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"This textbook explores the theory of Cosserat continuum mechanics, and covers fundamental tools, general laws and major models, as well as applications to the mechanics of granular media. While classical continuum mechanics is based on the axiom that the stress tensor is symmetric, theories such as that expressed in the seminal work of the brothers Eugène and François Cosserat are characterized by a non-symmetric stress tensor. The use of von Mises motor mechanics is introduced, for the compact mathematical description of the mechanics and statics of Cosserat continua, as the Cosserat continuum is a manifold of oriented “rigid particles” with 3 dofs of displacement and 3 dofs of rotation, rather than a manifold of points with 3 dofs of displacement. Here, the analysis is restricted to infinitesimal particle displacements and rotations. This book is intended as a valuable supplement to standard Continuum Mechanics courses, and graduate students as well as researchers in mechanics and applied mathematics will benefit from its self-contained text, which is enriched by numerous examples and exercises. "

"This book presents, in a uniform way, several problems in applied mechanics, which are analysed using the matrix theory and the properties of eigenvalues and eigenvectors. It reveals that various problems and studies in mechanical engineering produce certain patterns that can be treated in a similar way. Accordingly, the same mathematical apparatus allows us to study not only mathematical structures such as quadratic forms, but also mechanics problems such as multibody rigid mechanics, continuum mechanics, vibrations, elastic and dynamic stability, and dynamic systems. In addition, the book explores a wealth of engineering applications. "

"ABSTRAKWe present a software package JMATRIX1,consisting of two computer codes written in FORTRAN 95 and parallelized with OpenMP, implementing the so called J matrix method, applied to elastic scattering of electrons on the radial potential, vanishing faster than the Coulomb potential. In the J matrix method, the physical scattering problem is replaced by using a well defined model which is solved analytically. The presented software implements both non relativistic and relativistic versions of the method, and allows calculations of scattering phase shifts as well as cross sections, in cases when the scattering potential is given through an analytical formula. We performed test calculations for the scattering potential modeled as a truncated Coulomb potential. We show that the numerical phase shifts to converge as we increase the size of the basis used to truncate the scattering potential, and that the method is suitable for calculating the total differential momentum transfer and spin polarization cross sections, using the partial wave analysis."

"Penelitian ini didasarkan pada kebutuhan akan peningkatan akurasi dalam memprediksi properti reservoir, yang sangat penting untuk eksplorasi dan produksi hidrokarbon yang efektif. Metode tradisional sering kali kurang akurat dalam memberikan estimasi yang tepat, sehingga adopsi MARS bertujuan untuk mengatasi kekurangan ini. Penerapan Metode MARS bertujuan untuk mengevaluasi sensitivitas dan dampak transformasi Multi Attribute Rotation Scheme (MARS) dalam meningkatkan karakterisasi reservoir di Lapangan X, Cekungan Sunda. Metode ini bekerja dengan memperkirakan atribut baru dalam arah perubahan maksimum properti target dalam ruang Euclidean berdimensi n yang dibentuk oleh beberapa atribut, kemudian menskalakan atribut ini ke properti unit target. Hasil MARS diterapkan untuk memprediksi distribusi porositas, volume shale, dan saturasi air menggunakan atribut elastis yang diturunkan dari data seismik. Hasil penelitian menunjukkan bahwa metode MARS memiliki sensitivitas yang cukup terhadap perubahan atribut elastis, menghasilkan transformasi optimal untuk memprediksi sifat petrofisika reservoir. Transformasi MARS meningkatkan akurasi karakterisasi reservoir dibandingkan dengan metode konvensional. Pola distribusi porositas, volume shale, dan saturasi air yang diperoleh dari metode MARS konsisten dengan data log dan karakteristik geologi Cekungan Sunda. Temuan ini menunjukkan bahwa MARS dapat menjadi alat yang berharga untuk meningkatkan prediksi properti reservoir, yang mengarah pada pengambilan keputusan yang lebih baik dalam eksplorasi dan produksi hidrokarbon.

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This research is based on the need to improve the accuracy of predicting reservoir properties, which is crucial for effective hydrocarbon exploration and production. Traditional methods often lack precision in providing accurate estimates, thus the adoption of MARS aims to address these shortcomings. The application of the Multi Attribute Rotation Scheme (MARS) method aims to evaluate the sensitivity and impact of the MARS transformation in enhancing reservoir characterization in Field X, Sunda Basin. This method works by estimating new attributes in the direction of maximum change of the target property in an n-dimensional Euclidean space formed by multiple attributes, and then scaling these attributes to the target unit properties. The MARS results are applied to predict the distribution of porosity, shale volume, and water saturation using elastic attributes derived from seismic data. The research findings show that the MARS method has sufficient sensitivity to changes in elastic attributes, producing optimal transformations for predicting reservoir petrophysical properties. The MARS transformation improves the accuracy of reservoir characterization compared to conventional methods. The distribution patterns of porosity, shale volume, and water saturation obtained from the MARS method are consistent with log data and the geological characteristics of the Sunda Basin. These findings suggest that MARS can be a valuable tool for enhancing reservoir property predictions, leading to better decision-making in hydrocarbon exploration and production."

"These proceedings gather a selection of peer-reviewed papers presented at the 7th International Conference on Fracture Fatigue and Wear (FFW 2018), held at Ghent University, Belgium on 9–10 July 2018.The contributions, prepared by international scientists and engineers, cover the latest advances in and innovative applications of fracture mechanics, fatigue of materials, tribology and wear of materials.The book is intended for academics, including graduate students and researchers, as well as industrial practitioners working in the areas of fracture fatigue and wear."

"Latihan kekuatan otot non mesin merupakan latihan yang dapat meningkatkan kemampuan fungsional dalam hal ini otot tungkai. Tujuan: Penelitian ini bertujuan mengetahui efek latihan kekuatan otot non mesin selama 10 minggu terhadap kekuatan otot tungkai, daya tahan otot tungkai, kecepatan berjalan dan keseimbangan berjalan sebagai variabel kemampuan fungsional otot. Penelitian ini juga untuk mengetahui apakah latihan kekuatan otot jenis kombinasi weight bearing dan elastic resistance memberikan peningkatan yang lebih besar dibandingkan dengan latihan jenis weight bearing yang dilanjutkan dengan elastic resistance. Metode: Subyek terdiri dari 36 orang karyawan pra usia lanjut (45-56 tahun) sehat tidak terlatih yang dibagi menjadi 2 kelompok. Kelompok A melakukan latihan jenis kombinasi weight bearing dan elastic resistance sedangkan kelompok B melakukan latihan jenis weight bearing saja dan kemudian dilanjutkan dengan latihan elastic resistance saja. Kedua kelompok tersebut melakukan latihan dengan frekuensi 2-3 xlminggu selama 1 jam dengan intensitas 1-3 setlgerakan dan tiap set terdiri dari 8-12 ulangan/repetisi. Hasil: Hasil menunjukan kedua jenis latihan memberikan peningkatan terhadap kemampuan fungsional otot tungkai (Uji Anova p=0,00), namun jenis kombinasi weight bearing dan elastic resistance memberikan peningkatan yang lebih besar (Uji t p=0,01-0,04). Latihan kekuatan otot tungkai jenis kombinasi weight bearing dan elastic resistance memberikan peningkatan kekuatan otot (59,93%), daya tahan otot (58,42%), kecepatan berjalan (36,88%) dan keseimbangan berjalan (47,12%) sedangkan jenis weight bearing dilanjutkan elastic resistance memberikan peningkatan kekuatan otot (39,66%), daya tahan otot (31,69%), kecepatan bedalan (23,33%) dan keseimbangan berjalan (25,90%). Seluruh variabel kemampuan fungsional tersebut mempunyai korelasi yang kuat satu dengan lainnya (Uji korelasi Pearson p=0,000-0,001). Selain itu melalui kuesioner didapatkan bahwa subyek merasa nyaman dengan latihan jenis kombinasi dan menambah minat mereka terhadap latihan jasmani. Kesimpulan: Dari hasil penelitian dapat disimpulkan bahwa latihan kekuatan otot jenis kombinasi weight bearing dan elastic resistance memberikan peningkatan yang lebih besar terhadap variabel kemampuan fungsional otot pada kelompok karyawan pra usila sehat tidak terlatih.

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Non machine muscle strength exercises can be used to increase functional ability, especially the lower limb muscle. Purpose: The purpose of this research was to evaluate the effects of 10 weeks of non machine muscle strength exercises on muscle functional ability. The variables for functional ability will be muscle strength, muscle endurance, speed of walk and balance of walk. And to determine if simultaneously combined weight bearing and elastic resistance exercises will be better than weight bearing followed by elastic resistance exercises on increasing muscle strength. Methods: The subjects were 36 healthy untrained employees aged between 45-56 years. They were divided randomly into 2 groups, groups A and B. Group A was trained with a simultaneous combination of weight bearing and elastic resistance exercises while group B was first trained with weight bearing exercises and then with elastic resistance exercises. Both groups exercised 2-3 times a week for 1 hour with an intensity of 1-3 sets/motion and 8-12 repetitions/set. Results: Results showed both types of exercises increased muscle functional ability (ANOVA test p-0.00), but the simultaneous combination of weight bearing and elastic resistance exercises was better (t test p=O.01-0.04). The simultaneous combination of weight bearing and elastic resistance exercises increased muscle strength (59.93%), muscle endurance (58.42%), speed of walk (36.88%), and balance of walk (47.12%), while the succeeding weight bearing and elastic resistance exercises increased muscle strength (39.66%), muscle endurance (31.69%), speed of walk (23.33%), and balance of walk (25.90%). All muscle functional ability variables were strongly correlated to one other (Pearson correlation test p=0.000-0.001). From the questionnaires given, it was found that the subjects enjoyed the simultaneous combination exercises which increased their motive for physical exercise. Conclusion: It was concluded that muscle strength exercises which simultaneously combined weight bearing with elastic resistance exercises were better in increasing muscle functional ability in healthy untrained young older employees."

"Sambungan kunci geser baja merupakan sambungan dimana kunci geser tersebut terdiri dari dua (2) bagian yaitu key male dan key female. Sambungan ini terdapat pada sambungan jembatan yang menggunakan beton pracetak segmental. Kunci geser ini berfungsi untuk mentransfer kedua gaya baik gaya lateral dan gaya vertikal ke sambungan serta untuk mencegah terjadinya perpindahan vertikal antara elemen-elemen pada sambungan sehingga kunci geser ini menjadi seperti pengunci pada gelagar jembatan. Kajian ini bertujuan untuk mendapatkan gambaran mengenai besar beban potensi retak dengan variasi yang digunakan adalah mutu betonnya, mutu baja lunak, diameter kunci geser, gaya prategang pada beton, serta jumlah kunci geser. Pada permodelan ini menggnakan dua tipe permodelan.Permodelan tipe 1 menggunakan data-dat linear elastis, sedangkan permodelan tipe 2 menggunakan data-data multilinier isotropic hardening.Hasil simulasi menunjukkan bahwa variasi mutu terbesar, dengan diameter 90 mm, dan gaya pratekan sebesar 3,45 MPa yang menghasilkan beban potensi retak terbesar, serta kunci geser dengan jumlah tiga yang menghasilkan beban potensi retak maupun leleh terbesar

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Metal shear key is a joint resembling a key that consist of two parts which are key male and key female. This joint is located as a connection between segmental conceret precast bridge. The function of shear key is to transfer both lateral or vertical forces from the element of bridge to the joint so that shear key could become like a fastener at the girder.

The purpose of the study is to obtain the load related to potential crackfrom the variations of shear key that are quality of the concrete, quality of the mild steel, diameter of shear key, prestress, and the number of shear key. This research uses two type of modelling. The first type using linear elastic data, while the second type uses multilinier isotropic hardening data.

The result of the study shows that the highest quality od concrete and mild steel, with 90 mm diameter, and prestress force is 3,45 MPa producesthe maximumload related to potential crack, and the three shear key also produces both the maximumload related to potential crack and the maximum load related to potential failure for steel."