous phase on the contact angle of such microparticles. The main finding is that the wettability of CML microparticles is governed by the carboxylic group density on the particle surface rather than their ionisation. We demonstrate that the type of Pickering emulsions is governed by the wettability of microparticles at the oil–water interface. We study the effect of the initial impregnation of porous particles with polar or non–polar phases on their attachment at liquid interfaces both theoretically and experimentally. Model supra–particles have been prepared by using building blocks of smaller colloid particles packed in a spherical aggregate. The particles were produced by drying latex particle suspensions of various particle volume fractions and concentrations, followed by partial fusion of the particles achieved by thermal annealing. We have studied the particle surface morphology and porosity and showed how the annealing temperature, the initial particle volume fraction of sulphate latex suspension and the evaporation temperature can be used to control the supra–particle final structure and porosity. Furthermore, we have investigated the link between the wettability of the porous supra–particle building blocks, i.e. sulphate latex particles, and the macroscopic (apparent) contact angle of the porous supra–particle when attached to liquid surfaces. The contact angles of porous supra–particles infused with water at the oil–water interface were found to be much bigger than those at the air–water interface as expected. We also show how the type of liquid filling the pores of the supra–particle affects its macroscopic contact angle at the oil–water interface

Design of digital electricity meter

Common Electricity meters, which are currently used in houses, shops and some factories are bulky expensive and inaccurate. Such features are incompatible with modern technological trends of miniaturization accuracy and neat devices. This project presents the design and the model of a low cost digital energy meter to overcome the short comings of the present meters. It is anticipated that a new neat design based on integrated circuit technology employing digital measurement techniques will have a great impact on electricity meters locally and worldwide. With a data storage capability and some form of processing, it can provide the consumers with vital information on the trend of their energy consumption. Such information will assist them in rationalizing their consumption. Intelligent energy meters may be seen as most suitable and efficient way to facilitate easy solutions to the problem of rational consumption

Spectroscopic Study of some Schiff Bases Derived from Dibenzoylmethane

A series of Schiff bases 7-11 derived from dibenzoylmethane have been prepared. The UV, IR, 1H NMR and mass spectra revealed theses compounds were existed mainly as the keto-enamine tautomer in the solution. The absorption bands which appeared in the range λmax = 376-406 nm were assigned to the electronic transitions which arised from the central hydrogen bonded chelated unsaturated ring system in this tautomer. The appearance of the broad singlet near d  = 13 ppm due to the N-H proton and a singlet near d  = 6 ppm due to the –C=C-H proton inaddition to benzoyl fragment ion     signal m/z =105 in the mass spectra supported the above suggested products

The prevalence of physical activity and its socioeconomic correlates in Kingdom of Saudi Arabia: A cross-sectional population-based national survey

AbstractObjectivesTo determine the levels of physical activity in the Saudi population and to assess its socio-demographic correlates.MethodsThe data were part of a cross-sectional representative national survey of 4758 participants conducted in Kingdom of Saudi Arabia. A multistage stratified cluster random sampling design was used. Physical activity was assessed using the Global Physical Activity Questionnaire (GPAQ) version 2.0. Logistic regression analyses were used to identify the determinants and were adjusted in relation to various factors.ResultsOverall, physical inactivity was found to be 66.6% (95% C.I.: 65.3%–68%), 60.1% (95% C.I.: 58.1%–62.1%) for males and 72.9% (95% C.I.: 71.1%–74.7%) for females. Leisure time physical inactivity was found to be 87.9%, 85.6% for males and 90.2% for females. The northern and central regions reported the highest prevalence of no physical activity at work, leisure and transportation. Gender, geographical location and employment status exhibited a statistically significant correlation.ConclusionsThere is a high level of physical inactivity in various regions and population groups in the Kingdom of Saudi Arabia. Population interventions are greatly needed, especially those focusing on physical activity in their leisure time

Effect of Feeding Pellets Containing Different Concentrate to wheat Straw Ratios on the Rumen Fermentation Characteristics of Awassi Lambs

اجريت الدراسة في منطقة السياحي- محافظة بابل للتحري عن تأثير تغذية نسب مختلفة من العلف المركز الى تبن الحنطة على خصائص تخمرات الكرش. حضرت خمسة علائق خليطة كلية تضمن تركيبها 30:70 و40:60 و 50:50 و 60:40 و 70:30 من العلف المركز الى تبن الحنطة كبست بصورة مكعبات وقدمت بصورة حرة الى الحملان العواسية. اظهرت النتائج ان زيادة نسبة العلف المركز الى الخشن قد ارتبطت بانخفاض معنوي (P<0.01) في الاس الهيدروجيني في سائل الكرش وسجلت اقل القيم,  6.60و 6.50 و 6.53 في النماذج المسحوبة من مجموعة الحملان المغذاة على المكعبات الحاوية على العلف المركز الى التبن بنسبة 50:50 و 60:40 و 70:30 على التوالي. كما تميزت تلك النماذج باقل (P<0.01) تركيز نيتروجين الامونيا,  4.85و 4.45 و 4.35 ملغم/100  مل, وأعلى (P<0.01) تركيز للأحماض الدهنية الطيارة الكلية.This study was carried out in Alsiyahii area– Babylon Province to investigate the effect of feeding Awassi lambs different ratios of concentrate: wheat straw (C: R) on rumen fermentation characteristics. Five pellets of total mixed rations (TMR) containing 30:70, 40:60, 50:50, 60:40 and 70:30 of C: R ratios were prepared and offered to lambs ad libitum. Results revealed that increasing C: R ratio was associated with a significant (P<0.01) reduction in pH, lower values of 6.60, 6.50 and 6.53 were recorded in samples of rumen liquor collected from lambs fed pellets containing C: R ratios of 50:50, 60:40 and 70:30, respectively. Those samples were also characterized with lower (P<0.01) concentration of ammonia nitrogen, 4.85, 4.45 and 4.38 mg/100 ml, and higher (P<0.01) concentration of total volatile fatty acids.&nbsp

Effect of Feeding Pellets Containing Different Concentrate to Wheat Straw Ratios on the Blood Parameters of Awassi Lambs

اجريت الدراسة للتحري عن تأثير تغذية الحملان العواسية على نسب مختلفة من العلف المركز الى تبن الحنطة على معايير الدم. حضرت مكعبات خمسة علائق خليطة كلية تضمن تركيبها 30:70 و40:60 و 50:50 و 60:40 و 70:30 من العلف المركز الى تبن الحنطة وقدمت بصورة حرة الى الحملان. اظهرت النتائج ان زيادة نسبة العلف المركز الى الخشن ادت الى حصول زيادة معنوية ((P<0.01 في تركيز الكلوكوز وسجلت اعلى القيم, 75.38 و 75.59 ملغم/100 مل في نماذج الدم المسحوبة من الحملان المغذاة على المكعبات الحاوية على العلف المركز الى التبن بنسبة 40:60 و 30:70 على التوالي. كما تميزت تلك النماذج بأعلى ((P<0.01 تركيز للبروتين الكلي والكليسريدات الثلاثية في الدم. اما تركيز نيتروجين اليوريا فقد سجلت اعلى ((P<0.01 القيم, 44.15 و 42.68 و 44.98 ملغم/100 مل في نماذج الدم المسحوبة من الحملان المغذاة على المكعبات الحاوية على العلف المركز الى التبن بنسبة 50:50 و 40:60 و 30:70 على التوالي.This study was carried out to investigate the effect of feeding Awassi lambs different ratios of concentrate: wheat straw (C: R) on blood parameters. Five pellets of total mixed rations (TMR) containing 30:70, 40:60, 50:50, 60:40 and 70:30 of C: R ratios were prepared and offered to lambs ad libitum. The results showed that increasing the C: R ratio significantly (P<0.01) increased the blood glucose. Higher concentration, 75.38 and 75.59 mg/100 ml were recorded in blood samples withdrawn from lambs fed on pellets containing 60:40 and 70:30 of C: R ratios respectively. similarly, those blood samples were characterized with higher (P<0.01) concentrations of total protein and triglycerides. With regard to urea nitrogen, higher (P<0.01) concentration, 44.15, 42.68 and 44.98 mg/100 ml were detected in blood samples withdrawn from lambs fed pellets containing 50:50, 60:40 and 70:30, respectively

Esomeprazole as a prophylactic agent for acid aspiration syndrome in adult patients undergoing elective surgery: A triple blind placebo controlled clinical trial

Background: To explore the effect of single oral dose of esomeprazole 20 mg, administered a night before surgery, on intragastric pH and volume in adult patients undergoing elective surgery by excluding cases contaminated with duodenogastric refluxate.Patients and Methods: This prospective, triple blind, randomised and placebo controlled clinical trial was conducted to explore the effect of single oral dose of esomeprazole 20 mg, administered a night before surgery, on intragastric pH and volume on 120 adult inpatients of either sex, American Society of Anaesthesiologist physical status I-II, and aged 15–70 years. The patients in Group C (control) received placebo while Group E (Esomeprazole) received esomeprazole orally at 9.00 pm, the night before elective surgery.On the day of surgery, the gastric contents were aspirated with a large bore, multi-orifice gastric tube passed through an endotracheal tube placed blindly in the oesophagus after tracheal intubation and analysed for pH, volume and the presence of bile salts.Results: Thirty nine samples (33%) out of 117 were contaminated with duodenal contents. Duodenogastric reflux significantly affected pH and volume in Group C (p value 0.0003 and 0.0016) and E (p value 0.0401 and < 0.0001). Esomeprazole, after excluding samples contaminated with duodenal fluid, significantly increased pH (p 25 ml/kg) at the time of induction of anaesthesia excluding samples contaminated with duodenogastric reflux

Education: the quest for the lost wisdom in the maze of knowledge

A novel method to assess the complex Education process has been devised. The technique involves the quantification of Learning Outcome, which has hitherto been largely subjective and cumbersome despite the technological advance in learning and teaching aids. The new technique presents an objective assessment in a mathematical form. The approach is an innovated Metric Suit based on a measure of Entropy related to learning outcome. The ‘Information’ entropy is computed and used as a measure of Knowledge. Another learning outcome is the proper application of relevant knowledge termed ‘Wisdom’. Wisdom can also be measured using entropy computations. In this sense, entropy is related to the factor of disorder. The various parameters are represented by random variables. Because the amount of the required computations is very large, only the most effective of variables will be considered. The results obtained so far are encouraging. However, more tests on the proposed Metric Suit from various areas of application will further ascertain its robustness. Comprehensive tests and thorough analyses will provide a strong basis for evaluation judgment. The model treats the education process as a communications channel. The transfer of information between the sender and the recipient depends on the amount of uncertainty presented by each of the components that constitute the system. The computations of “Entropy” involve all the programs that constitute a discipline at university level

Intelligent Dynamic Traffic Light Sequence Using RFID

The proposed RFID traffic control avoids problems that usually arise with standard traffic control systems, especially those related to image processing and beam interruption techniques. This RFID technique deals with a multi-vehicle, multilane, multi road junction area. It provides an efficient time management scheme, in which a dynamic time schedule is worked out in real time for the passage of each traffic column. The real time operation of the system emulates the judgment of a traffic policeman on duty. The number of vehicles in each column and the routing are proprieties, upon which the calculations and the judgments are based

Ubiquitous RFID network for highway monitoring and management

A simplified approach for the implementation of ubiquitous RFID networks in a Highway Management System is presented. The technique aims at deploying tagging identification in transport statistical analysis. The RFID network architecture has been designed as part of an existing system to make it more cost effective with a higher reliability. The usefulness and the merits of this easy access and user friendly approach are identified and discussed