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Abstrak :
Latar Belakang : External counterpulsation (ECP) ditunjukkan dapat mengurangi gejala angina dan memperbaiki kualitas hidup pasien penyakit jantung koroner (PJK) dengan angina refrakter. Efek protektif jangka panjang ini dipikirkan merupakan efek dari peningkatan pulsatile shear stress pada endotel vaskular sehingga terjadi perbaikan pada fungsi endotel. Dalam proses ini, sekelompok miRNA berfungsi meregulasi ekspresi gen dan dipengaruhi oleh shear stress, diantaranya adalah miR-92a yang bersifat proatherosklerosis. Tujuan : Mengetahui pengaruh ECP terhadap kadar miR-92a di plasma pada pasien PJK dengan angina refrakter. Metode : Sebanyak 50 pasien PJK dan angina refrakter direkrut dan diacak ke salah satu dari kelompok terapi ECP atau sham (1:1), dan menjalani 35 sesi yang berdurasi 1 jam tiap sesi. Terapi sham serupa dengan terapi ECP namun memberikan tekanan yang jauh lebih rendah. Level miR-92a di sirkulasi diukur di plasma darah sebelum dan sesudah selesai seluruh terapi, kemudian besar perubahan pada kedua kelompok dibandingkan. Hubungan antara keluaran klinis seperti keluhan angina, kapasitas fisik dan ejection fraction (EF) ventrikel kiri dengan kadar miR-92a juga dinilai. Hasil : miR-92a di plasma meningkat bermakna pada kelompok ECP [+5.1 (+4.2 s.d +6.4) menjadi +5.9 (+4.8 s.d +6.4), p value <0.001] dan sham [+5.2 (+4.1 s.d +9.4) menjadi +5.6 (+4.8 s.d +6.3), p value 0.008]. Besar perubahan dan fold changes cenderung lebih besar pada kelompok ECP namun tidak berbeda bermakna secara statistik dibandingkan kelompok sham. Kadar miR-92a post intervensi berkorelasi signifikan dengan rasio diastolik/sistolik selama terapi dan perbaikan EF pasca intervensi. Selain itu, perubahan miR-92a berkorelasi positif dengan perbaikan kapasitas fisik. ......Background : Noninvasive modality External counterpulsation (ECP) can improve angina frequency and exercise capacity in refractory angina (RA) patients. The long term benefit is thought to be the result of increase in shear stress on vascular endothelial cells resulting in improvement of endothelial dysfunction. In this process, a group of miRNA regulating gene expression in relation to shear stress is called flow-sensitive miRNA, among them is miR-92a. Aim : To evaluate ECP effect on plasma miR-92a level in RA patients. Method : Fifty subjects with RA were enrolled and randomized to either one of ECP or sham therapy (1:1 randomization). Each therapy session was one hour, for a total of 35 sessions. As a control, sham gave same sensation as ECP but with lower pressure. Plasma miR-92a level was measured before and after therapy and delta changes was compared between group. Secondary clinical outcome such as angina class, physical capacity and left ventricle Ejection Fraction (EF) were also measured and correlated with miR-92a level. Result : Plasma miR-92a level increased in both treatment groups [in ECP group +5.1 (+4.2 to +6.4) to +5.9 (+4.8 to +6.4), p value <0.001, in sham group +5.2 (4.+1 to 9.4) to +5.6 (+4.8 to +6.3), p value =0.008]. There was higher delta increase and fold changes in ECP group, however the difference did not reach statistically significant. miR-92a level post intervention correlated significantly with Diastolic/Systolic ratio during intervention and improvement in ejection fraction (EF) post intervention. Moreover, changes in miR- 92a correlated positively with improvement in physical capacity. Conclusion : ECP did not cause significant different increase of miR-92a compared to sham.

Abstrak :
ABSTRACT
The aim of the paper is to present the influence of selected deflocculants on decreasing the hydromixture viscosity and as a consequence decreasing the wall shear stresses in a flowing medium. Adding deflocculants to improve the conditions encountered in a pipeline during the hydromixture flow is called chemical processing. The experimental studies presented in the article were performed for a hydromixture with a mass concentration of 20% and 43% consisting mostly of solids with the averaged diameter equal to 45.5 μm. The measurements were performed for varied doses of deflocculants in three proportions in a wide range of shear rates. The results of experiments have confirmed that the influence of the deflocculant on the wall shear stress is complex as there is an opposing phenomenon strongly depending on the doses of deflocculant samples. The results of the experiments are discussed and major conclusions are drawn.

Abstrak :
Latar Belakang: Penyakit AAA sebagian besar berlokasi pada infrarenal. Mortalitas meningkat dengan ruptur. Faktor risiko utama ruptur adalah diameter aneurisma dan hipertensi. Analisis computational fluid dynamic (CFD) pada aliran darah memungkinkan untuk mengetahui predileksi area tempat terjadinya ruptur. Wall shear stress (WSS) dan tekanan dinding merupakan parameter yang bisa dianalisis melalui CFD untuk melihat potensi ruptur pada AAA. Tujuan: Mengetahui morfologi aneurisma AAA infrarenal beserta sebaran nilai WSS dan tekanan dinding aneurisma berdasarkan CFD untuk memprediksi ruptur aneurisma. Metode: Studi cross-sectional dengan analisis CT angiogram pasien AAA infrarenal di Divisi Vaskular dan Endovaskular-Departemen Bedah dan Departemen Radiologi RSUPN Dr. Cipto Mangunkusumo pada bulan Juli–Desember 2022. Data CT angiografi diolah dengan Radiant Viewer untuk dijadikan model 3D. Dari keseluruhan sampel, dikelompokkan menjadi 5 tipe aneurisma. Kemudian masing-masing model dilakukan proses pembuatan solid vessel dengan Meshmixer. Proses selanjutnya adalah geometri, meshing, setup parameter CFD, dan solution untuk menghasilkan kontur WSS dan tekanan dinding pada berbagai kecepatan dan tekanan darah dengan program ANSYS 2022 R2 Academic Student. Hasil visual pada tiap tipe dianalisis dan dibandingkan. Uji statistik non-parametrik WSS dan tekanan dinding pada tiap tipe dan antar grup menggunakan SPSS 25.0 dengan nilai p dianggap bermakna jika p<0,05. Hasil: Dari 93 CT angiogram, setelah eksklusi didapatkan 40 sampel. Median usia 67 (47-76 th), dengan 90% adalah laki-laki. Sebanyak 25% sampel memiliki komponen sakular. Hasil analisis visual, terdapat korelasi area antara WSS terendah dengan tekanan dinding tertinggi. Perubahan kecepatan dan tekanan darah inisial juga mengubah nilai dan luas area pada kontur WSS dan tekanan dinding aorta, meskipun pusat perubahan kontur masih berada pada area yang relatif sama. Terdapat perbedaan bermakna pada WSS dan tekanan dinding (p=0,038 dan p<0,001). Kesimpulan: Area WSS terendah berkaitan dengan lokasi tekanan dinding tertinggi. Berubahnya kecepatan dan tekanan darah, mempengaruhi luas dan nilai dari WSS dan tekanan dinding. ......Background: AAA disease is mostly located in infrarenal. Mortality increases with rupture. The main risk factors for rupture are diameter sac and hypertension. Computational fluid dynamic (CFD) analysis of blood flow allows for a detection where rupture area will occur. Wall shear stress (WSS) and wall pressure are parameters that can be analyzed through CFD to see the potential location for rupture in AAA. Objective: Knowing the morphology of infrarenal AAA along with the distribution of WSS values ​​and aneurysmal wall pressure based on CFD to predict aneurysm rupture. Method: Cross-sectional study with CT angiogram analysis of infrarenal AAA patients in the Vascular and Endovascular Division-Department of Surgery and the Department of Radiology RSUPN Dr. Cipto Mangunkusumo in July–December 2022. CT angiography data was processed with Radiant Viewer to be used as a 3D model. From the whole sample, grouped into 5 types of aneurysms. Then for each model the process of making a solid vessel is carried out with the Meshmixer. The next process is geometry, meshing, CFD parameter setup, and solutions to produce WSS and wall pressure contours at various speeds and blood pressures with the ANSYS 2022 R2 Academic Student program. Visual results for each type were analyzed and compared. WSS and wall pressure non-parametric statistical test were performed for each type and between groups using SPSS 25.0 with a p-value considered significant if p <0.05. Results: Of the 93 CT angiograms, after exclusion, 40 samples were obtained. Median age 67 (47-76 years), with 90% were men. As much as 25% of the sample had a saccular component. The results of the visual analysis showed that there was an area correlation between the lowest WSS and the highest wall pressure. Changes in velocity and initial blood pressure also changed the value and area of ​​the WSS and the aortic wall pressure contours, although the center of the contour change was still in the relatively same area. There was a significant difference in WSS and wall pressure (p=0.038 and p<0.001). Conclusion: The area of ​​lowest WSS corresponds to the location of the highest wall pressure. Changes in blood velocity and pressure affect the area and value of WSS and wall pressure.

Abstrak :
Sambungan kunci geser merupakan bagian yang sangat penting pada jembatan pracetak segmental karena berfungsi mendistribusikan gaya geser dari satu segmen ke segmen lainnya dan menyatukan antar segmen pracetak sehingga menjadi satu kesatuan struktur yang utuh. Penelitian yang dilakukan merupakan penelitian yang bersifat eksperimental dan numerik terhadap sambungan kunci geser tanpa perekat. Kunci geser yang digunakan merupakan kunci geser dari material ferro cast ductile dengan tipe male-female shear key. Selain dilakukan secara eksperimental, penelitian ini juga dilakukan dengan simulasi numerik dengan program ANSYS dengan analisis non linear sebagai perbandingan dari hasil penelitian eksperimental. Penelitian ini bertujuan untuk mengetahui kekuatan sambungan kunci geser dari material ferro cast ductile dengan menerapkan variasi besar gaya pratekan yang diberikan. Hasil penelitian menujukan bahwa semakin besar gaya pratekan yang diberikan maka semakin besar pula nilai tegangan geser maksimum sambungan kunci geser ferro cast ductile karena gaya pratekan yang semakin besar menghasilkan gaya friksi yang semakin besar pula. Akan tetapi, pada variasi gaya pratekan yang besar untuk sambungan kunci geser ferro cast ductile dapat menyebabkan kegagalan pertama terjadi bukan pada beton melainkan pada male shear key karena ferro cast ductile merupakan material yang relatif getas. Hal ini sesuai dengan hukum konstitutif ferro cast ductile dimana ferro cast ductile lebih kuat terhadap tekan dari pada tarik. Selain itu, Analisis eksperimental dan analisis numerik memberikan hasil nilai tegangan geser maksimum yang tidak jauh berbeda. Grafik hubungan tegangan geser dan perpindahan vertikal pada hasil eksperimen dan analisis numerik memiliki pola yang hampir sama. ...... Shear key connection is a very important part of the precast segmental bridge because has the function to distribute shear force from one segment to another segment and to connect the precast segments of concrete become a complete structure of bridge. This study is experimental and numerical research which discusses about the shear key connection without epoxy. The material of shear key is ferro cast ductile and the type of shear key is male female shear key. This study also implemented by numerical simulation using ANSYS program with non linear analysis. The purpose of this study is to know the strength of ferro cast ductile shear key connection by applying variation of prestressing. The results of this study show that the highest maximum shear stress of ferro cast ductile shear key connection is resulted by the shear key connection which has the biggest prestressing because the bigger prestressing produces the bigger friction force. However, the larger prestressing for ferro cast ductile shear key connection can cause the first failure is occurred in the male shear key because ferro cast ductile is a brittle material. It is based on the constitutive law of ferro cast ductile which have better behavior in compressive constitutive law than tensile constitutive law. The experimental analysis and numerical analysis produce the maximum shear stress which have similar value. The graph of shear stress and vertical displacement which are resulted by experiment and numerical analysis have similar plot.

Abstrak :
Minyak atsiri merupakan senyawa penting dalam bahan alam, yang memiliki banyak khasiat bagi kesehatan manusia. Minyak atsiri dapat diambil dari bahan alam dengan proses ekstraksi. Salah satu proses ekstraksi yang sedang menjadi tren penelitian adalah ekstraksi ultrasonik, yang dinilai memiliki banyak keunggulan, seperti kemudahan operasi, energi yang relatif rendah, dan operasi pada temperatur rendah yang dapat menjaga stabilitas senyawa biokimia dalam bunga telang. Salah satu kebaruan dalam penelitian ini adalah adanya penambahan mekanisme probe yang bergerak secara oksilasi, memungkinkan sumber gelombang ultrasonik menjadi dinamis. Selain itu, juga ditambahkan variasi intensitas ultrasonik sebagai parameter optimasi universal dalam ekstraksi ultrasonik. Adapun metode yang digunakan dalam analisis adalah metode kuantitatif dengan pengukuran data-data temperatur dan perhitungan fraksi massa minyak atsiri sebagai representasi kuantitas minyak atsiri, metode kualitatif dengan analisis visual perubahan warna emulsi dan distribusi temperatur terhadap waktu, serta metode analitik dengan perhitungan kinetik proses ekstraksi ultrasonik, untuk mengetahui nilai yield, yang direpresentasikan oleh kuantitas senyawa phenolic dengan perhitungan konstanta Peleg. Hasil penelitian menunjukkan bahwa, dengan penambahan probe oksilasi, dapat menyeragamkan distribusi temperatur dan ikatan antara pelarut dan senyawa biokimia dalam bahan alam, atau dengan kata lain, meningkatkan kualitas minyak atsiri yang dihasilkan. Di sisi lain, intensitas ultrasonik yang semakin tinggi dapat meningkatkan volume minyak atsiri yang dihasilkan, yang direpsentasikan fraksi massa minyak atsiri dan analisis kinetik yield terhadap waktu, serta meningkatkan laju ekstraksi yang terlihat dari analisis kinetik dan perubahan warna emulsi terhadap waktu. Hal ini disebabkan karena intensitas ultrasonik meningkatkan efek sonokemistri, kavitasi, turbulensi dan tegangan geser yang meningkatkan kuantitas dan laju ekstraksi. Hal penting yang harus diperhatikan dalam optimasi proses ekstraksi ultrasonik adalah turbulensi yang terlalu tinggi dapat menyebabkan agitasi dan temperatur yang terlalu tinggi dapat berpotensi merusak senyawa biokimia aktif dalam bunga telang. ......Essential oil is an important compound in natural substances, which has many benefits for human health. Essential oil can be produced from natural substances through the process of extraction. One of the trending extraction processes is ultrasonic extraction, which is considered to have many advantages, including, ease of operation, relatively low energi consumption, and capability to operate at low temperature which keep stabilitizing biochemical compounds inside natural substances, which in this research used butterfly pea flower (Clitoria Ternatea L). The novelty of this research was the application of a mechanism of osscilating moving probe, enabling ultrasonic wave source to be dynamic. Additionally, varieties of ultrasonic intensities was also applied as an universal parameter in optimizing the process of ultrasonic extraction. The methods used in the research were quantitative methods by measuring data of temperatures and calculating essential oil mass fraction, as representatives of essential oil quantity, qualitative methods by visual analysis of emulsion color evolution and temperature distribution through time, as well as analytical method by calculating the kinetics of ultrasonic extraction process, to determine yield, represented by phenolic compound quantity with Peleg’s constant calculation. The results of the research showed that oscilating probe addition could evenly distribute temperature and enhanced the bonds between solvent and biochemical compounds inside the natural substances, in other words, improving the quality of essential oil produced. On the other hand, a rise in ultrasonic intensities could increase essential oil volume produced, which was represented by essential oil mass fraction and kinetic analysis of yield through time, as well as increasing the extraction rate, as shown in kinetic analysis and emulsion color evolution. This was due to higher ultrasonic intensities enhanced sonochemistry effect, cavitation, turbulence and shear stress which increased essential oil quantity and the rate of extraction process. The important issues that needed to be considered in optimizing ultrasonic extraction process was over turbulence which could cause agitation and overhigh temperature which potentially could damage the active biochemical compounds inside butterlfy pea flower as a natural susbtance.

Abstrak :
ABSTRAK Ice slurry adalah salah satu jenis es yang terdiri dari dua fase, yaitu padat dan cair yang terbuat dari campuran larutan antara air sebagai pelarut dan zat aditif sebagai zat terlarut yang berfungsi untuk menurunkan titik beku. Zat aditif yang digunakan dalam pembuatan ice slurry dapat berupa glikol, NaCl, dan ethanol. Investigasi karakteristik fluida dalam penelitian ini bertujuan untuk membuktikan bahwa fluida ice slurry dengan menggunakan monoethylene glycol sebagai zat penurun titik beku adalah fluida non ndash;Newtonian tetapi belum diketahui jenisnya, antara pseudoplastik atau dilatan. Percobaan dilakukan dengan mengukur pressure drop dan juga debit untuk nantinya dihitung hubungan antara shear stress dan shear rate untuk mendapatkan gradien power law index yang digunakan untuk mengkategorikan jenis dari fluida ini. Percobaan pertama dilakukan dengan pipa uji berdiameter 24 mm, dengan lima variasi kecepatan dan variasi konsentrasi awal monoethylene glycol 5 , 7 dan 10 dalam 30 liter air menghasilkan rentang power law index n sebesar 1,07 ndash; 1,11. Lalu percobaan kedua menggunakan pipa uji 21 mm menghasilkan n sebesar 1,24 ndash; 1,29 dan percobaan ketiga menggunakan pipa uji 14 mm menghasilkan n sebesar 1,43 ndash; 1,58. Jika suatu fluida non-Newtonian mempunyai n > 1 maka bisa dikategorikan fluida tersebut adalah fluida non-Newtonian bentuk dilatan. Ice slurry yang digunakan dalam pengujian ini merupakan fluida non-Newtonian bentuk dilatan karena mempunyai rentang n > 1.

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ABSTRACT
Ice slurry is a solid ndash liquid ice which made up of a mixture between additive compound as solute and water as solvent. The additive compound is used to lower the freezing point temperature and some of the compounds used to make ice slurry initial solutions are kind of glycols, sodium chloride, ethyl alcohol or ethanol, etc. In this research, investigation of fluid flow characteristic is to proof that ice slurry with monoethylene glycol as freezing point depressant is a non Newtonian fluid, either as pseudoplastic or dilatant fluid. Experiment was done by measuring pressure drop or head loss and volume flow rate as variable to determine the relation between shear stress and shear rate to calculate the power law index gradient, which is used this kind of non Newtonian fluid. The first experiments were performed in 24 mm test tube, with five variation of pump speed, and variation of freezing point depressants initial concentrations of monoethylene glycol are 5 , 7 , and 10 in 30 liters of water solutions and give results in power law index value range of 1,07 ndash 1,11. The second experiments were using 21 mm test tube and gave results in power law index value range of 1,24 ndash 1,29. The third experiments were using 14 mm test tube and gave results in power law index value range of 1,43 ndash 1,58. If non Newtonian fluid has n 1 then it can be categorized as non Newtonian fluid with dilatant form. Type of ice slurry used in this experiments prooved as a non Newtonian fluid with dilatant form because the value of power law index resulted were exceeding 1 n 1 .

Abstrak :
The book is designed for advanced graduate students as well as postdoctoral researchers across several disciplines (e.g., mathematics, physics and engineering), as it provides them with tools and techniques that are essential in performing research on the flow problems of visco-plastic fluids. The following topics are treated; analysis of classical visco-plastic fluid models, mathematical modeling of flows of visco-plastic fluids, computing flows of visco-plastic fluids, rheology of visco-plastic fluids and visco-plastic suspensions, application of visco-plastic fluids in engineering sciences, and complex flows of visco-plastic fluids.

Abstrak :
The shear key is an important part of a precast segmental concrete bridge. Aside from its function of contributing to the distribution of shear force from one concrete segment to another, it helps to join precast concrete segments to become a complete bridge structure and provide continuity of movement for vehicles and pedestrian traffic. This numerical study discusses the behavior of a full-scale shear key connection without epoxy joining two concrete blocks representing segmental precast concrete at which two external forces load the blocks. Ferro Casting Ductile (FCD) is used as the metal shear key material where the shear key consists of two parts, a male and a female shear key. Numerical simulation is conducted using the ANSYS academic package, with nonlinear analysis implemented accordingly. The appropriate constitutive materials in relation to the numerical program, both for concrete and FCD, are taken from the appropriate literature. Two criteria are employed in the study; failure of the concrete block and yielding of the shear key that follows the von Mises criterion. Shear key connection system capacity is evaluated by applying different magnitudes of horizontal force. The validation of two numerical simulation studies is conducted by two experimental programs that cover laboratory experimentation of full-scale shear keys connecting two concrete blocks. The numerical and experimental results produce an almost similar relation of shear stress at the male shear key and vertical displacements of the upper block relative to the lower concrete block. Finally, a contour of shear key shear stress as a function of the different magnitudes of equivalent prestressing and different quality of concrete compressive strength is proposed.

Abstrak :
Pengukuran perubahan kekentalan zat cair yang sangat komplek sangat diperlukan oleh para insinyur dalam hal aplikasi industri. Tujuan dari penelitian ini adalah untuk mengetahui hambatan gesek pada Lumpur lapindo. Lumpur dengan variasi kepadatan 30% dan 45% diuji sifat perubahan kekentalannya dengan menggunakan viscometer pipa horizontal. Diameter pipa d = 12.7 mm dan panjang l = 800 mm variasi debit aliran diukur bersamaan dengan nilai selisih kerugian tekanan dengan manometer. Hubungan kurva aliran antara tegangan geser dengan perubahan kecepatan diplot dalam grafik. Nilai rasio kepadatan 45% menunjukan fluida pseudoplastik (plastic semu)dengan index power law n = 0.93 - 1.0. hubungan koefisien gesek dengan generalis bilangan Reynolds menunjukan semakin tinggi kepadatan Lumpur diikuti kenaikan nilai koefisien gesek. ......Measurement of liquid viscosity Change complex very needed by engineer in the case of industrial application. Intention of this research is to know friction of coefficient lapindo mud slurry. Mud with the variation of density 30% and 45% tested by the nature of its viscosity change by using viscometer of pipe horizontal. diameter of Pipe d = 12.7 mm and length l = 800 mm variation of charge the stream measured at the same time with the value of difference of pressure loss with the manometer. Relation of stream Curve among tension shift with the speed change plotted in graph. Assess the density ratio 45% representing of fluid pseudoplastik (plastic semu) index of power law n = 0.93 - 1.0. coefficient of mud slurry bigger than coefficient of water.

Abstrak :
Kekentalan fluida dan sifat fluida saat mengalir dalam pipa sangat penting untuk diketahui dalam menentukan alat transportasi (pompa atau kompresor) yang tepat. Tujuan penelitian ini adalah menguji sifat-sifat kekentalan aliran dan membuat kurva aliran larutan gliserin dengan alat koaksial silinder putar viskometer. Perhitungan tegangan geser dan gradien kecepatan dengan mengukur kecepatan sudut pada silinder luar dan torsi dari silinder. Fluida uji berupa air murni dan 40% dan 60% larutan gliserin. Hasil menunjukkan koefisien torsi dari koaksial silinder untuk larutan gliserin menunjukkan proporsional dengan tegangan geser dan gradien kecepatan.

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Fluid viscosity and fluid characteristic flow on the pipe is very important to know for decide kind of transportation (pump or compressor) suitable. The purpose of this study was to examine the viscous properties and to make flow curve of glycerin solutions by coaxial cylinder rotating viscometer. Calculated shear stress and the shear strain by measure angular velocity on outer cylinder and the torque on inner cylinder of vertical coaxial cylinder viscometer. Test fluids were tap water and 40, 60 wt% of glycerin solutions. The result indicated moment coefficient of coaxial cylinder for glycerin solution shown proportional with shear stress and shear strain.