Melting dynamics of large ice balls in a turbulent swirling flow

We study the melting dynamics of large ice balls in a turbulent von Karman flow at very high Reynolds number. Using an optical shadowgraphy setup, we record the time evolution of particle sizes. We study the heat transfer as a function of the particle scale Reynolds number for three cases: fixed ice balls melting in a region of strong turbulence with zero mean flow, fixed ice balls melting under the action of a strong mean flow with lower fluctuations, and ice balls freely advected in the whole flow. For the fixed particles cases, heat transfer is observed to be much stronger than in laminar flows, the Nusselt number behaving as a power law of the Reynolds number of exponent 0.8. For freely advected ice balls, the turbulent transfer is further enhanced and the Nusselt number is proportional to the Reynolds number. The surface heat flux is then independent of the particles size, leading to an ultimate regime of heat transfer reached when the thermal boundary layer is fully turbulent

Emerging Trends in Cybercrime Awareness in Nigeria

The study examined the current trend in cybercrime awareness and the relationship such trend has with cybercrime vulnerability or victimization. Selecting a sample of 1104 Internet users from Umuahia, Abia State, Nigeria, We found that: 1) awareness of information security was high in that about 2 in every 3 (68%) participants demonstrated a favorable awareness of information security and cybercrime. It was, however, revealed that such a high level of awareness could be partial and weak. 2) most Internet users demonstrated the awareness of fraud-related cybercrime categories (39%), e-theft (15%), hacking (12%), and ATM theft (10%). However, they were rarely aware of sexually related offenses, cyber-terrorism, malware attacks, spam emails, and identity theft as their proportion hovered around 8% and below. 3) Internet users significantly demonstrated more awareness of computer-assisted (M = 2.5; SD = 1.7) than that of computer-focused cybercrime categories (M = 2.2, SD = 1.3), t(1103) = 2.9, p=.000, r =.2. 4) Internet users significantly demonstrated more awareness of property cybercrime (M = 2.54; SD = 1.6) than that of violent cybercrime categories (M = 1.82, SD = 1.2), t(1103) = 5.94, p=.000, r =.3. 5) cybercrime awareness is positively correlated to cybercrime victimization experiences in that participants who demonstrated more awareness of cybercrime experienced significantly more cybercrime victimization (M = 1.66; SD = 1.7) than those who did not demonstrate awareness of cybercrime (M = .73, SD = 1.4), t(1103) = 7.55, p=.000, r =.52

Ent-kaurene and ent-beyerene diterpenoids and other constituents of Thecacoris batesii

Two novel diterpenoids, thecacorins A (1) and B (2), were isolated from Thecacoris batesii and their structures were established as ent-3b,20-epoxy-16-kaurene-3a,12b-diol and ent-15-beyerene-2b,3b-diol, respectively, on the basis of extensive spectroscopic analysis, especially, 1D NMR spectra, in conjunction with 2D experiments, COSY, NOESY, HMQC and HMBC. KEY WORDS: Diterpenoids, Thecacorin A, Thecacorin B, Ent-3b,20-epoxy-16-kaurene-3a,12b-diol, Ent-15-beyerene-2b,3b-diol, Thecacoris batesii  Bull. Chem. Soc. Ethiop. 2007, 21(1), 89-94

Amputation‑Related Phantom Limb Pain in Nigeria: A Prospective Cohort Study

Background: Phantom limb pain (PLP) is a common and distressing complication of limb amputations. Literature on PLP in Nigeria and indeedAfrica is scant despite the high rate of amputations in published works. We sought to highlight the burden of PLP among Nigerian amputeesin order to improve awareness and care by health‑care providers. Patients and Methods: In this prospective cohort study, consecutive limb amputees were recruited and relevant data were collected by in‑person interview at 1 week postamputation and subsequently by telephone survey at 6 months and 12 months. The sociodemographic and clinical   information of the amputees were recorded, as well as presence of PLP and the treatment offered by the attending physician. The Chi‑square test of statistical significance and multivariate analysis using binary logistic regression were used in the analysis, and the level of statistical significance was determined by P < 0.05. Results: One hundred and fourteen consecutive limb amputations were carried out in 113 patients over a 1‑year period. The period prevalence of PLP was 63.6%, and of these, only 8.6% had this documented in their medical record. No predictor of PLP was identified in the cohort. Conclusion:  PLP is highly prevalent among limb amputees in our cohort. We call for improved awareness and practice relating to PLP among  health‑care providers and partners, considering the vast population of amputees in the region. Keywords: Africa, American Society of Anesthesiologists physical status grade, amputees, phantom limb pai

ANTIDIABETIC ACTIVITY AND TOXICOLOGICAL EVALUATION OF THE METHANOL-DICHLOROMETHANE ROOT BARK EXTRACT OF NAUCLEA DIDERRICHII (DE WILD) MERR

Objective: In southeastern Nigeria, Nauclea diderrichii (De Wild) Merr is used in the treatment of a wide range of ailments including diabetes mellitus (DM). This study evaluates the antidiabetic activity and toxicological profile of the methanol-dichloromethane root bark extract of N. diderrichii in normoglycemic and alloxan-induced diabetic models.Methods: Dried root barks of N. diderrichii were extracted using methanol and dichloromethane (1:1) to obtain N. diderrichii extract (NDE). The acute and sub-chronic toxicity tests were performed using standard procedures. The effect on alanine aminotransferase (ALT) aspartate aminotransferase (AST), alkaline phosphatase (ALP), total protein (TP), packed cell volume (PCV), hemoglobin concentration (HB) and total white blood cell (TWBC) count was determined in the rats after treatment. In order to elucidate its antidiabetic mode of action, an oral glucose tolerance test (OGTT) was performed using glucose (2 g/kg) as substrate and alloxan (100 mg/kg; i. v.) induced diabetic model. Glibenclamide (GLI 0.2 mg/kg) was used as the reference standard drug.Results: The results indicated that the LD50 of the extract is>5000 mg/kg. ALT, AST, ALP PCV, HB and TWBC were insignificantly (p>0.05) different compared with the control. No significant changes were observed in the organ weights compared with the control. In the acute and prolonged antidiabetic study, NDE (100, 200 and 400 mg/kg) significantly reduced the blood glucose level (BGL) by 14.66, 18.9, 25.80% and 75.11, 80.24, 83.74% respectively. In comparison, GLI, when administered, reduced BGL by 38.18 and 92.86% respectively.Conclusion: N. diderrichii possesses antidiabetic activity with good toxicological profile

Antihepatotoxic and Antioxidant Activities of Methanol Extract and Isolated Compounds from Ficus chlamydocarpa

Free radicals, in particular radical oxygen species (ROS), play an important role in the aetiology and pathogenesis of various diseases. Current research in many countries focuses on the use of local medicinal plants as a promising source of liver protective agents. This paper describes the hepatoprotective effects of the methanol extract and four isolated compounds from Ficus chlamydocarpa on CCl4-induced liver damage, as well as the possible antioxidant mechanisms involved in this protection. The DPPH test, along with the ß-Carotene-Linoleic Acid Model System and Ferric-Reducing Antioxidant Power assays, as well as the inhibition of microsomal lipid peroxidation were used to measure radical-scavenging and antioxidant activities. Pretreatment of rats with the methanol extract of F. chlamydocarpa before CCl4administration, significantly prevented serum increase of hepatic enzyme markers, glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT), in a dose-dependent manner. The hepatoprotection was also associated with a significant enhancement in hepatic reduced glutathione (GSH) and a marked decrease of liver malondialdehyde (MDA). Among the four compounds 1-4, isolated from the methanol extract, α-amyrin acetate (1) and luteolin (4) showed a significant hepatoprotective activity, as indicated by their ability to prevent liver cell death and lactate dehydrogenase (LDH) leakage during CCl4intoxication

Smart two-tank water quality and level detection system via IoT

The two-tank water system is common practice for the storage and distribution of water in many homes. Water is transported via a pipeline network from the storage tank (lower tank) to the distribution tank (overhead tank) using an electric pumping machine. Due to limited control in the existing pumping system, water wastage becomes inevitable. Determining the quality of water in the overhead tank before supply in the home is still unaddressed. In this work, an integrated Android mobile App and a control system were developed to assess the water quality, perform level check in the overhead tank, and activate intelligent pumping control. An ultrasonic pulse-echo technique was used for water level checks, while the water turbidity and pH signals were used for water quality checks. Three-level control conditions (LC_1, LC_2, LC_3) and two water quality check conditions (QC_1 and QC_2) were devised and used in the intelligent control algorithm of the system. Control valve1 regulates the flushable poor water quality while valve2 regulates the house's supply of good water quality. The absolute relative error between the expected time and the system time of filling the tank level was observed to be less than 10% when the water volume is less than 81%. Hence, distortion in the sensory signals increases and worsen as the water level approaches the ultrasonic sensor position. The poor internet signal network was observed to affect the real-time monitoring and automation of the system control through delay in system responses to commands. However, the average recorded response time of the system is 3 s, and it could be less in the situation of good internet network services