Simulation of sub-drains performance using visual MODFLOW for slope water seepage Problem

Numerical simulation technique was used for investigating water seepage problem at the Botanic Park Kuala Lumpur. A proposed sub-drains installation in problematic site location was simulated using Modular Three-Dimensional Finite Difference Groundwater Flow (MODFLOW) software. The results of simulation heads during transient condition showed that heads in between 43 m (water seepage occurred at level 2) until 45 m (water seepage occurred at level 4) which heads measurement are referred to mean sea level. However, elevations measurements for level 2 showed the values between 41 to 42 m from mean sea level and elevations for level 4 between 42 to 45 m from mean sea level. These results indicated an increase in heads for level 2 and level 4 between 1 to 2 m when compared to elevations slope at the level 2 and level 4. The head increases surpass the elevation level of the slope area that causing water seepage at level 2 and level 4. In order to overcome this problems, the heads level need to be decrease to 1 until 2 m by using two options of sub-drain dimension size. Sub-drain with the dimension of 0.0750 m (diameter), 0.10 m (length) and using 4.90 m spacing was the best method to use as it was able to decrease the heads to the required levels of 1 to 2 m

Simulation of sub-drains performance using visual MODFLOW for slope water seepage Problem

Numerical simulation technique was used for investigating water seepage problem at the Botanic Park Kuala Lumpur. A proposed sub-drains installation in problematic site location was simulated using Modular Three-Dimensional Finite Difference Groundwater Flow (MODFLOW) software. The results of simulation heads during transient condition showed that heads in between 43 m (water seepage occurred at level 2) until 45 m (water seepage occurred at level 4) which heads measurement are referred to mean sea level. However, elevations measurements for level 2 showed the values between 41 to 42 m from mean sea level and elevations for level 4 between 42 to 45 m from mean sea level. These results indicated an increase in heads for level 2 and level 4 between 1 to 2 m when compared to elevations slope at the level 2 and level 4. The head increases surpass the elevation level of the slope area that causing water seepage at level 2 and level 4. In order to overcome this problems, the heads level need to be decrease to 1 until 2 m by using two options of sub-drain dimension size. Sub-drain with the dimension of 0.0750 m (diameter), 0.10 m (length) and using 4.90 m spacing was the best method to use as it was able to decrease the heads to the required levels of 1 to 2 m

Impact of Teaching Cohesive Devices on L2 Students\u27 Language Accuracy in Written Production

A well-written text is not only grammatical, but also cohesive and coherent. Cohesive devices play the most basic role in cohesion of a text and should be taken into consideration in teaching writing. This paper reports on a study investigating the impact of teaching academic text cohesive devices on L2 students\u27 language accuracy in written production. The main objective of the study is to find out if teaching cohesive devices would enhance students\u27 prior knowledge and subsequently result in increased written language accuracy. Based on a pre-post-test research design, 40 students enrolled in English for Academic Purposes course at a university in Malaysia were engaged as participants. A note-taking test was conducted prior to and post intervention. The intervention consisted of lessons on academic text cohesive devices. The data was then analysed and reported using descriptive statistics and paired sample t-test. From the findings, it is clear that there is an increase in the minimum and maximum scores as well as in the mean scores between the pre- and post-test. More importantly, there is evidently a significant improvement in the participants\u27 post-test language accuracy as evaluated through number of error-free t-units. In sum, the teaching of academic text cohesive devices does have a significant impact on language accuracy in written production. Hence, this study recommends L2 learners\u27 prior knowledge activation to enhance written language accuracy

Performance Investigation of Dual Wavelength Fiber Laser using different SOAs

We investigated the performance of a dual wavelength fiber laser (DWFL) using different types of semiconductor optical amplifiers (SOAs) utilizing fiber Bragg gratings (FBGs) as comb filter. The lasing performances of linear SOA (LSOA), nonlinear SOA (NLSOA) and booster optical amplifier (BOA) at different current setting were observed. LSOA produced the flattest spectrum based on its peak power difference at only 4.5 dB as compared to 66.4 dB using BOA. BOA has the worst flatness because its polarization sensitivity is the highest as compared to LSOA and NLSOA. Overall, the best lasing performance is when LSOA is used due to the lowest peak power difference with high peak power at -17.6 dBm

Determining the Compressive, Flexural and Splitting Tensile Strength of Silica Fume Reinforced Lightweight Foamed Concrete

This study investigated the performance of the properties of foamed concrete in replacing volumes of cement of 10%, 15% and 20% by weight. A control unit of foamed concrete mixture made with ordinary Portland cement (OPC) and 10%, 15% and 20% silica fume was prepared. Three mechanical property parameters were studied such as compressive strength, flexural strength and splitting tensile of foamed concrete with different percentages of silica fume. Silica fume is commonly used to increase the mechanical properties of concrete materials and it is also chosen due to certain economic reasons. The foamed concrete used in this study was cured at a relative humidity of 70% and a temperature of ±28°C. The improvement of mechanical properties was due to a significant densification in the microstructure of the cement paste matrix in the presence of silica fume hybrid supplementary binder as observed from micrographs obtained in the study. The overall results showed that there is a potential to utilize silica fume in foamed concrete, as there was a noticeable enhancement of thermal and mechanical properties with the addition of silica fume

The use of locus specific microsatellite markers for detecting genetic variation in hatchery bred probarbus jullieni.

This study is to demonstrated that microsatellites markers developed for Tor tambroides can be used to amplify microsatellite loci in other family. It is assumed that microsatellite loci are more conserved for aquatic species compared to terrestrial ones due to aquatic environments are less mutagenic than terrestrial ones. Development of microsatellites still requires investment of time and resources. Thus using loci already developed in a related species may provide a cost-effective alternative to microsatellite isolation and development in a species of interest in present study, Probarbus jullieni. In this study we investigated the possibility of the conservation of microsatellite flanking regions among different species. Nine pairs of SSR primers, five gave very strong banding profile (SYK1, SYK 2, SYK 5 SYK 8 and SYK 9) which could be used for population studies by using the nested protocol. Results showed that SYK 2 and SYK 9 flanked the same (CA)n repeats and thus are highly conserved in a different species. The products of the SYK 5, 8 and 1 primer pairs showed differences in the microsatellite regions which they flanked in Probarbus jullieni when compared to those of the source species, Tor tambroides. The mean observed heterozygosity levels for all the primers ranged 0.23-0.81. The primers are all polymorphic with the mean number of alleles from 2-5

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

A Review: Study on Spent Garnet as Construction Material

Numerous environmental problems are mitigated by natural resource depletion, with yearly global use of nearly 25 billion tonnes, including aggregates. Fast industrial growth has witnessed the ever-increasing exploitation of sand from rivers for various construction resolves, which caused an over-exploitation of rivers’ beds and disturbed the eco-system. This problem is also related to the amount of waste produced each year. The volume of waste is estimated to rise, reducing available space and causing pollution. Many studies have discovered inventions and ideas to deal with this situation. Some researchers use the spent garnet in a concrete mix as a partial fine aggregate replacement. The alternative in a concrete mix depends on the properties of the spent garnet that is used and its appropriateness. In this paper, a critical review of spent garnet were discussed in detail

A Review: Study on Spent Garnet as Construction Material

Numerous environmental problems are mitigated by natural resource depletion, with yearly global use of nearly 25 billion tonnes, including aggregates. Fast industrial growth has witnessed the ever-increasing exploitation of sand from rivers for various construction resolves, which caused an over-exploitation of rivers’ beds and disturbed the eco-system. This problem is also related to the amount of waste produced each year. The volume of waste is estimated to rise, reducing available space and causing pollution. Many studies have discovered inventions and ideas to deal with this situation. Some researchers use the spent garnet in a concrete mix as a partial fine aggregate replacement. The alternative in a concrete mix depends on the properties of the spent garnet that is used and its appropriateness. In this paper, a critical review of spent garnet were discussed in detail

Component commonality in multistage production system: Models with capacity constraints

Common components are used extensively for production postponement, reduction of proliferated product lines cost, reduction of the cost of safety stock, increase productivity, improve flexibility, expediting new product development and so on. The authors consider a multistage assemble-to-order system with two products have uniformly distributed demand, one common component and product-specific components. We develop optimization models for minimizing the level of inventory of the components and allocated to products to meet capacity limitation. A numerical example is used to verify and compare the models with similar models