ITB Journal
Not a member yet
5999 research outputs found
Sort by
Modelling the Impact of Decomposed Disease-Induced Dead Cashew Plants on Fusarium Wilt Dynamics in South-Eastern Tanzania
Get PDFCashew Fusarium wilt disease transmitted by Fusarium oxysporum is dangerous and destroys many cashew plants in Tanzania. The effect of this disease leads households and the government to experience a decrease in overall cashew production and income due to this disease’s capacity to harm cashew plants. This study aimed to ascertain the role of Fusarium wilt-decayed disease-induced dead plants in spreading the disease among cashew plants. A mathematical model was created based on the dynamics of the disease and a stability analysis was conducted using theories of ordinary differential equations. Data from two regions in Tanzania, Lindi, and Mtwara, were used in model fitting and parameter estimation. Additionally, the parameters were estimated using maximum likelihood estimation (MLE). The outcome suggests that the disease’s prevalence and spread increase during an outbreak as decomposed diseased-induced dead plants contribute to the saturation of chlamydospores in the soil
analisis, kemampuan, teknik dasa ANALISIS TEKNIK DASAR SEPAKBOLA PADA ANAK USIA DINI DI SEKOLAH SEPAKBOLA (SSB) KABUPATEN KARAWANG
No full textSetiap pemain sepakbola harus menguasai keterampilan teknik dasar yang dijadikan fundamental dalam mengembangkan skill permainan. Teknik dasar diajarkan di Sekolah Sepakbola (SSB). Penelitian ini dilakukan untuk mengetahui kemampuan taknik dasar siswa SSB bertujuan untuk memberikan data kepada pelatih agar dapat mengembangkan dalam menyusun perencanaan program latihan. Penelitian ini merupakan penelitian deskriptif, analisis data yang digunakan adalah metode kuantitatif. Populasi penelitian meliputi 8 SSB yang ada di kabupaten karawang , dengan teknik sampling adalah purposive sampling, semua pemain yang masuk usia 12 tahun sebanyak 50 anak. Pengumpulan data dilakukan melalui observasi langsung. Hasil penelitian menunjukkan kemampuan teknik dasar permainan sepakbola anak usia dini di Kabupaten karawang termasuk kategori sedang. Saran yang diberikan bagi anak dengan kemampuan teknik kategori kurang sebaiknya dilakukan latihan intensif; bagi anak yang termasuk kategori sedang ditambah porsi latihan; dan bagi anak-anak dengan kemampuan teknik kategori baik terus dilakukan latihan rutin untuk maintenance kemampuan teknik dasarnya.Setiap pemain sepakbola harus menguasai keterampilan teknik dasar yang dijadikan fundamental dalam mengembangkan skill permainan. Teknik dasar diajarkan di Sekolah Sepakbola (SSB). Penelitian ini dilakukan untuk mengetahui kemampuan taknik dasar siswa SSB bertujuan untuk memberikan data kepada pelatih agar dapat mengembangkan dalam menyusun perencanaan program latihan. Penelitian ini merupakan penelitian deskriptif, analisis data yang digunakan adalah metode kuantitatif. Populasi penelitian meliputi 8 SSB yang ada di kabupaten karawang , dengan teknik sampling adalah purposive sampling, semua pemain yang masuk usia 12 tahun sebanyak 50 anak. Pengumpulan data dilakukan melalui observasi langsung. Hasil penelitian menunjukkan kemampuan teknik dasar permainan sepakbola anak usia dini di Kabupaten karawang termasuk kategori sedang. Saran yang diberikan bagi anak dengan kemampuan teknik kategori kurang sebaiknya dilakukan latihan intensif; bagi anak yang termasuk kategori sedang ditambah porsi latihan; dan bagi anak-anak dengan kemampuan teknik kategori baik terus dilakukan latihan rutin untuk maintenance kemampuan teknik dasarnya
Studi Karakteristik Kuat Tekan Beton Geopolimer Berbahan Dasar Fly Ash
Get PDFThe use of concrete is generally used to make road pavement, building structures, foundations, roads, pedestrian bridges, parking structures, bases for fences/gates, and cement in brick or block walls, causing the demand for cement material to be increasingly high, building construction materials experts also conducted various research on concrete. One of the research carried out was on Geopolymer Concrete. Geopolymer concrete is a type of geosynthetic concrete that is made without using any portland cement as a binding agent, and as a substitute for portland cement, fly ash mixed with an alkali activator is used.Geopolymer concrete mix planning uses the weight comparison method for each concrete composition using a w/fa factor of 0.25. The test object is cylindrical in shape with an activator alkali ratio of Na2SiO3: NaOH (sodium silicate and sodium hydroxide) of 1/2, 2/2, 3/2, 4/2 and 5/2. Cylindrical specimens with a diameter of 10 cm and a height of 20 cm were tested for compressive strength at the age of 14 days and 28 days to see the development and comparison of each variation of the alkali activator mixture for the results of the concrete compressive strength values.The average compressive strength of Geopolymer concrete with an alkali activator composition ratio of 1/2 and 2/2 cannot be used as structural concrete because the concrete compressive strength test results are below 18 MPa and geopolymer concrete with an alkali activator composition ratio of 3/2 to 5/2 can be used as an alternative substitute for concrete. conventional because the results obtained have reached the minimum concrete compressive strength requirements for the structural concrete category, namely > 18 MPa.
Keywords: Geopolymer Concrete, Alkali Activator, Fly Ash, Compressive StrengthPemanfaatan beton pada umumnya digunakan untuk membuat perkerasan jalan, struktur bangunan, pondasi, jalan, jembatan penyeberangan, struktur parkiran, dasar untuk pagar/gerbang, dan semen dalam bata atau tembok blok sehingga menyebabkan permintaan penggunaan material semen semakin tinggi, para ahli material konstruksi bangunan juga melakukan berbagai penelitian mengenai beton. Salah satu penelitian yang dilakukan adalah tentang Beton Geopolimer. Beton Geopolimer adalah suatu jenis beton geosintetik yang dibuat tanpa menggunakan sedikitpun semen portland sebagai bahan pengikat, dan sebagai bahan pengganti semen portland digunakan fly ash dicampur dengan alkali aktivator. Perencanaan campuran beton geopolimer mengunakan metode perbandingan berat pada setiap komposisi penyusun beton dengan menggunakan faktor w/fa sebesar 0,25. Benda uji berbentuk silinder dengan perbandingan alkali aktvator Na2SiO3 : NaOH (Natrium silikat dan natrium hidroksida) sebesar 1/2, 2/2, 3/2, 4/2 dan 5/2. Benda uji silinder dengan ukuran diameter 10 cm dan tinggi 20 cm dilakukan pengujian kuat tekan pada umur 14 hari dan 28 hari untuk melihat perkembangan serta perbandingan pada setiap variasi campuran alkali aktivator untuk hasil nilai kuat tekan beton. Hasil kuat tekan pada Beton geopolimer dengan perbandingan komposisi alkali aktivator 1/2 dan 2/2 tidak dapat digunakan sebagai beton struktural dikarenakan hasil uji kuat tekan beton dibawah 18 MPa dan beton geopolimer dengan perbandingan komposisi alkali aktivator 3/2 hingga 5/2 dapat dijadikan sebagai alternatif pengganti beton konvensional karena hasil yang didapatkan telah mencapai syarat ketentuan kuat tekan beton minimum untuk kategori beton struktural yaitu > 18 MPa.
Kata kunci : Beton Geopolimer, Alkali Aktivator, Fly Ash, Kuat Teka
Two-Dimensional Analysis of Lower Extremities to Predict Best Initial Condition on Marching Movement
Get PDFHimpunan Mahasiswa Mesin ITB has a specific type of marching that follows a march song’s rhythm called “derap”. In practice, derap was a hard move to maintain and unify in a group. This difficulty was observed by noting the differences that occur between the subjects' initial and middle march motion conditions. The most noticeable difference was the height of the group. This study intends to observe and find how the differences vary in this motion. The differences that occur corresponded to the relative knee and ankle angle. This study utilized five active markers to reconstruct the lower extremities' activity during motion, one action camera at 60 fps, and a workstation. This study was also constrained by using three cycles of march song at 115 bpm. Direct Linear Transformation was used to obtain the intrinsic factor of the camera to reconstruct the motion. Evaluating the angular kinematic parameters of relative knee and ankle angle, the authors found the relative knee angle has increased from 110° to around 130°, which happened at the second song cycle and kept stable at the rest of the song. This result brought the conclusion that more extended derap motion would tend to a steady condition of relative knee angle and suggested that the subject should begin with 130° of relative knee angle to give less effort on marching.Himpunan Mahasiswa Mesin ITB has a specific type of marching that follows a march song’s rhythm called derap. In practice, derap movement in a group was harder to be maintained and aligned. This difficulty was observed by noting the height differences that occur in the individual's movements during the initial and middle of the march. This study intends to observe and find how the differences vary during this motion. This study utilized five active markers to track the landmarks of the right side of the lower extremities while the motion was captured using a 60 frames per-second (fps) action camera. The duration of the movement in this study was also constrained with three cycles of marching song at 115 bpm. The direct Linear Transformation (DLT) method was used to calibrate the camera and reconstruct the movements using captured marker positions. As the results, the knee angle ROM has decreased from 26.55° to around 15°, which happened during the second song cycle and kept stable for the rest of the movement. This result brought the conclusion that the more extensive derap motion would tend to change the form of the body compared to the initial state
The Behavioral Response of Komodo Dragons (Va- ranus komodoensis OUWENS, 1912) During Mating and Nesting Periods towards Tourist Presence in Loh Buaya, Komodo National Park
Get PDFIt has been recognized in many studies that wildlife tourism practices might generate a negative impact on wildlife, particularly during the reproductive period. Some wildlife may lower their sensitivity towards tourist presence, for instance in Komodo. Understanding to what extenthabituation occurs in Komodo would be necessary for tourism management in Komodo National Park (KNP). Therefore, this study aimed to identify the response of Komodo to tourist presence during mating and nesting activities. The observation was conducted in Loh Buaya, which is one of the tourism sites in KNP. Komodo’s responses were divided into (1) avoidance; (2) neutral; and (3) aggressive under categorized stimulus: tourist number (i.e., < 5 persons; 5-10 persons; and > 10 persons) and distance (i.e., < 5 m; 5-10 m; and > 10 m). Correlation analysis was performed to identify any influences on mating and nesting activities. Our results revealed that Komodo inhabiting tourism facilities havebeen habituated to tourist presence. Different tourist frequencies did not influence Komodo mating activities (r(20)= 0.036, p=0.873), the nest preparing activity (i.e., digging proportion; r(22)= 0.054, p=0.803) and the guarding activity (i.e., nesting proportion; r(22)= 0.314, p=0.135).Nevertheless, our results indicated possible impacts due to tourism activities and its supporting facilities, such as dominated mating pairs, threats to female reproductive success, and human-Komodo conflicts. Therefore, habituation evi- dence must be carefully considered in order todevelop more corresponding strategies and achieve sustainable tourism practices
Perancangan Buku Ilustrasi Digital Untuk Masyarakat Umur 20-35 Tahun Tentang Kekerasan Terhadap Anak Usia Dini Dan Pengaruhnya Pada Perkembangan Psikologis
Get PDFThe early childhood phase, spanning from ages 0 to 6 years, is considered the golden age for human growth and development, significantly influencing an individual's future life. Regrettably, instances where children are subjected to maltreatment, particularly violence, hinder their holistic development. Acts of violence adversely impact both the physical and psychological well-being of a child. To address this issue, a digital illustrated book media has been designed to explore the impacts of violence on early childhood and its effects on children's psychological development. This research aims to provide education and awareness regarding the consequences of violence on children to individuals aged 20-35, including both parents and non-parents. The study adopts a descriptive qualitative approach, utilizing the ADDIE model to develop the media. The research findings indicate that the target community can enhance their awareness of child development and minimize adverse psychological effects on children, thereby potentially preventing occurrences of violence from their immediate environment directed towards children.Masa kanak-kanak merupakan masa keemasan bagi pertumbuhan dan perkembangan seorang manusia pada usia 0-6 tahun yang memiliki pengaruh terhadap kehidupannya kelak. Namun sangat disayangkan apabila seorang anak menerima perlakuan yang buruk bagi perkembangannya seperti kekerasan. Tindak kekerasan berdampak buruk pada fisik dan psikologis anak. Sebagai solusi untuk mencegah kekerasan terhadap anak, dilakukan perancangan sebuah media yang membahas dampak kekerasan terhadap anak usia dini dan pengaruhnya terhadap perkembangan psikologis anak berupa buku ilustrasi digital. Penelitian ini bertujuan memberikan edukasi dan kesadaran mengenai dampak kekerasan terhadap anak kepada masyarakat usia 20-35 tahun, baik secara umum maupun yang sudah memiliki anak. Penelitian ini bersifat deskriptif kualitatif dengan metode yang dilakukan guna penciptaan media adalah model ADDIE. Hasil penelitian ini adalah masyarakat mampu meningkatkan kesadaran terhadap anak dan mengurangi dampak buruk bagi psikologis anak, sehingga diharapkan mampu mencegah terjadinya tindak kekerasan dari lingkungan terdekat terhadap anak
STAYCATION: TREN PARIWISATA BARU UNTUK MEMAHAMI PERILAKU WISATAWAN (TOURIST BEHAVIOR) MILLENIAL PASCA COVID-19 DI KOTA BANDUNG
Get PDFThe purpose of the study was to determine millennial tourist behaviour regarding the decision to doing staycation in hotel during the Covid-19 pandemic. Study Design: This research in the study was descriptive using a quantitative method. Methodology: The study population was consumer or millennial tourist who have stayed in hotels and accommodation around Bandung City. The researchers determined a sample size of 235 respondents. The data collection was performed using a questionnaire consist of multiple choice by selecting a Likert scale. The data processed using SPSS 25. Result: From the profile of 300 respondents of millennial tourist with range 20 – 39 y.o who have stayed in hotel accommodation during the Covid-19 pandemic most of female tourist by 69.4%. Millennial tourist dominated with jobs as a new employees that explain a monthly expenditure budget that can belong to the lower middle class, this group has a good interest in staying at Budget Hotel. Conclusion: From this study we can concluded that the characteristics of millennial tourist choose staycation during Covid-19 pandemic because they need as relaxation. Millennial tourist considered stay at hotel accommodation that have implemented health protocol policies to maintain tourist safety as CHSE Certification.Tujuan dari penelitian ini adalah untuk mengetahui perilaku wisatawan milenial mengenai keputusan untuk melakukan staycation di hotel selama pandemi Covid-19. Desain Studi: Penelitian dalam penelitian ini bersifat deskriptif dengan menggunakan metode kuantitatif. Metodologi: Populasi penelitian adalah wisatawan konsumen atau milenial yang pernah menginap di hotel dan akomodasi di sekitar Kota Bandung. Para peneliti menentukan ukuran sampel 235 responden. Pengumpulan data dilakukan dengan menggunakan kuesioner yang terdiri dari pilihan ganda dengan memilih skala Likert. Data diolah menggunakan SPSS 25. Hasil: Dari profil 300 responden wisatawan milenial dengan kisaran 20-39 tahun yang pernah menginap di akomodasi hotel selama pandemi Covid 19 mayoritas wisatawan wanita sebesar 69,4%. Wisatawan milenial didominasi dengan pekerjaan sebagai karyawan baru yang menjelaskan anggaran pengeluaran bulanan yang bisa dimiliki oleh kalangan menengah ke bawah, kelompok ini memiliki minat yang baik untuk menginap di Budget Hotel. Kesimpulan dari penelitian ini adalah bahwa karakteristik wisatawan milenial memilih staycation di masa pandemi Covid 19 karena mereka membutuhkan relaksasi. Wisatawan milenial dipertimbangkan menginap di akomodasi hotel yang telah menerapkan kebijakan protokol kesehatan untuk menjaga keamanan wisatawan
Antibacterial Activity of Gyrinops versteegii Fruit Extracts against Staphylococcus aureus and Escherichia coli and GC-MS Analysis
Get PDFGyrinops versteegii is widely used in the perfume, incense, and cosmetic industries as a raw material. Other potential uses of the plant are being explored, including in food and medicine. Therefore, this study carried out antibacterial assay and gas chromatography-mass spectroscopy of G. versteegii fruit extracts in three solvents with different polarities, i.e., n-hexane, dichloromethane, and methanol. The agar well diffusion method was then used to test the extracts against Staphylococcus aureus and Escherichia coli. The dichloromethane extract showed the most effective antibacterial activity against S. aureus at a concentration of 40%, with a zone of inhibition of 13.17 mm compared to E. coli, for which it was 7 mm. Furthermore, the bacterial species showed different responses to the extracts. Total and partial inhibition was shown by the G. versteegii fruit extracts against S. aureus and E. coli, respectively. Furthermore, GC-MS identified the following compounds in G. versteegii fruit extract: palmitic, oleic, and stearic acid, as well as bis-(2-ethylhexyl) phthalate, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, methyl octadec-9-enoate, squalene, and 2-monopalmitin derivates. The results showed antibacterial potency of G. versteegii fruit extract against pathogenic bacteria. Additionally, the antibacterial activity of the extract was stronger against S. aureus compared to E. coli