201 research outputs found
Convective boundary layer flow in generalized Newtonian nanofluid under various boundary conditions
The four mathematical models of boundary layer flow solved under different boundary
conditions. The first problem considered the unsteady squeezing flow of the Carreau
nanofluid over the sensor surface, where three different nanoparticles were suspended
in the base fluid. A comparison of the results of suspended materials in liquids proved
that increased surface permeability leads to increased heat transfer. The second
problem described the magnetohydrodynamics (MHD) Darcy-Forchheimer model,
which considers Maxwell nanofluids' flow. It was observed that an increase in the Biot
number coefficient increased heat transfer. The third problem evaluated activation
energy and binary reaction effect on the MHD Carreau nanofluid model. Buongiorno
nanofluid model was applied to shear-thinning or pseudoplastic fluid over the
pereamble surface. The relationship between the activation energy and chemical
reaction is influential and controls heat transfer processes. The fourth problem
analyzed the radiative Sutterby model over a stretching/shrinking sheet towards
stagnation point flow. Dual solutions were found using the scaling group
transformation, which was examined by a stability approach. Such a problem found an
increment in the suction parameter, the Deborah number, and the nanoparticle volume
fraction delayed the flow separation. The influence of various pertinent parameters on
the velocity and temperature distributions has been presented. The most relevant
results by the forceful impacts of thermo-physical properties on fluids were analyzed
through this work. Modeled equations are based on the conservation laws under the
boundary layer approximation. The similarity transformation method is used to
convert the governing partial differential equations into ordinary differential
equations. They are then solved using a numerical technique, known as the Runge�Kutta-Fehlberg method with shooting technique in the MAPLE 17 or bvp4c method in
the MATLAB 2019a
Studying the Crystal Structure, Topography, and Anti-bacterial of a Novel Titania (TiO2 NPs) Prepared by a Sol-gel Manner
في هذا البحث تم تحضير جسيمات ثنائي أكسيد التيتانيوم النانوية (TiO2) باستخدام طريقة صّل-جلّ عند وسط حامضي (pH3). جسيمات ثنائي أكسيد التيتانيوم تم تحضيرها من ثلاثي كلوريد التيتانيوم (TiCl3) وهيدروكسيد الامونيوم (NH4OH) وبنسبة 3:1 عند درجة حرارة 50 درجة مئوية، الجلّ المحضر تم تجفيفه عند درجة حرارة 70 درجة مئوية وذلك للحصول على المسحوق النانوي. المسحوق الناتج من عملية التجفيف تم معاملته حراريا عند درجات حرارة 500و700 درجة مئوية . تم دراسة التركيب البلوري ومورفولوجيا السطح والحجم الحبيبي باستخدام جهاز حيود الاشعة السينية (X-ray) و مجهر القوة الذرية (AFM) والمجهر الإلكتروني الماسح (SEM). أظهرت النتائج تكون طور (Anatase) من ثنائي أكسيد التيتانيوم وبمعدل حجم حبيبي (110) نانومتر عند درجة حرارة 500 درجة مئوية. في حين اظهرت النتائج طور مخلوط من (Anatase-Rutile) من ثنائي أكسيد التيتانيوم وبمعدل حجم حبيبي 118.1 نانومتر عند درجة حرارة 700 درجة مئوية. تم دراسة الفعالية ضد البكتيريا باستخدام طريقة كيريبي – باور (اختبار الحساسية بطريقة الانتشار). حيث أظهرت النتائج فعالية جيدة لجسيمات ثنائي أكسيد التيتانيوم والعمل على تثبيط بكتيريا زائفة زنجارية سالبة الغرام و البكتيريا الكروية العنقودية موجبة الغرام و إشريكية قولونية سالبة الغرام. أن حساسية البكتيريا لجسيمات ثنائي أكسيد التيتانيوم تعتمد وبشكل كبير على الشكل البلوري ، مساحة السطح ، المسامية ، حجم الجسيم ، وحالة الأكسدة. حيث ان جسيمات ثنائي أكسيد التيتانيوم ذات الحجم الحبيبي الصغير اظهرت فعالية عالية ضد البكتريا في حين أن جسيمات ثنائي أكسيد التيتانيوم ذات الحجم الحبيبي الاكبر اظهرت فعالية أقل. نستنتج من ذلك انه يمكن استعمال مادة ثنائي أكسيد التيتانيوم النانوية على قتل بعض انواع البكتيريا. In this research, titanium dioxide nanoparticles (TiO2 NPs) were prepared through the sol-gel process at an acidic medium (pH3).TiO2 nanoparticles were prepared from titanium trichloride (TiCl3) as a precursor with Ammonium hydroxide (NH4OH) with 1:3 ratio at 50 °C. The resulting gel was dried at 70 °C to obtain the Nanocrystalline powder. The powder from the drying process was treated thermally at temperatures 500 °C and 700 °C. The crystalline structure, surface morphology, and particle size were studied by using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), and Scanning Electron Microscope (SEM). The results showed (anatase) phase of titanium dioxide with the average grain size of 110 nm at 500 °C calcination temperature, and (anatase- rutile) mixed phase of titanium dioxide with the average particle size of 118.1 nm at 700 °C calcination temperature. The anti-bacterial activity of the synthesis specimens was recorded through the Kirby-Bauer disc method (disc devotion method). The results displayed a pretty excellent antibacterial activity of TiO2 NPs to bacteria strains: Gram positive staphylococcus aureus, gram negative pseudomonas aeruginosa, and "gram negative escherichia coli. The sensitivity of the tested bacteria to TiO2 NPs depends on the oxidation state of the TiO2 NPs, particle size, volume, and the density of the unit cell. The small- average particle size of titanium dioxide particles showed high antibacterial activity against bacteria, while the larger- average particle size of titanium dioxide particles showed less antibacterial activity. The novelty of this production is the manufacturing of a novel kind of TiO2 NPs and achievement its best antibacterial activity
Analisis Pengaruh Jumlah Tenaga Kerja, Besarnya Net Ekspor, dan Besarnya Konsumsi Terhadap PDRB: Studi Provinsi Di Indonesia
Economic globalization provides opportunities and risks to economic growth in Indonesia. This study aims to analyze the effect of the number of workers, net exports and household consumption on the GRDP of the provinces in Indonesia. This study uses the Fixed Effect Model (FEM) panel data analysis model using the variables GRDP, percentage of labour, total net exports, and household consumption for each province in Indonesia in 2015-2020. The results showed that household consumption and exports contributed positively to the GRDP for each province, although in small amounts. Meanwhile, the workforce has not contributed to economic growth. Therefore, it is recommended for each region to increase cooperation in increasing development and increasing investment in the field of export commodities so that there is an increase in export volume, which has a positive impact on economic growth. The policy of creating jobs through increased investment needs to be carried out to reduce unemployment and affect economic growt
An analysis of multimodal route via Iraq to the Mediterranean and Europe compared to the Suez Canal
Seroprevalence of HBV Infection Among Normal Population and Healthcare Workers in Baghdad
Objective: In this study we verified the epidemiology of HBV infection among normal population and healthcare workers (HCWs) in Baghdad by analyzing the prevalence of specific viral markers (anti-HBs, anti-HBc and HBsAg). Method: A total of 797 serum specimens (588-normal population, 209-HCWs) were tested using ELISA technique and positive HBsAg specimens were confirmed by VIDAS technique. Results: In normal population group, the HBsAg, anti-HBs and anti-HBc Total were 1.02%, 10.54%, 5.44%, respectively. The HBsAg result was significantly lower (P< 0.05) than previous studies were done in Iraq. Significant correlation (P < 0.05) in prevalence of HBsAg was found between age groups and males had higher positive HBsAg marker than females (P < 0.05). The prevalence of anti-HBs was insignificant (P>0.05) between age groups but significant importance (P < 0.05) was recorded between both sexes. Highly significant (P<0.01) was recorded between ages groups regarding to anti-HBc Total marker but insignificantly (P>0.05) between both sexes were noticed. In HCWs group the HBsAg, anti-HBs, anti-HBc Total were 0.96%, 26.7%, 1.44% respectively and the prevalence of HBsAg was significantly less (P < 0.05) than previous studies. The comparison between normal population and HCWs groups showed significant correlation (P < 0.05) related to HBsAg and highly significant correlation (P<0.01) regarding anti-HBs and anti-HBc Total. The HBsAg and anti-HBs among HCWs was significantly increased (P<0.05) with advancing ages, whereas no such variation was observed between both sexes. The HBsAg was high among those with poor health education but it was with significantly importance (P< 0.05) among different occupational types as well as among vaccinated, incomplete vaccinated and unvaccinated HCWs groups. Additionally, HCWs who had only 1st, only 2nd and those who had 3rd doses showed significant correlation between number of vaccinated individuals and prevalence of anti-HBs. Keywords: Seroprevalence of HBV, HBsAg, anti-HBs, HCWs, normal population Abbreviations: anti-HBs, antibody anti-HBs; anti-HBc, antibody anti-HBc; HBsAg, antigen HB
PERANCANGAN SISTEM OTOMATISASI PALANG PINTU KERETA API BERBASIS MOTION DETECTION
ABSTRAK
Pada tahun 2009 sampai 2011 prosentase penyebab kecelakaan kereta api yang terjadi di luar faktor eksternal, didominasi oleh human error atau sumber daya manusia (SDM) dari operator yakni mencapai 24%. Pada penelitian ini telah dirancang sebuah sistem teknologi pada palang pintu kereta api yang merupakan penyempurnaan dari penelitian sebelumnya. Pada penelitian sebelumnya, didapatkan waktu bahwa palang pintu kereta api menutup sempurna selama 15,92 detik dengan delay pengiriman informasi ke palang pintu sebesar 1,5 detik dari jarak 1,2 Km[1]. Namun, pada penilitian sebelumnya belum ada analisis keakuratan dari sensor deteksi yang digunakan.
Pada penelitian kali ini diberikan analisis dari pendeteksian kereta api dengan video processing dengan menggunakan metode motion detection sebagai deteksi objek bergeraknya dan Transformasi Hough sebagai deteksi bentuk objek, sehingga terlihat keakuratan metode yang digunakan pada teknologi palang pintu kereta api otomatis. Output dari proses deteksi kereta api yang menggunakan kedua metode tersebut dikirimkan ke arduino. Arduino mengeksekusi instruksi selanjutnya sesuai dengan output yang diterima. Jika hasil yang terdeteksi merupakan kereta api, maka palang pintu kereta api tertutup. Namun jika bukan kereta api, palang pintu tidak tertutup.
Perbedaan antara penelitian ini dengan penelitian sebelumnya adalah dalam hal deteksi kereta api. Bila penelitian sebelumnya menggunakan sensor untuk dapat mendeteksi kereta api, pada penelitian ini digunakan vision untuk dapat mendeteksi kereta api. Hasil yang diperoleh dari penelitian ini adalah sistem dapat mendeteksi objek bergerak yang berupa kereta api dengan 0.03538 detik dan dengan tingkat keakuratan mencapai 100%. Hasil tersebut adalah hasil maksimal yang diperoleh oleh sistem dalam mendeteksi objek berupa kereta api.
Kata kunci: Kereta api, Motion detection, Transformasi Hough, Arduino.</p
ANALISA KARAKTERISTIK ARUS LALU LINTAS DENGAN MODEL METODE GREENSHIELDS GREENBERG UNDERWOOD PADA RUAS JALAN A. H. NASUTION MEDAN JOHOR STA 3+350 S/D 3+
Analisa dilakukan mengetahui bagaimana karakteristik jalan A.H. Nasution dengan melihat hubungan volume, kepadatan, kecepatan menggunakan model greenshields, greenberg, underwood dikarenakan berdasarkan probabilitas, di jalan A.H. Nasution adanya berbagai kendaraan, kemungkinan akan terjadi permasalahan lalu lintas kedepan dan bagaimana ruas jalan mampu mengantisipasi lonjakan pertumbuhan kedepan maka diperlukan karakteristik jalan dari sekarang. Arah underpass ke fly over, Model greenshields, greenberg, underwood hari sabtu merupakan model yang terbaik hubungan V-D dengan nilai = 0,983. Arah fly over ke underpass, Model greenshields, greenberg, underwood hari sabtu merupakan model yang terbaik hubungan V-D dengan nilai yaitu = 0,988. Hasil perhitungan dengan model greenshields, greenberg, underwood, bahwan model greenshields memiliki hasil untuk Vm, Sff, Dj, sementara untuk model greenberg memiliki hasil Vm dan Dj, untuk Sff didapat hasil ¥ (tidak terbatas), kemudian untuk model underwood memiliki hasil untuk Vm dan Sff, untuk Dj didapat hasil ¥ (tidak terbatas). Arah underpass ke fly over menggunakan model greenshields hari selasa, Dm 34,386, Sm 23,733, Hd 29,17, Sp 26,17, mengasilkan Vm 813,69 smp/jam. Kemudian, arah fly over ke underpass menggunakan model greenshields hari selasa, Dm 35,734, Sm 23,036, Hd 27,98 dan Sp 24,98, mengasilkan Vm 823,16 smp/jam. kondisi ini yang diharapkan dimana arus lalu lintas bergerak
PERHITUNGAN STRUKTUR BETON BERTULANG GEDUNG 6 LANTAI (KANTOR KESYAHBANDARAN DAN OTORITAS PONTIANAK)
ABSTRAK Gedung Kantor Kesyahbandaran Dan Otoritas Pontianak merupakan salah satu sarana untuk mendapatkan pelayanan berkualitas, yang merupakan lembaga pelayanan lalu lintas dan keselamatan pelayaran di perairan Pelabuhan. Gedung beralamat di Jalan Rahadi Usman, Tengah, KecamatanPontianak kota, Kota Pontianak, Kalimantan Barat. Gedung 6 lantai dengan struktur beton bertulang, dimana gedung pelabuhan wajib memiliki kekuatan terhadap beban luar yang memiliki potensi mengakibatkan kegagalan pada struktur. Adapun beban yang sering diabaikan dalam menghitung struktur gedung di Pontianak adalah beban gempa. Hal tersebut dapat terlihat diperaturan terbaru yang menunjukkan Kota Pontianak termasuk zona gempa ringan. Perhitungan ulang struktur pada gedung memperhitungkan beban gempa dimana struktur direncanakan dengan Sistem Rangka Pemikul Momen dan dibatasi hanya untuk perencanaan struktur atas bangunan (pelat lantai, balok, kolom) serta struktur bawah bangunan (fondasi). Analisis struktur dilakukan dengan bantuan program analisis struktur dengan dimensi struktur yang digunakan pelat lantai dengan tebal 100 mm, balok induk 350/600 mm, dan 300/500 mm, serta kolom K1 500×500 mm dengan menggunakan fondasi tiang pancang dengan spun pile berdiameter 30 cm dan kedalaman 38 m. Kategori desain seismik untuk gedung ini termasuk dalam KDS C sehingga hasil penelitian ini, sistem struktur pemikul gaya seismik yang digunakan adalah Sistem Rangka Pemikul Momen Menengah (SRPMM). Kata Kunci: Analisis struktur, Gedung Kantor Kesyahbandaran Dan Otoritas Pontianak, Sistem Rangka Pemikul Momen Menengah
A Compact Single-Feed Patch Antenna with Frequency and Polarization Diversity
A new compact single feed square ring patch antenna using meandered 4λ transformer is designed, for frequency and polarization diversity. The proposed antenna is constructed from a square ring patch antenna, and two orthogonal meandered cascaded 4λ transformer (OMCT), incorporated with six switches for frequency and polarization reconfiguration purposes. The OMCT with switches is necessary to get good impedance bandwidth (BW) and axial ratio bandwidth (ARBW) for circular polarization state. In addition, it utilized to excite the antenna at two orthogonal locations, with equal magnitude and quadratic in phase, for achieving circular polarization mode at resonant frequencies 2.44GHz, 4.7GHz, and 5.6GHz. Moreover, it can excite the antenna as non-orthogonal modes for various other frequency bands, such as 2.89 GHz, 3.49 GHz, 4.9 GHz, 5.2GHz, 5.49GHz, 6.16GHz and 3.1GHz as linear polarization (LP) state. The proposed antenna has a compact low profile planar structure with area equal to 23mm2. Simulation and measured results show that the proposed antenna demonstrates a reasonable impedance bandwidth, and axial ratio in the circularly polarized state. Simulation results have been obtained from commercial CST-2014 Microwave Studio. The proposed antenna is fabricated for simulation result verification, and the implemented antenna is tested using R&S ZVL13 Vector Network Analyzer. The experimental confirms the simulation results
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