Acta Crystallographica Section E Crystallographic Communications
Cs2GdNb6Cl15O3, dicaesium gadolinium hexaniobium pentadecachloride trioxide, was synthesized by s... more Cs2GdNb6Cl15O3, dicaesium gadolinium hexaniobium pentadecachloride trioxide, was synthesized by solid-state reactions starting from a stoichiometric mixture of CsCl, Gd2O3, Nb, NbCl5, and Nb2O5. The crystal structure is based on octahedral Nb6 cluster units (point group symmetry 3.2) with composition [(Nb6Cl i 9O i 3)Cl a 6]5– where i and a denote inner and outer ligands. Cs2GdNb6Cl15O3 exhibits 14 valence electrons per cluster unit. The cluster units are linked to each other by CsI and GdIII atoms, whereby CsI (site symmetry 3..) is 12-coordinated by six Cl i and six Cl a ligands belonging to six neighboring cluster units and GdIII (site symmetry 3.2) is 9-coordinated by three O i and six Cl i ligands belonging to three adjacent cluster units. The arrangement of cluster units corresponds to a stacking of …AA′A… layers along [001]. Cs2GdNb6Cl15O3 is isotypic with Cs2UNb6Cl15O3.
OpenAcces Water hyacinth (Eichhornia crassipes) is one of the potential feedstocks for bioethanol... more OpenAcces Water hyacinth (Eichhornia crassipes) is one of the potential feedstocks for bioethanol production due to their higher cellulose content. It needs the optimization of pretreatment to remove lignin and release cellulose and hemicellulose from lignocellulosic complex. Pretreatment was done using sulfuric acid, sodium hydroxide, and calcium hypochlorite as soaking agents. Experiment was carried out at 121 °C for 15 minutes. Pretreatment with 1% sulfuric acid decreased lignin by 6.74%, 4.0% sodium hydroxide reduced lignin content by 11.23%, whereas pretreatment with 0.3% calcium hypochlorite removed lignin by 8.30% from original lignin content lignocellulosic substrate. Therefore, sodium hydroxide pretreatment showed highest efficacy in delignification processes, followed by calcium hypochlorite, and sulfuric acid pretreatments.
Development of interactive multimedia has been conducted and applied to learning the periodic sys... more Development of interactive multimedia has been conducted and applied to learning the periodic system of elements in tenth grade IPA SMAN 14 Palembang. Development was done by using a modified Rowntree model with formative evaluation of Tessmer with stages of planning, development, self valuation, one to one, small group and field test. The validity of interactive multimedia by two expert of material, expert of media and expert of pedagogic. Value of material validity of 0.84 with high validity category, value of media validity of 0.92 with high validity category and value of pedagogic validity of 0.83 with high validity category. Average validity score of 0.84 with high validity category. Practicality of interactive multimedia seen from questionnaire at one to one and small group. Obtained the average practice questionnaire score of 0,81 with high practicality category. The effectiveness of interactif multimedia measured from student learning outcomes at field test stage, obtained N...
The development of multimedia-based teaching materials valid, practical and effective has been do... more The development of multimedia-based teaching materials valid, practical and effective has been done and tested in the study of oxidation and reduction reactions class X.1 SMA 13 Palembang. The results of the expert review, one to one evaluations, small group and field tests indicate that multimedia-based teaching materials have met the criteria validity, practicality and effectiveness. The validity of the material by 43, the validity of the pedagogic of 53, the validity of the design of 60, praktikalitas 96% completeness and effectiveness of learning by 90%. This suggests that multimedia-based teaching materials produced by researchers have met the criteria validity, practicality and effectiveness in learning the oxidation and reduction reactions class X.
Composite hard magnet NdFeB materials were made using powdered rapidly quenched Nd-Fe-B (MQP-B) a... more Composite hard magnet NdFeB materials were made using powdered rapidly quenched Nd-Fe-B (MQP-B) and polymers (bakelite). The proportion of the polymer matrix was varied (2.0, 5.0, 7.0, and 10 wt.%). The composite hard magnet NdFeB materials were compacted using one-sided uniaxial hot pressing at 160 °C for 20 min. The bulk density of the composite hard magnet NdFeB was measured using the Archimedes method. Compression tests were carried out using the Universal Testing Machine. The results show that a permanent magnet composite with a 2 wt.% bakelite binder composition exhibits higher bulk density and superior magnetic parameters (i.e., remanence, coercivity, and energy product), but slightly lower compressive strength of approximately 845 kgf/cm 2 .
Pengembangan lembar kerja siswa (LKS) interaktif telah dilakukan dan diujicobakan untuk pembelaja... more Pengembangan lembar kerja siswa (LKS) interaktif telah dilakukan dan diujicobakan untuk pembelajaran larutan elektrolit dan non elektrolit di kelas X SMA Negeri 1 Indralaya. LKS interaktif dikembangkan melalui tahapan Define (pendefenisian), Design (design), Develop (pengembangan) dan ujicoba Tessmer pada tahap develop . Hasil penelitian berdasarkan analisis data angket menunjukkan bahwa LKS interaktif telah valid dan layak digunakan dengan perolehan nilai analisis 4,2 dalam uji validitas materi, 4,1 dalam uji validitas media, 4 dalam uji validitas pedagogik serta 4,28 dalam ujicoba one to one dan 4,45 dalam ujicoba small group . Berdasarkan analisis tes berupa pretest dan posttest menunjukkan bahwa lembar kerja siswa interaktif telah efektif dan berpotensi meningkatkan hasil belajar siswa dengan nilai rata-rata 81,43 dan nilai N-gain score 0,54. Hasil penelitian menunjukkan bahwa pengembangan lembar kerja siswa interaktif untuk pembelajaran larutan elektrolit dan non elektrolit di ...
Pengembangan Modul Interaktif Berbasis Komputer Materi Redoks di Kelas X. Pengembangan modul inte... more Pengembangan Modul Interaktif Berbasis Komputer Materi Redoks di Kelas X. Pengembangan modul interaktif berbasis komputer materi redoks telah dilakukan dan diterapkan di Kelas X.F SMAN 1 Tanjung Batu. Penelitian ini dilakukan dengan model pengembangan ADDIE dan Tessmer Evaluation . Kevalidan modul interaktif ini dinilai oleh tiga pakar yakni ahli materi, ahli desain, dan ahli pedagogik. Kevalidan materi memiliki rata-rata skor sebesar 3,48 dengan kategori valid, kevalidan desain memilik rata-rata skor sebesar 3,00 dengan kategori valid, dan kevalidan pedagogik memilik rata-rata skor sebesar 3,30 dengan kategori valid. Kepraktisan modul interaktif dilhat dari data angket one to one dan small group dengan rata-rata skor angket kepraktisan sebesar 3,40 dengan kategori praktis. Berdasarkan test hasil belajar, nilai n-gain yang didapatkan dari hasil pretest dan posttest adalah sebesar 0,44 dengan kategori sedang. Hal ini menunjukkan bahwa modul interaktif ini tergolong efektif untuk digu...
Pengembangan LKPD interaktif berbasis web dengan pendekatan Contextual Teaching and Learning (CTL... more Pengembangan LKPD interaktif berbasis web dengan pendekatan Contextual Teaching and Learning (CTL) telah dilakukan dan diterapkan dalam pembelajaran Termokimia di kelas XI IPA SMA Negeri 2 Prabumulih. LKPD ini dikembangkan menggunakan model penelitian ADDIE yang terdiri dari 5 tahapan, yaitu Analysis, Design, Development, Implementation, dan Evaluation. Evaluasi produk menggunakan model evauasi Tessmer dan diperoleh nilai validitas pedagogic sebesar 3,3 dengan kriteria sangat valid, validitas konten sebesar 3,3 dengan kriteria sangat valid, dan validitas desain sebesar 3,4 dengan kriteria sangat valid. Kepraktisan diperoleh dari tahap ujicoba one to one dan small group. Pada tahap one to one diperoleh nilai sebesar 3,29 dengan kriteria sangat praktis dan pada tahap small group diperoleh nilai sebesar 3,52 dengan kriteria sangat praktis. Keefektifan produk diperoleh dari nilai pretest dan posttest yang menunjukkan bahwa LKPD interaktif berbasis web dinyatakan efektif dengan nilai N-g...
Pengembangan multimedia interaktif untuk pembelajaran bentuk molekul di SMA. Pengembangan multi... more Pengembangan multimedia interaktif untuk pembelajaran bentuk molekul di SMA. Pengembangan multimedia interaktif untuk pembelajaran bentuk molekul telah diujicobakan dan dilakukan di kelas XI IPA SMAN 1 Prabumulih. Data dikumpulkan dengan teknik uji pakar, angket, dan tes hasil belajar. Berdasarkan teknik analisa data diperoleh skor kevalidan materi 113 dengan kategori sangat baik, skor kevalidan pedagogik 109 dengan kategori sangat baik, skor kevalidan media 20 dengan kategori baik, kepraktisan 86,79%, dan keefektifan 88,24%. Hasil penelitian menunjukkan bahwa pengembangan multimedia interaktif untuk pembelajaran bentuk molekul di kelas XI IPA SMA Negeri 1 Prabumulih telah memenuhi kriteria kevalidan, kepraktisan, dan keefektifan. Keywords: Interactive Multimedia, Molecular Shape
Pengaruh konsentrasi H 2 SO 4 dan NaOH dalam delignifikasi serbuk bambu telah diteliti untuk menu... more Pengaruh konsentrasi H 2 SO 4 dan NaOH dalam delignifikasi serbuk bambu telah diteliti untuk menurunkan kadar lignin. Delignifikasi dilakukan pada suhu 121 0 C selama 30 menit dengan variasi konsentrasi. H 2 SO 4 : 0,5%, 1,0%, 1,5%, 2,0%, dan 2,5% (v/v) sedangkan variasi NaOH adalah 2,0%, 4,0%, 6,0%, 8,0%, dan 10% (b/v). Kadar lignin dianalisis menggunakan metode Kappa. Peningkatan konsentrasi H 2 SO 4 dan NaOH sejalan dengan peningkatan kadar lignin terurai. Penguraian optimum sebesar 5,37% dicapai pada saat konsentrasi H 2 SO 4 2,5% sedangkan pada saat konsentrasi NaOH 6,0% penguraian optimum sebesar 9,53%.
Cette these porte sur la synthese et l'etude de nouveaux oxyhalogenures a clusters triangulai... more Cette these porte sur la synthese et l'etude de nouveaux oxyhalogenures a clusters triangulaires et octaedriques de niobium ou de tantale. Leurs structures cristallines determinees par diffraction X sur monocristal comportent des motifs presentant differents taux d'oxygene selon le compose et dans lesquels le cluster est tres deforme en raison de la presence simultanee des ligands halogene et oxygene. Ces resultats structuraux completes par ceux rapportes prealablement pour les autres oxychlorures a clusters octaedriques nous ont permis de discuter l'evolution sterique et electronique du motif en fonction du nombre de ligands oxygene par motif et de leur repartition entre les positions inner et apicales, ainsi que l'influence de ces ligands sur les connexions intermotifs et les sites cationiques. Nous avons ainsi pu degager certaines caracteristiques structurales et electroniques propres aux oxychlorures a clusters octaedriques et montre leur influence sur les propri...
The composite magnet NdFeB has been made using magnetic powder MQP-B and polyvinyl alcohol (PVA) ... more The composite magnet NdFeB has been made using magnetic powder MQP-B and polyvinyl alcohol (PVA) as the binder. The mixing compositions of raw materials used are: 95 wt% NdFeB-5 wt% PVA, 92.5 wt% NdFeB-7.5 wt% PVA, 90 wt.% NdFeB-10 wt% PVA, and 87.5 wt% NdFeB-12.5 wt% PVA. Both raw materials are weighed according to the composition, and then mixed until homogeneous. Furthermore, pellet forming was made using dry pressing at 50 kgf/cm 2 pressures and continued with drying at 100 °C and 10 mmbar for 4 hours. The characterization includes bulk density, hardness, compressive strength measurements, and magnetic properties testing. The characterization results show that the optimal composition of binder PVA is achieved at 5-7.5 wt% NdFeB composite magnet with following properties: bulk density = 5.21-5.25 g/cm 3 , hardness = 302.17-304.32 Hv, compressive strength = 25.17-3.17 kgf/cm 2 , magnetic flux = 1150-1170 Gauss, remanence = 70.90-74.97 emu/g or 4.7-5.0 kGauss, coercivity = 8.68-8.76 kOe, and energy product = 2.89-3.04 MgOe.
Influence of addition Ba-Ferrite on the hardness, magnetic properties and corrosion resistance of... more Influence of addition Ba-Ferrite on the hardness, magnetic properties and corrosion resistance of hybrid bonded magnet NdFeB.
The hybrid bonded magnet NdFeB-BaFe12O19 has been made. The composition of BaFe12O19 was varied a... more The hybrid bonded magnet NdFeB-BaFe12O19 has been made. The composition of BaFe12O19 was varied as 0, 3, 5, 8, and 10 wt%. The preparation process was started by mixing BaFe12O19 powder with NdFeB (MQP-B+), then mixed with exopy resin binder of 8 wt% and subsequently compacted with a pressure of 60 MPa to form a pellet. The pellet samples were heated in 10 mmbar of vacuum dryer at 90°C for 1 hour. Some parameters were measured such as mechanical properties (compressive strength), magnetic properties (magnetic flux density and hysteresis curve) and corrosion resistance. The results show that the hybrid bonded magnet NdFeB with 10 wt% BaFe12O19 exhibits the highest compressive strength of about 268,15 kgf/cm 2. While the optimum corrosion resistance of bonded magnet NdFeB-BaFe12O19 is obtained by 5 wt% BaFe12O19 addition. It has a flux magnetic density of 1340 Gauss, remanence Br of 3,827 kG and coercivity Hcj of 8,924 kOe. According to the corrosion test result, it is found that the sample with higher content of Ba-ferrite has a better corrosion resistance compare to the sample with small content of Ba-ferrite.
The SnO2/Sn3O4 were successfully prepared using a one-step hydrothermal method and exhibit the he... more The SnO2/Sn3O4 were successfully prepared using a one-step hydrothermal method and exhibit the heterostructure formation. The heterostructure formation facilitates the enhancing of visible-light photoresponse of SnO2 which well known as the UV-light activated semiconductor. The heterostructure formation also exhibits high efficient photocatalytic performance by completely degrading 10 ppm of DB71 in 120 minutes after adding 50 mg of prepared-Tin oxide with a kinetic rate constant of 4.636 x 10-2 min-1. The kinetic constant rate of prepared-Tin oxide has 2.5 and 3 times faster compared to the kinetic constant rates of SnO2 and Sn3O4, respectively. The high efficient photocatalytic degradation was generated by the improvement of carrier mobilities through manipulating band alignment between SnO2 and Sn3O4 and prevented the recombination of photogenerated hole-electron which commonly generated in the intrinsic semiconductor. Heterostructure SnO2/Sn3O4 was not only forming high-efficiency photocatalytic degradation but also exhibiting blue shifting phenomenon. The UV-Vis adsorption response approaches were used to investigate and propose the photocatalytic degradation mechanism. After 120 minutes, there were only benzene adsorption peaks detected indicating the mineralization of DB71 dyes.
The effort to enhance the visible-light photoresponse of SnO 2 and SnO has been designed by the h... more The effort to enhance the visible-light photoresponse of SnO 2 and SnO has been designed by the heterostructure formation of tin oxide. The formation was conducted by controlling the oxidation state of precursor through adjusting the precursor acidity. The result shows that the transformation route as a function of precursor initial pH involve the formation of intermediate phase began by SnO 2 to SnO 2 /Sn 3 O 4 to SnO/Sn 3 O 4 , and finally SnO. The characterization indicated that Sn 3 O 4 played the important role in enhancing the visible light response of both SnO 2 and SnO in the heterostructure formation.
IOP Conference Series: Materials Science and Engineering, 2017
View the article online for updates and enhancements. You may also like Synthesis BaFe 12 O 19 ba... more View the article online for updates and enhancements. You may also like Synthesis BaFe 12 O 19 based on natural iron sand with Cu and Ni doping using coprecipitation method B U P Elinda, Susilawati, Kosim et al.-Comparison of temperature dependent magnetic properties of uncoated and SiO 2 coated BaFe 12 O 19 nanoparticles K Nadeem, J Z Minhas, F Zeb et al.-Magnetic and microwave absorbing properties of BaFe 122x Co x Zn x O 19 (x = 0.0; 0.2; 0.4; 0.6) nanocrystalline E Handoko, S Iwan, Setia Budi et al.
The development of teaching materials by using Web in Kesetimbangan Kimia Study was applied in XI... more The development of teaching materials by using Web in Kesetimbangan Kimia Study was applied in XI IPA SMA Negeri 11 Palembang. The validity of this development was assessed by three experts involved materials expert, pedagogic expert, and media expert. The validity of teaching materials is 50 in good category, the validity of pedagogic is 47 in good category, and the validity of media is 21 in excellent category. Practicality of teaching materials was seen by using average value of questionnaire in one to one step and small group step. The average value of Practicality is 3.32 in excellent category. The effectiveness of teaching materials was seen by using the result of test in field test step. Based on the test, there are 81,08% students who got score ≥ 70. It shows that the teaching materials are effective to be used in Kesetimbangan Kimia Study
Acta Crystallographica Section E Crystallographic Communications
Cs2GdNb6Cl15O3, dicaesium gadolinium hexaniobium pentadecachloride trioxide, was synthesized by s... more Cs2GdNb6Cl15O3, dicaesium gadolinium hexaniobium pentadecachloride trioxide, was synthesized by solid-state reactions starting from a stoichiometric mixture of CsCl, Gd2O3, Nb, NbCl5, and Nb2O5. The crystal structure is based on octahedral Nb6 cluster units (point group symmetry 3.2) with composition [(Nb6Cl i 9O i 3)Cl a 6]5– where i and a denote inner and outer ligands. Cs2GdNb6Cl15O3 exhibits 14 valence electrons per cluster unit. The cluster units are linked to each other by CsI and GdIII atoms, whereby CsI (site symmetry 3..) is 12-coordinated by six Cl i and six Cl a ligands belonging to six neighboring cluster units and GdIII (site symmetry 3.2) is 9-coordinated by three O i and six Cl i ligands belonging to three adjacent cluster units. The arrangement of cluster units corresponds to a stacking of …AA′A… layers along [001]. Cs2GdNb6Cl15O3 is isotypic with Cs2UNb6Cl15O3.
OpenAcces Water hyacinth (Eichhornia crassipes) is one of the potential feedstocks for bioethanol... more OpenAcces Water hyacinth (Eichhornia crassipes) is one of the potential feedstocks for bioethanol production due to their higher cellulose content. It needs the optimization of pretreatment to remove lignin and release cellulose and hemicellulose from lignocellulosic complex. Pretreatment was done using sulfuric acid, sodium hydroxide, and calcium hypochlorite as soaking agents. Experiment was carried out at 121 °C for 15 minutes. Pretreatment with 1% sulfuric acid decreased lignin by 6.74%, 4.0% sodium hydroxide reduced lignin content by 11.23%, whereas pretreatment with 0.3% calcium hypochlorite removed lignin by 8.30% from original lignin content lignocellulosic substrate. Therefore, sodium hydroxide pretreatment showed highest efficacy in delignification processes, followed by calcium hypochlorite, and sulfuric acid pretreatments.
Development of interactive multimedia has been conducted and applied to learning the periodic sys... more Development of interactive multimedia has been conducted and applied to learning the periodic system of elements in tenth grade IPA SMAN 14 Palembang. Development was done by using a modified Rowntree model with formative evaluation of Tessmer with stages of planning, development, self valuation, one to one, small group and field test. The validity of interactive multimedia by two expert of material, expert of media and expert of pedagogic. Value of material validity of 0.84 with high validity category, value of media validity of 0.92 with high validity category and value of pedagogic validity of 0.83 with high validity category. Average validity score of 0.84 with high validity category. Practicality of interactive multimedia seen from questionnaire at one to one and small group. Obtained the average practice questionnaire score of 0,81 with high practicality category. The effectiveness of interactif multimedia measured from student learning outcomes at field test stage, obtained N...
The development of multimedia-based teaching materials valid, practical and effective has been do... more The development of multimedia-based teaching materials valid, practical and effective has been done and tested in the study of oxidation and reduction reactions class X.1 SMA 13 Palembang. The results of the expert review, one to one evaluations, small group and field tests indicate that multimedia-based teaching materials have met the criteria validity, practicality and effectiveness. The validity of the material by 43, the validity of the pedagogic of 53, the validity of the design of 60, praktikalitas 96% completeness and effectiveness of learning by 90%. This suggests that multimedia-based teaching materials produced by researchers have met the criteria validity, practicality and effectiveness in learning the oxidation and reduction reactions class X.
Composite hard magnet NdFeB materials were made using powdered rapidly quenched Nd-Fe-B (MQP-B) a... more Composite hard magnet NdFeB materials were made using powdered rapidly quenched Nd-Fe-B (MQP-B) and polymers (bakelite). The proportion of the polymer matrix was varied (2.0, 5.0, 7.0, and 10 wt.%). The composite hard magnet NdFeB materials were compacted using one-sided uniaxial hot pressing at 160 °C for 20 min. The bulk density of the composite hard magnet NdFeB was measured using the Archimedes method. Compression tests were carried out using the Universal Testing Machine. The results show that a permanent magnet composite with a 2 wt.% bakelite binder composition exhibits higher bulk density and superior magnetic parameters (i.e., remanence, coercivity, and energy product), but slightly lower compressive strength of approximately 845 kgf/cm 2 .
Pengembangan lembar kerja siswa (LKS) interaktif telah dilakukan dan diujicobakan untuk pembelaja... more Pengembangan lembar kerja siswa (LKS) interaktif telah dilakukan dan diujicobakan untuk pembelajaran larutan elektrolit dan non elektrolit di kelas X SMA Negeri 1 Indralaya. LKS interaktif dikembangkan melalui tahapan Define (pendefenisian), Design (design), Develop (pengembangan) dan ujicoba Tessmer pada tahap develop . Hasil penelitian berdasarkan analisis data angket menunjukkan bahwa LKS interaktif telah valid dan layak digunakan dengan perolehan nilai analisis 4,2 dalam uji validitas materi, 4,1 dalam uji validitas media, 4 dalam uji validitas pedagogik serta 4,28 dalam ujicoba one to one dan 4,45 dalam ujicoba small group . Berdasarkan analisis tes berupa pretest dan posttest menunjukkan bahwa lembar kerja siswa interaktif telah efektif dan berpotensi meningkatkan hasil belajar siswa dengan nilai rata-rata 81,43 dan nilai N-gain score 0,54. Hasil penelitian menunjukkan bahwa pengembangan lembar kerja siswa interaktif untuk pembelajaran larutan elektrolit dan non elektrolit di ...
Pengembangan Modul Interaktif Berbasis Komputer Materi Redoks di Kelas X. Pengembangan modul inte... more Pengembangan Modul Interaktif Berbasis Komputer Materi Redoks di Kelas X. Pengembangan modul interaktif berbasis komputer materi redoks telah dilakukan dan diterapkan di Kelas X.F SMAN 1 Tanjung Batu. Penelitian ini dilakukan dengan model pengembangan ADDIE dan Tessmer Evaluation . Kevalidan modul interaktif ini dinilai oleh tiga pakar yakni ahli materi, ahli desain, dan ahli pedagogik. Kevalidan materi memiliki rata-rata skor sebesar 3,48 dengan kategori valid, kevalidan desain memilik rata-rata skor sebesar 3,00 dengan kategori valid, dan kevalidan pedagogik memilik rata-rata skor sebesar 3,30 dengan kategori valid. Kepraktisan modul interaktif dilhat dari data angket one to one dan small group dengan rata-rata skor angket kepraktisan sebesar 3,40 dengan kategori praktis. Berdasarkan test hasil belajar, nilai n-gain yang didapatkan dari hasil pretest dan posttest adalah sebesar 0,44 dengan kategori sedang. Hal ini menunjukkan bahwa modul interaktif ini tergolong efektif untuk digu...
Pengembangan LKPD interaktif berbasis web dengan pendekatan Contextual Teaching and Learning (CTL... more Pengembangan LKPD interaktif berbasis web dengan pendekatan Contextual Teaching and Learning (CTL) telah dilakukan dan diterapkan dalam pembelajaran Termokimia di kelas XI IPA SMA Negeri 2 Prabumulih. LKPD ini dikembangkan menggunakan model penelitian ADDIE yang terdiri dari 5 tahapan, yaitu Analysis, Design, Development, Implementation, dan Evaluation. Evaluasi produk menggunakan model evauasi Tessmer dan diperoleh nilai validitas pedagogic sebesar 3,3 dengan kriteria sangat valid, validitas konten sebesar 3,3 dengan kriteria sangat valid, dan validitas desain sebesar 3,4 dengan kriteria sangat valid. Kepraktisan diperoleh dari tahap ujicoba one to one dan small group. Pada tahap one to one diperoleh nilai sebesar 3,29 dengan kriteria sangat praktis dan pada tahap small group diperoleh nilai sebesar 3,52 dengan kriteria sangat praktis. Keefektifan produk diperoleh dari nilai pretest dan posttest yang menunjukkan bahwa LKPD interaktif berbasis web dinyatakan efektif dengan nilai N-g...
Pengembangan multimedia interaktif untuk pembelajaran bentuk molekul di SMA. Pengembangan multi... more Pengembangan multimedia interaktif untuk pembelajaran bentuk molekul di SMA. Pengembangan multimedia interaktif untuk pembelajaran bentuk molekul telah diujicobakan dan dilakukan di kelas XI IPA SMAN 1 Prabumulih. Data dikumpulkan dengan teknik uji pakar, angket, dan tes hasil belajar. Berdasarkan teknik analisa data diperoleh skor kevalidan materi 113 dengan kategori sangat baik, skor kevalidan pedagogik 109 dengan kategori sangat baik, skor kevalidan media 20 dengan kategori baik, kepraktisan 86,79%, dan keefektifan 88,24%. Hasil penelitian menunjukkan bahwa pengembangan multimedia interaktif untuk pembelajaran bentuk molekul di kelas XI IPA SMA Negeri 1 Prabumulih telah memenuhi kriteria kevalidan, kepraktisan, dan keefektifan. Keywords: Interactive Multimedia, Molecular Shape
Pengaruh konsentrasi H 2 SO 4 dan NaOH dalam delignifikasi serbuk bambu telah diteliti untuk menu... more Pengaruh konsentrasi H 2 SO 4 dan NaOH dalam delignifikasi serbuk bambu telah diteliti untuk menurunkan kadar lignin. Delignifikasi dilakukan pada suhu 121 0 C selama 30 menit dengan variasi konsentrasi. H 2 SO 4 : 0,5%, 1,0%, 1,5%, 2,0%, dan 2,5% (v/v) sedangkan variasi NaOH adalah 2,0%, 4,0%, 6,0%, 8,0%, dan 10% (b/v). Kadar lignin dianalisis menggunakan metode Kappa. Peningkatan konsentrasi H 2 SO 4 dan NaOH sejalan dengan peningkatan kadar lignin terurai. Penguraian optimum sebesar 5,37% dicapai pada saat konsentrasi H 2 SO 4 2,5% sedangkan pada saat konsentrasi NaOH 6,0% penguraian optimum sebesar 9,53%.
Cette these porte sur la synthese et l'etude de nouveaux oxyhalogenures a clusters triangulai... more Cette these porte sur la synthese et l'etude de nouveaux oxyhalogenures a clusters triangulaires et octaedriques de niobium ou de tantale. Leurs structures cristallines determinees par diffraction X sur monocristal comportent des motifs presentant differents taux d'oxygene selon le compose et dans lesquels le cluster est tres deforme en raison de la presence simultanee des ligands halogene et oxygene. Ces resultats structuraux completes par ceux rapportes prealablement pour les autres oxychlorures a clusters octaedriques nous ont permis de discuter l'evolution sterique et electronique du motif en fonction du nombre de ligands oxygene par motif et de leur repartition entre les positions inner et apicales, ainsi que l'influence de ces ligands sur les connexions intermotifs et les sites cationiques. Nous avons ainsi pu degager certaines caracteristiques structurales et electroniques propres aux oxychlorures a clusters octaedriques et montre leur influence sur les propri...
The composite magnet NdFeB has been made using magnetic powder MQP-B and polyvinyl alcohol (PVA) ... more The composite magnet NdFeB has been made using magnetic powder MQP-B and polyvinyl alcohol (PVA) as the binder. The mixing compositions of raw materials used are: 95 wt% NdFeB-5 wt% PVA, 92.5 wt% NdFeB-7.5 wt% PVA, 90 wt.% NdFeB-10 wt% PVA, and 87.5 wt% NdFeB-12.5 wt% PVA. Both raw materials are weighed according to the composition, and then mixed until homogeneous. Furthermore, pellet forming was made using dry pressing at 50 kgf/cm 2 pressures and continued with drying at 100 °C and 10 mmbar for 4 hours. The characterization includes bulk density, hardness, compressive strength measurements, and magnetic properties testing. The characterization results show that the optimal composition of binder PVA is achieved at 5-7.5 wt% NdFeB composite magnet with following properties: bulk density = 5.21-5.25 g/cm 3 , hardness = 302.17-304.32 Hv, compressive strength = 25.17-3.17 kgf/cm 2 , magnetic flux = 1150-1170 Gauss, remanence = 70.90-74.97 emu/g or 4.7-5.0 kGauss, coercivity = 8.68-8.76 kOe, and energy product = 2.89-3.04 MgOe.
Influence of addition Ba-Ferrite on the hardness, magnetic properties and corrosion resistance of... more Influence of addition Ba-Ferrite on the hardness, magnetic properties and corrosion resistance of hybrid bonded magnet NdFeB.
The hybrid bonded magnet NdFeB-BaFe12O19 has been made. The composition of BaFe12O19 was varied a... more The hybrid bonded magnet NdFeB-BaFe12O19 has been made. The composition of BaFe12O19 was varied as 0, 3, 5, 8, and 10 wt%. The preparation process was started by mixing BaFe12O19 powder with NdFeB (MQP-B+), then mixed with exopy resin binder of 8 wt% and subsequently compacted with a pressure of 60 MPa to form a pellet. The pellet samples were heated in 10 mmbar of vacuum dryer at 90°C for 1 hour. Some parameters were measured such as mechanical properties (compressive strength), magnetic properties (magnetic flux density and hysteresis curve) and corrosion resistance. The results show that the hybrid bonded magnet NdFeB with 10 wt% BaFe12O19 exhibits the highest compressive strength of about 268,15 kgf/cm 2. While the optimum corrosion resistance of bonded magnet NdFeB-BaFe12O19 is obtained by 5 wt% BaFe12O19 addition. It has a flux magnetic density of 1340 Gauss, remanence Br of 3,827 kG and coercivity Hcj of 8,924 kOe. According to the corrosion test result, it is found that the sample with higher content of Ba-ferrite has a better corrosion resistance compare to the sample with small content of Ba-ferrite.
The SnO2/Sn3O4 were successfully prepared using a one-step hydrothermal method and exhibit the he... more The SnO2/Sn3O4 were successfully prepared using a one-step hydrothermal method and exhibit the heterostructure formation. The heterostructure formation facilitates the enhancing of visible-light photoresponse of SnO2 which well known as the UV-light activated semiconductor. The heterostructure formation also exhibits high efficient photocatalytic performance by completely degrading 10 ppm of DB71 in 120 minutes after adding 50 mg of prepared-Tin oxide with a kinetic rate constant of 4.636 x 10-2 min-1. The kinetic constant rate of prepared-Tin oxide has 2.5 and 3 times faster compared to the kinetic constant rates of SnO2 and Sn3O4, respectively. The high efficient photocatalytic degradation was generated by the improvement of carrier mobilities through manipulating band alignment between SnO2 and Sn3O4 and prevented the recombination of photogenerated hole-electron which commonly generated in the intrinsic semiconductor. Heterostructure SnO2/Sn3O4 was not only forming high-efficiency photocatalytic degradation but also exhibiting blue shifting phenomenon. The UV-Vis adsorption response approaches were used to investigate and propose the photocatalytic degradation mechanism. After 120 minutes, there were only benzene adsorption peaks detected indicating the mineralization of DB71 dyes.
The effort to enhance the visible-light photoresponse of SnO 2 and SnO has been designed by the h... more The effort to enhance the visible-light photoresponse of SnO 2 and SnO has been designed by the heterostructure formation of tin oxide. The formation was conducted by controlling the oxidation state of precursor through adjusting the precursor acidity. The result shows that the transformation route as a function of precursor initial pH involve the formation of intermediate phase began by SnO 2 to SnO 2 /Sn 3 O 4 to SnO/Sn 3 O 4 , and finally SnO. The characterization indicated that Sn 3 O 4 played the important role in enhancing the visible light response of both SnO 2 and SnO in the heterostructure formation.
IOP Conference Series: Materials Science and Engineering, 2017
View the article online for updates and enhancements. You may also like Synthesis BaFe 12 O 19 ba... more View the article online for updates and enhancements. You may also like Synthesis BaFe 12 O 19 based on natural iron sand with Cu and Ni doping using coprecipitation method B U P Elinda, Susilawati, Kosim et al.-Comparison of temperature dependent magnetic properties of uncoated and SiO 2 coated BaFe 12 O 19 nanoparticles K Nadeem, J Z Minhas, F Zeb et al.-Magnetic and microwave absorbing properties of BaFe 122x Co x Zn x O 19 (x = 0.0; 0.2; 0.4; 0.6) nanocrystalline E Handoko, S Iwan, Setia Budi et al.
The development of teaching materials by using Web in Kesetimbangan Kimia Study was applied in XI... more The development of teaching materials by using Web in Kesetimbangan Kimia Study was applied in XI IPA SMA Negeri 11 Palembang. The validity of this development was assessed by three experts involved materials expert, pedagogic expert, and media expert. The validity of teaching materials is 50 in good category, the validity of pedagogic is 47 in good category, and the validity of media is 21 in excellent category. Practicality of teaching materials was seen by using average value of questionnaire in one to one step and small group step. The average value of Practicality is 3.32 in excellent category. The effectiveness of teaching materials was seen by using the result of test in field test step. Based on the test, there are 81,08% students who got score ≥ 70. It shows that the teaching materials are effective to be used in Kesetimbangan Kimia Study
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