Modulation strategy for new asymmetrical multilevel inverter topology using nearest dc level modulation technique

Multilevel inverters (MLI) have an important portion in power processing in power systems. These inverters have some inherent advantages such as ability to operate with high power and voltage, improved output waveform quality, and flexibility, which make them attractive and more popular. In recent years, research on multilevel inverters with reduction of components is gaining interest. The reduction offers plenty of advantages namely, the reliability, volume and control simplicity. In this project, Nearest DC Level Control (NLC) modulation technique will be studied and designed for a newly developed multilevel inverter with reduction in components. The proposed NLC modulation is a fundamental frequency switching technique that may have some advantages when applied to multilevel inverters as compared to conventional carrier based PWM modulation. For the study, new topology of nine-level asymmetrical multilevel inverter model will be developed using MATLAB. A proposed NLC techniques will be also developed. The inverter model will be simulated using the same resistor load value. The discussion will be on the shape of the harmonics profile and Total Harmonic Distortion (THD) value

Inbound and Outbound Marketing

Digital marketing has changed how businesses operate nowadays. When it comes to reaching and engaging consumers, effective marketing strategy is the key. Besides, in order to compete with the competitors, the companies should know everything about their customers from what their need is, how they can satisfy it and to what need they can further create (Hubspot, 2016) – of which a role mostly played by the marketing team

Implementing gold investment for Malaysian Employees Provident Fund (EPF)

The Employees Provident Fund (EPF) was established under the Provident Fund Act 1991 (Act 452) which provides retirement benefits to its contributors under an efficient and trusted management appointed by the government. Both private and public sector employees are allowed to contribute; whereby EPF acts as a fund manager on behalf of the contributors and provides a guaranteed minimum dividend of 2.5 per cent per annum. Majority of EPF investments are of low risk financial instruments; and this is done as to ensure the contributors enjoy the minimum returns. As majority of EPF contributors are Muslims, two critical issues have risen, especially when EPF seems to be ignorant by not investing in shariah compliant instruments on top of its uncompetitive returns. As gold investment has so far shown to produce high long term investment return, we examined the suitability of introducing shariah compliant gold investment saving account as one of the EPF portfolio investment instruments. We suggested that EPF allocates around 15 per cent of its investment portfolio in shariah compliant gold account for the benefit of EPF contributors as to maintain their purchasing power after retirement. As gold hedges against inflation, investing in shariah– compliant gold investment account solves the dilemma of Muslim EPF contributors in non-permissible investment

Depression, anxiety and stress among dental undergraduate students: Prevalence, stressors and relieving factors

Aim: To investigate the depression, anxiety and stress, stressors and relieving factors among dental students at Kulliyyah of Dentistry (KOD). Materials and methods: A cross-sectional study was conducted among 222 dental students. Their socio-demographic data, self-reported depression, anxiety and stress (DASS-21) scores, causes and relieving factors were collected using validated semi-structured pre-tested questionnaires. The data was analysed using percentages, chi-square test and Binary logistic regression tests with SPSS version 24. Results: The prevalence of depression, anxiety and stress was 41%, 68.9% and 34.2% respectively. Cross analysis showed that academic-related and laboratory or clinical related reasons were significantly associated with the depressive symptoms [(X2= 15.86, p<0.0001) and (X2= 10.45, p=0.001) respectively] and stress symptoms [(X2= 19.95, p<0.0001) and (X2= 6.11, p<0.05) respectively] among dental student. Furthermore, the item ‘examination’ being the highest factor chosen in academic-related stressors. The response for stress-relieving factors was high for Islamic ritual prayer/spiritual activities (94.6%), sleeping (86.5%) and doing exercise/playing sports (76.1%), while ‘seeking professional help’ (19.8%) was the least. Conclusions: This study shows that depressive, anxiety and stress symptoms are prevalent among dental students. Islamic ritual prayer and involvement in spiritual related activities was found to be the most preferred way for students to relief stress. Hence, it is vital that the university continually evaluates the psychological health of the students, tailor preventive measures and spiritual related programs to help students to cope with stress

3β-Chloro-6-[2-(2-cyano­acet­yl)hydrazin-1-yl­idene]-5α-cholestane

The asymmetric unit of the title compound, C30H48ClN3O, contains two mol­ecules, A and B. In both mol­ecules, the three cyclo­hexane rings in the steroid fused ring systems adopt chair conformations, while the cyclo­pentane rings adopt envelope and twist conformations in mol­ecules A and B, respectively. In mol­ecule B, the cyano group is disordered over two orientations with refined site-occupancies of 0.593 (8) and 0.407 (8). An intra­molecular C—H⋯N inter­action forms an S(10) ring in both mol­ecules. In the crystal, mol­ecules are linked by N—H⋯O, C—H⋯O and C—H⋯N inter­actions, resulting is chains propagating along the a-axis direction

Characterization of calcium carbonate extracted from eggshell waste at various calcination temperature

An efficient method to waste utilization is to successfully transform it into high value products. Chicken eggshell contain potential useful minerals of calcium carbonate in which can be processed into biomaterials used in biomedical application. The objective of this study is to derived calcium carbonate from eggshell and analyze the effect of various calcination temperatures on the properties of calcium carbonate. Fourier transform infrared (FTIR) spectroscopy indicates that all calcined samples reveals calcium carbonate is no longer present after calcination as it is already converted to calcium oxide. This also supported by x-ray diffraction (XRD) graphs notably on 900°C. Scanning electron microscopy (SEM) and particle size analysis are applied to determine morphological properties and mean sizes of particles for both raw and calcined samples

Thermogravimetric analysis of polyhydroxyalkanoates (PHA)/nano-calcium phosphate (nCaP)/chitosan biocomposite for heat-related manufacturing process

Nowadays, the adaptability of biodegradable Polyhydroxyalkanoates (PHA) polymer has been thoroughly assessed to its full potential including shape, mechanical characteristics, thermal properties and biocompatibility. Additionally, PHA has been produced as biomaterials with potential applications in bone regeneration. Similar to the mineral apatite found in human bones, nano calcium phosphates (nCaP) are minerals that are necessary for tissue development and cell adhesion, which have an impact on newly formed apatite. This study aims to investigate the influence of additives on thermal stability of biocomposite via thermogravimetric analysis (TGA) machine. PHA pellets were mixed with nCaP as filler ranging from 3-15wt% and 10wt% of chitosan binder via conventional melt compounding. Thermal analysis showed that the addition of bio-filler improves thermal stability of PHA with highest onset temperature recorded at 208.1°C. Morphological analysis showed that the addition of nCaP and chitosan alters the flow characteristics of the composite resulting in surface roughness. Subsequently, in order to prevent the biocomposite from decomposing, all heatrelated activities particularly those involving machining, it is recommended to perform at temperatures that do not exceed the onset temperatur

3β-Chloro-5α-cholestan-6-one

The asymmetric unit of the title compound, C27H45ClO, consists of two crystallographically independent mol­ecules. In both mol­ecules, the three cyclo­hexane rings in the steroid fused-ring systems adopt chair conformations, while the cyclo­pentane ring adopts a half-chair conformation in one mol­ecule and an envelope conformation in the other. In the crystal, the mol­ecules are linked into a two-dimensional network by weak C—H⋯O hydrogen bonds. The crystal studied is a nonmerohedral twin with a refined ratio of twin components of 0.264 (3):0.736 (3)

A step by step of content validity assessment process on approach towards safety knowledge, safety climate and SMEs safety performance framework

This article examines the issues and the conceptual basis in the operationalized definition of safety knowledge. The importance of safety knowledge emphasizes the mediation role of safety knowledge in the indirect link between safety climate and safety performance assessment in small and medium enterprises and the functional nature of content validity by applying a step-by-step content validity assessment. A content validation assessment process aims to increase representativeness, relevancy, clarity, comprehensiveness of the measurement's validity besides to ensure the instrument answers the research question. In business, social science, and management science, many variables of interest and research outcomes are abstract concepts and its function by robust theoretical and conceptual explanation. Thus, a step-by-step content validity assessment offered a bridge to achieve a valid and reliable measurement, and it was an essential element of quality research

Ethyl 4-fluoro-3-nitro­benzoate

In the title compound, C9H8FNO4, C—H⋯O inter­molecular inter­actions form dimers with R 2 2(10) motifs. These dimers are arranged into chains parallel to the b axis and the chains are stacked down the c axis