Concentration Ratio Values Research Articles

Green’s function analytical solution for free strain consolidation of soft soil improved by stone columns subjected to time-dependent loading

This paper proposes an analytical solution in terms of Green’s function formulations for axisymmetric consolidation of a stone column improved soft soil deposit subjected to time-dependent loading under free strain condition. The mathematical derivations incorporate the pore water flows in radial and vertical directions in stone column and soft soil synchronously. The capabilities of the proposed analytical solution are evaluated via worked examples investigating the influences of three common time-dependent external surcharges (namely step, ramp and sinusoidal loadings) on consolidation response of the composite ground. The examples show that a faster increase of load from an initial surcharge to an expected loading might generate more significant excess pore water pressure to be dissipated during the early stages of consolidation, but the dissipation rate in soft soil would speed up significantly afterwards. The column and soil settlements along with the differential settlement between them also proceed faster corresponding to the acceleration of loading – unloading processes. Finally, the proposed analytical solution is employed to evaluate the excess pore water pressure dissipation rate at an investigation point in soft clay of a case history foundation. The calculation results exhibit a reasonable agreement with field measurement data when various constant values of stress concentration ratio are substituted into the solution to reflect the increase of stress concentration ratio with consolidation time in real practice.

Performance and determination of Concentration Ratio for a parabolic solar concentrator using a thermographic technique

This work addresses the methodology to determine the exact concentration ratio (CR) for a parabolic solar concentrator (PSC) using thermographic imaging. The value of CR is commonly given in terms of the area of the receiver and not in terms of the area of the image produced by the concentrator on the receiver surface. With thermographic analysis, it is possible to know the real image generated by the PSC on the receiver, which helps to have a precise calculation of CR. It is important to measure the real CR not only for manufacturing purposes but also for the maintenance of solar concentrators, since its miscalculation lowers their energy efficiency or lifespan. In experiments, the real image on the receiver is divided into 4 regions, stratified with an equal temperature difference for each one. With this consideration, CR varied from 20 to 151. To complete the analysis, the energy efficiency is calculated. Since heating is a non-stationary process, thermal efficiency fluctuated during the time of experimentation, having a peak of 25% and a mean value of 15.3%. The irregularities of curvature in the concentrators significantly deteriorate the uniformity of the radiation flux and the energy efficiency due to unused areas of concentration.

Оцінювання вмісту 90Sr у деревині сосни звичайної на основі вимірювання щільності потоку бета-частинок із поверхні кори стовбура

This paper presents an approach for indirect measuring of 90Sr activity concentration in stem wood of Scots pine`s live trees within the Chernobyl exclusion zone based on values of beta-particles surface flux density from stem bark at a thee height of 1.3 m above the forest floor that obtained by use STORA-TU RKS-01 radiometer-dosimeter under field condition. The similar express-methods often consider in scientific publications so as they allow to obtain probable levels of radiation contamination without taking samples for laboratory measurements. That in turn can be used to optimize sampling or for example in the case of the need to preserve the intact initial state of the biota during long-term in situ or/and in vivo observations. The empirical data for validation of the method have received on 13 experimental sites of artificial (plantation) even-aged stands which consist only of one woody species: Scots pine. The correlation analysis discovered statistical significant relation at p-value=0.05 between arithmetic averages of beta-particles surface flux density from stem bark of pine trees at the forest sites and 90Sr activity concentration in stem wood elements (sap wood, heartwood and all stem wood), and functional dependencies among these parameters are described by a simple linear equation with only one slope parameters (R2 = 0.90–0.96) whose predicted values for sap wood, heartwood, and all stem wood are (± standard deviation) 23.1±8.5, 42.3±10.3, and 26.8±6.8 Bq·cm2·min·(kg·pcs)-1, respectively. Moreover, the influence of biometric indicators of individual trees (diameter, height, age) on this pattern was not detected. However, the average diameter (DBH) of stands has the strongest influence among forest inventory indicators on the value of the 90Sr activity concentration ratio between sap wood and heartwood (r = 0.93), that is, the radial distribution of the studied radionuclide in stem wood of pine trees. The results of these studies should be confirmed by a larger collection of observations for Scots pine given the small sample size for her in this paper. Also, scientists are necessary to include empirical data for other major forest-forming woody species within the research region due to the importance of using express-methods of radioactive contamination levels estimation for the planning and optimization of forest management.

Navier–Stokes transport coefficients for a model of a confined quasi-two-dimensional granular binary mixture

The Navier–Stokes transport coefficients for a model of a confined quasi-two-dimensional granular binary mixture of inelastic hard spheres are determined from the Boltzmann kinetic equation. A normal or hydrodynamic solution to the Boltzmann equation is obtained via the Chapman–Enskog method for states near the local version of the homogeneous time-dependent state. The mass, momentum, and heat fluxes are determined to first order in the spatial gradients of the hydrodynamic fields, and the associated transport coefficients are identified. They are given in terms of the solutions of a set of coupled linear integral equations. In addition, in contrast to the previous results obtained for low-density granular mixtures, there are also nonzero contributions to the first-order approximations to the partial temperatures Ti(1) and the cooling rate ζ(1). Explicit forms for the diffusion transport coefficients, the shear viscosity coefficient, and the quantities Ti(1) and ζ(1) are obtained by assuming steady state conditions and by considering the leading terms in a Sonine polynomial expansion. The above transport coefficients are given in terms of the coefficients of restitution, concentration, and the masses and diameters of the components of the mixture. The results apply, in principle, for arbitrary degree of inelasticity and are not limited to specific values of concentration, mass, and/or size ratios. As a simple application of these results, the violation of the Onsager reciprocal relations for a confined granular mixture is quantified in terms of the parameter space of the problem.

Effect of EDTA-based alkaline cleaning solution on TAZ removal in post CMP cleaning of copper interconnection

1,2,4-triazole (TAZ) has been proved to be an alternative to Benzotriazole (BTA) as an corrosion inhibitor in chemical mechanical polishing (CMP) of multilayer copper interconnection for integrated circuit. It has also become the main object to be removed in post CMP cleaning. In this paper, a new type of alkaline cleaning solution based on EDTA was proposed to remove TAZ on copper surface. The optimal concentration ratio and pH value of the alkaline cleaning solution were explored using electrochemical measurement, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) and scanning electron microscopy (SEM). When the components of the cleaning solution were 25mg/L ethylenediaminetetraacetic acid (EDTA) and 600mg/L dodecylbenzene sulfonic acid (LABSA) (pH = 10.6), the Cu-1,2,4-trazole compounds formed by TAZ contamination on the copper surface can be effectively removed. Density Functional Theory (DFT) was used to confirm that EDTA could break the bond of Cu-1,2,4-triazole through the strong interaction between O16、H2、H36 and copper surface. No corrosion was observed on the cleaned copper surface and surface roughness was lower, which indicated that the cleaning solution was suitable for the removal of TAZ on copper surface.

Physical appearance and arsenate removal efficiency of Fe(III)-modified clinoptilolite beads affected by alginate-wet-granulation process parameters

Fe(III)-modified clinoptilolite (Fe-Clin) was encapsulated into beads using sodium alginate (NaAlg) and Ca2+ and/or Fe3+ ions by a simple wet-gelation method to obtain Fe-Clin beads. The impacts of various parameters including mixture pH, type of cross-linker, concentration of cross-linking solution and initial mass ratio of NaAlg to Fe-Clin were investigated on the appearance of beads and also their performance in As(V) removal. To increase the net negative surface charge of alginate, pH value of the mixture was essentially adjusted to the level 12–13. This strong alkaline condition increased the ability of alginate mixture to form stable and well-shaped beads. Ca2+ acting as a cross-linker showed a less impact on the beads shape than Fe3+ due to the strong tendency of Fe3+ ions to react with oxygen atoms in carboxylate groups of alginate. A loosely cross-linked Ca2+-alginate network formed during preparation of Fe-Clin beads was considered as the main reason for their lower arsenate removal efficiency of 29.4% rather than 60.5% for those cross-linked in FeCl3. In addition, there were found optimal values of FeCl3 cross-linking solution concentration and initial mass ratio of NaAlg: Fe-Clin as 2% (w/v) and 1:4, respectively to achieve the maximum As(V) removal efficiency of 82%.

Theory of concentration distribution over the surface of axisymmetrical receiver in cylindrical parabolic mirror solar energy concentrator

This work is devoted to develop the theory of concentration distribution of radiation over the receiver surface in cylindrical parabolic concentrator of radiation with axisymmetrical (cylindrical) radiation receiver has been studied. The results will make it possible to estimate concentration distribution over the radiation receiver surface and to associate output characteristics of concentrator unit for various combinations of design parameters at the stage of engineering, to choose the best combination of such parameters and to optimize reflecting surface and radiation receiver. Photovoltaic module with cooling or without it, solar collector, photovoltaic thermal module, etc. may be applied as radiation receivers. Mathematical physics equations have been deduced that describe the specifics of incident radiation flux reflection from the concentrator’s surface and falling onto that of radiation receiver. Concentration distribution has been estimated, for various concentrator design parameters and various positions of receiver axis in relation to the focus of reflecting surface, on the symmetry plane. The most effective concentrator designs characterized by 100% optical efficiency correspond to options where the focus of concentrator’s reflecting surface is located inside radiation receiver. Analysis of design options using the developed theory is shown on examples for given values of average concentration ratio (2, 6, 8, 10, 15, 20, 50), as well as radius of radiation receiver, half concentrator aperture and distance between the focus line and the symmetry axis of radiation receiver in cross-section.

Coalescence Conditions for Bulk Nanobubbles

The coalescence of two nanobubbles with substantially different radii is considered. Studies of this problem have practical significance, because coalescence is an undesirable process (the nanobubbles lose their unique properties after enlargement). An energy-based approach is used with a simplified model of charged nanobubbles to demonstrate that bulk nanobubble coalescence can take place at specific values of surface charge density, concentration, and radius ratio, in contrast to the case of surface nanobubbles.

Synergistic effect of composite complex agent on BTA removal in post CMP cleaning of copper interconnection

Benzotriazole (BTA) is a common corrosion inhibitor for chemical mechanical polishing (CMP) of multilayer copper wiring of integrated circuit. It is also the main object to be removed in post CMP cleaning. In this study, a new type of alkaline cleaning solution based on composite complex agent was proposed to remove BTA effectively. The optimal cleaning concentration ratio and pH value of the new complex complexing agent were explored through electrochemical measurement and contact angle measurement. When the components of cleaning solution were 250 ppm diethylenetriaminepentaacetic acid (DTPA), 1000 ppm FA/OII chelating agent and 100 ppm polyethyleneimine (PEI) (pH = 10.5), the contact angle of copper surface contaminated by BTA can be reduced from 58.1° contaminated by BTA to 25.1°. Density Functional Theory (DFT) proved that DTPA could reduce the adsorption energy of BTA on copper surface. The result of atomic force microscopy (AFM) and scanning electron microscopy (SEM) on copper surface showed that composite complexing agent does not cause corrosion and a lower surface roughness was obtained after cleaning. X-ray photoelectron spectroscopy (XPS) results verified that the cleaning solution could complex copper ions, break the Cu-N bond and promote the decomposition of the Cu-BTA adsorbed chemically on Cu2O, so as to remove BTA effectively.

210Po in Сrimean salt lakes

This paper presents the results of radioecological monitoring study of natural radionuclide 210Po in 11 lakes located in different regions of the Crimean peninsula. These investigations of the Crimean salt lakes were conducted for the first time in the history. The main objectives of this work were: to determine the features of the 210Ро behavior in the salt lakes ecosystems, as well as calculation of the doses received by the lakes hydrobionts from α-radiation of absorbed 210Po. Concentrations of 210Po in the water, suspended matter, the bottom sediments and biota were determined by radiochemical processing and α-spectroscopy measurements. The concentrations of dissolved 210Po in the water of investigated lakes were in 0.9–327.1 times higher than in the Black Sea closest regions. The highest concentrations of 210Po in water were determined in the lakes of the Kerchenskaya group. These lakes are located on the territory of Crimea where oil is produced. The 210Ро activity concentrations in the bottom sediments from Crimean salt lakes were comparable with those of the Black Sea coastal zone. Concentration ratio (CR) of polonium in suspended matter ranged from 10 to 104 for different lakes. A significant trend in a decrease of CR values of 210Ро for suspended matter with increasing water salinity was revealed. High levels of 210Po accumulation were noted for adult crustacean Artemia spp. (typical inhabitant of the Crimean saline lakes). The CR of 210Po for adult Artemia spp. reached 105 while the CR of this radionuclide by their cysts was significantly lower. The absorbed doses from 210Po α-radiation calculated for adult Artemia spp. were more than 60 times lower than the permissible dose rate for biota (IAEA, 1992).The obtained results will be used to identify the biogeochemical peculiarities in behavior of the main dose-formative radionuclide 210Po, in the water ecosystems with different salinity, including water reservoirs poorly studied in the radioecological aspect and having extreme condition for the existence of lots of species of hydrobionts, such as hypersaline Crimean lakes.

Effect of Stress Concentration Ratio on Shear Strength of Soft Soils Improved with Stone Columns

Numerous studies have been performed on the behavior of stone columns subjected to vertical loads. However, little research has been focused on determining the shear strength and equivalent shear strength parameters of cohesive soils reinforced with stone columns. The performed research in this area mostly includes numerical analyses which do not consider the effect of stress concentration ratio, and the value of stress concentration ratio in such analyses is assumed to be 1. In this study, an experimental investigation has been carried out on stone columns subjected to vertical and shear loads, with the purpose of determining the actual value of stress concentration ratio. The experiments were performed in a large direct shear device. In this study, single, square and triangular arrangements of stone columns with three different area replacement ratios under three vertical loads were investigated. Soft clay was used as bed material, and stone column material was either crushed stone or fine-grained sand. Results showed that stress concentration ratio decreased with the increase in stone column diameter and vertical stress and the value of stress concentration ratio is highest for square arrangement and lowest for single stone columns. The equivalent shear parameters obtained from experiments and those predicted by analytical relationships were compared at stress concentration value of 1 and stress concentration values obtained from the experiments. Results also showed that the shear strength value and the equivalent shear strength parameters measured from experiments were higher than those predicted by analytical relationships.

Условия коалесценции объемных нанопузырьков

The paper considers the coalescence of two bulk nanobubbles with significantly different radii. The study of this issue is of practical importance,since coalescence is an undesirable process: nanobubbles lose their unique properties as they grow larger. In a simplified model of charged nanobubbles based on the energy approach, it is shown that, in contrast to surface nanobubbles , for bulk nanobubbles coalescence can occur at certain values of surface charge density, concentration , and radius ratio.

Yardımcı gıda teknolojileri ile elmadan probiyotik atıştırmalık üretiminin ön çalışması

A probiotic snack model food was formed with apple and Lactobacillus rhamnosus GG (LGG). The effects of dehydration process conditions with design of experiment (DoE) and dryer types used in the production were evaluated through optimization and probiotic qualification of the final product. Experiments on ultrasound assisted osmotic dehydration (US-OD) of apple cubes designed by Box-Behnken were conducted to obtain the maximum water reduction. Optimum values of sucrose solution concentration (40, 45, 50%), apple and solution ratio (1:4, 1:6, 1:8 w w-1) and ultrasound application time (10, 20, 30 min) variables of the design were determined. The DoE methodology introduced the results that maximum water loss was reached at the conditions of 50% sucrose concentration, 1:4 apple and solution ratio and 10.05 min; sucrose concentration was the most effective variable; quadratic model submitted a good fitting (R2=0.929) with the experimental results. Apple samples produced under the optimized conditions were dried with convectional and conventional dryers at specific temperature, 37 °C during 5 hours. The results showed that the remaining number of viable LGG cells (106-107cfu g-1) was sufficient to qualify dried products as probiotic.

Effects of circumsolar radiation on the optimal performance of a Stirling heat engine coupled with a parabolic dish solar collector

This paper investigates the effects of circumsolar radiation on the optimal performance of a coupled parabolic dish and a Stirling heat engine, referred to as the Dish/Stirling system. The presence of circumsolar radiation results in the widening of the solar cone in which the solar beam (direct) radiation is received by the parabolic dish. This beam radiation cone enlargement effectively degrades the collector performance, especially for the very high concentration ratio collectors such as the parabolic dish. The enlarged solar beam radiation cone angular width results in enhanced solar radiation flux spillage at the receiver due to the inability of the parabolic dish reflector surface to focus a significant fraction of incoming beam radiation. This reduces both the energy input as well as the maximum temperature of the Stirling heat engine cycle and causes a reduction in the overall thermal efficiency of the Dish/Stirling system. The present study analyzes this effect by considering various levels of circumsolar radiation, characterized by a parameter known as the circumsolar ratio. The data for the intercept factor of the parabolic dish collector is based on the circumsolar radiation measurements obtained by researchers at the Lawrence Berkeley Laboratory, and the results of analysis reported by researchers at the Solar Energy Research Institute (currently the National Renewable Energy Laboratory). For the present analysis, this intercept factor data is curve-fitted for different circumsolar ratio, mirror optical errors and the concentration ratio using a MATLAB® program. The overall thermal efficiency of the Dish/Stirling system is maximized with respect to the concentration ratio of the parabolic dish and the maximum temperature ratio of the Stirling heat engine using the first law of thermodynamics. This optimization process is performed using a MATLAB® program. Optimal values of concentration ratio for the parabolic dish collector, and the maximum temperature ratio of the Stirling cycle are obtained corresponding to the maximum overall thermal efficiency of the Dish/Stirling system. The study shows that, for a parabolic collector with low mirror optical error and rim angle of 60°, an increase in circumsolar ratio from 0.02 to 0.2 reduces the maximum overall thermal efficiency, optimal concentration ratio and optimal temperature ratio by about 13%, 18% and 7% respectively. In the case of parabolic collectors with high mirror optical error and rim angle of 60°, an increase in circumsolar ratio from 0.02 to 0.2 reduces the maximum overall thermal efficiency, optimal concentration ratio and optimal temperature ratio by about 10%, 11% and 5% respectively. Similar trends are observed for parabolic dish collectors with rim angle of 40°. Results from this study are presented in the form of performance charts that show the effects of varying circumsolar ratios, mirror optical errors, rim angles, non-dimensional radiation flux and non-dimensional convection loss parameters on the maximum overall thermal efficiency of the Dish/Stirling system.

Whole organism concentration ratios of radionuclides and metals in terrestrial vertebrates of an Australian tropical savanna environment

Preliminary values of whole organism concentration ratio (CRwo-soil) were derived for terrestrial vertebrates of an Australian tropical savanna environment. Wildlife groups included bird, bat, ground-dwelling mammal and reptile. Sample data for some of the wildlife groups (bird and bat in particular) were limited. The bird and bat CRwo-soil values were generally lower than the ground-dwelling mammal and reptile CRwo-soil values based on the available data. Arithmetic mean CRwo-soil values for two species of native marsupial and two species of non-native placental were not significantly different (p < 0.05) when tested using a one-way analysis of variance. The results hinted at possible sampling efficiencies for terrestrial vertebrates. However, verification with additional data was recommended. Used cautiously, the CRwo-soil values may assist in environmental assessments of Australian uranium mining sites. They also enhance the available data on radionuclide transfer to wildlife for use internationally.

Screening of cardiovascular agents in plasma with LC-MS/MS: A valuable tool for objective drug adherence assessment

Adherence to cardiovascular preventive agents is important to prevent short and long term cardiovascular events. Recently, qualitatively compound screening using liquid chromatography-tandem mass spectrometry (LC-MS/MS) has gained interest for drug adherence assessment in patients at high risk of cardiovascular events. Therefore, we developed and tested an assay including 52 compounds and metabolites, covering over 95% of the antihypertensive and antithrombotic agents available worldwide. Trichloroacetic acid was used as simple and fast method for protein precipitation. The assay was validated for lower limit of quantification (LLOQ), linearity, stability for freeze/thaw, room temperature, autosampler and matrix effects. The LLOQ for each compound was targeted under the population trough concentration (PTC) as reported in literature to assure high sensitivity for adherence detection. This was accomplished for 50 of 52 compounds with a LLOQ equal or lower compared to the PTC. Linearity was confirmed for all compounds (r2 > 0.995), except for acetylsalicylic acid (r2 = 0.991). For room temperature stability, 12 compounds showed degradation over 20% after 20 h. 3 compounds suffer from matrix effect with recoveries < 50%. After analytical validation, blood samples from 91 patients with difficult-to-treat hypertension were analyzed. Patients were unaware of adherence assessment. Adherence varied largely per agent and per concentration ratio (CR) (ratio of the detected concentration with LC-MS/MS and the PTC) cut-off value. Additionally, stratification by adherence group showed that the percentage of patients classified as non-adherent increased from 6.6% for qualitative analysis (pos/neg) to 19.8% for a CR cut-off of 0.5. The data imply that using the CR cut off values has a significant and relevant effect on patient adherence classification.

Full-scale model study on variations of soil stress in geosynthetic-reinforced pile-supported track bed with water level change and cyclic loading

This study presents a full-scale model investigation on variations of soil stress in a geosynthetic-reinforced pile-supported track bed at various water levels and loading cycles, with four testing procedures: water level rising, cyclic loading at high water level, water level lowering, and cyclic loading at low water level. The soil arching effect was revealed, characterized by higher stress above the pile cap. With the water level rising and loading cycles increasing at high water level, this effect becomes more pronounced, until a peak value of dynamic stress concentration ratio is reached. The stable state of soil arching is obtained earlier near the crown of soil arching, but this arching effect develops more significantly at the foot of soil arching. With the water level lowering and loading at low water level, the soil arching effect remains steady, with slightly changed dynamic stresses in the track bed. The geogrid shows a significant impact on the load transfer mechanism for the quasi-static stress: the quasi-static pile-cap stress presents higher values below the geogrid, whereas the opposite trend is observed for the water-bag (subsoil) area. Nevertheless, this mechanism is not obvious with respect to the dynamic stress, with the values showing no distinct difference above and below the geogrid.

Assessment of High Concentrated Photovoltaic/Thermal Collector in Hot Climate

This work investigates the performance of combined hybrid high concentrated photovoltaic/thermal collector (HCPV/T) in Kuwait harsh climate. The proposed system consists of triple junction solar cells (InGaP/InGaAs/Ge) attached to heat source to discharge thermal energy to cooling media. Published HCPV/T models do not consider the effect of shunt resistance which greatly affects the system performance. So, a single diode model employing five parameters including the effect of shunt resistance is adapted to analyze the proposed system. To analyze the thermal performance of the proposed system, a two-dimensional thermal model based on the technique of finite difference is introduced to determine the efficiency of the hybrid HCPV/T system. The present developed subroutines are integrated with other involved codes in TRNSYS software to calculate HCPV/T system efficiency. Electrical and thermal as well as the whole system efficiency at different weather circumstances are evaluated and assessed. The effect of different weather conditions, cell temperature, concentration ratio and the temperatures of the coolant fluid on system performance are studied. Current results indicate that the model of single diode is a reliable one rather than using the two-diode complex model. Compared to measurements provided by high concentrated PV manufacturer, the current results revealed a total root mean square error of approximately 1.94%. Present predictions show that PV cell temperature has logarithmic increase with the rise in concentration ratio but with low values till concentration ratio of 400 suns after that the rise is faster at higher concentration values up to 1500 suns. Results also revealed that hybrid HCPV/T system works effectively specially in severe hot climate where thermal efficiency increases with high surrounding temperature for higher values of concentration ratio. In addition, an increase of approximately 15% in thermal efficiency and 10% in total efficiency can be achieved by utilizing active cooling device in HCPV/T system.

Whole organism concentration ratios in freshwater wildlife from an Australian tropical U mining environment and the derivation of a water radiological quality guideline value

More than 10,000 whole organism concentration ratio (CRwo-water) values for freshwater wildlife were derived from radionuclide and stable element data representing an Australian tropical U mining environment. The CRwo-water values were summarised into five wildlife groups (bird, fish, mollusc, reptile and vascular plant). The summarised CRwo-water values represented 77 organism-element combinations. The CRwo-water values for U decay series elements were used in a tier 3 ERICA assessment. The assessment results were used to derive a water radiological quality guideline value (GV) for radiation protection of freshwater ecosystems in the context of the planned remediation of the Ranger U mine. The GV was an above-background water 226Ra activity concentration of 14 mBq L−1 (filtered fraction) or approximately 22 mBq L−1 (total fraction). The GV was based on the results of mollusc-bivalve as the limiting organism for the freshwater ecosystem.

STRUKTUR PASAR DAN ANALISIS KEUNTUNGAN KOPI ARABICA RAKYAT DI KECAMATAN SUMBER WRINGIN BONDOWOSO

Arabica coffee production in District Sumberwringin 2011 reached 6.08 tonnes with a productivity of 0.17 tonnes / ha. Total production and productivity is the largest number compared with other sub-districts in the regency, This study aims to: (1) find out the factors influencing the income of coffee farmers, (2) Proving the market structure formed at the level of smallholder coffee farmers is oligopsoni. Locations were selected in District Sumberwringin because it is a major production center or people's coffee-producing regency. The sampling technique using snowball sampling. The total number of samples are 30 people arabica coffee grower and 30 people robusta coffee grower. The analysis are linear regression and the concentration ratio (CR).The result in arabica coffee: the cost of drugs and labor costs have a significant effect on income, while the area of ​​land and the cost of fertilizer have no significant effect on income. The result in robusta coffee: land area and labor cost have real effect to income, while fertilizer cost and drug cost have no significant effect to income. By calculating the value of CR found more than 80 percent that the structure of the coffee market in the District Sumberwringin monopsony or oligopsony heavy concentration.