Effect of particle size on the surface properties and morphology of ground flax

Flax fibers were ground with a ball-mill and four fractions with different size ranges were collected by sieving. These were tested for water sorption, degree of polymerization (DP), copper number, hydroxyl number and analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and inverse gas chromatography (IGC). Significant differences were found between the properties of the flax fiber and those of the ground versions, including fragmentation of fibers, increase of water sorption, copper number, hydroxyl number and surface O/C ratio, and decrease of DP, crystallite size and dispersive component of surface energy (gammasd). Some parameters depended on the particle size: O/C ratio and hydroxyl number had local maxima at 315-630 μm, while gammasd increased steadily with the decrease of particle size. These relationships were explained by fiber disintegration, destruction of waxy surface layer, exposure of cellulosic components, increase of surface area and crystalline imperfections

Influence of surface tension in the surfactant-driven fracture of closely-packed particulate monolayers

A phase-field model is used to capture the surfactant-driven formation of fracture patterns in particulate monolayers. The model is intended for the regime of closely-packed systems in which the mechanical response of the monolayer can be approximated as a linearly elastic solid. The model approximates the loss in tensile strength of the monolayer as the surfactant concentration increases through the evolution of a damage field. Initial-boundary value problems are constructed and spatially discretized with finite element approximations to the displacement and surfactant damage fields. A comparison between model-based simulations and existing experimental observations indicates a qualitative match in both the fracture patterns and temporal scaling of the fracture process. The importance of surface tension differences is quantified by means of a dimensionless parameter, revealing thresholds that separate different regimes of fracture. These findings are supported by newly performed experiments that validate the model and demonstrate the strong sensitivity of the fracture pattern to differences in surface tension.Comment: 10 pages, 11 figures, and 3 table

Force Distributions in Frictional Granular Media

We report a joint experimental and theoretical investigation of the probability distribution functions (pdf's) of the normal and tangential (frictional) forces in amorphous frictional media. We consider both the joint pdf of normal and tangential forces together, and the marginal pdf's of normal forces separately and tangential forces separately. A maximum entropy formalism is utilized for all these cases after identifying the appropriate constraints. Excellent agreements with both experimental and simulational data are reported. The proposed joint pdf (which appears new to the literature) predicts giant slip events at low pressures, again in agreement with observations.Comment: 13 pages, 15 figure

Pembuatan Peta Zona Nilai Tanah Untuk Menentukan Nilai Indikasi Rata-rata (Nir) Harga Pasar Menggunakan Sistem Informasi Geografis Di Kecamatan Ngaliyan, Kota Semarang (Studi Kasus :Kecamatan Ngaliyan, Kota Semarang)

Zona Nilai Tanah (ZNT) are areas which show the relatively similar value of the terrain and the boundaries of land use are imaginary or real appropriate. Each area of ZNThave a different values based on a comparative analysis of market prices and costs. Considering ZNT based on market value, ZNT can be used for the determination of tariffs in land services, the public reference to the transaction, the determination of compensation, the inventory value of public assets and the assets of the community, monitoring the value and market of land, and the determination reference of Nilai Jual Objek Pajak (NJOP) for PBB (Building and Land Tax), to make it more fair and transparent.Based on Semarang Regional Regulation Number 13 of 2011 on PBB, NJOP is the basis for the determination reference of PBB, which is one of the local revenue that is essential to improve service to the public. Therefore, it is necessary to realize the information value of the land for the functions realization of the land. One if it is map of ZNT.In this study, ZNT maps formed based on the value of the land with the assessment of the masses (not paying attention to property and the specific characteristics of the tax object) and use a comparison of sales (sales comparative), where the object of the tax is to be assessed in comparison with the object value of another tax type is already known.The results of this study is ZNT map that consits of 68 zones of the NJOP data and the transaction survey data. The change difference of transaction land price and NJOP with the low price is 49,45% and the highest price is 768,13%

Analisis Pengaruh Kepadatan Penduduk Terhadap Kepadatan Ruas Jalan Menggunakan Sistem Informasi Geografis ( Studi Kasus : Kecamatan Tembalang, Semarang )

Jam is a complicated issue that have broad impact to the user community as well as the way economic actors. Jam associated with the volume of traffic passing on a road segment. This research analyzes the effect of population density value to the value of the density of roads in the city of Semarang District Tembalang. In this study, the population is divided into sub zones.To assist the process of analysis using statistical software and for mapping use the GIS software. Road density values calculated using reference Indonesian Highway Capacity Manual (MKJI, 1997). To obtain the value of capacity (C) and the degree of saturation (DS) based Permenhub No. 14 In 2006, the degree of saturation is divided into 4 criteria.The results of the study stated conditions the capacity of some roads in the District Tembalang can still accommodate traffic flow and some other roads do not have a large capacity so that the degree of saturation of the high road. Based on the analysis, the population density affect road density of 75.4% and 24.6% are influenced by other factors. In GIS there are 2 kinds of data, the spatial data such as maps and attribute data such as tables. Based on data compiled attributes, it can be made road Density Map, The Average Daily Traffic Map, and Highway Capacity Map

Fragility and hysteretic creep in frictional granular jamming

The granular jamming transition is experimentally investigated in a two-dimensional system of frictional, bi-dispersed disks subject to quasi-static, uniaxial compression at zero granular temperature. Currently accepted results show the jamming transition occurs at a critical packing fraction $\phi_c$. In contrast, we observe the first compression cycle exhibits {\it fragility} - metastable configuration with simultaneous jammed and un-jammed clusters - over a small interval in packing fraction ($\phi_1 < \phi < \phi_2$). The fragile state separates the two conditions that define $\phi_c$ with an exponential rise in pressure starting at $\phi_1$ and an exponential fall in disk displacements ending at $\phi_2$. The results are explained through a percolation mechanism of stressed contacts where cluster growth exhibits strong spatial correlation with disk displacements. Measurements with several disk materials of varying elastic moduli $E$ and friction coefficients $\mu$, show friction directly controls the start of the fragile state, but indirectly controls the exponential slope. Additionally, we experimentally confirm recent predictions relating the dependence of $\phi_c$ on $\mu$. Under repetitive loading (compression), the system exhibits hysteresis in pressure, and the onset $\phi_c$ increases slowly with repetition number. This friction induced hysteretic creep is interpreted as the granular pack's evolution from a metastable to an eventual structurally stable configuration. It is shown to depend upon the quasi-static step size $\Delta \phi$ which provides the only perturbative mechanism in the experimental protocol, and the friction coefficient $\mu$ which acts to stabilize the pack.Comment: 12 pages, 10 figure

Kajian Penggunaan Program Aplikasi Desain Kapal Tradisional Pada Galangan Kapal Kayu Di Kabupaten Batang

Kabupaten Batang terletak di pantai utara Jawa Tengah dimana wilayah pesisir kabupaten ini terdapat potensi yang dapat dikembangkan menjadi aset yang berharga bagi bangsa yaitu para pembuat kapal tradisional. Sebagian besar para pengrajin kapal kayu tradisional dalam pembangunan konstruksi kapal tanpa melalui proses rancang bangun secara modern. Dalam pelaksanaannya, baik tipe ataupun bentuk kapal yang dibangun, berdasarkan pengalaman kapal-kapal yang pernah dibuat sebelumnya dan tanpa melalui perhitungan dan penggambaran terlebih dahulu, sehingga dalam beberapa kasus terhadap pesanan kapal yang berbeda bentuknya, maka pengrajin ini akan mengalami kesulitan. Hal ini menyebabkan perlunya sosialisasi mengenai teknologi perkapalan kepada pengrajin kapal di kabupaten Batang terutama dibidang rancang bangun(design) dan konstruksi kapal agar terdapat standar baku mengenai konstruksi kapal kayu yang sesuai dengan standar yang ada seperti Biro Klasifikasi Indonesia (BKI) sehingga kapal akan memenuhi tingkat standar yang baku dan tidak terjadi konstruksi yang berlebihan(over construction). Dengan melakukan sosialisasi dan workshop yang dilaksanakan di galangan kapal kayu menggunakan program aplikasi fishipro membuat pekerjaan lebih efisien serta penggunaan program aplikasi lainnya untuk memudahkan proses desain kapal kayu yang diproduksi oleh CV. Abadi Group yang terletak di Kabupaten Batang

What Pediatricians Should Know Before Studying Gut Microbiota

Billions of microorganisms, or "microbiota", inhabit the gut and affect its homeostasis, influencing, and sometimes causing if altered, a multitude of diseases. The genomes of the microbes that form the gut ecosystem should be summed to the human genome to form the hologenome due to their influence on human physiology; hence the term "microbiome" is commonly used to refer to the genetic make-up and gene-gene interactions of microbes. This review attempts to provide insight into this recently discovered vital organ of the human body, which has yet to be fully explored. We herein discuss the rhythm and shaping of the microbiome at birth and during the first years leading up to adolescence. Furthermore, important issues to consider for conducting a reliable microbiome study including study design, inclusion/exclusion criteria, sample collection, storage, and variability of different sampling methods as well as the basic terminology of molecular approaches, data analysis, and clinical interpretation of results are addressed. This basic knowledge aims to provide the pediatricians with a key tool to avoid data dispersion and pitfalls during child microbiota study