Atomic swelling upon compression

The hydrogen atom under the pressure of a spherical penetrable confinement potential of a decreasing radius $r_{0}$ is explored, as a case study. A novel counter-intuitive effect of atomic swelling rather than shrinking with decreasing $r_{0}$ is unraveled, when $r_{0}$ reaches, and remains smaller than, a certain critical value. Upon swelling, the size of the atom is shown to increase by an order of magnitude, or more, compared to the size of the free atom. Examples of changes of photoabsorption properties of confined hydrogen atom upon its swelling are uncovered and demonstrated.Comment: 5 pages, 4 figure

Investigation of the role of endosomal Toll-like receptors in murine collagen-induced arthritis reveals a potential role for TLR7 in disease maintenance

INTRODUCTION Endosomal toll-like receptors (TLRs) have recently emerged as potential contributors to the inflammation observed in human and rodent models of rheumatoid arthritis (RA). This study aims to evaluate the role of endosomal TLRs and in particular TLR7 in the murine collagen induced arthritis (CIA) model. METHODS CIA was induced by injection of collagen in complete Freund's adjuvant. To investigate the effect of endosomal TLRs in the CIA model, mianserin was administered daily from the day of disease onset. The specific role of TLR7 was examined by inducing CIA in TLR7-deficient mice. Disease progression was assessed by measuring clinical score, paw swelling, serum anti-collagen antibodies histological parameters, cytokine production and the percentage of T regulatory (Treg) cells. RESULTS Therapeutic administration of mianserin to arthritic animals demonstrated a highly protective effect on paw swelling and joint destruction. TLR7-/- mice developed a mild arthritis, where the clinical score and paw swelling were significantly compromised in comparison to the control group. The amelioration of arthritis by mianserin and TLR7 deficiency both corresponded with a reduction in IL-17 responses, histological and clinical scores, and paw swelling. CONCLUSIONS These data highlight the potential role for endosomal TLRs in the maintenance of inflammation in RA and support the concept of a role for TLR7 in experimental arthritis models. This study also illustrates the potential benefit that may be afforded by therapeutically inhibiting the endosomal TLRs in RA

In silico simulation of reversible and irreversible swelling of mitochondria: The role of membrane rigidity

Mitochondria have been widely accepted as the main source of ATP in the cell. The inner mitochondrial membrane (IMM) is important for the maintenance of ATP production and other functions of mitochondria. The electron transport chain (ETC) generates an electrochemical gradient of protons known as the proton-motive force across the IMM and thus produces the mitochondrial membrane potential that is critical to ATP synthesis. One of the main factors regulating the structural and functional integrity of the IMM is the changes in the matrix volume. Mild (reversible) swelling regulates mitochondrial metabolism and function; however, excessive (irreversible) swelling causes mitochondrial dysfunction and cell death. The central mechanism of mitochondrial swelling includes the opening of non-selective channels known as permeability transition pores (PTPs) in the IMM by high mitochondrial Ca2+ and reactive oxygen species (ROS). The mechanisms of reversible and irreversible mitochondrial swelling and transition between these two states are still unknown. The present study elucidates an upgraded biophysical model of reversible and irreversible mitochondrial swelling dynamics. The model provides a description of the PTP regulation dynamics using an additional differential equation. The rigidity tensor was used in numerical simulations of the mitochondrial parameter dynamics with different initial conditions defined by Ca2+ concentration in the sarco/endoplasmic reticulum. We were able to estimate the values of the IMM rigidity tensor components by fitting the model to the previously reported experimental data. Overall, the model provides a better description of the reversible and irreversible mitochondrial swelling dynamics.Funding Agency USA NIGMS NIH SC1GM128210 Institute for Functional Nanomaterials (USA NSF) 1002410 PR NASA EPSCoR (USA NASA Cooperative Agreement) NNX15AK43Ainfo:eu-repo/semantics/publishedVersio

PERBANDINGAN PENAMBAHAN SEMEN DAN KAPUR PADA TANAH LEMPUNG EKSPANSIF TERHADAP SWELLING POTENTIAL

Jenis tanah lempung yang banyak terdapat kandungan mineral montmorilonite tergolong tanah lempung dengan plastisitas tinggi, mudah mengalami kembang susut. Tanah lempung jenis ini disebut juga sebagai tanah ekspansif.  Oleh sebab itu perlu dilakukan pemecahan masalah yang serius untuk mengatasi tentang tanah lempung ekspansif. Penelitian ini dilakukan di laboratorium Mekanika Tanah Jurusan  Sipil Unesa. Terdapat 2 jenis material tambahan yaitu semen dan kapur. Variasi kadar semen yang digunakan adalah 0%, 2,5%, 5%, 7,5% dan 10%, sedangkan variasi kadar kapur adalah 0%, 5%, 10%, 15% dan 20%. Macam tes yang dilakukan yaitu tes Atterberg Limit, tes Pemadatan Proctor Standar, dan tes Konsolidasi. Hasil penelitian yang dilakukan menunjukkan bahwa adanya penambahan semen  lebih effektif dibandingkan kapur apabila digunakan sebagai stabilisasi mengurangi Swelling Potential pada tanah ekspansif. Dengan penambahan kadar yang sama, yaitu 10% semen maka Swelling Potential yang dicapai adalah 2,1% termasuk tanah ekspansif dengan klasifikasi swelling sedang. Pada penambahan 10% kapur maka Swelling Potential yang dicapai adalah 8,54% termasuk tanah ekspansif dengan klasifikasi swelling tinggi. Key Words: Tanah ekspansif,  Swelling Potential, Semen, Kapur Soil type clay that many occurred montmorilonite mineral include clay with high plastisicy, easy experience shrink and swell. This clay type called also as soil expansive. Therefore need to be done problem solving that is serious to overcome about soil expansive of clay. This research made at the Mekanika Tanah Jurusan Sipil Unesa laboratory. There is 2 addition material type cement and lime. Cement degree variation used is 0%, 2,5%, 5%, 7,5% and 10%, while lime degree variation is 0%, 5%, 10%, 15% and 20%. Kinds test conducted among others Atterberg Limit test, standard Proctor compaction tests and soil development test (swelling). Result research conducted indicate that cement addition existence more effektif compared by lime if used as stabilization reduce Swelling Potential in soil expansive. With addition degree that is same, with 10% cement so Swelling Potential that achieved is 2,1% include soil expansive with swelling middle classification. While in addition 10% lime so Swelling Potential that achieved is 8,54% include soil expansive with swelling high classification. Key Words: Soil expansive,  Swelling Potential, cement, lime

Pengaruh Penambahan Clean Set Cement terhadap Potential Swelling pada Tanah Lempung Kembang – Susut

Tanah ekspansif atau tanah kembang susut adalah tanah yang mempunyai potensi swelling yang tinggi, sehingga sering menimbulkan masalah pada struktur bangunan di atasnya. Hasil tes awal pada tanah lempung yang diambil dari Citra Land Surabaya didapatkan nilai Index Plasticity (IP) kategori potential swelling yang sangat tinggi. Cara yang dipakai untuk proses stabilisasi tanah tersebut dengan stabilisasi kimia menggunakan clean set cement. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan clean set cement terhadap nilai potential swelling pada tanah lempung ekspansif di daerah Citra Land Surabaya. Penelitian ini merupakan penelitian eksperimen yang dilakukan di Laboratorium Mekanika Tanah UNESA dengan cara membuat campuran tanah lempung dan clean set cement dengan variasi campuran 0%, 5%, 10%, 15%, dan 20% dari berat tanah. Tes tanah dalam penelitian ini meliputi atterberg limit test (untuk mencari parameter IP), standart proctor test (untuk mencari parameter γd max dan Wc.opt) dan swelling test. Benda uji yang digunakan untuk swelling test dalam kondisi kepadatan tanah maksimum (γd max) dan kadar air optimum (Wc.opt) adalah tanah dari hasil standart proctor test. Jumlah benda uji untuk swelling test ada 5 buah dari masing-masing variasi campuran clean set cement. Hasil penelitian Potential Swelling pada tanah lempung dengan campuran 0%, 5%, 10%, dan 15% clean set cement masing-masing sebesar 19.56%, 16.31%, 9.35% dan 5.00% termasuk tanah dengan potential swelling tinggi, sedangkan untuk campuran 20% clean set cement mendapat nilai 3.25% termasuk tanah dengan potential swelling kategori sedang. Peneliti menyarankan untuk pekerjaan pemadatan tanah atau stabilisasi tanah menggunakan clean set cement agar menggunakan variasi campuran 20%, karena dengan komposisi campuran tersebut tanah lempung kembang-susut Citra Land sudah stabil dan dalam kategori swelling sedang. Kata Kunci : Tanah Ekspansif, Potential Swelling, Clean Set Cement, Stabilisasi, Tanah, Index Plasticity   Abstract Expansive soil or expanded-shrinkage soil is the soil that has a high swelling potential, as consequence, it causes problem inside the structure of the building that existing on it. The result of preliminary tests on clay taken from Citra Land Surabaya has shown the Index Plasticity (IP) value determining the category of potential swelling that is very high. The way that is used for the process of soil stabilization above by chemical stabilization is clean set cement. This research was aimed to determine the effect of the addition of clean set cement to the value of potential swelling in expansive clays in the area of Citra Land Surabaya. This research is categorized as the experiment research that is carried out in Soil Mechanics Laboratory of State University of Surabaya by creating a mixture of clay and clean set cement with the mixed variation of 0%, 5%, 10%, 15%, and 20% of the weight of the soil. The test of soil in this study covered Atterberg limits tests (finding the IP parameter), standard proctor test (to find parameters of (γd max) and (Wc.opt) and swelling test. The specimens for swelling test used in the conditions of maximum density of the soil (γd max) and optimum water rate (Wc.opt) is the soil from the result of the standard proctor test. The number of specimens for swelling test is 5 pieces of each mixture variation of clean set cement.   The result of the research dealing with Potential Swelling of clay with 0%, 5%, 10%, and 15% of mixed clean set cement each of 19.56%, 16. 31%, 9. 35% and 5.00% included the soil with high potential swelling , meanwhile for mixture 20% of clean set cement getting point on 3.25% included soil with potential swelling that is defined as medium categorized. Researcher suggests in term of soil compaction project or soil stabilization using clean set cement recommended to employ mixture variation 20%, since by using those mixed composition, the expanded-shrinked clay in Citra Land has been stable and categorized into medium swelling. Keywords: Expansive Soil, Swelling Potential, Clean Set Cement, Stabilization Soil, Index Plasticit

Effect of Polypropylene Fibers on Swelling Potential and Shear Strength of Clay

Expansive clays can cause major problems for urban development (roads, railways, infrastructure, etc.); therefore, reducing the swelling potential of clays has always been a concern in the geotechnical field. The presented paper investigates the effect of polypropylene reinforcement fibers on the swelling potential and shear strength of clay. The samples studied were taken from the clayey region of Mila, located in the northern east of Algeria. The experimental procedure adopted in this research consists first of the assessment of the physical, mechanical, and mineralogical characteristics of the soil samples without reinforcement. Then, swelling pressure, swelling rate, and swelling index are used to assess the swelling potential of these samples. After the reinforcement using a variety of polypropylene fiber concentrations (2 to 6% of the weight of the dry clay), the free swelling is clearly reduced. The optimum reinforcement rate in this case is 4%, in which the swelling was reduced by 90.7%. Finally, to offer more insights regarding the impact of clay reinforcement using polypropylene fibers, the effect of this later on the mechanical properties of the studied clay was also analyzed through the tangential shear strength. It was found that the polypropylene fibers increased the tangential shear resistance of Mila’s clay. Doi: 10.28991/CEJ-2023-09-03-04 Full Text: PD