Investigation of oil palm empty fruit bunches in biosoda pulping by tropical white-rot fungi, Ganoderma australe (Fr.) Pat.

Ganoderma australe, a white-rot fungus, is well-known as a decomposer of logs and stumps in the Malaysian forest. We investigated G. australe (KUM60848) strain for production of ligninolytic enzymes i.e. lignin peroxidase (LiP) and laccase, and hydrolytic enzymes, i.e. cellulase and xylanase, using oil palm empty fruit bunches (EFB) in solid-substrate fermentation (SSF). EFB was shown to support good mycelial growth for G. australe during 28 days of solid-substrate fermentation. All tested enzyme activities demonstrated highest activities of LiP (0.18±0.02 U/ml), laccase (1.92±0.03 U/ml), cellulase (0.72±0.11 U/ml) and xylanase (0.42±0.01 U/ml) throughout the 28 days of incubation. Compared to an untreated control, the pretreated EFB yield increased to a maximum of 18% during biopulping. Fourteen days of SSF had the highest degree of material dissolved, as shown by pulp yields and the optimum values (29.8 Nm/g tensile index and 2.73 Kpa m2/g burst index) acceptable to obtain paper sheets

Air cavity-based vibrational piezoelectric energy harvesters

Introduction. Known vibrational energy harvesting methods use a source of vibration to harvest electric energy. Piezoelectric material works as a sensing element converted mechanical energy (vibration) to electrical energy (electric field). The existing piezoelectric energy harvesting (PEHs) devices have low sensitivity, low energy conversion, and low bandwidth. The novelty of the proposed work consists of the design of PEH’s structure. Air cavity was implemented in the design where it is located under the sensing membrane to improve sensitivity. Another novelty is also consisting in the design structure where the flexural membrane was located at the top of electrodes. The third novelty is a new design structure of printed circuit board (PCB). The purpose of improvised design is to increase the stress in between the edges of PEH and increase energy conversion. With the new structure of PCB, it will work as a substrate that absorbs surrounding vibration energy and transfers it to sensing element. Methods. Three techniques were successfully designed in PEH and fabricated namely PEH A, PEH B, and PEH C were characterized by two experiments: load and vibration. The load experiment measured load pressure towards the PEH, whereas the vibration experiment measured stress towards the PEH. Results. PEH C has the highest induced voltage for a weight of 5.2 kg at the frequency of 50 Hz and the highest stored voltage for a period of 4 min. The three techniques applied in PEHs were showed improvement in transducer sensitivity and energy conversion. Practical value. A piezoelectric acoustic generator was used in the experiment to compare the performance of the designed PEH with available piezoelectric transducers in the market. The new flexible membrane worked as a sensing element was worked as a cantilever beam. PVDF was used as a sensing element due to the flexibility of the polymer material, which is expected to improve sensitivity and operating bandwidth.Вступ. Відомі методи збору вібраційної енергії використовують джерело вібрації для збору електричної енергії. П’єзоелектричний матеріал працює як чутливий елемент, перетворюючи механічну енергію (вібрацію) в електричну енергію (електричне поле). Існуючі пристрої збору п’єзоелектричної енергії (ЗПЕ) мають низьку чутливість, низьке перетворення енергії і малу смугу пропускання. Новизна запропонованої роботи полягає в проектуванні конструкції ЗПЕ. У конструкції реалізована повітряна порожнина, яка розташована під чутливої мембраною для підвищення чутливості. Ще один елемент новизни полягає в конструкції, в якій вигиниста мембрана розташована у верхній частині електродів. Третя новизна - це нова конструкція друкованої плати. Мета запропонованої конструкції - збільшити механічну напругу між краями ЗПЕ і підвищити перетворення енергії. Завдяки новій конструкції друкованої плати вона буде працювати як підкладка, яка поглинає навколишню енергію вібрації і передає її на чутливий елемент. Методи. Три методи були успішно використані для проектування ЗПЕ,  і відповідно названі виготовлені ЗПЕ A, ЗПЕ Б і ЗПЕ В були описані двома експериментальними характеристиками: навантаження і вібрація. В експерименті з навантаженням вимірювався тиск навантаження на ЗПЕ, в той час як в експерименті з вібрацією вимірювалася механічна напруга на ЗПЕ. Результати. ЗПЕ В має найвищу індуковану напругу для ваги 5,2 кг при частоті 50 Гц і найвищу збережену напругу протягом 4 хвилин. Три методи, що застосовуються для ЗПЕ, показали поліпшення чутливості перетворювача і перетворення енергії. Практична цінність. В експерименті використовувався п’єзоелектричний акустичний генератор для порівняння характеристик розробленого ЗПЕ з доступними на ринку п’єзоелектричними перетворювачами. Нова гнучка мембрана працювала як чутливий елемент, що представляв собою консольну балка. В якості чутливого елемента використовувався полівініліден фторид завдяки гнучкості полімерного матеріалу, який, як очікується, поліпшить чутливість і робочу смугу пропускання

Effect of operating temperature on direct recycling aluminium chips (AA6061) in hot press forging process

A method of solid-state recycling aluminum alloy using hot press forging process was studied as well as the possibility of the recycled chip to be used as secondary resources. This paper presents the results of recycled AA6061 aluminium alloy chip using different operating temperature for hot press forging process. Mechanical properties and microstructure of the recycled specimens and as-received (reference) specimen were investigated. The recycled specimens exhibit a good potential in the strength properties. The result for yield strength (YS) and ultimate tensile strength (UTS) at the minimum temperature 430˚C is 25.8 MPa and 27.13 MPa. For the maximum operating temperature 520˚C YS and UTS are 107.0MPa and 117.53 MPa. Analysis for different operating temperatures shows that the higher temperatures giving better result on mechanical properties and finer microstructure. The strength of recycled specimen increases due to the grain refinement strengthening whereas particle dispersion strengthening has minor effects. In this study, the recycled AA6061 chip shows the good potential in strengthening as the comparison of using only 17.5% of suggested pressure (70.0/400.0) MPa, the UTS exhibit 35.8% (117.58/327.69) MPa. This shows a remarkable potential of direct recycling by using hot press forging process

A Novel Right Handed Circular Polarization Folded Reflectarray Antenna at 60 GHz

A novel right-handed circular polarization (RHCP) folded reflectarray antenna with optimized parameters is presented at 60GHz. The RHCP folded reflectarray antenna is designed using left handed circularly polarized selective surface (LHCPSS) Pierrot unit cell. Through simulation, it is shown that the antenna operates well at 60GHz. The maximum antenna directivity is 19dB with a reflection coefficient below -15dB. The radiation patterns showed good responses with side lobes level below -10dB. In addition, the best axial ratio at 60GHz is achieved as 0.75dB

Miniturize flexible RFID antenna design using metamaterial structure

Radio Frequency Identification (RFID) is the application of electromagnetic fields to identify and track tags that attached on the objects. It transmits or reads the radio frequency waves in the system. However, due to rapid development of technology in telecommunication, a much more smaller and flexible device is needed. Therefore, in this paper, a new design of flexible RFID antenna using metamaterial structure has been proposed. At first, the basic rectangular microstrip patch antenna with resonant frequency of 900MHz is designed. Then, the CSRR metamaterial structure is introduced at the ground plane to reduce the size of the antenna while the polydimethylsiloxane (PDMS) material is being use as the antenna substrate for flexibility. All the simulation designs were done using CST software. The antenna performances such as resonant frequency, return loss, radiation pattern, gain and bandwidth are then be analyzed and presented. The results show good performances and can be applied for future application

Improvement of a Lightweight Aluminium Cylinder Block Design Using Finite Element Stress Analysis

A SAE technical paper (2012-01-0406) has discussed about the design and manufacturing method of a lightweight cylinder block made from cast iron. In applying the features discussed in the paper to an aluminium cylinder block with a different displacement, certain modifications need to be made to the previously proposed design. In addition to that and following the ongoing trend, many modern engines have a boosting system thus necessitating the engines to be designed to withstand a higher peak combustion pressure. The mentioned SAE paper has a proven design for a 2-liter cylinder block, but the maximum peak cylinder pressure is only about 85 bar representing the naturally-aspirated engine. Thus, the new proposed design simulating a boosted engine with maximum pressure up to 120 bar requires modifications to be made especially to the critical fasteners in terms of the bolt designs, engaged thread and the structural reinforcements of the bolt bosses. The cylinder block was modelled using CATIA V5 software and stress analysis of the baseline and proposed designs were done using the same software to analyse the critical area and force distribution. Two main areas have been investigated which are near cylinder head bolt thread area and near crankshaft bearing cap thread area. It was found that, the alterations manage to increase the factor of safety and eliminating the concentrated force at certain locations. The design modifications made can improve the factor of safety by decreasing the stress and adding more structural strength focusing on cylinder head bolt threaded area and crankshaft bearing cap thread area

The impact of regional development towards the well-being of rural community

Since before the British rule, the issues and problems of urban transformation growth have continued until today, especially in rural areas and small towns. Rural communities also have undergone significant transformations in recent decades. There are positive and negative impacts on adaptation the growth of regional development that impact significantly on the rural community, which needs to be addressed to overcome the adverse effects on those that involved. This also included the changes in a case study of rural areas that have been chosen, which is located in sub-district that categorize under rural areas at Johor Bahru due to Iskandar Malaysia region expansions. Furthermore, the developmental transformation has mainly affected the changes in the socio-economic well-being of rural communities. Therefore, the purpose of this paper is to provide an overview of studies on a factor of socio-economic well-being development in rural areas for creating a framework to measure the impact of regional development on the socio-economic well-being of the rural

Experimental investigation of recycled machining coolant mixed with nanofluids based Al2O3

Machining coolant is used in manufacturing industry for lubrication, rusting control and cooling which are crucial in operations such as grinding and cutting process. However, the machining coolant lose efficiency in months due to the thermal degradation and contamination. To recycle the used of machining coolant while enhancing the performance, the mixture of nanofluids (N) based Al2O3 with better thermal properties to synthesize with the recycled machining coolant (RMC). This study suspended Al2O3 nanofluids in four base ratios of recycled machining coolant (i.e. 0:100, 20:80, 40:60 and 60:40) by ultrasonic homogenies. The three main parameters in cooling rate performance and rusting control are thermal conductivity, dynamic viscosity and pH indication, respectively. The thermal conductivity and dynamic viscosity are then measured at temperature range of 30 to 60°C. The highest enhancement of thermal conductivity was evaluated to be 37.9% higher than machining coolant base fluid at the temperature of 60°C in 60:40 (N:RMC). However, the enhancement of dynamic viscosity was measured to be 4.5% for 60:40 (N:RMC) at 60°C. The pH value of 60:40 (N:RMC) at ambient temperature obtained 8.18 value was nearly neutral and decreased the rusting process. Therefore, this study recommends the use of recycled machining coolants based Al2O3 as cutting fluid in the ratio of 60:40 for application in machining operations

Dielectric study of electrolyzed rubber

Rubber was produced by placing rubber latex between two electrodes between which an external voltage was maintained. The thickness of the rubber deposited on the anode was measured as a function of time of electrolysis, voltage applied across the electrodes and distance between the electrodes. Based on the observed dielectric responses of rubber obtained through the electrolysis process, an electrical model of conductance and complex capacitance elements linked in parallel is proposed, indicating the additive nature of the individual responses in the system. Electrical representation of rubber obtained by simple drying however showed two different models. Natural rubber was found to have all the elements connected in parallel while that of vulcanized rubber was found to have a series connection of a pair of parallel connected conductance and capacitance elements