Insight into mechanics of AFM tip-based nanomachining: bending of cantilevers and machined grooves

Atomic force microscope (AFM) tip-based nanomachining is currently the object of intense research investigations. Values of the load applied to the tip at the free end of the AFM cantilever probe used for nanomachining are always large enough to induce plastic deformation on the specimen surface contrary to the small load values used for the conventional contact mode AFM imaging. This study describes an important phenomenon specific for AFM nanomachining in the forward direction: under certain processing conditions, the deformed shape of the cantilever probe may change from a convex to a concave orientation. The phenomenon can principally change the depth and width of grooves machined, e.g. the grooves machined on a single crystal copper specimen may increase by 50% on average following such a change in the deformed shape of the cantilever. It is argued that this phenomenon can take place even when the AFM-based tool is operated in the so-called force-controlled mode. The study involves the refined theoretical analysis of cantilever probe bending, the analysis of experimental signals monitored during the backward and forward AFM tip-based machining and the inspection of the topography of produced grooves

Development and Validation of the Inviting Teaching Effectiveness Scale based on the Invitational Theory

This study reports on a new instrument, the Inviting Teaching Effectiveness Scale (ITES), which is a 20-item measure based on the fundamental teaching competencies derived from the principles of Invitational Education (Purkey & Novak, 1984). The initial instrument had included 30 items and was then validated on a random sample of 640 students enrolled at the University of Bahrain. The final version of the developed Scale contains 20 items and measures four aspects of inviting teaching effectiveness: Invitational instruction, inviting relationships, invitational assessment and inviting classroom environment. As the new Scale displayed sound psychometric properties, it can be considered as a potentially useful tool to assess teacher performance and improve teaching practices at tertiary level of education. Information about test construction, reliability, validity, and generalizability are presented and implications and benefits associated with use of the instrument as a tool for measuring teaching effectiveness are discussed

The impact of nano fertilization and salicylic acid on growth, yield and anti-oxidant contents in rocket plant under salt stress

Saabunud / Received 20.01.2022 ; Aktsepteeritud / Accepted 24.04.2022 ; Avaldatud veebis / Published online 24.04.2022 ; Vastutav autor / Corresponding author: Duraid K. A. Al-Taey; [email protected] investigation aimed to study the effect of organic fertilizers, nano-fertilizers and salicylic acid on the growth and yield of rocket (Eruca sativa L.) and the content of active compounds and antioxidants when the plants were exposed to salt stress. The experiment was conducted using a randomized complete block design (RCBD) according to the split-plot system. The main factor was water quality (1.2 dS m–1 and 8 dS m–1). While the combination treatments of Nano fertilizer, Salicylic acid and poultry manure were distributed in sub-plots and each treatment included three replicates. The treatments irrigated with saline water showed a reduction of glucosinolate and ascorbate contents (58 μg g–1 and 105.71 μg g–1, respectively). Salinity led to an increase in glutathione and proline in the leaves (1146 and 2.2 μg g–1, respectively), while the fertilization treatments (poultry manure + nano-NPK; poultry manure + salicylic acid + nano-NPK) resulted in an increase in the glucosinolate content of the leaves under salt stress (85.6 and 89.2 μg g–1, respectively). The nano-NPK treatment achieved a high value of the leaves’ ascorbic acid content under the unstressed conditions (166.73 μg g–1), while the salicylic acid + nano-NPK treatment achieved the highest value of ascorbic acid under salt stress (137.4 μg g–1). The combination of salicylic acid + poultry manure + nano-NPK obtained the highest value of glutathione content in the leaves (1950 μg g–1) under the stress conditions. There is a positive correlation between salt stress and glutathione + proline, while the salt stress condition had a negative effect on glucosinolate, ascorbate and yield

The Effect of using Iraqi Plaster with Type III Dental Stone as Investing Materials on the Vertical Dimension of Occlusion in Acrylic Resin Complete Dentures (A comparative Study)

Aim of study: The aim of this study was to evaluate the Iraqi plaster when used as investing material and studies its effect on the changes of vertical dimension of occlusion of heat cured acrylic resin complete dentures using four different investing methods in compression molding technique.Materials and methods: Forty acrylic resin complete dentures were prepared from heat-cure acrylic resin denture base. The study include 4 groups depending on the type of investing method, Group 1: plaster- stone- mixed, Group 2: plaster- stone- plaster, Group 3: plaster- mixed- mixed, Group 4: plaster- mixed - stone. Each group of them contains 10 dentures. Changes in occlusal vertical dimension were measured before and after denture processing. Collected data were analyzed with analysis of variance and Tukey's test at 95% level of confidence (p=0.05).Results: The mean of changes in dimension of occlusion in different groups were: group1: (0.6337mm), group2: (0.6253mm group3: (1.0171mm), and group4: (0.9837mm).Conclusion: Less dimensional changes was observed in the group of dentures that invested with plaster-stone- plaster when compare with other investing methods. Keywords: Iraqi plaster, stone, flasking, vertical dimension of occlusion

Traffic flow measurement for smart traffic light system design

Determining congestions on intersection roads can significantly improve the performance of a traffic light system. One of the everyday problems on our roads nowadays is the unbalanced traffic on different roads. The blind view of roads and the dependency on the conventional timer-based traffic light systems can cause unnecessary delays on some arterial roads on expense of offering a needless extra pass time on some other secondary minor roads. In this paper, a foreground extraction model has been built in MATLAB platform to measure the congestions on the different roads constructing an intersection. Results show a satisfactory performance in terms of accuracy in counting cars and in consequence reducing the wait time on some major roads. System was tested under different weather and lighting conditions, and results were adequately promising

Correlation Of NAG, NGAL, and Oxidative Parameters For Patients With Diabetic Nephropathy

Background: Diabetic nephropathy is a clinical syndrome that is present in diabetic mellitus patients and characterized by albuminuria {>200 or >300 mg\day}, a gradual glomerular filtration rate decline along with hypertension. Objective: Study the correlation between N_acetyl-ß-D-glucamindase and human neutrophil gelatinase-associated lipocalin and oxidative parameters in diabetic nephropathy patients compared with a control group and several variables by Explaining the results scientifically. Method: The blood sample was collected from forty-five diabetic nephropathy patients and forty-five controls from Merjin Medical Hospital and Al-Imam Al-Sadiq Hospital in Iraq to assess N-acetyl-β-D-glucosaminidase and human neutrophil gelatinase-associated lipocalin levels by used Enzyme-Linked immunosorbent Assay technicality (ELISA) and also to determine the oxidative parameters (total oxidant system, total antioxidant capacity, malondialdehyde and glutathione) by used spectrophotometer. Result: positive correlation for N-acetyl-β-D-glucosaminidase with total oxidant status and malondialdehyde where the correlation coefficient (r=0.893**, 0.809**) at respectively and negative correlation with total antioxidant capacity and glutathione where the (r=-0.851**, -0.465**) at respectively, and exact correlation for human neutrophil gelatinase-associated lipocalin with total oxidant status, malondialdhyde, total antioxidant capacity, glutathione. Conclusion: The assessment of NAG, NAGL, and oxidant parameters can provide crucial information for the early diagnosis, management, and therapy of these patients with diabetic nephropathy

Shrinkage properties of plain and recycled steel–fibre-reinforced rapid hardening mortars for repairs

This article investigates the time dependent transport properties and shrinkage performance of rapid hardening plain and fibre reinforced mortars for repair applications. Two plain and two SFRC mixes with 45 kg/m3 of recycled clean steel fibres made with rapid hardening cements (CSA – calcium sulfoaluminate cement and RSC – calcium aluminate cement) are studied. It is found that mixes with CSA cement have much lower shrinkage values (around 220 and 365 microstrains) compared to mixes with RSC cement (around 2690 and 2530 microstrains), but most of the shrinkage in these mixes is autogenous. Nonetheless, fibres reduce the drying shrinkage of RSC cement mixes by approximately 12%. Model code 2010 and ACI equations can be used to estimate the shrinkage development with time for these mixes provided suitable parameters for each cement type are adopted. Inverse analysis using finite element method is successfully employed to determine the moisture diffusivity and the hygral contraction coefficient of each mix. A comparison is made between the values of shrinkage strain predicted by the numerical models over time, for different depths, and code equations. A simple analytical procedure is used to assess cracking and/or delamination risks due to restrained shrinkage for these materials in overlay applications

Assessments and Historical Changes the Water Quality of Sawa Lake, Southern Iraq for the Period 1977-2020

This investigation pertains to the evaluation of water quality in SAWA Lake, located in the Al-Muthanna province of Southern Iraq, from 1977 to 2020. Understanding the water quality and assessments of this Lake is of great importance. The Lake is home to small, transparent, blind fish measuring approximately 10 cm and is often referred to as the "wonderful" or "strange" Lake due to its many unique features. The study focuses on several elements to represent water quality, including total dissolved solids (TDS), electrical conductivity (EC), pH, and temperature (T), which were measured directly in the field. Additionally, scientific concepts such as K+, Ca2+, Cl-, HCO3, and KSO4 were used in each sample. Scientists have analyzed the density and salinity of the lake water and found that its water density exceeds that of seawater, and its salinity exceeds that of the Gulf of Arabia by about 1.5 times. The water is salty, surrounded by natural lime, and is automatically renewed by nature when it is broken. Its hardness also characterizes it, and its water volume fluctuates depending on the wet and dry seasons. The Lake is roughly 4.74 km in length, and all the elements under study showed an increase in concentration during the periods of 1977, 1983, and 2003 with NaSO4, which later changed to MgCl between 2007 and 2011. The study found that Sawa Lake water was unsuitable for drinking or irrigation purposes between 2016 and 2020 due to the increased concentration of certain elements. This increase in concentration is attributed to the Lake's location, nutrition, and the lack of rain, which means it relies solely on groundwater

Effects of buzzy device and distraction cards on pain relief during intravenous cannulation in children: A Randomized Controlled Trial

Background: Under ethical and legal professional obligations, nurses are required to utilize evidence-based methods to enhance the experience of children during intravenous cannulation. Non-pharmacological pain management techniques are increasingly employed in clinical settings, as they can be implemented without incurring additional costs or requiring extra time. The aim of this randomized controlled trial is to evaluate the effectiveness of a Buzzy device and distraction cards in reducing pain associated with peripheral intravenous catheter (PIVC) insertion among school-aged children. Methods: A randomized controlled trial study was conducted on 221 school-age children patients who underwent PIVC in emergency departments. Three groups of patients were randomly assigned using a lottery method: the Buzzy device group (n=73), the distraction cards group (n=71), and the control group (n=77) receiving the standard procedure without any interventions. The children were asked to evaluate the pain level immediately following PIVC using the Wong-Baker Faces Pain Scale. Using SPSS (version 26), the independent t-test, Fisher's exact test, analysis of variance, and chi-square test were used to analyze the data. Results: Children in the intervention groups experienced significantly less pain during the PIVC procedure compared to those in the control group, with a pain score of 5.45 ± 1.67 (p = 0.0001). There was no statistically significant difference in pain reduction between the two intervention methods: the distraction cards (2.54 ± 1.37) and the Buzzy device (2.43 ± 1.60), both showing effectiveness (p = 0.0001). Conclusion: The results of this study indicate that both the Buzzy device and distraction cards effectively reduce pain levels during intravenous cannulation when compared to the control group. Furthermore, the two strategies demonstrated equivalent effectiveness in pain reduction, as their outcomes were nearly identical. Therefore, it is recommended that these therapeutic approaches be employed to manage and alleviate pain associated with PIVC

Eleven-Year Surveillance of Methicillin-Resistant Staphylococcus aureus Infections at an Academic Health Centre

Introduction. Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen associated with nosocomial and community infections. There is a continual focus on the epidemiology of this public health threat owing to the increase in its spread and rapid development of resistance. Aim. We aimed to describe the clinical presentations of MRSA infections at an academic health centre by demonstrating the time trend of antibiotic resistance. Methodology. We retrospectively reviewed cases during an 11-year period (from January 2009 to December 2019) with positive cultures for MRSA from various clinical sites in King Fahad Hospital of the University, to understand their clinical and microbiological profiles. Screening and colonisation samples were excluded. Results. A total of 1338 MRSA isolates were identified, with an increasing trend from 5.2% to 14.5% during 2009–2019. Skin and soft tissue samples were the most common source (52.4%) of MRSA infections. Vancomycin activity remained stable against MRSA, and only one isolate showed resistance to linezolid (<1%). A significant reduction in susceptibility to clindamycin (p = 0.003), trimethoprim-sulfamethoxazole (p = 0.001), and rifampin (p <0.0001) was detected over the study period. Conclusion. MRSA infections still represent a significant burden on healthcare systems. Our data support the need for constant local and regional surveillance to devise relevant protocols to manage MRSA infections. Empirical therapy needs to consider the changing antimicrobial susceptibility trends among MRSA isolates