Determination of effective diffusion coefficient of immobilized Baker's yeast invertase in various concentration of PVA-alginate matrix

Baker's yeast invertase is immobilized in PVA-alginate matrix using an improved method. PVA beads were prepared by adding calcium alginate to improve its stability, mechanical and chemical properties. Boric acid was used as the cross-linking agent and additional chemicals consisting of 10% boric acid and sodium sulphate solution was used as a treatment solution to harden the PVA-alginate beads. The determination of the effective diffusion of PVA-alginate matrix the vital step in optimizing the preparation of immobilized and water-soluble biocatalyst. In this study the two-level full factorial design was used to investigate the effect of PVA and boric acid concentrations and diffusions coefficient. Diffusion coefficient (De) is one of the factors that significantly affect the mass transport within the immobilization matrix. De value varies for each concentration of PVA and boric acid. The result concluded that both factors significantly affect the De. A maximum De value of 5.0141 x 10(-5) cm2s-1 was obtained at boric acid and PVA concentraion of 7w/v and 10.5 w/v respectively

Biosugar production from oil palm mesocarp fiber (OPMF) using viscozyme

In this study, the performance of HNO3 and NaOH pretreatmentson oil palm mesocarp fiber (OPMF) was evaluated based on the residual carbohydrate. The best pretreatment condition was ascertained for reducing sugar and biosugar produced after saccharification with viscozyme. The pretreatment with 2 % (v/v) HNO3 improved cellulose concentration from 33.14 % to 60.0 %, while hemicellulose, lignin and ash were reduced by 25.59 %, 10.0 % and 25.9 % to 10.0 %, 5.33 % and 3.0 %, respectively. Enzymatic treatment using 1g solid loading, produce highest production in terms of arabinose 10.5 g/l, glucose (1.1 g/L) and xylose (0.42 g/L) was obtained under agitation. While for 10 grams solid loading, highest level of bio-sugar was obtained with arabinose (0.8 g/L) and glucose (1.6 g/L). FESEM-EDX and FTIR images before and after saccharification successfully showed the effect of enzymatic treatment on the mesocarp fiber

Analisis Stabilitas Lereng Embung Dengan Menggunakan Kombinasi Dinding Penahan Kantilever Dan Geotekstil Dengan Bantuan Perangkat Lunak

Lereng yang terbentuk dari pembangunan embung atau waduk dapat berpotensi terjadinya kelongsoran dan dapat mengakibatkan bukan hanya kerugian materil, tetapi juga nyawa. Dinding penahan menjadi salah satu solusi untuk mengatasi kelongsoran. Dinding penahan yang dibangun tersusun dari tiga bagian yaitu dinding penahan batu kali, bronjong dan dinding penahan kantilever. Namun dinding penahan tersebut mengalami ambles sehingga lereng yang ditahannya pun mengalami longsor. Dinding penahan yang memiliki tinggi 10 tersebut mengalami kegagalan struktur karena kondisi tanah yang tergolong jelek dan beban berlebih dengan menggunakan konstruksi bronjong dan pasangan batu kali, sehingga diperlukan analisis ulang pada kondisi dinding penahan tanah yang lama dan diganti dengan yang baru perkuatan dan perbaikan dengan bantuan perangkat lunak SLOPE/W dan Geo 5. Analisis stabilitas lereng eksisting dengan program SLOPE/W pada kondisi paling kritis diperoleh nilai angka keamanan 0,454. Sedangkan analisis stabilitas dinding penahan tanah eksisting dengan program Geo 5 didapatkan angka keamanan stabilitas guling sebesar 1,38, stabilitas geser 0,42 dan daya dukung sebesar 0,23. Hasil tersebut membuktikan struktur lereng dan dinding penahan tidak aman, maka dilakukanlah desain ulang menggunakan perkuatan geotekstil woven dengan jumlah 5 lapis, kapasitas tarik 200 kN/m, kohesi 3 kPa dan sudut geser terhadap tanah 38o, jarak vertikal 1 m. Perbaikan pada geometri lereng dibuat lebih landai dengan kemiringan sebesar 17 ̊. Hasil analisis stabilitas lereng yang diperkuat dengan geotekstil menggunakan SLOPE/W diperoleh nilai angka keamanan 2,312. Untuk analisis stabilitas dinding penahan dengan perkuatan geotekstil didapatkan angka keamanan stabilitas guling 11,73, stabilitas geser 2,226 dan daya dukung 3,856

Isolation and characterization of polyhydroxyalkanoates (PHAS) producing bacteria from brackish stream

Polyhydroxyalkanoates (PHAs) are biopolymers which have similar characteristics with petrochemical plastics but a step better due to its biodegradable property. A total of 23 strains were isolated from two different brackish sources. In order to detect the PHAs granules, the PHAs producing bacteria were first screened with Sudan Black B staining. Twenty strains were observed with lipid granules and were subjected to further confirmation with Nile blue staining. From the Nile blue staining, only 10 strains have the ability in producing PHAs and 2 were identified as strong PHAs producers. This study focuses on the 2 strains named S1 and L1. Further identification procedure was carried out and found that strain S1 and L1 belongs to Pseudomonas sp. L1 strain was found to be promising for PHAs production since it accumulated PHAs for about 88.3%. The PHAs produced by this strain was analyzed using Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) analysis and was identified as poly-3-hydroxybutyrate (P-3HB)

Development of hybrid coconut shell-peek adsorbent for methane adsorption: optimization using response surface methodology

Adsorbed natural gas (ANG) provides efficient and clean combustion, with minimal emissions compared to diesel and gasoline. This article was designed to develop techniques of ANG for transportation application by apply RSM and CCD to identify the optimum preparation conditions for preparation of stable adsorbent for methane adsorption. Coconut shell and poly ether ketone (PEEK) was selected for synthesis of activated carbon (AC). The effectiveness of the parameters was determined using response surface method (RSM) couple with central composite design (CCD). The analysis of variance (ANOVA) was applied to identify the significant parameters. The quadratic model was adopted, as it has the highest F-value of 21.62 and P-value of less than 0.05, which relate the parameters and response. Microwave power has the highest F-value of 62.36. The maximum methane uptake of 5.12mmol g-1 was achieved. Overall, the hybrid coconut-PEEK adsorbent was found to be suitable for CH4 adsorption

High Voltage Durability of Bambusa Vulgaris as a Bio-composite Material

This study is conducted in order to measure and identify the ability of a bio-composite material to the high voltage. According to it, the developed bio-composite material is tested to ensure the maximum voltage that the material can hold. The bio-composite material which made from a mixture of Bambusa Vulgaris and a selected polymer named as High Density Polyethylene (HDPE). The Bambusa Vulgarisis going through several processes before mixed together with HDPE using wood plastic composite (WPC) technique which also consists of several stages. There are several samples of bio-composite substance are fabricated. The difference among them is the composition of the raw materials (Bambusa Vulgaris and HDPE) used. In this research, the high voltage measurement which also called as breakdown voltage measurement of the bio-composite material is examined by using appropriate experiments. All the experimental results are presented and discussed in this paper

User friendly system for the visually impaired in learning Al-Quran

This study presents a method to enable the visually impaired Muslim to learn and read the Al-Quran using Braille Display with software help. The system reads the database which contains all verses of Al-Quran and user will need to select the verse and ayah to read. Besides that, this system can be used in a class to teach visually impaired students to learn Al-Quran. Every word or character typed by the instructor in the main Braille Panel will be transmitted to the sub Braille Panel that is connected to the main Braille Panel. The selected verse of Al-Quran and ayah will also generate an index before being transmitted to the Braille Panel. The index will be transmitted to the Braille Display for people to touch and read the display. A user friendly Graphical User Interface (GUI) will be used to fulfill the ergonomics for the visually impaired user's physical capabilities. Several approaches are used to design and implement the interface for the visually impaired like speech or sound output and Braille display. The Braille codes can be displayed using the Braille panel. The design interface and structure of the system for the visually impaired users in learning Al-Quran is presented

Microwave assisted K2CO3 palm shell activated carbon as sorbent for CO2 adsorption application

Carbon dioxide is believed to be a major greenhouse gas (GHG) that contributes to global warming. In this study, palm shells were used as a precursor to prepare CO2 activated carbon sorbents via carbonization, chemical impregnation with K2CO3 and microwave activation. Adsorption equilibrium data for CO2 adsorption on the porous carbon were obtained at different temperatures using static volumetric adsorption method. Langmuir, Freundlich, Sips and Toths models were used to correlate the experimental data. The CO2 adsorption capacity at 303.15, 343.15, 378.15 443.15 K and 1 bar on the sorbent was 2.71, 1.5, 0.77, 0.69 mmol/g respectively. Sips isotherm was found to have the best fit. The results indicated that the porous carbon sorbent prepared by carbonization and microwave K2CO3 assisted activation have good CO2 uptake. The porous carbons produced are therefore good candidates for CO2 adsorption applications

An improvement in support vector machine classification model using grey relational analysis for cancer diagnosis

To further improve the accuracy of classifier for cancer diagnosis, a hybrid model called GRA-SVM which comprises Support Vector Machine classifier and filter feature selection Grey Relational Analysis is proposed and tested against Wisconsin Breast Cancer Dataset (WBCD) and BUPA Disorder Dataset. The performance of GRA-SVM is compared to SVM’s in terms of accuracy, sensitivity, specificity and Area under Curve (AUC). The experimental results reveal that GRA-SVM improves the SVM accuracy of about 0.48 by using only two features for the WBCD dataset. For BUPA dataset, GRA-SVM improves the SVM accuracy of about 0.97 by using four features. Besides improving the accuracy performance, GRA-SVM also produces a ranking scheme that provides information about the priority of each feature. Therefore, based on the benefits gained, GRA-SVM is recommended as a new approach to obtain a better and more accurate result for cancer diagnosis

A review on environmental DNA (eDNA) metabarcoding markers for wildlife monitoring research

Environmental DNA or eDNA utilizes traceable genetic materials in the environment for monitoring the presence of organisms in a given area and it is now gaining popularity as an alternative for traditional monitoring methods. Thus, the selection of genetic markers is crucial for identification of species in wildlife monitoring. This paper aims to review several DNA markers which are appropriate and reliable for detection of organisms from the environmental samples. We performed systematic literature search from SCOPUS database to review all molecular markers of eDNA. This study focuses on the importance of markers selection which can be utilized by next-generation sequencing (NGS) for biodiversity monitoring. Cytochrome C oxidase Subunit I (COI) are noted as the most widely used marker in metabarcoding research for detection of targeted species