The performance of modified jatropha-based nanofluid during turning process

The industry's extensive use of petroleum-based metalworking fluid (MWF) harms the environment and humans. The production of bio-based MWF, especially from crude jatropha oil (CJO), has therefore taken numerous initiatives. This aimed to formulate newly modified jatropha oil (MJO) with the addition of 0.05wt.% hBN and 0.05wt.% MoS2 as the nanofluid for MWF. The performance of the nanofluids was determined through the turning process in terms of cutting temperature, workpiece surface roughness, tool life and tool wear of the tool lubricated by the nanofluids. The performance of the nanofluid samples was compared with the synthetic ester (SE). From the results, after conducted 100mm axial cutting length MJO+hBN+MoS2 recorded the lowest in cutting temperature and surface roughness compared to all samples. The result shows that MJO+hBN+MoS2 has longer tool life (6500mm) compared to SE (6000mm). Abrasion and adhesion were observed as the dominant tool wear mechanism. In conclusion, MJO+hBN+MoS2 shows better machining performance and has the potential to be an environmentally friendly metalworking fluid

Linear-nonlinear stiffness responses of carbon fiber-reinforced polymer composite materials and structures: a numerical study

The stiffness response or load-deformation/displacement behavior is the most important mechanical behavior that frequently being utilized for validation of the mathematical-physical models representing the mechanical behavior of solid objects in numerical method, compared to actual experimental data. This numerical study aims to investigate the linear-nonlinear stiffness behavior of carbon fiber-reinforced polymer (CFRP) composites at material and structural levels, and its dependency to the sets of individual/group elastic and damage model parameters. In this regard, a validated constitutive damage model, elastic-damage properties as reference data, and simulation process, that account for elastic, yielding, and damage evolution, are considered in the finite element model development process. The linear-nonlinear stiffness responses of four cases are examined, including a unidirectional CFRP composite laminate (material level) under tensile load, and also three multidirectional composite structures under flexural loads. The result indicated a direct dependency of the stiffness response at the material level to the elastic properties. However, the stiffness behavior of the composite structures depends both on the structural configuration, geometry, lay-ups as well as the mechanical properties of the CFRP composite. The value of maximum reaction force and displacement of the composite structures, as well as the nonlinear response of the structures are highly dependent not only to the mechanical properties, but also to the geometry and the configuration of the structures

Deep neural network method for the prediction of xylitol production

Bio-based chemical products such as xylitol have achieved remarkable attentions both in pharmaceutical and food industries due to their several advantages such as sugar substitute that can help diabetic patients and help in preventing tooth decay problem. To produce xylitol, recently, microbial host such as E. Coli often used as it is predicted that E. Coli can produce high level of xylitol. Therefore, metabolic engineering need to be done towards E. Coli and powerful tools are needed to manipulate, simulate and analyse the E. Coli metabolic pathway. Artificial intelligence methods such as deep neural network offer an efficient and powerful approach to be used to analyse the xylitol production value and at the same time to predict which genes and pathway that give biggest effect in the process to produce xylitol in E. Coli. Results show that, with an absence of genes pgi, tkt and tala, xylitol production can be boosted up to the higher level

Pendugaan Kedalaman Air Tanah Menggunakan Metode Geolistrik Konfigurasi Schlumberger Di Desa Bojongsari, Kecamatan Alian, Kabupaten Kebumen

Pendugaan kedalaman air tanah di Desa Bojongsari, Kecamatan Alian, Kabupaten Kebumen menggunakan metode Geolistrik konfigurasi Schlumberger telah dilaksanakan pada tanggal 9 Oktober 2015. Pengukuran geolistrik dilaksanakan dengan cara menginjeksikan arus listrik ke dalam bumi dan mengukur beda potensial yang terjadi di tiga titik lokasi yaitu Bojongsari 01, Bojongsari 02, dan Bojongsari 03. Pengolahan data dan pemodelan dilakukan hingga diperoleh data resistivitas yang merepresentasikan jenis-jenis lapisan batuan bawah permukaan di daerah penelitian. Pada titik Bojongsari 01 lapisan akuiferair tanah dangkal diperkirakan tersusun atas pasir berbutir halus (0,85 Wm) dengan kedalaman 7,35–10,78 m dan lempung pasiran (13,25 Wm) dengan kedalaman 10,78–29,44 m, sedangkan lapisanakuifer dalam tersusun atas pasir berbutir halus (0,44 Wm) pada kedalaman 33,72 – 85,76 m. Pada titik Bojongsari 02 lapisan akuifer dangkal diperkirakan tersusun atas lempung pasiran (19,43 Wm) pada kedalaman 7,61–26,65 m dan pasir lempungan (3,18 Wm) pada kedalaman 26,65–43,32 m, sedangkan lapisan akuifer dalam tersusun atas pasir lempungan (5,97 Wm) pada kedalaman 53,94 m. Pada titik Bojongsari 03 lapisan akuifer dangkal diperkirakan tersusun atas pasir berbutir halus (1,18 Wm) dengan kedalaman 11,28–38,25 m, sedangkan lapisan akuifer dalam tersusun atas lempungpasiran berbutir kasar (28,02 Wm) dengan kedalaman 77,25 m. Berdasarkan hasil pemodelan di atas, lapisan akuifer yang diperkirakan paling cocok dimanfaatkan untuk proyek pengadaan air bersih di Desa Bojongsari, Kecamatan Alian, Kabupaten Kebumen adalah lapisan akuiferair tanah dalam untuk titik Bojongsari 01

Pemanfaatan Limbah Jagung sebagai Substrat dalam Menghasilkan Poli-Β-Hidroksi Butirat (Phb) oleh Isolat Bakteri Asal Pabrik Gula Arasoe Bone

The research about Waste of Corn as Substrate In Produce Poly-β-Hydroxy Butyrate (PHB) by Bacterial Isolates Origin Sugar Factory Arasoe Bone. The research purpose to determine the ability of bacterial isolates from sugar mills Arasoe Bone is BA9 and MA4 and nitrogen concentration optimal for producing the PHB. With usewaste of corn as a source of carbon with a concentration 1%, 2%, 3% and as control positive glucose 1%, as well as use of ammonium sulfate as nitrogen source at a concentration of 0.05%, 0.1% and 0.15%. Total Analysis of PHB done with use UV-VIS spectrophotometer and a wavelength of 235 nm and using analysis a regression equation. The result of this study that use of corn as a source of carbon waste can produce PHB either by BA9 and MA4 isolates though still lower than glucose as the carbon source. The concentration of nitrogen source (ammonium sulfate), which accumulate PHB optimal concentration of ammonium sulfate that is at 0.1%

Metacognitive skills of Malaysian students in non-routine mathematical problem solving

Metacognitive skills play an important role in solving mathematical problems. However, there is a lack of empirical studies on the role of metacognitive skills in solving mathematical problems, particularly non-routine ones. Therefore, this study was undertaken to identify students' metacognitive skills and the impact of such skills on non-routine mathematical problem solving. By using a quantitative method, a total of 304 students in Johor Bahru district were involved in the study. A Self-Monitoring Questionnaire (SMQ) and a mathematical test were used in data collection. Data were analysed using descriptive and inferential statistics such as frequency, percentage, mean, the Mann-Whitney U test, and the Kruskal-Wallis H test. Results showed that the level of the students' performance in solving non-routine mathematical problems was very low. There was also a significant difference in the metacognitive skills among students with different performance levels in solving non-routine mathematical problems, and we concluded that these metacognitive skills should be emphasised in this process

Barrier to Adoption of Integration of Maize-Livestock in Maros, Gowa and Takalar Regency

The advantage of integration of corn and cattle has been promoted through demonstration plot and other extension ways. However, the rate of its adoption is still low and not widely accepted. The purpose of this study was to explore the factors that thwort of farmers from adopting the corn and cattle integration system. Survey method was used in this research and was conducted at Maros (glatinous corn production centre), Gowa district (Sweet corn production centre) and Takalar district (yellow and sweet corn production centre). Data collection were carried out using delphie method with three stages. First stage was to explore the factors that thwort of farmer from adopting the technology using FGD. FGDs were conducted with key informants such as farmers who plant corn and cattle and extension agents. Second and third stages were to reduce the factors into five most important factors. The result showed that the inhibiting factor in adopting utilization of corn stalk for animal feeding in Maros regency was lack of feed storehouse, in Takalar Regency was the lack of knowledge in preserving corn stalk and in Gowa was the availability of many other feed resources. The barrier to adoption of the use of manure as organic fertilizer was the lack of knowledge in composting (in Gowa and Takalar) and the cost of manure processing (in Maros)

Tarekat Naqshabandiyyah Khalidiyyah in Malaysia: a Study on the Leadership of Haji Ishaq Bin Muhammad Arif

: The Tarekat Naqshabandiyyah Khalidiyyah lead by Haji Ishaq has many followers and is also known especially among other tarekat followers in Malaysia. This article is navigating through the leadership of Haji Ishaq Bin Muhammad Arif, the emergence of tarekat Naqshabandiyyah Khalidiyyah he lead and its evolution in Malaysia. Beside the data collected through the manuscript written by Haji Ishaq, his murids works were also studied. Field observations were also performed at several sites that are identified to be the centers of the movement. Also, some senior students of Haji Ishaq were interviewed to strengthen the arguments of the manuscript data. This study had discovered that tarekat Naqshabandiyyah Khalidiyyah lead by Haji Ishaq was large group with many followers, made up of diverse backgrounds, including academicians and professionals. The power of this group is reflected in the extensive network of centers that are located in several states in Malaysia

Kinetic modeling of LDPE pyrolysis using coats-Redfern method

Pyrolysis of polymer waste can potentially be a source of renewable energy, as it is a possible way to produce liquid fuel. In order to industrialize the process, the kinetic behavior of the pyrolysis has to be well understood. In this study, pyrolysis of virgin low density polyethylene (LDPE) was studied using thermogravimetric analysis (TGA). The test was carried out from 303-923 K at 20K/min in a nitrogen atmosphere. The TGA result was used to develop suitable models to calculate the activation energy, E, and pre-exponential factor, A, using Coats-Redfern method. Proximate and elemental analysis was also carried out on the LDPE sample. It was discovered that all reaction models were able to produce satisfactory linear fit of the data, with high correlation coefficients. Therefore, Coats-Redfern method cannot be used alone, but must be coupled with other methods to determine the correct reaction mechanism for the pyrolysis. By assuming first-order reaction, the calculated activation energy and pre-exponential factor are 166.75 kJ/mol and 4.97 x 1011 s-1, respectively

Pattern of Residential Water Demand Analysis for Maiduguri Metropolis, North-Eastern Nigeria

This study investigated the projected 50-year water demand of Maiduguri township from 2006 to 2056. The impact of socio-economic factors on water consumption pattern of the population was also assessed. Data were collected from 200 households using structured questionnaires and analyzed using Statistical Package for the Social Science (SPSS). The results show that on an average, a household in Jere and Maiduguri consumes an estimated 421.85l L/day while areas worst hit are new layouts and those covered by the phase 2 water treatment plant (yet to be completed). In addition, it was found that, gender, education, household size and income were statistically significant predictors of water demand. Furthermore, the results revealed that in 2006, the combined population of Jere and Maiduguri was 749,123, which was later projected to be around 3,618,579 by the year 2056. Similarly, water demand was estimated to rise to approximately 154,443 M3/day by the year 2056 to meet the water demand of the growing population. However, in 2006, the combined water supplied from Maiduguri water treatment plant and all the functional boreholes (public boreholes) stands at 31,973M3/day while in 2016 it rose to 43,811 M3/day. The increase was due to additional supplies obtained from boreholes provided by some Non-Governmental Organization (NGOs) in some locations across the two areas. It is noteworthy that water supplied in the year 2016 to the population was grossly inadequate to meet the household water demand. Therefore, with the projected water demand of about 154,443 M3/day by 2056, it is recommended that all existing water supply schemes including the proposed phase 2 of the Maiduguri surface water treatment plant designed to cover West end, Wulari, Bulunkutu and Maduganari areas to be completed to increase the supply. Service boreholes in newly established layouts should be put to operate at full capacity including the additional ones drilled. Also, the Dala Alamdari mini water works constructed by International Committee of the Red Cross (ICRC) which is operated below its installed capacity due to poor management to be enhanced