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Strain-induced phase transformation in a dual-phase Mg–Li alloy after a severe deformation has been investigated. β-Li phase was transformed into α-Mg phase as a consequence of large strain cold rolling. The morphology and density of the strain-induced phase could be controlled by slip activation in the β-Li phase. A multi-direction rolling procedure was designed to enhance phase transformation behavior. High density strain-induced phase refined phase structure and greatly promoted the yield strength of the material without a sacrificing the ductility. Strain-induced phase transformation is a potential method for improving the mechanical properties in dual-phase alloys.

A parameterized effective potential method that was proposed earlier for the ground state has been developed for excited states with symmetry of the ground state. Various approximations for determining exchange-correlation potentials Vxc, have been discussed. In particular, one of the techniques for constructing a new class of Vxc, which is a functional of the external potential (electron–nucleus interaction) in contrast to traditional approaches, in which Vxc explicitly or implicitly depends on the electron density, have been presented on the basis of the Vxc symmetry requirement. The possibilities of the method have been investigated using the example of calculating the electronic dipole moments of the transition of an НеН molecule with a single-determinant wave function. It has been shown that the proposed method for calculating the transition dipole moments can be considered as a compromise between accuracy and computational effort.

Explicit solvent interactions can significantly alter the physical and chemical properties of noble metal (e.g., gold and silver) nanoclusters. In order to compute these solvent interactions at a reasonable computational cost, a quantum mechanical (QM)/molecular mechanics (MM) approach, where the metal nanocluster is treated with full QM and the water molecules are treated with a MM force field, can be used. However, classical MM force fields were typically parameterized using molecules containing main group elements as the reference. The accuracy of noble metal–solvent interactions obtained with these force fields therefore remains unpredictable. The effective fragment potential (EFP) force field, designed to model explicitly solvated systems, represents an attractive method to simulate solvated noble metal nanoclusters because it is derived from first principles and contains few or no fitted parameters, depending on implementation. At the density functional theory-optimized geometries, good correlation is obtained between the nanocluster–water interaction energies computed with EFP and those computed with the reference coupled cluster singles, doubles, and perturbative triples method. It is shown that the EFP method gives qualitatively accurate interaction energies at medium–large intermolecular distances for various molecular configurations. In order to achieve higher quantitative accuracy, the first solvation shell should be treated with full QM, if possible. EFP is therefore a promising method for the QM modeling of explicitly solvated silver and gold nanoclusters.

CO2 injection into subsurface formations is a potential method to reduce CO2 gas emissions in the atmosphere. Geological and geophysical studies are carried out as an effort to analyze the storage capacity and potential risks. The results are then used to analyze the response of reservoir rock to the injected CO2 fluid. The effect of fluid injection on reservoir rocks is complex and involves a coupled system of fluid flow-geomechanics. CO2 fluid injection can increase fluid pressure that affects the local stress conditions of reservoir and surrounding rock. Meanwhile, changes in temperature due to the presence of CO2 fluid also affect reservoir rock stress, although not significantly. The complexity of the subsurface reservoir system includes thermomechanical and hydromechanical analysis involving multi-phase and multi-component fluids. To study these complex interactions, a program which can simulate the coupling between multi-phase and multi-component fluid-flows-geomechanics is needed. To accommodate these needs, Rutqvist et al (2002) have proposed a numerical modeling approach by linking TOUGH2-ECO2N and FLAC3D. In this study we developed an external program that linking TOUGH2 with different fluid modul (ECO2M), and FLAC3D using these approaches to run the coupled THM simulation automatically and seamlessly until the end of simulation.

The article describes a direct connection between the natural electric potential and the dynamics of the temperature of volcanoes using the examples of observation of the natural electric potential on the surfaces of volcanoes. If the upper part of the volcano is hotter, positive potential anomalies are recorded, and conversely, if the lower part of the volcanoes is hotter, negative anomalies of the same potential are recorded. At the same time, the temperature processes occurring at great depths, as a rule, are closely related to long-lived deep faults. Therefore, observations of the natural potential over these faults will allow controlling the dynamics of deep temperature processes. Given this new direction of the natural potential method and its effective application in the search for non-ferrous metal ores, there is a need to create the map of the natural electrical potential of Russia. As a result, small-scale map would allow us more precise limitation of ore fields and purposefully search for previously undiscovered deposits of metal ores. In addition, a small-scale map would make it possible to most accurately track the development of deep tectonic fault zones and to study them in relation to volcanic activity and seismic events. In this regard, the method of natural electric potential hodograph is considered as one of the possible ways to predict seismic events.

A new method for calculating the pairwise effective potential on arbitrary shells of the binary disordered solid solutions is proposed with account for the linear size effect. The method is based on the fitting of the order–disorder temperature calculated by the model potential method to its known experimental value. In disordered Cu $${}_{3}$$ Au alloy, the pairwise effective potential is calculated and the short-range order parameters on the first fourteen shells are estimated using the Krivoglaz–Clapp–Moss method. A satisfactory coincidence with the experimental data is obtained.

Local electrodeposition by using a micropipette is a potential method for fabrication of 3D metallic micro/nano-structures by confining the electrochemical reaction in a liquid meniscus, which is formed between the nozzle of the micropipette and a substrate. One of the key problems associated with this method is the nozzle clogging due to the small size of the micropipette, where the nozzle aperture is on the order of 1 μm and the fast speed of electrochemical reaction. This paper presents a method for resolving the nozzle clogging problem inherently with the local electrodeposition of microstructures. The reason of micrometric nozzle clogging was firstly investigated. A new method by relieving the nozzle deformation as well as adjusting the liquid meniscus bridge during the electrodeposition procedure was proposed. Through this way, electrodeposition of microstructures could thus be carried out with a high reproductivity without influences of the nozzle clogging. Experiments were carried out to demonstrate the feasibility of the method. It is proved that the reproductivity, the nozzle condition, as well as the surface quality of the microstructures in local electrodeposition could be improved based on the proposed method.

An autocatalytic set (ACS) is a graph. On the other hand, the Potential Method (PM) is an established graph based concept for optimization purpose. Firstly, a restricted form of ACS, namely, weak autocatalytic set (WACS), a derivation of transitive tournament, is introduced in this study. Then, a new mathematical concept, namely, fuzzy weak autocatalytic set (FWACS), is defined and its relations to transitive PM are established. Some theorems are proven to highlight their relations. Finally, this paper concludes that any preference graph is a fuzzy graph Type 5.

The high-throughput (HT) computational method is a useful tool to screen high-performance functional materials. In this work, using the deformation potential method under the single band model, we evaluate the carrier relaxation time and establish an electrical descriptor (χ) characterized by the carrier effective masses based on the simple rigid band approximation. The descriptor (χ) can be used to reasonably represent the maximum power factor without solving the electron Boltzmann transport equation. Additionally, the Gruneisen parameter (γ), a descriptor of the lattice anharmonicity and lattice thermal conductivity, is efficiently evaluated using the elastic properties, omitting the costly phonon calculations. Applying two descriptors (χ and γ) to binary chalcogenides, we HT compute 243 semiconductors and screen 50 promising thermoelectric materials. For these theoretically determined compounds, we successfully predict some previously experimentally and theoretically investigated promising thermoelectric materials. Additionally, 9 p-type and 14 n-type previously unreported binary chalcogenides are also predicted as promising thermoelectric materials. Our work provides not only new thermoelectric candidates with perfect crystalline structure for the future investigations but also reliable descriptors to HT screen high-performance thermoelectric materials.

Analytical solution of tensile stress of square specimen under splitting load was obtained through Fourier Series Solution of plane stress problems. According to the stress distribution of the un-cracked square specimen, the calculation formula of Mode I fracture toughness of cracked straight through the square specimen, CSTSS, under splitting load was obtained, and the shape function was corrected by the finite element interaction integration method. In order to verify the correctness of the formula, a CSTSS splitting test was performed. The test results indicated that the stress distribution on the axis of symmetry is consistent with the theoretical results, and the minimum tensile stress occurs at the center point of the un-cracked specimens. The Mode I fracture toughness of CSTSS, KIC, was stabilized in relative range and the average value of KIC was 0.140MPa×m1/2. The three-point-bend experiment was introduced as a comparative test and the average value of KIC was 0.158MPa×m1/2 which was slightly larger than that of CSTSS. The test results indicated that both of the two tests could be reliable and the CSTSS under splitting load could be a potential method to determine the Mode I fracture toughness of rock.

In the present paper, the linear theory of viscoelasticity for binary porous mixtures is considered. The fundamental solution of the system of steady vibration equations is constructed, and its basic properties are established. Green’s identities of this theory are obtained. The uniqueness theorems for classical solutions of the internal and external basic boundary value problems (BVPs) of steady vibrations are proved. The surface and volume potentials are introduced, and their basic properties are established. The determinants of symbolic matrices of the singular integral operators are calculated explicitly, and the BVPs are reduced to the always solvable singular integral equations for which Fredholm’s theorems are valid. Finally, the existence theorems for classical solutions of the internal and external BVPs of steady vibrations are proved by means of the potential method and the theory of singular integral equations.

Surface texturing has become a potential method to obtain a low friction coefficient under dry/lubricated conditions for different mechanical product surfaces. The mechanism of friction and wear reduction from a micro-texture on the surface of cemented carbide cutting tools was investigated by dry cutting a titanium alloy. Three kinds of micro-textures, namely, line, sinusoidal and rhombic grooves, with different area occupancy rates were produced by a laser on the cemented carbide surface. Experiments and finite element simulation of ABAQUS were used to investigate the tribological characteristics of micro-textured cemented carbide. The results indicated that the line-textured cemented carbide with an area occupancy rate of 10% showed a low friction coefficient of 0.076, which is approximately 34% of the non-textured sample. Few adhesives appeared on the textured surface, while a large number of adhesives were attached to the smooth surface after 30 min of dry friction between the cemented carbide and the titanium alloy balls. Moreover, among the three textures, the line-groove texture has the smallest friction coefficient and a good anti-wear effect. The results show that the existence of a groove texture can effectively reserve the wear debris, reduce the bond wear and weaken the furrow effect.

In a combined experimental and theoretical study we probe the transient anion states (resonances) in cyanogen. Experimentally, we utilize electron energy loss spectroscopy which reveals the resonance positions by monitoring the excitation functions for vibrationally inelastic electron scattering. Four resonances are visible in the spectra, centered around 0.36 eV, 4.1, 5.3 and 7.3 eV. Theoretically, we explore the resonant states by using the regularized analytical continuation method. A very good agreement with the experiment is obtained for low-lying resonances, however, the computational method becomes unstable for higher-lying states. The lowest shape resonance (2Πu) is independently explored by the complex adsorbing potential method. In the experiment, this resonance is manifested by a pronounced boomerang structure. We show that the naive picture of viewing NCCN as a pseudodihalogen and focusing only on the CC stretch is invalid.

Today, in an era of integration of artificial intelligence systems in almost every industry, very demand are studies of classification methods that, prior to their introduction into decision support systems. Compare analysis of the secant planes method, method of the potentials and potential method in the field of receptors are shown in the paper. At first, in introduction, authors shew needs of autonomic systems of adaptive perception on visible diapason of specter. As particularly aim, these methods are compared by criteria of speed, accuracy and amount of storage used after training. As general idea we are looking for we are looking for methodic of the best combination of method for different condition on observe field of visual spectral diapason. Theories of the every method are presented, and then tables of compare analysis of results are shown. Step-by-step comparative experiments are described in detail. Changes at each step are shown in detail in the tables of the corresponding signs. Moreover, at the end of the paper, comparative characteristics of each method with the same learning time in same type of experiments for each method are presented. As a result, in the first group of tables , we see a difference in the recognition time and the amount of memory required for correct operation. Those are truth tables for two points, three points, two points and two planes, three points and two planes, three points and three planes, three points and seven planes. The conclusion gives a thorough explanation of where to use the best method. The needs of the system for computing resources in the application of each mode are presented and corresponding dependencies are derived. Next, If you train several times on the same object (ie, train several times), you can expect that the errors in the breakdown of the receptor space will be different. In this case, you can improve the performance of the algorithm by parallelizing its process into several threads. Using this method simultaneously and independently of each other on the same image is multi-threaded learning on multiple computer kernels. When recognizing new objects, they will refer to some image, not necessarily the same. The final decision is made by "vote" - the object refers to the image to which it was attributed to a greater number of parallel streams.

The new hypersingular integral equations (HSIEs) for the multiple cracks problems in both upper and lower parts of the bonded dissimilar materials are formulated using the modified complex potential method, and with the help of the continuity conditions of the resultant force function and displacement. The crack opening displacement is the unknown and the traction along the crack as the right term of the equations. The appropriate quadrature formulas are used in solving the obtained HSIEs for the unknown coefficients. Numerical results for the multiple inclined or circular arc cracks subjected to the remote shear stress are presented.

Sheath region of an electronegative magnetized plasma consisting of q-nonextensive electrons, Boltzmann distributed negative ions and positive ions with finite temperature is investigated by using a steady state fluid model. Considering Sagdeev's pseudo potential method, a modified Bohm criterion is derived. Taking into account the new formation criterion, the fluid model is then solved numerically and the density distribution of charged particles in the sheath region is studied for different values of the initial positive ion velocity at the sheath edge.

In this paper, a finite-element method with unstructured mesh is used to numerically simulate the line source model of three-dimensional borehole-to-surface electrical potential method. A new total field potential is synthesized using the calculated anomalous field potential and the analytic solution of the background field. In solving for the original total field potential and background potential, this method can guarantee a small near-field error in the new total field potential without the need to densely mesh the region with the source. By comparing the synthesized total field and analytic solution, the high accuracy of the numerical solution is verified. The results of model calculation show that the detection effectiveness of the borehole-to-surface electrical method depends on the length of the line source. The detection effectiveness increases substantially with increasing length of the line source within a certain range. However, when the line source is excessively long, the increase in detection effectiveness for anomalies is insignificant. For a low-resistance anomaly of a given volume, the borehole-to-surface electrical method is more sensitive to changes in the lateral area than to changes in the thickness. When the gob contains only a small amount of water (e.g., Model IV containing 5% of water by volume), it will appear as a low-resistance anomaly. In addition, the detection of a water-logged gob by the borehole-to-surface electrical method depends on the depth and size of the gob. The borehole-to-surface method can accurately delineate the profile boundary of an anomaly, even though the side closer to the source is susceptible to the effect of source current. These results are significant for guiding the field exploration of the borehole-to-surface electrical method, improving result interpretation, and assisting the application.

Electrical grounding is a system to remove undesired electrical charge to the ground via grounding mass. The unwanted electrical charged maybe created due to grounding fault of electrical apparatus and transient. Without proper grounding system, any structure will have exposed to the risk that caused by fault current and lightning. This situation will contribute to the loss of life and damaging the equipment. The purpose of this research is to investigate the behavior of bentonite and coconut husk as additive material to improve the performance grounding system by reducing grounding resistance value. At the same time, the proposed grounding system is also installed in two different topologies which are the single driven rod as the first topology and the radial multiple driven rod as the second topology instead of the conventional method that installing multiple rod in straight line. After the installation process is completed, the measurement of grounding resistance work was conducted using fall of potential method and recorded within 64 days. The data gained then was compared and analyzed to identify the best material to be used as the grounding enhancement or additive material. The results obtained show that the Bentonite has better performance than coconut husk in reducing grounding resistance. This research also found that the new configuration of multiple driven rod topology was able to reduce grounding resistance compared to the single driven rod.

The AlGaN/GaN high electron mobility transistor with a step–doped channel (SDC–HEMT) is first proposed in this paper. The potential distribution and the electric field (E–field) distribution of the device are explored by the numerical approach and analytical approach simultaneously. By introducing extra dopants to the channel layer, the E–field distribution along the AlGaN/GaN heterojunction interface is reshaped, resulting in an improved breakdown characteristic. An optimized doping concentration gradient of channel layer of 2 × 1016 cm−3/step is proposed and verified by simulations. The breakdown voltage (BV) of the optimized SDC–HEMT reaches 1486 V with a 59.8% improvement compared with conventional AlGaN/GaN HEMT. In addition, the average E–field in the region between gate and drain improves from 1.5 to 2.5 MV/cm. Based on the equivalent potential method (EPM), an analytical model of the E–field and potential distribution is presented. The veracity and effectiveness of the proposed methodology is verified by the good agreement between the simulated and modeled results.

The transient behavior of the finite-buffer queueing model with batch arrivals and generally distributed repeated vacations is analyzed. Such a system has potential applications in modeling the functioning of production systems, computer and telecommunication networks with energy saving mechanism based on cyclic monitoring the queue state (Internet of Things, wireless sensors networks, etc.). Identifying renewal moments in the evolution of the system and applying continuous total probability law, a system of Volterra-type integral equations for the time-dependent queue-size distribution, conditioned by the initial buffer state, is derived. A compact-form solution for the corresponding system written for Laplace transforms is obtained using an algebraic approach based on Korolyuk’s potential method. An illustrative numerical example presenting the impact of the service rate, arrival rate, initial buffer state and single vacation duration on the queue-size distribution is attached as well.

Stretchable ultrasonic arrays have great potential for applications in neuromodulation, ultrasound therapy, and wearable devices. However, the relative positions of the elements are changed when the array is deformed, which brings inconvenience to focus the ultrasound waves. In this work, a stretchable ultrasonic array with row and column electrodes was presented firstly. Three-dimensional scanning was performed to rapidly obtain the surface geometry and position of elements when the array was attached on a skull model. According to the scanning results, the signal time delay of each element was readjusted to focus the ultrasound waves. The final simulation results indicated that three-dimensional scanning could be a potential method for guiding stretchable arrays to achieve the spatial focus of the ultrasound waves.

Recently, a combination of unmanned aerial vehicles (UAVs) and free-space optics (FSO) has been investigated as a potential method for high data-rate front-haul communication links. The aim of this work was to address the performance of UAV-to-ground station-based FSO communications in terms of the symbol error rate (SER). The system proposes utilizing subcarrier intensity modulation and an avalanche photo-diode (APD) to combat the joint effects of atmospheric turbulence conditions and pointing error due to the UAV’s fluctuations. In the proposed system model, the FSO transmitter (Tx) is mounted on the UAV flying over the monitoring area, whereas the FSO receiver (Rx) is placed on either the ground or top of a high building. Unlike previous works related to this topic, we considered combined channel parameters that affect the system performance such as transmitted power, link loss, various atmospheric turbulence conditions, pointing error loss, and the total noise at the APD receiver. Numerical results have shown that, for the best system SER performance, the value of an average APD gain at the Rx can be selected, varying from 18 to 30, whereas the equivalent beam waist radius at the Tx should be in a range from 2 to 2.2 cm in order to decrease the effects from the UAV’s fluctuations.

This paper deals with the effects of soil inhomogeneity in the equation that describes the grounding resistance. This issue is relevant in order to circumvent the classical assumption that the soil is homogeneous and that the equivalent geometry of the grid is hemisphere. As the medium homogeneity is a rare condition in real soils, supported by the Average Potential Method and by the Images Theory, a derivation in the existing analytical formulation to calculate the grounding resistance in non-homogeneous soils is proposed for different equivalent grounding systems. The study is validated and supported by simulations performed in the software Ansys Maxwell 3D.

The aim of this research project was to investigate the scattering acoustic field by a rigid cavity in a rigid plane insonified by an arbitrary deterministic incident field. The Kobayashi potential method was used in order to derive the scattered acoustic field in a modal form. A previous model was developed using the same method for an incident plane wave (Khanfir et al. in J Sound Vib 361:251, 2016). The incident spherical source was then decomposed into plane waves. The total scattered field was determined by summing all the elementary scattered fields. In this paper, we present a new technique allowing the scattered acoustic field determination without using the decomposition into plane waves technique. This new model was compared to numerical results obtained using the previous model, the boundary element modeling method and experimental results for two rectangular cavities insonified by a spherical source. A good agreement between numerical and experimental results was obtained supporting the validity of the model.

Understanding electrode–electrolyte interfaces at the molecular level is crucial for further progress in electrochemistry, with numerous practical applications in store for society. Molecular dynamics (MD) is a natural technique of choice for accessing molecular-level detail, and the constant potential method (CPM) enables physically realistic and computationally feasible simulations of large systems between conductive electrodes with a specified potential difference. As such, this review aims to introduce readers to the most important concepts of the CPM, such as dynamic charge updating methods, importance sampling in the constant potential ensemble, and optimal periodic boundary conditions for calculating long-range electrostatic interactions. The CPM has been used to study the capacitance of room-temperature ionic liquid supercapacitors and the relationship with electrolyte layering near charged electrodes, the mechanisms and kinetics of charging and discharging, and the utility of nanoporous electrodes in achieving ionic nanoconfinement and superionic states. These areas highlight the flexibility of CPM MD and the additional physical realism that is achieved over simpler fixed charge methods when studying complex electrolyte–electrode interfaces. Nonetheless, there are many potentially fruitful ways to further optimize CPM MD simulations, alongside numerous areas where the application of this technique could yield novel and interesting results.

Ion dynamics exhibits inherent multiscale characteristics because it contains both atomistic and hydrodynamic behaviors. Although atomic-scale ab initio molecular dynamics is the subject of intense research on warm dense matter, the macroscopic relaxation process contained in the zero-frequency mode of the ionic dynamic structure factor (DSF) cannot be demonstrated due to the limitation of simulation sizes. Here, we fill this gap via the machine-learning deep potential method. To capture the ion dynamics near the hydrodynamic limit with ab initio accuracy, an accurate and efficient electron-temperature-dependent interatomic potential was constructed. We quantitatively verify the consistency of thermal diffusivities obtained from hydrodynamics and the fluctuation-dissipation theorem and further provide a microscopic perspective of energy transport to understand the zero-frequency mode of DSF. As implemented in two temperature states, a competitive mechanism is found to account for the damping of the zero-frequency mode.

U doktorskoj disertaciji je predložen inovativni metodološki okvir za mjerenje i povezivanje stupnja usvojenosti zadružnih načela s poslovnim pokazateljima efikasnosti zadružnog poslovanja. Zadruge se od konvencionalnih oblika poduzetništva razlikuju u primjeni sedam zadružnih načela. Koncept svakog zadružnog načela u sebi sadrži sociološke čimbenike koji zadružno poslovanje reguliraju na istovjetan način kao što tržište reguliraju ekonomski čimbenici. Upravo zbog zadružnih načela zadruge predstavljaju praktičan model poslovanja za ispitivanje povezanosti između socijalnih i financijskih pokazatelja, ili za mjerenje utjecaja pokazatelja socijalnog kapitala na konačan financijski rezultat zadružnog poslovanja. Interes doktorske disertacije je usmjeren prema ispitivanju međusobne povezanosti između zadružne dobiti i pokazatelja usvojenosti zadružnih načela. U tu svrhu empirijski je ispitan stupanj usvojenosti zadružnih načela među dionicima poljoprivrednih zadruga i postavljen je socioekonomski model optimizacije zadružnog poslovanja. Za potrebe empirijske analize je provedeno terensko istraživanje na području pet županija Slavonije, Baranje i zapadnog Srijema. Pomoću anketnog upitnika je ispitano 202 dionika koji surađuju s 23 poljoprivredne zadruge. Anketom su prikupljeni socioekonomski podaci, ispitano je poznavanje zadružnih načela i prikupljeni su podaci o organizaciji zadružnog poslovanja. Ekonomski pokazatelji poslovanja poljoprivrednih zadruga su dobiveni od strane Financijske agencije (FINA). Pomoću Analize omeđivanja podataka su analizirani poslovni podaci poljoprivrednih zadruga u vremenskom razdoblju od pet godina. Rezultati analize su pokazali da samo dvije zadruge istodobno postižu ukupnu tehničku, čistu tehničku efikasnost i efikasnost razmjera, i predstavljaju idealan obrazac poslovanja. Još tri zadruge postižu čistu tehničku efikasnost. Međutim, unatoč efikasnom korištenju resursa ove zadruge posluju iznad svojih optimalnih razina zbog čega postižu padajuće stope povrata i rastuće prosječne troškove proizvodnje. Pokazatelji za mjerenje stupnja usvojenosti zadružnih načela od strane dionika zadružnog poslovanja analizirani su korištenjem Konfirmatorne faktorske analize. Analiza je potvrdila robustnost (invarijantnost) modela koji sadrži dvadeset i jedan pokazatelj raspoređenih na šest mjernih konstrukata koji sadržajno odgovaraju teoriji zadružnih načela: demokratičnost poslovanja (N2), gospodarsko sudjelovanje (N3), autonomija poslovanja (N4), zadružna edukacija (N5), suradnja među zadrugama (N6) i briga za lokalnu zajednicu (N7). Na kraju je provedena Metoda potencijala koja je potvrdila ekonomsku važnost zadružnog poduzetništva. Zadružna načela gospodarsko sudjelovanje i suradnja među zadrugama zauzimaju prva dva vodeća mjesta na obje razine samodualne hijerarhije, uz male razlike u ukupnom poretku. Kada se zadružna načela rangiraju obzirom na poslovne pokazatelje načelo gospodarsko sudjelovanje zauzima prvo, a načelo suradnje među zadrugama zauzima drugo mjesto u poretku. Kod rangiranja načela s uvažavanjem postojanja sinergije između zadružnih načela dolazi do zamjene njihovih pozicija i prvo mjesto zauzima načelo suradnje među zadrugama, a drugo mjesto u poretku načelo gospodarsko sudjelovanje. Značaj ovog istraživanja proizlazi iz prilagodljivosti i fleksibilnosti metodološkog okvira koji omogućuje jednostavnu interpretaciju rezultata o usvojenosti zadružnih načela. Pri tome, objedinjuje sve kriterije koji opisuju teoriju zadružnog poduzetništva, daje jasan uvid koja zadružna načela su poželjnija i koji je kriterij uzrok tome. Metodološki okvir može pomoći u mjerenjima efikasnosti u drugim regijama RH (i šire) i zadružnim sektorima. On predstavlja opću paradigmu znanstvene metodologije za mjerenje efikasnosti zadružnog poslovanja uz istodobno uvažavanje teorije zadružnih načela. Metodologija predstavlja koristan dodatak klasičnim financijskim analizama koje se obično koriste za mjerenje efikasnosti investicijski usmjerenih poduzeća jer istodobno mjeri višekriterijsku učinkovitost zadružnog poslovanja. The doctoral dissertation proposes an innovative methodological framework for measuring and linking the cooperative principle's acceptance indicators with the business efficiency indicators. Cooperative entrepreneurship differs from other conventional business forms in the application of seven coop principles. The concept of each principle contains sociological factors that regulate cooperative business in the same manner as economic factors control the market. Because of these principles, cooperatives represent a practical business model for examining the relationship between social and financial indicators or measuring the impact of social capital indicators on the final financial result of cooperative business. The scientific interest of the doctoral dissertation is to examine the interrelationship between profit and the principle’s acceptance indicators. For this purpose, the strength of accepting principles among stakeholders is examined, and the socio-economic optimization model of cooperative business activity is constructed. The field research is conducted in the five counties of Slavonija, Baranja, and Western Srijem. The questionnaire is used to survey 202 stakeholders that are collaborating with 23 agricultural cooperatives. The survey collects data about the stakeholder’s socio-economic status, member’s attitudes towards principles, and information about the business organization. The Financial Agency (FINA) provided business indicators of cooperatives. In the first step, the business indicators during the five years were analyzed using Data Envelopment Analysis. The results show that two cooperatives achieve overall technical, pure technical efficiency, and scale efficiency simultaneously and represent an ideal business pattern. The three other cooperatives achieved only pure technical efficiency. However, despite their efficient allocation of resources, these cooperatives operate above optimal levels, decrease returns to scale and increase average production costs. In the second step, Confirmatory Factor Analysis confirmed the validity of the indicators measuring the strength of cooperative principles acceptance by stakeholders. The analysis confirms the robustness (invariance) of the model, which contains the six latent constructs with twenty-one indicators that correspond to the theory of cooperative principles: democratic member control, economic participation, autonomy (independence), education, cooperation among cooperatives, and concern for the local community. In the final step, the Potential Method confirmed the economic importance of cooperative entrepreneurship. Cooperative principles of economic participation (N3) and cooperation among cooperatives (N6) take two leading positions at both levels of the dual hierarchy, with minor differences in the overall ranking. According to business indicators, economic participation takes first place, while cooperation among cooperatives takes second place. They switch their positions when we are ranking principles concerning the existence of synergy between cooperative principles. The principle of cooperation among cooperatives is now in the first place, while economic participation takes second place. The importance of the research arises in the adaptability and flexibility of the methodological framework that allows simple interpretation of the results about principles acceptance. Also, it combines all essential criteria of the theory of cooperative entrepreneurship and clarifies what principles are preferable and which criterium is the cause. The framework can assist in measuring efficiency in other Croatian regions (or beyond) and sectors. It would represent a general paradigm of scientific methodology for measuring cooperative business efficiency while respecting the theory of principles. This method could be a valuable addition to the classic financial analyzes commonly used to measure the efficiency of investment-oriented firms. Also, it allows the multicriteria efficiency measurement of co-op business activity.

Rational preparation of an adaptive cavity-like enzyme is a great challenge for chemists. Herein, a new self-assembly strategy for the rational preparation of metal–organic tubes with nano-channels has been developed; both 1D metal–organic tube and corresponding 2D layered assemblies can be selectively synthesized driven by different templates; reversible sheet-to-tube transformation can be realized and the key intermediate has been identified. Furthermore, the newly formed nano-channel displays excellent polarity-selectivity for encapsulation of guest molecules, and can be further expanded or contracted through guest-driven adaptive deformation; even induced by very similar guest molecules, the adaptive deformations can also be obviously distinguished. Finally, the key chemicals benzene/hexane with a similar size can also be effectively separated by such nano-channels in the liquid phase. Our work not only provides a new synthetic strategy for the rational synthesis of metal–organic tubes with a reversible sheet-to-tube transformation character, but also gives a potential method for the construction of adaptive host-like enzymes and an in-depth understanding of the nature of adaptive host and guest molecules., A new strategy for preparing metal–organic tubes with reversible sheet-to-tube transformation character has been developed. The new-formed tube can selectively recognize and separate guest molecules with similar size.

Single point incremental forming (SPIF) process has proven benefits in terms of formability, flexibility, and low cost as compared to conventional sheet forming, although it has some issues such as dimensional accuracy and low quality of surface finish for some materials. The SPIF is considered as a potential method of producing customised medical parts such as craniofacial implants using a titanium sheet. This investigation aims to analyse the overall surface roughness of grade 1 pure titanium along the wall of the hyperbolic truncated cone formed by the SPIF process with different forming parameters (i.e., forming tool diameter, step size, and feed rate). Focus variation microscopy was used to measure the surface roughness experimentally along the wall of the truncated cone. Abaqus/Explicit was used to predict the equivalent stress and equivalent plastic strain along the wall of the truncated cone part from the top to the fractured region to evaluate the relationship between the stress, strain, and roughness distribution. It was found that the surface roughness changes with the deformed part height and rough surface could be produced in the region of high equivalent stress and low equivalent plastic strain. Such a surface roughness and equivalent stress and plastic strain correlation has a clear implication to the design and the surface quality of sheet parts made by SPIF.

This paper concerns the coupled linear theory of elasticity for isotropic porous materials. In this theory the coupled phenomena of the concepts of Darcy’s law and the volume fraction is considered. The basic internal and external boundary value problems (BVPs) of steady vibrations are investigated. Indeed, the fundamental solution of the system of steady vibration equations is constructed explicitly by means of elementary functions, and its basic properties are presented. The radiation conditions are established and Green’s identities are obtained. The uniqueness theorems for the regular (classical) solutions of the BVPs are proved. The surface (single layer and double layer) and volume potentials are constructed and the basic properties of these potentials are given. Finally, the existence theorems for classical solutions of the BVPs are proved by means of the potential method (boundary integral equation method) and the theory of singular integral equations.

Based on the impact of the vehicle velocity on the potential field function, considering the overall lane-keeping performance and vehicle stability, the yaw angular adjusting factor is introduced to regulate the potential field function. The proportions of vehicle velocity and yaw angle factors in potential field function are distributed by extension decision. The sliding mode controller is designed based on the two-degree-of-freedom vehicle dynamics model to obtain the front wheel steering angle. The fuzzy decision is made for the dynamic thresholds of distance deviation and angle deviation of lane-keeping system to avoid the control frequently start-up. Next, the combined control strategy of active steering and differential braking systems is designed based on vehicle driving safety boundary, and the yaw angle rate and mass-centroid sideslip angle are selected as the characteristic variables for dividing the vehicle driving safety regions. The different weights are determined for the steering and braking systems in different regions. Finally, the simulation by Carsim/Simulink and the hardware-in-loop test are carried out to demonstrate that it is effective and superior by adopting the sliding-mode controller based on the improved artificial potential function and the coordination strategy of steering and braking systems.

The polishing efficiency and accuracy for optical elements are strongly affected by the removal characteristics of the polishing tool and are commonly evaluated using a tool influencing function(TIF). During most polishing processes, the TIF is obtained through offline measurements, which are time-consuming. Consequently, the use of polishing forces collected online to evaluate TIF, including its spot shape and efficiency, was investigated as a means of reducing measurement times. Based on the elastic theory, the formation mechanism for an elliptical TIF spot during a bonnet polishing process is thought to have a long axis length that is close to a predefined value and a short axis length that is proportional to the third root of the normal force. Based on the above finding, a polishing force-based prediction model for TIF spot shape was derived and validated. The predicted results agreed well with experimental results. Afterwards, a polishing force-based, semi-quantitative prediction model for TIF efficiency was developed by combining Preston’s law and Hertz contact theory. The model was validated experimentally and successfully predicted changing trends in TIF efficiency. Based on this study, the spot shape and efficiency of the TIF can be predicted using polishing forces collected online. This approach provides a potential method that could be used in engineering applications to optimize bonnet polishing processes through a reduction in the time needed for offline measurements.

Drought is one of the biggest problems for the community, this problem will be slightly resolved by the compilation of regions with groundwater sources. This research has been carried out in the karst area, Druju Village, Sumbermanjing District, Wetan Regency, Malang. The purpose of this study is to determine the distribution of underground air and the pattern between underground rivers in the Wonorejo draw well and spring sources in the Kaligoro River, Wonorejo Hamlet.The method that used is the Self Potential (SP) method to set the moving electrode (leap frop) with 104 measurement points. The results of this study indicate the value of electric potential shown between 0-13.5 mV, and assume that a low potential value (0-1 mV) is an indication of groundwater distribution. Areas with low potential values are found in the empathy area. When taking a distribution of water on the surface of the land that appears through the Kaligoro River, it does not need to go out in one stream with an underground river flowing in the wells of the residents. The area with the lowest potential value is a reference in making wells

With the outbreak of product miniaturization, the demand of micro-tools fabrication is increasing. Tungsten is a widely used material when fabricating micro-tools. However, tungsten is difficult to machine due to its high hardness. Electrochemical micro-machining (EMM) has many advantages over conventional machining processes, which makes it a potential method to manufacture tungsten micro-tools. This paper proposes a novel EMM fabrication method of high aspect ratio micro-tools with a reverse conical shape tip. During the machining process, a tungsten rod is passed through the electrolyte liquid membrane and makes a linear reciprocating motion. The anodic dissolution occurs only in the region where the rod and electrolyte are in contact. Comparing to the conventional method, this proposed method can improve the shape accuracy of micro-tools. A mathematical model is developed to predict the final diameter of the tool. Furthermore, the effects of main parameters, including electrolyte concentration, feeding rate, the thickness of electrolyte, and the position of the micro-tools, are investigated experimentally. Finally, optimum parameters are selected, and a high aspect ratio micro-tools with a reverse conical shape tip are successfully fabricated using these parameters.

The optimum profile modification curve of a gear pair is usually determined according to the fluctuation minimization of static transmission error (STE). For the calculation of STE, the potential energy method dismisses the correlative tooth deflection induced by gear body elastic coupling effects, and the finite element method requires high calculation cost. In order to simultaneously obtain high calculation accuracy and efficiency, the single tooth deflection is calculated through analytical integration about the Hertz contact pressure based on the conformal map method. The correlative tooth deflection is calculated based on the power series solution of the mixed boundary problem of an elastic annulus. Via combination of deflection compatibility and the force equilibrium condition, a contact analysis model of a spur gear pair is built. Based on the model, the STE is first calculated and compared with the finite element analysis result to verify the model rationality. Then, the optimum profile modification curve which renders constant STE is calculated. For a gear pair with the obtained modification curve, fluctuation of dynamic transmission error also decreases and the optimization effect is verified.

Electromagnetic-assisted forming (EMAF) combining quasi-static stamping and electromagnetic forming (EMF) is a potential method for controlling the springback of aluminium alloy materials. In this study, to further promote the application of EMAF in the high-precision forming of aluminium alloy sheet parts, the springback during electromagnetic-assisted bending of aluminium alloy sheet was investigated using a custom-designed U-shaped bending tool with the optimised curved spiral coils. Two types of conditions to control springback were designed: gapless and gap conditions, and the springback under these conditions was studied both experimentally and using numerical simulations. In addition, the effects of the discharge parameters on springback were analysed. Finally, the mechanism for controlling springback under different forming conditions was revealed. The results showed that the efficiency of springback control was significantly higher under gap conditions compared with gapless condition. With increasing gap, the springback angle decreased, but negative springback easily occurred when using excessively wide gaps. As the discharge voltage or number of discharges increased, the tangential stress of the fillet area decreased, thereby reducing the springback angle. Stress oscillations under the gapless condition reduced the tangential stress of the fillet area to a certain extent, while inertial motions under gap conditions greatly reduced the tangential stress, which were the essential mechanism for the observed springback reduction.

Radiation imaging is one potential method to verify nuclear weapons dismantlement. We present a method to discriminate between non-multiplying and multiplying neutron sources using a neutron coded aperture imaging system. This method applies time-correlated pulse-height (TCPH) analysis to identify neutrons in fission chain reactions and recreate images using only these events. This analysis was applied to measurements of weapons-grade plutonium (WGPu) metal and 252Cf performed at the Nevada National Security Site (NNSS) Device Assembly Facility in July 2015. The results demonstrate it is possible to eliminate the non-fissile 252Cf source from the image while preserving the fissile WGPu source. TCPH analysis was also applied to additional scenes in which the WGPu and 252Cf sources were measured individually. The results of these separate measurements further demonstrate the ability to remove the non-fissile 252Cf source and retain the fissile WGPu source. Simulations performed using MCNPX-PoliMi indicate that in a one hour measurement, hollow WGPu spheres are retained at a 1 σ level for neutron multiplications M ≃ 2 . 7 and above. This work has potential application to dismantlement verification where it may be valuable to verify that all neutron sources in an image are multiplying.

Mixed mode fracturing behaviors in brittle materials are ubiquitous occurring in practicing engineering. Especially for rocks, tensile-shear loadings are one type of basic factors inducing failures. This paper presented analytical and numerical solutions to investigate the variations of stress field over crack front vicinity under different complex loading conditions and geometrical parameters. An analytical solution for crack under mixed loadings and various geometrical parameters (i.e. inclination angle α and shape parameter m of crack) was proposed, which also considers shear loadings both applying on internal boundary (i.e. crack surface) and external boundary (i.e. distance far away crack). The analytical solution for the model by complex potential method has been suggested. Numerical simulations have been carried out to verify the analytical solution of stress distribution adjacent to crack tip, in which the analytical solutions show good agreement with the numerical results. Three dimensionless loading coefficients ( λ 1 , λ 2 , λ 3 ) were defined to reflect the magnitudes of biaxial loading, external shearing and internal shearing, respectively. The characteristics of stress distribution, shearing effects and initiation stress were studied deeply under different λ 1 , λ 2 , λ 3 with various α , m , and the effects of varied conditions on stress magnitude variations have been discussed. According to the solution, we derived the explicit expressions of stress intensity factor (SIF) under different loading situations. Considering the effects of various crack inclination angles and shear loadings, the variations of normalized SIF ratio 2 π a r c t a n K I / K II with various conditions also have been discussed. In conclusion, loadings and geometrical variations both have strongly effects on stress distributions around the tip, and the influences have the relationship with different situations.

Decreasing the dimension of p-n junctions in microcircuits down to micron sizes and the analogy to the dimensions of biological cells and sub-cell components, provides a motivation for using microdosimetry in microelectronics. Since single-event upsets (SEU) are the most important errors in microelectronic devices, in this work, the microdosimetric one-hit detector model was evaluated to determine the SEU cross-section for microelectronic devices. There were three main assumptions: 1) the device cells are the sensitive volumes. 2) The cells possess the same critical charges and 3) the probability of SEU induction in a cell is a step function. Moreover, the critical charge was considered as the free parameter of the model. Therefore, the number of upsets was obtained equal to the number of effective particle traversals (events) in the device, derived from the single-event microdosimetric distributions. Then, the SEU cross-section was determined. In the calculations there was no need to the electronic response of the device. To examine the model, a 1 k (i.e. 210 bytes memory) 65 nm CMOS bulk SRAM was considered for which the SEU cross-section due to low energy protons obtained by RPP model and experiment had been reported in the literature. Each cell was a rectangle with a dimension of 1.2 μm × 0.6 μm × 1 μm. The single-event distributions for 9 proton energies from 2 MeV to 10 MeV were calculated by Geant4 simulation toolkit. Obtained results showed that for a critical specific energy of 70 Gy (equivalent to a critical charge of 35.56 fC), the SEU cross-sections were found in the best agreement with the reported experimental values within a maximum difference about 40%. Also, the results were comparable with those obtained by the conventional Rectangular Parallelepiped (RPP) model. Eventually, the microdosimetry approach proposed in this work may be considered a potential method to determine the SEU cross-section in any microelectronic device.

This paper presented a numerical and experimental investigation of the performance of flexure-critical pre-stressed concrete (PSC) structures using the electro-mechanical admittance (EMA) of piezoceramic transducers (PZT). In the numerical analysis, three-dimensional finite element modeling was developed for a PSC beam subjected to four-point bending loads. The focus of the numerical analysis was the accurate detection of concrete cracking, and its growth using EMA signatures obtained from a multi-physics harmonic analysis of the electro-mechanical coupled fields. In the experimental study, two PSC beams with different grouting conditions were subjected to four-point bending tests until failure, and were simultaneously monitored by five surface-mounted PZTs. The crack observations, strain measurements, and load–deflection curves were recorded as references for the qualitative and quantitative assessments of the PSC structural flexural performance by the extraction of EMA signature characteristics, root mean square deviation (RMSD) and its rate indices. The experimental results revealed that the proposed method offered a higher sensitivity in comparison with conventional methods. The EMA characteristics could detect concrete cracking and reinforcement yielding in advance; the RMSD rate was more sensitive in the prediction of uploading and failure in the specimens; and the structural performance states such as crack initiation, propagation and penetration, yield and failure were effectively determined using RMSD characteristics. The promising findings in this study provided a potential method for the assessment of flexure-critical PSC structural performances.

Influence of wettability to petrophysical responses in low permeability reservoirs is increasingly evident, but research of nuclear magnetic resonance (NMR) technology on wettability calibration in such reservoirs is very limited even though it has been used promisingly. The challenge is that the empirical interpretation model only applies to simple pore structure. It is urgent to develop a relatively simple, quick, and practicable model for wettability evaluation in low permeable reservoirs. This paper presents an experimental NMR study, integrating with Amott tests, X-ray diffraction, and scanning electron microscope (SEM) measurements, on wettability characterization of five typical core samples from different low-permeability reservoirs. NMR relaxation mechanisms and the effect of the aging were analyzed in detail. The study showed that all the core samples had a shift of T2 (spin-spin relaxation time) spectra between before and after aging. According to the shift characteristics, the core samples were divided into two types. The first type is that the wettability alteration relied on the aging and it displaced crude oil into original water-wet movable pore spaces to restore reservoir wettability. This type of formation is generated in distant-source reservoirs, which mainly involves fluid transport through buoyancy. Another type is that the wettability alteration was attributed to the natural oil-wet property of the rock matrix. This formation is mainly found in inner-source or near-source reservoirs, which may generate abundant oil-wet materials. Thus, the wettability alteration is the result of hydrocarbon accumulation modes. Based on the observations, a potential method for obtaining the wettability index was proposed. The method uses both the ratio of oil-wetted to water-wetted pore surface areas and diffusion-relaxation diagrams. The estimated results corresponded reasonably to the independent Amott tests. This study demonstrates that NMR relaxation is an effective solution to analyze and quantify wettability in low permeability reservoirs.

The optimum allocation of resources for a Gale problem of supply and demand with uncertain factors is considered. The Dantzig-Wolfe decomposition and the generalized potential method developed earlier by the author for a deterministic version of the problem are used to construct and validate the algorithm for a numerical solution.

Coherent transition radiation (CTR) is widely used in determining the longitudinal e-beam dimensions in the accelerator technology applications. In this study, the CTR process is investigated in a real Au-target for the sake of measuring the size characteristics of the electron bunches with lengths from 100 to 300 nm, and possible applications of such targets is demonstrated.

Solution for electromagnetic scattering from a perfect electric conducting strip buried in a planar grounded dielectric slab is determined by using the Kobayashi Potential Method. It is assumed that the dimension of mediums, above and within the slab, is non-integer in the direction normal to interface of the slab. The scattering problem is divided into two parts. In the first part, fields in the absence of strip are determined for plane wave excitation. In the second part, presence of the strip is taken into account. It has been assumed that spacings between the strip and interfaces of the slab are comparatively very larger than the wavelength of monochromatic operating frequency. Due to this assumption, scattered field after reflection from the interfaces has no interaction with the strip. In order to gains more insight, several special cases of the geometry are treated. Using saddle point method, far-zone scattered field for region above the grounded slab is also determined.

To improve fiber orientation in ultra-high performance concrete (UHPC), one L-shape device was developed to control the flow of fresh mixture. A smoothed particle hydrodynamics (SPH) method was used to analyze and simulate the motion of steel fibers in UHPC with flow through this L-shape apparatus. SPH simulation indicated that steel fibers tended to rotate to be parallel with local streamlines and most fibers were aligned in the horizontal channel of this L-shape device, inducing an improvement of fiber orientation in hardened specimens. This modification effect of fiber orientation can be a little strengthened with the decreasing height of the horizontal channel. On the other hand, a colorless, transparent and viscous concentrated suspension was obtained by adding super absorbent polymer (SAP) into water for representing fresh UHPC matrix and the visualization of fiber motion was achieved. This visualization approach, coupled with image analysis of steel fibers in hardened UHPC specimens, well verified the SPH numerical simulation results. Therefore, this type of L-shape apparatus provides a potential method to manually improve the steel fiber orientation in UHPC for better mechanical properties.

In the side-by-side offloading problem, the gap resonance is usually overestimated by the potential theory bas ed methods. This article reviews the up-to-date research on this topic and discusses the existing methods to modify the potential method, in order to obtain a reasonable estimate of the wave elevation. Then a wall damping method is proposed to damp out the wave elevation. This method models the energy loss on the ship hull surface. Thus, a lid is no longer needed. The validity of the method is established through comparisons against the experimental data. Consistent results are obtained for the wave gauge in the middle of the gap. This method is the first step to develop the categories of methods without lid. The motivation is to use the small amount of measured data and a simplified model to generate engineering acceptable results. Given more data, more improvements can be made upon this method and a more general and powerful model can be developed in the future.

The solution of an infinite elastic plane containing a macro-crack and a cluster of micro-cracks is presented based on Muskhelishvili’s complex potential method. A step-by-step sub-problem procedure is used to satisfy the stress boundary conditions on each crack surface. A local damage parameter expressed by stress intensity factor is presented to evaluate the damage magnitude. Three damage configurations as parallel, radiating and arbitrarily oriented micro-cracks have been designed to simulate the damage around the macro-crack tip. The results show the micro-cracks located in front of the macro-crack tip have the amplifying effect on macro-crack growth, and the amplifying effect increases with the number of micro-cracks increase. Moreover, when the macro-crack length decreases or the distance between micro-cracks and macro-crack increases, the damage parameter of macro-crack and micro-cracks will decrease. It is found that the largest damage is the damage configuration of arbitrarily oriented micro-cracks among three damage configurations.