Diagnosing students' difficulties in learning mathematics

This study considers the results of a diagnostic test of student difficulty and contrasts the difference in performance between the lower attaining quartile and the higher quartile. It illustrates a difference in qualitative thinking between those who succeed and those who fail in mathematics, illustrating a theory that those who fail are performing a more difficult type of mathematics (coordinating procedures) than those who succeed (manipulating concepts). Students who have to coordinate or reverse processes in time will encounter far greater difficulty than those who can manipulate symbols in a flexible way. The consequences of such a dichotomy and implications for remediation are then considered

A Review of Recent Studies on Simulations for Flow around High-Speed Trains

Fluid flow around bluff bodies occurs in numerous fields of science and engineering, such as flows pass vehicles, cables, towers and bridges. These flows have been studied experimentally and numerically for the last several decades. The investigation of flow around high-speed trains is an important application of bluff bodies. Fluid flow, aerodynamic forces and moments, separation and wake region have been studied for the last several decades. This paper brings together a comprehensive review of the research on air flow around high-speed trains and their impacts

Influence of depression literacy, mental health beliefs, and stigma on help-seeking behaviour : a semi-systematic review

Despite having a mental health act and clinical practice guideline, Malaysian patients with depression frequently progress to severe disease with poor prognosis. Understanding the underlying factors which influence help-seeking behaviour using a patient journey approach can provide insights for designing effective interventions. The study aimed to determine the different stages of patients journey for depression including awareness, screening, diagnosis, treatment, adherence, and control using a semi-systematic review. The review was conducted through (i) structured keyword search in Embase, MEDLINE, and BIOSIS databases using OVID platform for English articles published between 2005 and 2021; and (ii) an unstructured search on websites of Google, Incidence and Prevalence Database, World Health Organization, and Malaysian Ministry of Health. Studies included in the semi systematic review were based on Malaysian patients aged ≥18 years at different journey stages for depression and publications from year 2005 to July 2021. Thesis abstracts, letters to the editor, editorials, and case studies, or articles representing smaller population subgroups were excluded. Three articles out of 1062 retrievals through structured search and two articles out of four retrievals through the unstructured search were included in the final synthesis. We have found that the prevalence of major depressive disease (2.3%), low initial screening (20%), diagnosis (50% to 60%) and adherence (30% to 40%), despite high awareness (76.9%) and initiation of treatment (75.3%). Low education level, ethnicity, stigma regarding mental health, and irrational prescription pattern of primary care physicians were associated with poor mental health help-seeking behaviour. Depression literacy can improve the help-seeking behaviour of the patients

Comprehensive study of antimicrobial susceptibility pattern and extended spectrum beta-lactamase (ESBL) prevalence in bacteria isolated from urine samples

Nowadays, increasing extended-spectrum β-lactamase (ESBL)-producing bacteria have become a global concern because of inducing resistance toward most of the antimicrobial classes and making the treatment difficult. In order to achieve an appropriate treatment option, identification of the prevalent species which generate ESBL as well as their antibiotic susceptibility pattern is essential worldwide. Hence, this study aimed to investigate the prevalence of ESBL-producing bacteria and assess their drug susceptibility in Fardis Town, Iran. A total of 21,604 urine samples collected from patients suspected to have urinary tract infection (UTI) were processed in the current study. The antimicrobial susceptibility of the isolates was tested by the disk diffusion method. The ESBL producing bacteria were determined by Double Disc Synergy Test (DDST) procedure. Bacterial growth was detected in 1408 (6.52) cases. The most common bacterial strains causing UTI were found E. coli (72.16), followed by K. pneumoniae (10.3) and S. agalactiae (5.7). Overall, 398 (28.26) were ESBL producer. The highest ESBL production was observed in E. coli, followed by Klebsiella species. ESBL producers revealed a higher level of antibiotic resistance compared with non-ESBLs. In conclusion, ESBL production in uropathogens was relatively high. Carbapenems and Aminoglycosides were confirmed as the most effective treatment options for these bacteria. © 2021, The Author(s)

A mobile air particle system using an optical sensor for haze measurement

This paper presents a development of a mobile haze measurement system which can measure the amount of particulate matter and display in real time. The current haze measurement system called high volume sampler is difficult to move around due to its big size and the reading is not available in real time. Therefore, an alternative for the haze measurement system need to be developed. It uses an optical sensor as a working principle and Arduino board as a microcontroller. The measurement system is able to measure particulate matter from the smoke generated using a mosquito coil. The reading from the developed haze measurement system is verified using a commercial sensor called Dust Mate

Effect of cavity thickness on copper alloy corrosion resistance

This investigation inspects on the effect of cavity’s thickness during metal casting process on the corrosion resistance of copper alloy product. As the thickness increases, the cooling rate becomes higher due to higher latent heat available in the thicker and larger cavity volume. As such the quantity of Dendritic Arm Spacing, DAS and its Secondary, SDAS per unit area becomes higher. This eventually results in better properties such as the higher hardness and good corrosion resistance because its correlation with DAS and SDAS distribution in the microstructure. The copper alloy used in this project is Nickel Aluminium Bronze (NAB) alloy which consists of elements such as the copper, aluminium, iron, nickel and manganese. Sand casting process has been used and the NAB alloys have been fabricated according to the ASTM B148 UNS 95,800 standards with the usage of 1.1% degassing agent. A range of product cavity’s thickness have been fabricated for gating system and proper machining processes have been carried out to prepare the specimens for the immersion test. The specimens were immersed in sea water for a period of 17 weeks and changes in the specimen mass and pH and TDS values of the sea water used was measured. The data analysis revealed that the specimens were not corroded yet for the period of 17 weeks as there are not much changes in the specimen mass. The pH and TDS values are showing changes but these changes are very small comparatively

Effects of Reinjection on Flow Field of Open Jet Automotive Wind Tunnel Test Section

The distributions of axial static pressure coefficient and flow fluctuation in the test section which affect aerodynamic measurement in an open jet wind tunnel is presented. In this paper, the flow characteristics of the open jet automotive wind tunnel with passive reinjection and active reinjection were simultaneously investigated by experimental and numerical approaches. The axial static pressure coefficient variations can be reduced by passive or active reinjection, and recycle flow returns to the test section from the loophole is the main reason. The more mass flow rate improves the effect. Meanwhile, it is found that the improvement of the axial static pressure coefficient by reinjection is always better in the condition of 0° collector angle. The turbulence intensity in the collector angle of 15° is lower than that of 0°, and the reinjection increases the turbulence intensity near the collector. The increase of the turbulence intensity by active reinjection in the collector angle of 0° is greater than the collector angle of 15° for the 3.28° diffusion angle. There are some peaks emerging at the frequencies of 40 Hz and 50 Hz, which indicates that the flow field fluctuations may have induced structural vibration. The peaks at several frequencies increase when the passive and active reinjection are conducted, and the increase of peak is correlate with the increase of the reinjection flow rate. Due to the reduction of average static pressure coefficient and increase of flow fluctuations, the application of passive and active reinjection should be considered at the same time