Ihzza Hanafi - Academia.edu (original) (raw)

Papers by Ihzza Hanafi

IEEE Transactions on Electron Devices, 2005

Numerical simulation-based study of double-gate (DG) field-effect transistors (FETs) leads to the... more Numerical simulation-based study of double-gate (DG) field-effect transistors (FETs) leads to the possibly viable concept of extremely scaled but nonself-aligned DG CMOS. Predictions of off-state current, on-state current, and circuit performance, accounting for short-channel effects and energy-quantization effects, in 25-nm DG FETs suggest that moderate back-gate underlap does not severely undermine the superior performance and leakage current of nanoscale DG CMOS relative to those of bulk-Si CMOS. The reverse back-gate biasing scheme for leakage reduction in DG CMOS is shown to be much more efficient than the reverse body biasing scheme in bulk Si even with moderate back-gate underlap.

The Journal of the Egyptian …, 2006

This study aimed at assessing the level of patients&a... more This study aimed at assessing the level of patients' satisfaction with primary heath care services after implementation of the electronic medical record system (EMR). Also, to explore the relationship of some participants' characteristics with satisfaction which are of importance in planning, managing and evaluation. A descriptive cross-sectional approach was adopted. Ten primary health care centers (out of total 78) related to the five health regions in Kuwait were randomly selected. A random sample of 200 people (at age of 18 years and above) attending the two-shift periods of the chosen centers were included. Through an exit interview, a well trained investigator interviewed them about their satisfaction with the primary heath care services provided after implementation of electronic medical record system. A structured questionnaire for measuring satisfaction was used. The response rate was 93.02% of whom 47.5% were males and 52.5% were females. The mean overall satisfaction percent score as reported by subjects was 85.6% (SD 4.9). There were statistically significant associations between mean percent satisfaction score of the participants and their age, level of education visiting the center at morning shift, and waiting less than 10 minutes before the examination. The vast majority of participants indicated that overall service at the center had greatly improved after EMR implementation. The system also helped in improvement of the physician performance, arrangement of patient's turn, dispense medication from pharmacy, written guidance of medication, accuracy and easiness of follow up for health status, time spent to retrieve medical record and that for receiving medication. However, it didn't achieve much improvement in physician selection or waiting time. The majority of interviewees (96.5%) were totally satisfied with the overall quality of service at the center, location of the center (96.5%), hours when the center is open (96.5%), thoroughness of examination and accuracy of diagnosis (97.0%), advices to avoid illness (96.0%) and outcome of medical care (97.0%). However, the lowest items of satisfaction were those related to explanation of medical procedures and tests (46.5%) and ease of seeing physician of choice (61.0%). Almost 62.0% of the interviewed persons expressed their satisfaction with overall PHC service provided after EMR implementation. The leading two items of dissatisfaction that showed by the majority of dissatisfied participants were non-compliance of physician with good practice in prescription writing (75.0%) and inability to see the same physician in every visit (72.4%). The results showed that although the overall satisfaction was relatively high, certain aspects of the service showed some degree of dissatisfaction. This study demonstrated patient acceptance and support for the electronic medical record system at the primary care setting. These findings should encourage physicians to promote the use of electronic medical record system.

uinsuska.info

Islamic Education As A Paradigm of Freedom: A Study on Paulo Friere's Idea: Criticisms which alwa... more Islamic Education As A Paradigm of Freedom: A Study on Paulo Friere's Idea: Criticisms which always come up in Islamic Education is a doctrinal, dogmatic learning model that gives no freedom to learners. This study attempts to describe an Islamic learning model that is based on the paradigm of freedom. It is theoretically on the basis of the epistemology of Paulo Friere on oppressed people. According to him the oppressed people who internalize themselves with those oppressing them and adapted themselves with their way of thinking will bring a feeling of severe threat. Actually, they need real freedom and responsibility, not the freedom provided by Friere. There is no doubt that Islamic education is emancipation i.e. releasing people from being shackled in any form that is expected to encourage them to be brave to obey God's instructions. Islam prioritizes mankind, upholds democratic values and justice, appreciates what men have done, teaches people how to speak truly and behave properly, and loves the week and the oppressed. It is in this position that freedom fits those values.

Polymer Testing, 2008

Natural rubber latex films were soaked in potassium hydroxide solution of various pH. The effects... more Natural rubber latex films were soaked in potassium hydroxide solution of various pH. The effects of soaking on the crosslink density, extractable protein content and tensile properties of the films were investigated. Potassium hydroxide solution was believed to be effective in reducing ...

Polymer Testing, 2008

The effect of acid treatment on the extractable protein content and tensile properties of natural... more The effect of acid treatment on the extractable protein content and tensile properties of natural rubber latex films was studied. The main aim was to introduce an alternative method to tackle the protein allergy in natural rubber latex products. Natural rubber latex was treated with ...

In this work, the influence of silane (bis (3-triethoxysilylpropyl) tetrasulfide) or Si69 couplin... more In this work, the influence of silane (bis (3-triethoxysilylpropyl) tetrasulfide) or Si69 coupling agent on properties of EPDM/mica composites was studied. Both EPDM/mica composites with silane and without silane were compounded using two roll mill at various filler loading (i.e., 100/0, 100/10, 100/30, 100/50, 100/70). The tensile and thermal properties as well as fracture surfaces of composites were tested using Instron Universal Testing Machine, Thermal Gravimetric Analysis (TGA) and Emission Scanning Electron Microscope (SEM). The results indicated that the optimum cure (t90), scorch time (ts2) value was lower, while maximum torque (MH) value slightly higher for EPDM/mica composites with silane compared to EPDM/mica composites without silane. The tensile properties, M100 and M300 value increased for EPDM/mica composites in the presence of silane and the optimum filler loading for those properties occurred at 50 phr. In addition, thermal stability and swelling ratio for both composites improved with increasing filler loading. However, EPDM/mica composites with silane show better thermal stability and swelling ratio due to stronger linkage taking place at the rubberfiller boundary and it promotes filler dis-agglomeration.

Biodegradable film blends of soya bean flour with poly(vinyl alcohol) (PVA) were prepared by solu... more Biodegradable film blends of soya bean flour with poly(vinyl alcohol) (PVA) were prepared by solution mixing and solution casting. The main goal of this study is to investigate the effect of soya bean flour content in the PVA film. Mechanical properties of the obtained blends were assessed by tensile testing, whereas the biodegradability were assessed by subjected the films in natural weathering. The incorporation of soya bean flour decreased the tensile strength and elongation at break of PVA film. However, the tensile modulus increased with the addition of soya bean flour. The reduction in tensile properties of the PVA/soya bean flour blend films revealed that the presence of soya bean flour show positive effect in degradation. Materials. Poly(vinyl alcohol) (PVA, Elvanol) with an average molecular weight of 146,000-186,000 g/mol was supplied by Sigma-Aldrich (M) Sdn. Bhd. Soya bean flour (SBF) was used as a filler in this study. It was obtained from Hasrat Bestari (M) Berhad with an average granular size of 12 µm and 56% of protein content. De-ionized water was used as a solvent.

Background: Concordance in plasma HIV-1 viral load quantification at the lower limit of quantific... more Background: Concordance in plasma HIV-1 viral load quantification at the lower limit of quantification (LLOQ) is crucial for current commercial assays. Objective: To compare the performance of three commercial viral load assays and carry out a correlation study with the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test, the Roche Cobas Amplicor HIV-1 MONITOR test, and the Abbott RealTime HIV-1 assay. Study design: Assay agreement was analyzed using linear regression and Bland-Altman plots. Concordance near the clinically critical LLOQ was measured by Cohen's kappa statistics. Intra-assay precision was assessed, and assay reproducibility was measured at 50 copies/mL across all three platforms. Results: While good overall correlation was observed between the assays (r ≥ 0.93), quantitative differences exceeded 0.5 log 10 copies/mL among paired results in 3.7 to 8.3% of specimens. The degree of concordance between the assays near the LLOQ was unsatisfactory, with Cohen's kappa ranging from 0.14 to 0.38. The intra-assay precision of the Abbott RealTime HIV-1 assay ranged from 0.04 to 0.15 (SD log 10) and 1.34% to 8.37% (CV). Reproducibility at 50 copies/mL for RealTime HIV-1, TaqMan, and Amplicor was 10.05, 11.04 and 5.07 (% CV), respectively. Conclusion: Although good correlation was observed between the assays across their linear range, their concordance at the clinically critical LLOQ was poor. The accurate quantification of low-level viremia remains elusive, and the lack of correlation of these assays presents a challenge to the interpretation of such results and in the clinical management of HIV-infected patients.

Oil palm leaves is a waste material. Phenolic compound was extracted from oil palm leaves and kno... more Oil palm leaves is a waste material. Phenolic compound was extracted from oil palm leaves and know as natural antioxidant that could possibly used in natural rubber compound. The present study involves the effect of natural antioxidants that obtained from oil palm leaves on cure characteristics and crosslink density of natural rubber vulcanisate. The natural rubber had been cured at 160°C in three different vulcanization systems which were conventional (CV), efficient (EV) and semi-efficient (SEV). The cure characteristic was been conducted by using Mosanto Rheometer at 160°C for 30 minutes. For swelling test, the specimens were immersed in toluene solvent for 22 hours. The specimens were weighed before and after immersed. CV system showed better result in M90 and curing rate due to higher degree of crosslinking as compared to SEV and EV system. Meanwhile, EV and SEV system showed comparable result in crosslink density with CV system. This is due stronger bonding between monosulphide crosslink. Finally, the results indicated that natural antioxidant has a tendency to substitute commercial antioxidant (TMQ) in the rubber field.

univ-ubs.fr

Les propriétés d'usinabilité des composés polyamides (PA 6 et PA 66-GF30 renforcé avec 30% d... more Les propriétés d'usinabilité des composés polyamides (PA 6 et PA 66-GF30 renforcé avec 30% de fibres de verre) en terme de la force d'usinage sont étudiées expérimentalement. Les facteurs ayant été considérés comprennent la vitesse de coupe et la vitesse d'avance. ...

lib.uin-malang.ac.id

... FAKULTAS EKONOMI UNIVERSITAS ISLAM NEGERI MAULANA MALIK IBRAHIM MALANG 2009 ... SKRIPSI Diaju... more ... FAKULTAS EKONOMI UNIVERSITAS ISLAM NEGERI MAULANA MALIK IBRAHIM MALANG 2009 ... SKRIPSI Diajukan Kepada : Universitas Islam Negeri Maulana Malik Ibrahim Malang untuk Memenuhi Salah Satu Persyaratan dalam Memperoleh Gelar Sarjana Ekonomi (SE) ...

Journal of Social Sciences, 2007

Technical-Vocational Education and Training (TVE) system plays important role in providing highly... more Technical-Vocational Education and Training (TVE) system plays important role in providing highly skilled workforce to fulfill the needs of industries. An empirical research of TVE system is necessary to identify effective TVE system to successfully equip students with technical skills that would enable them to fulfill the current work demands and professional expectations. The objective of this paper is to present the findings of TVE system implementation in one of the technical training institution in Malaysia. Research sample has been selected using a simple random method from the third year students. A total of 162 students participated in this research. The result shows that mean score for overall employability skills was quite high. Two aspects of the employability skills, namely, thinking skills and resource management competence and system & technology competence were slightly lower than the mean score. Respondents have slightly higher than the mean scores on basic informational competence interpersonal competence. The mean score of personal quality is the highest among all the aspects of variables of employability skills.

In order to obtain a desirable deposition thickness, nanostructured ternary CoNiCu alloys have be... more In order to obtain a desirable deposition thickness, nanostructured ternary CoNiCu alloys have been electrodeposited from salt solutions containing Co 2+ , Ni 2+ and Cu 2+ in the presence of a neutral surfactant alkyl polyglucoside (APG). Electrodeposition of CoNiCu was carried out in a three-electrode cell with indium-tin oxide (ITO) on glass plate, platinum wire and saturated calomel electrode (SCE) as working electrode, counter electrode and reference electrode, respectively. The nanostructured alloys were characterized by means of atomic force microscopy (AFM) and supported by field emission scanning electron microscopy (FESEM). The nanostructured CoNiCu alloys prepared in sulphate solutions in the presence of APG produced a thinner layer of nanoparticles of the alloys compared with the one deposited in the absence of APG. For a fixed deposition time, 160s and at an applied potential of-875mV (SCE) the layer thickness was about 56 nm for electrodepositionin the presence of 3.25 wt.% APG and about 110 nm without APG. Only a small increase in thickness was observed when the potential was increased to more negative values i.e.-875 to-950 mV(SCE).

The effects of styrene butadiene rubber/virgin acrylonitrile butadiene rubber (SBR/NBRv) blends a... more The effects of styrene butadiene rubber/virgin acrylonitrile butadiene rubber (SBR/NBRv) blends and styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) blends on properties such Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were carried out. Results indicated that, based on intensity of amine peak from FTIR at 85/15 blend ratio (R15) revealed optimum formation of crosslink

ABSTRACT A study on effect of chemical treatment using maleic anhydride-grafted polypropylene (MA... more ABSTRACT A study on effect of chemical treatment using maleic anhydride-grafted polypropylene (MAPP) and 3-aminopropyltiethoxysilane (3-APE) was investigated. The performance of the MAPP and 3-APE were investigated by means of torque development, mechanical properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy morphology, and water absorption. The results revealed that the use of MAPP or 3-APE in the composites has increased the stabilization torque, tensile strength, Young's modulus, water absorption, and thermal stability of the PP/NR composites. The incorporation of MAPP in the composites shows higher stabilization torque, tensile strength, EB, Young's modulus, and lower water uptake when compared with the use of 3-APE in the PP/NR composites. TGA and DSC results indicated that primary and secondary peak of DTG curve, initial degradation temperature (T0), degradation temperature (Tdeg), melting temperature (Tm), heat of fusion of composites (ΔHf(com)), crystallinity of composites (XPP), and PP (XPP) increased, while total weight loss and thermal degradation rate decreased for both treated composites. The MAPP-treated RNP-filled PP/NR composites were found to be more thermal resistance and more crystalline than 3-APE-treated filled PP/NR RNP composites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Considering the increasing prospective regarding the various applications of Poly Ether Ether Ket... more Considering the increasing prospective regarding the various applications of Poly Ether Ether Ketone reinforced with 30% carbon fibres (PEEK CF30), there is a crucial need to investigate its machinability. In this work, focus is centered on non-linear regression based models that can be built to predict roug hness parameters Ra and Rt associated to turning of PEEK CF30 when using TiN coated cutting tool. Attention was paid to one-variant models that can be proposed to represent the effect of the cutting speed on the surface finish parameters. A broad class of non-linear interpolation models was considered. Their aptness to be used in modelling this particular application was assessed. The identification of the various mathematical models was performed by using experimental results that were obtained from CNC turning of PEEK samples. Based on statistical analysis, all the considered non-linear regression models proved to be highly significant and succeeded to fit adequately the experimental results.

Non-reinforced and reinforced Poly-Ether-Ether-Ketone (PEEK) plastics have excellent mechanical a... more Non-reinforced and reinforced Poly-Ether-Ether-Ketone (PEEK) plastics have excellent mechanical and thermal properties. Machining is an efficient process that can be used to manufacture specific mechanical parts made from PEEK composites. Researchers have focused on improving the performance of machining operations with the aim of minimizing costs and improving quality of manufactured products, in order to get the best surface roughness and the minimum cutting force. The parameters evaluated are the cutting speed, the depth of cut and the feed rate. In this paper, the effect of the mentioned parameters on surface roughness and cutting force, in dry turning of reinforced PEEK with 30% of carbon fibers (PEEK CF30) using TiN coated cutting tools, is analyzed through using robust design techniques such as Taguchi's design method, signal-to-noise (S/N) ratio and statistical analysis tools such as Pareto-ANOVA. The obtained results have shown that Taguchi method and Pareto ANOVA are suitable for optimizing the cutting parameters with the minimum possible number of experiments, and the optimized process parameters were determined for surface roughness and cutting force criteria.

IEEE Transactions on Electron Devices, 2005

Numerical simulation-based study of double-gate (DG) field-effect transistors (FETs) leads to the... more Numerical simulation-based study of double-gate (DG) field-effect transistors (FETs) leads to the possibly viable concept of extremely scaled but nonself-aligned DG CMOS. Predictions of off-state current, on-state current, and circuit performance, accounting for short-channel effects and energy-quantization effects, in 25-nm DG FETs suggest that moderate back-gate underlap does not severely undermine the superior performance and leakage current of nanoscale DG CMOS relative to those of bulk-Si CMOS. The reverse back-gate biasing scheme for leakage reduction in DG CMOS is shown to be much more efficient than the reverse body biasing scheme in bulk Si even with moderate back-gate underlap.

The Journal of the Egyptian …, 2006

This study aimed at assessing the level of patients&a... more This study aimed at assessing the level of patients' satisfaction with primary heath care services after implementation of the electronic medical record system (EMR). Also, to explore the relationship of some participants' characteristics with satisfaction which are of importance in planning, managing and evaluation. A descriptive cross-sectional approach was adopted. Ten primary health care centers (out of total 78) related to the five health regions in Kuwait were randomly selected. A random sample of 200 people (at age of 18 years and above) attending the two-shift periods of the chosen centers were included. Through an exit interview, a well trained investigator interviewed them about their satisfaction with the primary heath care services provided after implementation of electronic medical record system. A structured questionnaire for measuring satisfaction was used. The response rate was 93.02% of whom 47.5% were males and 52.5% were females. The mean overall satisfaction percent score as reported by subjects was 85.6% (SD 4.9). There were statistically significant associations between mean percent satisfaction score of the participants and their age, level of education visiting the center at morning shift, and waiting less than 10 minutes before the examination. The vast majority of participants indicated that overall service at the center had greatly improved after EMR implementation. The system also helped in improvement of the physician performance, arrangement of patient's turn, dispense medication from pharmacy, written guidance of medication, accuracy and easiness of follow up for health status, time spent to retrieve medical record and that for receiving medication. However, it didn't achieve much improvement in physician selection or waiting time. The majority of interviewees (96.5%) were totally satisfied with the overall quality of service at the center, location of the center (96.5%), hours when the center is open (96.5%), thoroughness of examination and accuracy of diagnosis (97.0%), advices to avoid illness (96.0%) and outcome of medical care (97.0%). However, the lowest items of satisfaction were those related to explanation of medical procedures and tests (46.5%) and ease of seeing physician of choice (61.0%). Almost 62.0% of the interviewed persons expressed their satisfaction with overall PHC service provided after EMR implementation. The leading two items of dissatisfaction that showed by the majority of dissatisfied participants were non-compliance of physician with good practice in prescription writing (75.0%) and inability to see the same physician in every visit (72.4%). The results showed that although the overall satisfaction was relatively high, certain aspects of the service showed some degree of dissatisfaction. This study demonstrated patient acceptance and support for the electronic medical record system at the primary care setting. These findings should encourage physicians to promote the use of electronic medical record system.

uinsuska.info

Islamic Education As A Paradigm of Freedom: A Study on Paulo Friere's Idea: Criticisms which alwa... more Islamic Education As A Paradigm of Freedom: A Study on Paulo Friere's Idea: Criticisms which always come up in Islamic Education is a doctrinal, dogmatic learning model that gives no freedom to learners. This study attempts to describe an Islamic learning model that is based on the paradigm of freedom. It is theoretically on the basis of the epistemology of Paulo Friere on oppressed people. According to him the oppressed people who internalize themselves with those oppressing them and adapted themselves with their way of thinking will bring a feeling of severe threat. Actually, they need real freedom and responsibility, not the freedom provided by Friere. There is no doubt that Islamic education is emancipation i.e. releasing people from being shackled in any form that is expected to encourage them to be brave to obey God's instructions. Islam prioritizes mankind, upholds democratic values and justice, appreciates what men have done, teaches people how to speak truly and behave properly, and loves the week and the oppressed. It is in this position that freedom fits those values.

Polymer Testing, 2008

Natural rubber latex films were soaked in potassium hydroxide solution of various pH. The effects... more Natural rubber latex films were soaked in potassium hydroxide solution of various pH. The effects of soaking on the crosslink density, extractable protein content and tensile properties of the films were investigated. Potassium hydroxide solution was believed to be effective in reducing ...

Polymer Testing, 2008

The effect of acid treatment on the extractable protein content and tensile properties of natural... more The effect of acid treatment on the extractable protein content and tensile properties of natural rubber latex films was studied. The main aim was to introduce an alternative method to tackle the protein allergy in natural rubber latex products. Natural rubber latex was treated with ...

In this work, the influence of silane (bis (3-triethoxysilylpropyl) tetrasulfide) or Si69 couplin... more In this work, the influence of silane (bis (3-triethoxysilylpropyl) tetrasulfide) or Si69 coupling agent on properties of EPDM/mica composites was studied. Both EPDM/mica composites with silane and without silane were compounded using two roll mill at various filler loading (i.e., 100/0, 100/10, 100/30, 100/50, 100/70). The tensile and thermal properties as well as fracture surfaces of composites were tested using Instron Universal Testing Machine, Thermal Gravimetric Analysis (TGA) and Emission Scanning Electron Microscope (SEM). The results indicated that the optimum cure (t90), scorch time (ts2) value was lower, while maximum torque (MH) value slightly higher for EPDM/mica composites with silane compared to EPDM/mica composites without silane. The tensile properties, M100 and M300 value increased for EPDM/mica composites in the presence of silane and the optimum filler loading for those properties occurred at 50 phr. In addition, thermal stability and swelling ratio for both composites improved with increasing filler loading. However, EPDM/mica composites with silane show better thermal stability and swelling ratio due to stronger linkage taking place at the rubberfiller boundary and it promotes filler dis-agglomeration.

Biodegradable film blends of soya bean flour with poly(vinyl alcohol) (PVA) were prepared by solu... more Biodegradable film blends of soya bean flour with poly(vinyl alcohol) (PVA) were prepared by solution mixing and solution casting. The main goal of this study is to investigate the effect of soya bean flour content in the PVA film. Mechanical properties of the obtained blends were assessed by tensile testing, whereas the biodegradability were assessed by subjected the films in natural weathering. The incorporation of soya bean flour decreased the tensile strength and elongation at break of PVA film. However, the tensile modulus increased with the addition of soya bean flour. The reduction in tensile properties of the PVA/soya bean flour blend films revealed that the presence of soya bean flour show positive effect in degradation. Materials. Poly(vinyl alcohol) (PVA, Elvanol) with an average molecular weight of 146,000-186,000 g/mol was supplied by Sigma-Aldrich (M) Sdn. Bhd. Soya bean flour (SBF) was used as a filler in this study. It was obtained from Hasrat Bestari (M) Berhad with an average granular size of 12 µm and 56% of protein content. De-ionized water was used as a solvent.

Background: Concordance in plasma HIV-1 viral load quantification at the lower limit of quantific... more Background: Concordance in plasma HIV-1 viral load quantification at the lower limit of quantification (LLOQ) is crucial for current commercial assays. Objective: To compare the performance of three commercial viral load assays and carry out a correlation study with the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test, the Roche Cobas Amplicor HIV-1 MONITOR test, and the Abbott RealTime HIV-1 assay. Study design: Assay agreement was analyzed using linear regression and Bland-Altman plots. Concordance near the clinically critical LLOQ was measured by Cohen's kappa statistics. Intra-assay precision was assessed, and assay reproducibility was measured at 50 copies/mL across all three platforms. Results: While good overall correlation was observed between the assays (r ≥ 0.93), quantitative differences exceeded 0.5 log 10 copies/mL among paired results in 3.7 to 8.3% of specimens. The degree of concordance between the assays near the LLOQ was unsatisfactory, with Cohen's kappa ranging from 0.14 to 0.38. The intra-assay precision of the Abbott RealTime HIV-1 assay ranged from 0.04 to 0.15 (SD log 10) and 1.34% to 8.37% (CV). Reproducibility at 50 copies/mL for RealTime HIV-1, TaqMan, and Amplicor was 10.05, 11.04 and 5.07 (% CV), respectively. Conclusion: Although good correlation was observed between the assays across their linear range, their concordance at the clinically critical LLOQ was poor. The accurate quantification of low-level viremia remains elusive, and the lack of correlation of these assays presents a challenge to the interpretation of such results and in the clinical management of HIV-infected patients.

Oil palm leaves is a waste material. Phenolic compound was extracted from oil palm leaves and kno... more Oil palm leaves is a waste material. Phenolic compound was extracted from oil palm leaves and know as natural antioxidant that could possibly used in natural rubber compound. The present study involves the effect of natural antioxidants that obtained from oil palm leaves on cure characteristics and crosslink density of natural rubber vulcanisate. The natural rubber had been cured at 160°C in three different vulcanization systems which were conventional (CV), efficient (EV) and semi-efficient (SEV). The cure characteristic was been conducted by using Mosanto Rheometer at 160°C for 30 minutes. For swelling test, the specimens were immersed in toluene solvent for 22 hours. The specimens were weighed before and after immersed. CV system showed better result in M90 and curing rate due to higher degree of crosslinking as compared to SEV and EV system. Meanwhile, EV and SEV system showed comparable result in crosslink density with CV system. This is due stronger bonding between monosulphide crosslink. Finally, the results indicated that natural antioxidant has a tendency to substitute commercial antioxidant (TMQ) in the rubber field.

univ-ubs.fr

Les propriétés d'usinabilité des composés polyamides (PA 6 et PA 66-GF30 renforcé avec 30% d... more Les propriétés d'usinabilité des composés polyamides (PA 6 et PA 66-GF30 renforcé avec 30% de fibres de verre) en terme de la force d'usinage sont étudiées expérimentalement. Les facteurs ayant été considérés comprennent la vitesse de coupe et la vitesse d'avance. ...

lib.uin-malang.ac.id

... FAKULTAS EKONOMI UNIVERSITAS ISLAM NEGERI MAULANA MALIK IBRAHIM MALANG 2009 ... SKRIPSI Diaju... more ... FAKULTAS EKONOMI UNIVERSITAS ISLAM NEGERI MAULANA MALIK IBRAHIM MALANG 2009 ... SKRIPSI Diajukan Kepada : Universitas Islam Negeri Maulana Malik Ibrahim Malang untuk Memenuhi Salah Satu Persyaratan dalam Memperoleh Gelar Sarjana Ekonomi (SE) ...

Journal of Social Sciences, 2007

Technical-Vocational Education and Training (TVE) system plays important role in providing highly... more Technical-Vocational Education and Training (TVE) system plays important role in providing highly skilled workforce to fulfill the needs of industries. An empirical research of TVE system is necessary to identify effective TVE system to successfully equip students with technical skills that would enable them to fulfill the current work demands and professional expectations. The objective of this paper is to present the findings of TVE system implementation in one of the technical training institution in Malaysia. Research sample has been selected using a simple random method from the third year students. A total of 162 students participated in this research. The result shows that mean score for overall employability skills was quite high. Two aspects of the employability skills, namely, thinking skills and resource management competence and system & technology competence were slightly lower than the mean score. Respondents have slightly higher than the mean scores on basic informational competence interpersonal competence. The mean score of personal quality is the highest among all the aspects of variables of employability skills.

In order to obtain a desirable deposition thickness, nanostructured ternary CoNiCu alloys have be... more In order to obtain a desirable deposition thickness, nanostructured ternary CoNiCu alloys have been electrodeposited from salt solutions containing Co 2+ , Ni 2+ and Cu 2+ in the presence of a neutral surfactant alkyl polyglucoside (APG). Electrodeposition of CoNiCu was carried out in a three-electrode cell with indium-tin oxide (ITO) on glass plate, platinum wire and saturated calomel electrode (SCE) as working electrode, counter electrode and reference electrode, respectively. The nanostructured alloys were characterized by means of atomic force microscopy (AFM) and supported by field emission scanning electron microscopy (FESEM). The nanostructured CoNiCu alloys prepared in sulphate solutions in the presence of APG produced a thinner layer of nanoparticles of the alloys compared with the one deposited in the absence of APG. For a fixed deposition time, 160s and at an applied potential of-875mV (SCE) the layer thickness was about 56 nm for electrodepositionin the presence of 3.25 wt.% APG and about 110 nm without APG. Only a small increase in thickness was observed when the potential was increased to more negative values i.e.-875 to-950 mV(SCE).

The effects of styrene butadiene rubber/virgin acrylonitrile butadiene rubber (SBR/NBRv) blends a... more The effects of styrene butadiene rubber/virgin acrylonitrile butadiene rubber (SBR/NBRv) blends and styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) blends on properties such Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were carried out. Results indicated that, based on intensity of amine peak from FTIR at 85/15 blend ratio (R15) revealed optimum formation of crosslink

ABSTRACT A study on effect of chemical treatment using maleic anhydride-grafted polypropylene (MA... more ABSTRACT A study on effect of chemical treatment using maleic anhydride-grafted polypropylene (MAPP) and 3-aminopropyltiethoxysilane (3-APE) was investigated. The performance of the MAPP and 3-APE were investigated by means of torque development, mechanical properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy morphology, and water absorption. The results revealed that the use of MAPP or 3-APE in the composites has increased the stabilization torque, tensile strength, Young's modulus, water absorption, and thermal stability of the PP/NR composites. The incorporation of MAPP in the composites shows higher stabilization torque, tensile strength, EB, Young's modulus, and lower water uptake when compared with the use of 3-APE in the PP/NR composites. TGA and DSC results indicated that primary and secondary peak of DTG curve, initial degradation temperature (T0), degradation temperature (Tdeg), melting temperature (Tm), heat of fusion of composites (ΔHf(com)), crystallinity of composites (XPP), and PP (XPP) increased, while total weight loss and thermal degradation rate decreased for both treated composites. The MAPP-treated RNP-filled PP/NR composites were found to be more thermal resistance and more crystalline than 3-APE-treated filled PP/NR RNP composites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Considering the increasing prospective regarding the various applications of Poly Ether Ether Ket... more Considering the increasing prospective regarding the various applications of Poly Ether Ether Ketone reinforced with 30% carbon fibres (PEEK CF30), there is a crucial need to investigate its machinability. In this work, focus is centered on non-linear regression based models that can be built to predict roug hness parameters Ra and Rt associated to turning of PEEK CF30 when using TiN coated cutting tool. Attention was paid to one-variant models that can be proposed to represent the effect of the cutting speed on the surface finish parameters. A broad class of non-linear interpolation models was considered. Their aptness to be used in modelling this particular application was assessed. The identification of the various mathematical models was performed by using experimental results that were obtained from CNC turning of PEEK samples. Based on statistical analysis, all the considered non-linear regression models proved to be highly significant and succeeded to fit adequately the experimental results.

Non-reinforced and reinforced Poly-Ether-Ether-Ketone (PEEK) plastics have excellent mechanical a... more Non-reinforced and reinforced Poly-Ether-Ether-Ketone (PEEK) plastics have excellent mechanical and thermal properties. Machining is an efficient process that can be used to manufacture specific mechanical parts made from PEEK composites. Researchers have focused on improving the performance of machining operations with the aim of minimizing costs and improving quality of manufactured products, in order to get the best surface roughness and the minimum cutting force. The parameters evaluated are the cutting speed, the depth of cut and the feed rate. In this paper, the effect of the mentioned parameters on surface roughness and cutting force, in dry turning of reinforced PEEK with 30% of carbon fibers (PEEK CF30) using TiN coated cutting tools, is analyzed through using robust design techniques such as Taguchi's design method, signal-to-noise (S/N) ratio and statistical analysis tools such as Pareto-ANOVA. The obtained results have shown that Taguchi method and Pareto ANOVA are suitable for optimizing the cutting parameters with the minimum possible number of experiments, and the optimized process parameters were determined for surface roughness and cutting force criteria.