The Effect of Functionalization Carbon Nanotubes (CNTs) on the Performance of PES-CNTs Mixed Matrix Membrane

A new type of mixed matrix membrane consisting of functionalized carbon nanotubes (CNTs) and polyethersulfone (PES) is prepared for biogas purification. PES mixed matrix membrane with and without modification of carbon nanotubes were prepared by a dry/wet phase inversion technique using a pneumatically flat sheet membrane casting machine system. The modified carbon nanotubes were prepared by treating the carbon nanotubes with chemical modification using Dynasylan Ameo (DA) silane agent to allow PES chains to be grafted on carbon nanotubes surface. The results from the FESEM, DSC and FTIR analysis confirmed that chemical modification on carbon nanotubes surface had taken place. Meanwhile, the nanogaps in the interface of polymer and carbon nanotubes were appeared in the PES mixed matrix membrane with unmodified of carbon nanotubes. The modified carbon nanotubes mixed matrix membrane increases the mechanical properties, the productivity and purity of biogas. For PES-modified carbon nanotubes mixed matrix membrane the maximum selectivity achieved for CO2/CH4 is 36.7

Application of Activated Carbon Mixed Matrix Membrane for Oxygen Purification

This study is performed primarily to investigate the effect of activated carbon on oxygen separation performance of polyethersulfone mixed matrix membrane. In this study, polyethersulfone (PES)-activated carbon (AC) mixed matrix membranes were fabricated using dry/wet technique. This study investigates the effect of polyethersulfone concentration and activated carbon loading on the performance of mixed matrix membrane in terms of permeability and selectivity of O2/N2 gas separation. The fabricated flat sheet mixed matrix membranes were characterized using permeation test, Field Emission Scanning Electron Microscopy (FESEM) analysis and Differential Scanning Calorimetry (DSC). It was found that the activated carbon loading affected the gas separation performance of mixed matrix membrane. PES- 1wt% AC membrane yielded 3.75 of O2/N2 selectivity, however 5 wt% of AC can produced 5 O2/N2 selectivit

Penerapan Metode Retad Untuk Mengurangi Waktu Set Up Pada Mesin Milling P1 Dan P2 Departemen Machining PT. Kubota Indonesia

Pengurangan waktu produksi dalam suatu proses produksi dapat dilakukan dengan meminimalkan waktu setup pada proses produksi tersebut. Untuk mengurangi waktu setup diperlukan suatu cara untuk membantu operator dalam melaksanakan proses milling sehingga dapat meminimalkan waktu setup serta dapat menghilangkan elemen kerja yang tidak produktif tersebut. Metode RETAD (Rapid Exchange of Tooling and Dies) merupakan pengembangan dari metode SMED (Single Minuite Exchange of Dies) yang bertujuan mengurangi waktu setup, menghapus scrap dan rework. Dari hasil pengolahan data dan analisis untuk proses milling pada mesin Milling Vertikal P1, waktu elemen kerja membersihkan jig dari geram dapat dikurangi dari 5.53 detik sebelum perbaikan menjadi 1.54 detik setelah perbaikan dan untuk mesin Milling Vertikal P2, waktu elemen kerja membersihkan jig dari geram dapat dikurangi dari 5.15 detik menjadi 1.54 detik. Dari hasil di atas maka dapat disimpulkan bahwa terjadi perbaikan waktu setup pada proses milling pada Mesin Milling Vertikal P1 dan P2 di Cylinder Head Line, perbandingan waktu standar proses milling dari 258.505 detik sebelum perbaikan menjadi 254.518 detik setelah perbaikan pada mesin Milling Vertikal P1 dan 256.002 detik sebelum perbaikan menjadi 252.392 detik setelah perbaikan pada mesin Milling Vertikal P2 Untuk penelitian ini hasil tersebut merupakan hasil maksimal yang dapat dicapai, namun dapat dikembangkan lebih lanjut pada mesin-mesin produksi lainnya. Kata kunci : RETAD, waktu setup, elemen kerj

Effect of different additives on the physical and chemical CO 2 absorption in polyetherimide hollow fiber membrane contactor system

Porous asymmetric polyetherimide (PEI) hollow fiber membranes were fabricated via a phase-inversion method using ethanol, glycerol and acetone as the additives in the spinning dope. Also, hollow fiber PEI membrane without additives was fabricated. An aqueous solution of 1-methyl-2-pyrrolidone (80 wt.%) was used as bore fluid to prevent forming of an inner dense skin layer. The precipitation rate of the polymer dopes with the different additives was studied using cloud point measurement. The effect of the additives on the resulting membrane structure, surface porosity, pore size, critical water entry pressure, collapsing pressure and physical and chemical CO2 absorption performance by distilled water and NaOH (1 M) solution in a gas–liquid membrane contactor system were investigated and compared. Cloud point diagrams indicated that the precipitation rate of the polymer dopes increased following the trend of ethanol > acetone > glycerol. Results of gas permeation tests showed that ethanol and glycerol as additives provided the membranes with the largest and smallest pore size, respectively. Moreover, all the additives resulted in an increase in the effective surface porosity. The cross-section of the membranes was examined via a scanning electron microscopy. Ethanol in the spinning dope provided the membrane structure with a sublayer with finger-like macrovoids, originating from the inner and outer surfaces of the hollow fiber and extending to the middle section of the hollow fiber wall, which resulted in a larger pore size and higher CO2 absorption rate than the other PEI hollow fiber membranes

Foam Behaviour of an Aqueous Solution of Piperazine- N-Methyldiethanolamine (MDEA) Blend as a Function of the Type of Impurities and Concentrations

This study focuses on the effect of impurities in the natural gas stream on the characteristic of foam behaviour in the blended piperazine and MDEA solution. Hydrocarbon liquids, Iron Sulphide, Sodium Chloride, Acetic Acid, Methanol and Polyethylene Glycol were used as the impurities. The results indicated that the type of impurities determined the foam formation of the amine solution. The concentration of piperazine-MDEA blends also enhanced to the increasing of the foam height of blended piperazine-MDEA. Iron sulfide, hydrocarbon and sodium chloride are the impurities which apparently contributed to the high foaming tendency of the solutions. At the same concentration of the impurities, iron sulfide appeared as the most influential contaminant to the foam formation, which promoted the highest foamability in any concentrations of the blend piperazine-MDE

Fabrication and Characterization of Polyimide-CNTs Hybrid Membrane to Enhance High Performance CO2 Separation

This study investigates the CO2 separation performance of a hybrid membranes flat sheet based on polyimide incorporated with carbon nanotubes (CNTs) particles. CNTs was selected and its loading were a 1 wt% in total solid. The hybrid composite membranes were fabricated in order to increase their separation performance for the gaseous mixture of CO2 and CH4. Hybrid Composite membrane incorporated carbon nanotubes were mannufactured by the dry-wet phase inversion technique using flat sheet membrane casting machine system, in which the CNTs were embedded into the polyimide membrane and the resulting membranes were characterized. The results from the FESEM, DSC and FTIR analysis confirmed that chemical modification on carbon nanotubes surface had taken place. Sieve-in-a-cage\u27 morphology observed shows the poor adhesion between polymer and unmodified CNT. The results revealed that the good multi-wall carbon nanotubes dispersion leads to enhanced gas permeation properties. It is also concluded that addition of carbon nanotubes particles into the matrix of Polyimide polymer has significant effect on the membrane structure and properties

The effect of short duration resistance training on insulin sensitivity and muscle adaptations in overweight men

The aim of the study was to investigate the effects of 6 weeks of resistance exercise training, composed of one set of each exercise to voluntary failure, on insulin sensitivity and the time course of adaptations in muscle strength/mass. Ten overweight men (age 36 ± 8 years; height 175 ± 9 cm; weight 89 ± 14 kg; body mass index 29 ± 3 kg m−2) were recruited to the study. Resistance exercise training involved three sessions per week for 6 weeks. Each session involved one set of nine exercises, performed at 80% of one‐repetition maximum to volitional failure. Sessions lasted 15–20 min. Oral glucose tolerance tests were performed at baseline and post‐intervention. Vastus lateralis muscle thickness, knee‐extensor maximal isometric torque and rate of torque development (measured between 0 and 50, 0 and 100, 0 and 200, and 0 and 300 ms) were measured at baseline, each week of the intervention, and after the intervention. Resistance training resulted in a 16.3 ± 18.7% (P < 0.05) increase in insulin sensitivity (Cederholm index). Muscle thickness, maximal isometric torque and one‐repetition maximum increased with training, and at the end of the intervention were 10.3 ± 2.5, 26.9 ± 8.3, 18.3 ± 4.5% higher (P < 0.05 for both) than baseline, respectively. The rate of torque development at 50 and 100 ms, but not at 200 and 300 ms, increased (P < 0.05) over the intervention period. Six weeks of single‐set resistance exercise to failure results in improvements in insulin sensitivity and increases in muscle size and strength in young overweight men

Subdural collections due to non-typhi Salmonella infections in two Malaysian children.

Subdural collections caused by Salmonella infection are rarely encountered in children. We present two cases caused by non-typhi Salmonella, one a four-and-a-half-month-old boy presenting with subdural effusion, and the other, a 16-month-old boy with empyema. The diagnosis was confirmed on blood and subdural pus cultures. One patient had status epilepticus following focal fit, and the other had prolonged fever without any localising signs of infection on admission. They responded well to prompt surgical drainage and prolonged systemic antibiotic therapy. Contrary to previous reports, both patients showed favourable outcome in terms of neurological sequela

The Impact of Corporate Reputation on Organizational Performance

The empirical study is carried out in Enterprises. The data was collected using a questionnaire distributed among 100 of the employees. The questionnaire is intended to measure the banks perceived credibility on building and developing the business correlations with the clientele. Regarding the hypothesis’s validation, Multiple Regression Linear statistics were performed using the SPSS software. The research findings revealed a direct interrelation between the independent variables (reputation, image, and culture) and the dependent variable. The higher the organizations importance is, the better its performance