Computer-aided recycling process planning for end-of-life electrical and electronic equipment

The significant environmental cost associated with management of products at the end-of-life has resulted in the emergence of ‘producer responsibility’ legislations to encourage increase in recovery and recycling practices. In the case of electrical and electronic equipment, one such legislation, namely the ‘Waste from Electrical and Electronic Equipment Directive’, requires manufacturers to assume financial and legal liability for recovery and recycling of their products at the end-of-life. The current recycling applications of electrical and electronic waste are often developed on ad hoc basis and mainly attributable to the hidden economic value within used products. However, owing to stricter regulations on end-of-life product recycling, it is now essential to evaluate the recycling costs and environmental benefits of reclaimed products and materials as well as the selection of appropriate recycling strategy. The present paper describes the initial investigation in the realization of a computer-aided recycling process planner for electrical and electronic products. The assertion made is that such a systematic approach to producing bespoke eco-efficient recycling process plans for individual products will significantly improve the value recovery from recycling activities

A noninvasive molecular approach: exploiting species-locus-specific PCR primers in defeating numts and DNA cross-contamination of cercopithecidae

The lack of a standardized, noninvasive molecular approach to studying genetic aspects of primates has made it hard for primatologists to decode the evolutionary history of these species. Researchers must optimize their own techniques to fully exploit the available samples. Lack of species-locus-specific primers also contributes to difficulties in using noninvasive genetic samples. Thus, the objectives of this study were to develop a standardized technique to collecting samples noninvasively, propose newly designed species-locus-specific primers, and optimize conditions for polymerase chain reaction (PCR) for Macaca fascicularis, M. nemestrina, Trachypithecus cristatus, and T. obscurus. Nine new species-locus-specific primers for three different loci of mitochondrial DNA, namely D-loop, cytochrome oxidase subunit I (COI), and cytochrome b, were successfully designed. These primers proved to be efficient in amplifying larger datasets (up to ~1,000 bp) of the targeted species in the optimized PCR conditions. The species-locus-specific primers are able to anneal to host DNA alone in highly contaminated feces of highlighted species. They can also offer alternatives measures in avoiding contamination related to nuclear insertion of mitochondrial pseudogenes (numts)

Characterisation and Py-GC/MS analysis of Imperata Cylindrica as potential biomass for bio-oil production in Brunei Darussalam

Bio-oil production from renewable sources has been seen as suitable alternative to supply future energy demand. Perennials grasses are currently being developed as a suitable second-generation biofuel feedstock. It has advantages such as rapid growth rate, easy to grow, minimal maintenance and utilise marginal land without competing with food supply. Taking into account of the various challenges attributed to the transformation of second-generation biomass for energy production, this work systematically looks at the ecological perspective and the availability for bioenergy production from Imperata Cylindrica in Brunei Darussalam. Biomass characterisation was carried out to determine the properties and energy content, meanwhile py-GC/MS study was conducted to identify building blocks of value-added chemical from I. cylindrica. The physicochemical properties of feedstock was thoroughly evaluated using thermogravimetric analysis, proximate analysis, elemental analysis, compositional analysis, calorific value, and analytical pyrolysis interfaced with gas chromatograph (Py-GC/MS). Characterisation results indicate that Imperata Cylindrica has a calorific value of 18.39 MJ/kg, with low ash content and high percentage of volatile matter. Py-GC/MS analysis revealed the presence of furfural, 2,3-dihydrobenzofuran, 4-vinylguaiacol, propenylguaiacol, guaiacol and 4-ethylphenol. The fixed-bed pyrolysis experiment of imperata cylindrica showed that the yield of bio-oil increases with the increase of temperature and it reached a peak of 37.16% at 500 °C. These results show that Imperata Cylindrica is suitable as feedstock for bio-oil production via pyrolysis process

Development of Blumlein Line Generator and Reactor for Wastewater Treatment

There are several wastewater treatment methods and techniques which have been introduced such as by using biological, chemical, and physical process. However, it is found that there are some shortcomings in the current available methods and techniques. For instance, the application of chlorine can cause bacterial disinfection but produce secondary harmful carcinogenic disinfection. In order to acquire a better understanding in wastewater treatment process, a study of wastewater treatment system and hybrid discharge reactor to acquire gas liquid phase corona like discharge is carried out. In addition to the laboratory experiment, designing and development of the Blumlein pulse power circuit and modification of reactor for wastewater treatment are accomplished as well. The Blumlein pulse power circuit generates nanosecond high voltage pulses. The Hybrid Discharge reactor can produce both spark discharge in gas phase and liquid phase (spark-spark discharge). Analysis of the emission spectrum of the occurring discharge found the existence of various chemicals such as OH radicals. In addition, a drastic improvement in terms of oxygen content and conductivity level of the wastewater sample is also observed.

Asymmetric fiber taper for narrow linewidth comb filter

The employment of asymmetric optical fiber taper as a means for producing narrow linewidth comb filter is proposed and demonstrated. Fiber taper with different values set for the up-taper and down-taper transition regions was used to produce narrow linewidth comb filter through coupling interaction of light in the asymmetric fiber. Two configurations; single-pass and bidirectional fiber taper filters were studied and analyzed in this project. Results showed narrower 3-dB linewidth for asymmetric taper compared with uniform taper for single pass configuration. The asymmetric taper linewidth was improved further in bidirectional configuration, narrowing down to 2 nm. Bidirectional asymmetric taper filter recorded extinction ratio of 27.14 dB, which was 18 dB and 3 dB better than single-pass asymmetric taper and bidirectional uniform taper respectively. The findings emphasize the attractiveness of bidirectional asymmetric taper as a high performance optical filter

Microbiological quality on food handlers’ hands at primary schools in Hulu Langat District, Malaysia

A total of 85 food handlers participated in this study to determine the hygienic status of their hands in primary schools located in the state of Selangor (Malaysia). Overall findings revealed that the fecal contamination and personal hygiene of the food handlers were well maintained with the range of mean bacterial counts from 0.18 to 0.47 log 10 Colony Forming Units/cm 2 during the three intervals of hand swabbing (before, during and after) preparation of ready-to-eat foods. However, the general indication of the microbiological quality (Aerobic Plate Count) was out of the standard (range of mean bacterial counts from 1.39 to 1.56 log 10 Colony Forming Units/cm 2) based on previous literature. This study highlighted that the food handler’s adherence to Good Manufacturing Practice and Sanitation Standard Operating Procedures was insufficient and suggested that attention should be emphasized on their practices at the intervals of school recess: before, during and after the preparation of ready-to-eat foods. In addition, there is also a need in the implementation of an effective HACCP program in Malaysia school foodservice operations

Analysis on Preparation, Application, and Recycling of Activated Carbon to Aid in COVID-19 Protection

Activated carbon (AC) is an extremely porous carbonaceous adsorptive substance which has a rigid carbon matrix with high surface area and broad functional groups. The structure is connected by chemical bonds; arranged irregularly, generating a highly porous arrangement of corners, crevices, claps, and cracks between the carbon layers. Activated carbons are produced high-temperature and chemical activation of waste biomass. The pores in the lattice network of activated carbon permit the removal of impurities from gaseous and liquid medium through adsorption. At present, the COVID-19 disease is the prime concern around the whole world because of its exponential infections and death rate. There is no medicine for this virus, and protection is the only remedy to survive from this contagious disease. Using a face mask is one of the best methods to get rid of COVID-19. The mask combined with activated carbon can be beneficial for adsorbing and disinfecting the virus as it is the versatile adsorbent for the elimination of the organic, inorganic, and pathogenic contaminants

Partial Discharge Monitoring System on High Voltage Equipments using Electroacoustic Technique

Partial discharge (PD) monitoring system is considered as one of the most promising solutions for monitoring and detecting possible faults. PD is able to diagnose faults within the system in the most fundamental and simplest way. PD monitoring and measurement of high voltage equipment substations panel and power transformers have not gained the same attention in the electrical community as compared to those of rotating machines. PD tests are conducted on-site to verify the insulation of bushings, termination box and windings. The cost of an unexpected outage may be considerably more significant for a high voltage substation panel and power transformers system than just for a single motor failure. In this research, the electroacoustic PD monitoring technique is used, which is a combination of internal PD detection and ultrasound or surface PD detection was used. The testing equipment which will be used in this research is UltraTEV Plus+ equipment from EA Technology. Result shows the transient earth voltage (TEV) PD magnitude fluctuates with time. Significant high value of PD magnitude (> 19 dB) was detected and recorded at several switchgear panel and transformer. However, for the ultrasound or surface PD, from the monitoring and measurement record, no detection of PD signal was recorded at the UltraTEV Plus+ testing equipmen

Hydrous ferric oxide-magnetite-reduced graphene oxide nanocomposite for detection of arsenic using surface plasmon resonance

Surface plasmon resonance sensor coated with hydrous ferric oxide-magnetite-reduced (Fe2H2O4-Fe3O4-rGO) graphene oxide nanocomposite film was demonstrated to detect two toxic heavy metals; Arsenic (III) [As(III)] and Arsenic (V) [As(V)] in aqueous solution. The proposed nanocomposite film exhibited successful absorption of As with enhanced sensitivity and selectivity. Resultantly, when tested with different concentrations of As(III) and As(V), (0.1-1.0 ppb) the sensor ranged linearly with sensitivity of 2.196 °ppb-1 and 0.960 °ppb-1, respectively, and achieved a detection limit as low as 0.1 ppb. These results validate the potential of Fe2H2O4-Fe3O4-rGO nanocomposite material for optical sensing applications in As detection

Characterization and thermal behavior study of biomass from invasive acacia mangium species in brunei preceding thermochemical conversion

Acacia mangium is a widely grown tree species across the forests in Brunei Darussalam, posing a threat to the existence of some native species in Brunei Darussalam. These species produce large quantities of lignocellulosic biomass from the tree parts comprising the phyllodes, trunk, bark, twigs, pods, and branches. This study examined the thermochemical characteristics and pyrolytic conversion behavior of these tree parts to assess the possibility of valorization to yield bioenergy. Proximate, ultimate, heating value, and Fourier Transform Infrared Spectroscopy (FTIR) analyses were performed to assess the thermochemical characterization, while thermogravimetric analysis was conducted to examine the pyrolytic degradation behavior. Proximate analysis revealed a moisture content, volatile, fixed carbon, and ash contents of 7.88–11.65 wt.%, 69.82–74.85 wt.%, 14.47–18.31 wt.%, and 1.41–2.69 wt.%, respectively. The heating values of the samples were reported in a range of 19.51–21.58 MJ/kg on a dry moisture basis, with a carbon content in the range of 45.50– 50.65 wt.%. The FTIR analysis confirmed the heterogeneous nature of the biomass samples with the presence of multiple functional groups. The pyrolytic thermal degradation of the samples occurred in three major stages from the removal of moisture and light extractives, hemicellulose and cellulose decomposition, and lignin decomposition. The bio‐oil yield potential from the biomass samples was reported in the range of 40 to 58 wt. %, highlighting the potential of Acacia mangium biomass for the pyrolysis process