Sound propagation in viscous flows using piezoelectric sensors and non-destructive propagation techniques and its applications

Structural non-destructive evaluation techniques are applied to viscous flows to detect fluid property changes. The main operating principle consists of an actuator which provides a stimulus, and a sensor to receive a signal traveling to a fluid domain. The main challenge of the operating principle consists of investigating waves traveling in a viscous flow. Traveling waves utilizing a piezoelectric actuator-sensor pair are modeled and the results are validated experimentally. ANSYS models, coupled with a two-way fluid-solid interaction model, are built to investigate how far a signal travels and what frequency ranges are of interest. The numerical model includes modeling three different geometries (square, circular, triangular) for the actuator-sensor pair manufactured with three different piezoelectric materials (PZT4, PZT5A, PMN32). Numerical work is validated with experimental work using a pair of circular actuator-sensors manufactured with PZT5A and immersed in a large container of water and glycerin. Furthermore, in order to establish mesh independence of the results, three mesh refinement levels (coarse, medium and fine) were utilized with different materials, geometries and fluid viscosity values. The actuator receives a 0.5 VAC signal ranging from 100 Hz to 40 MHz. The sensor records the signal at varying distances from the actuator, and the result is labeled as the gain or the ratio of received to send wave magnitude. The pattern of decay for both numerical and experimental results are in close agreement (the numerical decay are 10.825 and 11.4 for water and glycerin, respectively, while the experimental are 11.254 and 14.48 for water and glycerin, respectively). Numerically, the results show that the maximum acoustic pressure can be obtained by using a square piezoelectric actuator- sensor pair fabricated with PMN32. Numerically, the results show that the maximum acoustic pressure can be obtained by using a square piezoelectric actuator- sensor pair fabricated with PMN32. A viscosity probe for medical applications is developed using a piezoelectric actuator-sensor pair. The design constraints were size and cost. The actuator-sensor pair is manufactured with PZT5A with a rectangular shape to fit a 3 mL vacutainer. The actuator is excited by 0.5 VAC sinusoidal waves with varying frequencies ranging from 100Hz to 40 MHz. The sensor will detect the produced wave in the fluid. Also, the phase shift is recorded for different concentrations of glycerin and water to simulate different viscosities ranging from 1 to 1600 cP. The numerical analysis, a modal analysis, of the probe was performed and the results showed that the first, second and third modes of the device were in the range of 684–2358 Hz for air, 500–1080 Hz for water, and 469–625 Hz for glycerin. From the harmonic acoustic analysis, the results showed that the highest phase shifts, and maximum gain, occurs at the ultrasonic frequency range, 6 to 9 MHz. Hence, there is no relation between the natural frequencies of the probe and the ultrasonic frequency for the phase shift. Most importantly, a correlation between the phase shift and viscosity is found, making the probe a feasible device for measuring viscosity in an inexpensive, small, and disposable way

The general Common positive solutions for adjointable Bounded operator equations

The aim of this work, given the general common positive solutions of some types of adjointable boundedoperator equations define on complex Hilbert space, also introduce the general common positive solutionsfor system of operator equations upon some necessary and sufficient conditions for existence these solutionsvia g-inverse operator.Keywords: key words, positive solution, common positive solution

Remodelling façade design for improving daylighting and the thermal environment in Abuja’s low-income housing

The housing typologies that were developed as part of Abuja’s master plan over 30 years ago are still in use today as prototypes for low-income housing developments. The value of the local climate received only cursory consideration in the early developments; as the process was mainly focused on the delivery of units needed to accommodate those involved in the construction of the city. More detailed records of the climate have become available since the mid-1990s. Yet, despite the availability of such data and the global interest in eco-friendly architecture, energy use per household has increased in Abuja over the last two decades. Nigeria is already struggling to meet its current energy demands; therefore, it is important to examine whether improvements made to future housing design can assist in reducing their energy use. This paper evaluates the performance of four of Abuja’s common housing types and examines the impact of changing their fenestration design on occupants’ comfort, using validated simulation. Assessing the performance of the buildings in their existing state revealed clear overheating problems and excessive natural lighting. However, the investigation indicated a 4-6% reduction in the frequency of thermal discomfort and a 4-29% reduction in visual discomfort by adjusting the orientation of the facades. Integrating external shading components can also reduce thermal and visual discomfort by up to 4% and 29%, respectively

Availability and Utilization of E-Learning Technologies in Teaching Agricultural Science in Senior Schools in Ilorin South L.G.A, Kwara State

E-learning technologies are necessary to meet the challenges of the contemporary world education competitiveness in scientific and technological advancement. This study investigated the Availability and utilization of e-learning technologies in teaching agricultural science in senior schools in Ilorin South L.G.A, Kwara State. 60 Agricultural science teachers participated in the study. A researcher-developed forty-five-items questionnaire was used to collect data. Four research questions and two research hypotheses guided the conduct of the study. Data were analyzed using frequency, mean, standard deviation and t-test. Results show that some of the listed e-learning technologies were available for teaching agricultural science in senior schools to a high extent. Some of these include printers, tablets and laptop computers while some like public address system, projectors, interactive whiteboards among others are not available. Results also, revealed that agricultural science teachers use e-learning technologies to a moderate extent. The benefits of e-learning technologies as revealed by the study include for effective classroom management, makes teaching interesting and encourages individual learning among others. Challenges include: lack of functional computer laboratories, inadequate finance, irregular power supply, high cost of e-learning facilities among others. The researchers recommended (among others) that ICT training should be made compulsory for teachers and it should be subsidized by governments, government should incorporate e-learning education into school syllabus, there should be an alternative source of power supply in E-learning libraries in schools. DOI: 10.7176/JEP/12-16-01 Publication date:June 30th 202

Batch and flow injection spectrophotometric methods for determination of Ceftazidime in pharmaceutical formulations

  تم وصف تقنيتين طيفيتين لقياس كمية السيفتازيديم (CFT) في الأدوية والتركيبات الصيدلانية.  فهي بسيطة وحساسة وانتقائية ودقيقة وفعالة.  يستخدم الأسلوب الأول وسيطًا قلويًا لتحويل السيفتازيديم إلى ملح الديازونيوم ، والذي يتم دمجه بعد ذلك مع كواشف1-Naphthol (1-NPT) و2)2-Naphthol-NPT).  تم إنتاج صبغة الآزو باللونين البني والأحمر ، مع كثافة امتصاص تصل إلى ƛmax 585nm and max 545nm ، على التوالي.  تم اتباع قانون بير من حيث مدى التركيز (3-40) لـ (CFT-1-NPT) و (CFT-2 NPT) ، كانت حدود الكشف 1.0096 and 0.8017 g.ml-1على التوالي ، وكانت الامتصاصية المولية  0.7926×104 and 0.5466×104 L.mol1cm-1. 0تُستخدم طريقة تحليل حقن التدفق (FIA) لتقدير السيفتازيديم وتسجيل القياسات باستخدام نهج الأشعة فوق البنفسجية المرئية في الإجراء الثاني.  يسمح حقن التدفق بتقدير دقيق للعقار في ظل ظروف تجريبية مثالية.  كانت التركيزات في نطاق(3-50)  لـ (CFT-1-NPT) و (CFT-2-NPT) ، وكانت حدود الكشف0.8102, 1.2809g.ml-1 . ، والامتصاصية المولية 0.9565×104  ,0.7106×104 L.mol-1. cm-1, على التوالي تم استخدام الأسلوبين المقترحين لتقدير السيفتازيديم في المستحضرات الصيدلانية بنجاح حيث تميزت هذه الطريقة بالبساطة والسرعة والدقة والتكلفة المنخفضة.It is generally accepted that there are two spectrophotometric techniques for quantifying ceftazidime (CFT) in bulk medications and pharmaceutical formulations.  The methods  are described as simple, sensitive, selective, accurate and efficient techniques. The first method used an alkaline medium to convert ceftazidime to its diazonium salt, which is then combined with the 1-Naphthol (1-NPT) and 2-Naphthol (2-NPT) reagents. The azo dye that was produced brown  and red in color with absorption intensities of ƛmax 585 and 545nm respectively. Beer's law was followed in terms of concentration ranging from  (3-40) µg .ml-1 For (CFT-1-NPT) and (CFT-2-NPT), the detection limits were 1.0096 and 0.8017 µg.ml-1, respectively, and the molar absorptivity was 0.7926×104 and 0.5466×104 L.mol-1.cm-1. The Flow Injection Analysis (FIA) method is used to estimate ceftazidime and in the second procedure record measurements using the UV-Visible approach. The Flow injection allows for exact drug estimation under ideal experimental conditions. The concentrations were in the range of (3-50) µg .ml-1 For (CFT-1-NPT) and (CFT-2-NPT), the detection limits were 0.8102, 1. 2809µg.ml-1, and the molar absorptivity was 0.9565×104 ,0.7106×104 L.mol-1.cm-1, respectively. The proposed two methods for determination Ceftazidime in Pharmaceutical formulation were successfully applied, as these methods were characterized by simplicity, speed, accuracy, and low cost

Corrosion Protection Study of Carbon Steel and 316 Stainless Steel Alloys Coated by Nanoparticles

The Corrosion protection effectiveness of Alimina(Al2O3,50nm)and Zinc oxide (ZnO,30nm) nanoparticales were studied on carbon steel and 316 stainless steel alloys in saline water (3.5%NaCl)at four temperatures: (20,30,40,50 OC)using three electrodes potentiostat. An average corrosion protection efficiencies of 65 %and 80% was achieved using Al2O3 NP's on carbon steel and stainless steel samples respectively, and it seems that no effect of rising temperature on the performances of the coated layers. While ZnO NP'S showed protection efficiency around 65% for the two alloys and little effected by temperature rising on the performanes of the coated layers. The morphology of the coated spesiemses was examined by Atomic force microscope

Artificial intelligence and cardiovascular magnetic resonance imaging in myocardial infarction patients.

Cardiovascular magnetic resonance (CMR) is an important cardiac imaging tool for assessing the prognostic extent of myocardial injury after myocardial infarction (MI). Within the context of clinical trials, CMR is also useful for assessing the efficacy of potential cardioprotective therapies in reducing MI size and preventing adverse left ventricular (LV) remodelling in reperfused MI. However, manual contouring and analysis can be time-consuming with interobserver and intraobserver variability, which can in turn lead to reduction in accuracy and precision of analysis. There is thus a need to automate CMR scan analysis in MI patients to save time, increase accuracy, increase reproducibility and increase precision. In this regard, automated imaging analysis techniques based on artificial intelligence (AI) that are developed with machine learning (ML), and more specifically deep learning (DL) strategies, can enable efficient, robust, accurate and clinician-friendly tools to be built so as to try and improve both clinician productivity and quality of patient care. In this review, we discuss basic concepts of ML in CMR, important prognostic CMR imaging biomarkers in MI and the utility of current ML applications in their analysis as assessed in research studies. We highlight potential barriers to the mainstream implementation of these automated strategies and discuss related governance and quality control issues. Lastly, we discuss the future role of ML applications in clinical trials and the need for global collaboration in growing this field